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Sample records for advanced turbocharger rotor

  1. Advanced turbocharger rotor for variable geometry turbocharging systems

    Energy Technology Data Exchange (ETDEWEB)

    Stafford, R.J.; Mulloy, J.M.; Yonushonis, T.M.; Weber, H.G.; Patel, M.J. [Cummins Engine Co., Inc., Columbus, IN (United States)

    1997-12-31

    Turbocharging of diesel engines has enhanced fuel economy and reduced diesel engine emissions. The initial applications of turbochargers to heavy duty diesel engines during the early 1970`s reduced Bosch smoke (a measure of particulate matter used at the time) from 2.4 to 0.6 units. Current turbochargers are optimized at one set of engine conditions and by necessity, at the off-design conditions or transient conditions the fuel economy and emissions performance are penalized. A rotor was designed and a prototype fabricated which showed as much as a 10% efficiency improvement at off-design conditions. The leading edges are blunt and rounded to accept the flow from the turbine nozzles at a variety of inlet conditions with a minimum of losses. The rotor efficiency is better at all conditions and the advantage improves as it operates at conditions further from the design point. Unfortunately, the conventional materials from which this turbine rotor was constructed had inadequate strength to allow its use on engines, and had such high rotational inertia that transient response would have been severely compromised.

  2. The Influence of Rotor Unbalance on Turbocharger Rotor Dynamics

    OpenAIRE

    Knotek Jiří; Novotný Pavel; Maršálek Ondřej; Raffai Peter; Dlugoš Jozef

    2015-01-01

    This paper describes the influence of an unbalance on turbocharger rotor dynamics. The structural model of the turbocharger rotor and the hydrodynamic model of the journal floating ring bearing are described and assembled in multibody dynamics software. Moreover, the paper presents various results describing rotor dynamics where the influence of an unbalance is discussed.

  3. The Influence of Rotor Unbalance on Turbocharger Rotor Dynamics

    Directory of Open Access Journals (Sweden)

    Knotek Jiří

    2015-12-01

    Full Text Available This paper describes the influence of an unbalance on turbocharger rotor dynamics. The structural model of the turbocharger rotor and the hydrodynamic model of the journal floating ring bearing are described and assembled in multibody dynamics software. Moreover, the paper presents various results describing rotor dynamics where the influence of an unbalance is discussed.

  4. Dynamics and stability of turbocharger rotors

    Energy Technology Data Exchange (ETDEWEB)

    Schweizer, Bernhard [University of Kassel (Germany). Department of Mechanical Engineering, Multibody Systems

    2010-09-15

    The paper discusses the bifurcation and stability behavior of (automotive) turbochargers with full-floating ring bearings. Turbocharger rotors exhibit a highly nonlinear behavior due to the nonlinearities introduced by the floating ring bearings. A flexible multibody model of the rotor/bearing system is presented. Numerical run-up simulations are compared with corresponding test rig measurements. The nonlinear oscillation effects are thoroughly investigated by means of simulated and measured rotor vibrations. The influence of various system parameters on the bifurcation behavior of the rotor/bearing system is analyzed. The article examines rotors supported in full-floating ring bearings with plain circular bearing geometry in the inner and outer oil gap. By recapitulating the well-known oil whirl and oil whip phenomena for single and double oil film bearings, the paper gives an overview on the fundamental dynamic effects occurring in turbocharger systems. (orig.)

  5. Preliminary analysis of turbochargers rotors dynamic behaviour

    Science.gov (United States)

    Monoranu, R.; Ştirbu, C.; Bujoreanu, C.

    2016-08-01

    Turbocharger rotors for the spark and compression ignition engines are resistant steels manufactured in order to support the exhaust gas temperatures exceeding 1200 K. In fact, the mechanical stress is not large as the power consumption of these systems is up to 10 kW, but the operating speeds are high, ranging between 30000 ÷ 250000 rpm. Therefore, the correct turbochargers functioning involves, even from the design stage, the accurate evaluation of the temperature effects, of the turbine torque due to the engine exhaust gases and of the vibration system behaviour caused by very high operating speeds. In addition, the turbocharger lubrication complicates the model, because the classical hydrodynamic theory cannot be applied to evaluate the floating bush bearings. The paper proposes a FEM study using CATIA environment, both as modeling medium and as tool for the numerical analysis, in order to highlight the turbocharger complex behaviour. An accurate design may prevent some major issues which can occur during its operation.

  6. 14 CFR 33.34 - Turbocharger rotors.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Turbocharger rotors. 33.34 Section 33.34 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Reciprocating Aircraft Engines § 33.34...

  7. Investigation into nonlinear dynamics of rotor-floating ring bearing systems in automotive turbochargers

    OpenAIRE

    Tian, Liang

    2012-01-01

    As a high speed rotating device, a modern turbocharger rotor is commonly supported by floating ring bearings (FRBs), owing to their cost effectiveness for mass production and good damping performance. Thanks to the rapid growth of the power of the modern computer, rotordynamic analysis of turbocharger rotor-bearing systems becomes feasible, and it is closely related to the healthy operation and noise generation of turbochargers. The work in this thesis is concerned with the nonlinear rotordyn...

  8. Stability Analysis of a Turbocharger Rotor System Supported on Floating Ring Bearings

    OpenAIRE

    Zhang, Hongyu; Shi, Zhanqun; Zhen, Dong; Gu, Fengshou; Ball, Andrew

    2012-01-01

    The stability of a turbocharger rotor is governed by the coupling of rotor dynamics and fluid dynamics because the high speed rotor system is supported on a pair of hydrodynamic floating ring bearings which comprise of inner and outer fluid films in series. In order to investigate the stability, this paper has developed a finite element model of the rotor system with consideration of such exciting forces as rotor imbalance, hydrodynamic fluid forces, lubricant feed pressure and dead weight. T...

  9. Influence of Turbine and Compressor Wheel Mass and Inertia on the Rotor Dynamics of Turbocharger

    Directory of Open Access Journals (Sweden)

    J. Knotek

    2016-03-01

    Full Text Available This paper describes the influence of the compressor and turbine wheel mass and inertia change on the turbocharger rotor dynamics. The model of the turbocharger is presented, the hydrodynamic model of the journal bearing is described and assembly of the whole model in MBS is also presented. The article presents various results describing rotor dynamics on which the influence of compressor and turbine wheel mass and inertia change is discussed.

  10. Influence of Turbine and Compressor Wheel Mass and Inertia on the Rotor Dynamics of Turbocharger

    OpenAIRE

    J. Knotek; P. Novotný; O. Maršálek; Raffai, P.; J. Dlugoš

    2016-01-01

    This paper describes the influence of the compressor and turbine wheel mass and inertia change on the turbocharger rotor dynamics. The model of the turbocharger is presented, the hydrodynamic model of the journal bearing is described and assembly of the whole model in MBS is also presented. The article presents various results describing rotor dynamics on which the influence of compressor and turbine wheel mass and inertia change is discussed.

  11. Stability Analysis of a Turbocharger Rotor System Supported on Floating Ring Bearings

    Science.gov (United States)

    Zhang, H.; Shi, Z. Q.; Zhen, D.; Gu, F. S.; Ball, A. D.

    2012-05-01

    The stability of a turbocharger rotor is governed by the coupling of rotor dynamics and fluid dynamics because the high speed rotor system is supported on a pair of hydrodynamic floating ring bearings which comprise of inner and outer fluid films in series. In order to investigate the stability, this paper has developed a finite element model of the rotor system with consideration of such exciting forces as rotor imbalance, hydrodynamic fluid forces, lubricant feed pressure and dead weight. The dimensionless analytical expression of nonlinear oil film forces in floating ring bearings have been derived on the basis of short bearing theory. Based on numerical simulation, the effects of rotor imbalance, lubricant viscosity, lubricant feed pressure and bearing clearances on the stability of turbocharger rotor system have been studied. The disciplines of the stability of two films and dynamic performances of rotor system have been provided.

  12. Stability Analysis of a Turbocharger Rotor System Supported on Floating Ring Bearings

    International Nuclear Information System (INIS)

    The stability of a turbocharger rotor is governed by the coupling of rotor dynamics and fluid dynamics because the high speed rotor system is supported on a pair of hydrodynamic floating ring bearings which comprise of inner and outer fluid films in series. In order to investigate the stability, this paper has developed a finite element model of the rotor system with consideration of such exciting forces as rotor imbalance, hydrodynamic fluid forces, lubricant feed pressure and dead weight. The dimensionless analytical expression of nonlinear oil film forces in floating ring bearings have been derived on the basis of short bearing theory. Based on numerical simulation, the effects of rotor imbalance, lubricant viscosity, lubricant feed pressure and bearing clearances on the stability of turbocharger rotor system have been studied. The disciplines of the stability of two films and dynamic performances of rotor system have been provided.

  13. Failure Analysis and Optimization of the Rotor System in a Diesel Turbocharger for Rotor Speed-Up Test

    OpenAIRE

    Zhai, Liming; Luo, Yongyao; Wang, Zhengwei; Liu, Xin

    2014-01-01

    During turbocharger rotor speed-up tests, the sensor installed in the compressor greatly affects the rotor dynamics. The effect of the floating bearing stiffness coefficient on the critical rotational speeds and the shaft dynamic response due to the unbalanced mass were both analyzed using rotor dynamics theory and a finite element analysis. The results illustrate that the initial sensor design reduced the 3rd order critical speed to lower than the maximum normal operating speed which leads t...

  14. Dynamic Stability Evaluation of an Automotive Turbocharger Rotor-Bearing System

    OpenAIRE

    Alsaeed, Ali A.

    2005-01-01

    This project was initiated to more fully understand the dynamic stability of an automotive turbocharger rotor-bearing system using both linear and nonlinear analyses. The capabilities of a commercial Finite Element Analysis (FEA) code (computer program) were implemented in the investigation process. Several different hydrodynamic journal bearings were employed in the study of the turbocharger linearized dynamic stability. The research demonstrates how the linear analysis of a t...

  15. Rotordynamics of Automotive Turbochargers Linear and Nonlinear Rotordynamics – Bearing Design – Rotor Balancing

    CERN Document Server

    Nguyen-Schäfer, Hung

    2012-01-01

    This book deals with rotordynamics of automotive turbochargers while encompassing the analysis of the dynamics of rotating machines at very high rotor speeds of 300,000 rpm and above. This interdisciplinary field involves 1. thermodynamics and turbo-matching knowledge to compute working conditions of turbochargers, 2. fluid and bearing dynamics to calculate various operating thrust loads and to design the rotating floating ring bearings (two-oil-film bearings), and 3. tribology to improve the rotor stability and to reduce the bearing friction. Mathematical background in modeling and simulation methods is necessary; however, the prerequisites have been kept to a minimum. The book addresses both practitioners working in the field of rotordynamics of automotive turbochargers and graduate students in mechanical engineering.

  16. Turbocharger

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Harold Huimin; Hanna, Dave; Zhang, Jizhong; Hu, Liangjun; Krivitzky, Eric M.; Larosiliere, Louis M.; Baines, Nicholas C.

    2013-08-27

    In one example, a turbocharger for an internal combustion engine is described. The turbocharger comprises a casing containing an impeller having a full blade coupled to a hub that rotates about an axis of rotation. The casing includes a bleed port and an injection port. The full blade includes a hub edge, a casing edge, and a first distribution of angles, each angle measured between the axis of rotation and a mean line at the hub edge at a meridional distance along the hub edge. The full blade includes a second distribution of angles, each angle measured between the axis of rotation and a mean line at the casing edge at a meridional distance along the casing edge. Further, various systems are described for affecting the aerodynamic properties of the compressor and turbine components in a way that may extend the operating range of the turbocharger.

  17. Effects of semi-floating ring bearing outer clearance on the subsynchronous oscillation of turbocharger rotor

    Science.gov (United States)

    Liang, Feng; Zhou, Ming; Xu, Quanyong

    2016-06-01

    Semi-floating ring bearing(SFRB) is developed to control the vibration of turbocharger rotor. The outer clearance of SFRB affects the magnitude and frequency of nonlinear whirl motion, which is significant for the design of turbocharger. In order to explore the effects of outer clearance, a transient finite element analysis program for rotor and oil film bearing is built and validated by a published experimental case. The nonlinear dynamic behaviors of rotor-SFRB system are simulated. According to the simulation results, two representative subsynchronous oscillations excited by the two bearings respectively are discovered. As the outer clearance of SFRB increases from 24 μm to 60 μm, the low-frequency subsynchronous oscillation experiences three steps, including a strong start, a gradual recession and a combination with the other one. At the same time, the high-frequency subsynchronous oscillation starts to appear gradually, then strengthens, and finally combines. If gravity and unbalance are neglected, the combination will start starts from high rotor speed and extents to low rotor speed, just like a "zipper". It is found from the quantitative analysis that when the outer clearance increases, the vibration amplitude experiences large value firstly, then reduction, and suddenly increasing after combination. A useful design principle of SFRB outer clearance for minimum vibration amplitude is proposed: the outer clearance value should be chosen to keep the frequency of two subsynchronous oscillations clearly separated and their amplitudes close.

  18. Dynamic behaviours of a full floating ring bearing supported turbocharger rotor with engine excitation

    Science.gov (United States)

    Tian, L.; Wang, W. J.; Peng, Z. J.

    2011-09-01

    The rotor dynamic behaviour of turbochargers (TC) has been paid significant attention because of its importance in their healthy operation. Commonly, the TC is firmly mounted on engines and they will definitely suffer from the vibrations originated from engines in operation. However, only a limited number of papers have been published with consideration of this phenomenon. In this paper, a finite element model of a TC rotor supported by nonlinear floating ring bearings has been established. The nonlinear bearing forces have been calculated by a newly proposed analytical method. An efficient numerical integration approach has been employed to conduct the investigation including the traditional unbalance and the considered engine excitation effects in question. The results show that the unbalance will place considerable influence on the rotor response at a low working speed. At high speeds, the effect will be prevented by the dominant sub-synchronous vibrations, which also prohibit the appearance of a chaotic state. The novel investigation with the proposed model considering engine excitation reveals that the engine induced vibration will greatly affect the TC rotor response at relatively lower rotor speeds as well. At higher speed range, the dominant effect of sub-synchronous vibrations is still capable of keeping the same orbit shapes as that without engine excitation from a relative viewpoint.

  19. Nonlinear effects of unbalance in the rotor-floating ring bearing system of turbochargers

    Science.gov (United States)

    Tian, L.; Wang, W. J.; Peng, Z. J.

    2013-01-01

    Turbocharger (TC) rotor-floating ring bearing (FRB) system is characterised by high speed as well as high non-linearity. Using the run-up and run-down simulation method, this paper systematically investigates the influence of unbalance on the rotordynamic characteristics of a real TC-FRB system over the speed range from 0 Hz to 3500 Hz. The rotor is discretized by the finite element method, and the desired oil film forces at each simulation step are calculated by an efficient analytical method. The imposed unbalance amount and distribution are the variables considered in the performed non-stationary simulations. The newly obtained results evidently show the distinct phenomena brought about by the variations of the unbalance offset, which confirms that the unbalance level is a critical parameter for the system response. In the meantime, the variations of unbalance distribution, i.e. out-of-phase and in-phase unbalance, can lead to entirely different simulation results as well, which proves the distribution of unbalance is not negligible during the dynamic analysis of the rotor-FRB system. Additionally, considerable effort has been placed on the description as well as discussion of a unique phenomenon termed Critical Limit Cycle Oscillation (CLC Oscillation), which is of great importance and interest to the TC research and development.

  20. Multi Body Analysis Of A Turbocharger Supported By A Fully Floating Ring Bearing

    OpenAIRE

    Knotek Jiří; Novotný Pavel; Maršálek Ondřej; Raffai Peter

    2015-01-01

    This paper describes an advanced tool for turbocharger rotor dynamics analysis and its development. The hydrodynamic model of the journal bearing based on Reynolds equation is presented. The paper also describes assembly of the turbocharger rotor model. At the end the basic results are presented and analyzed.

  1. Multi Body Analysis Of A Turbocharger Supported By A Fully Floating Ring Bearing

    Directory of Open Access Journals (Sweden)

    Knotek Jiří

    2015-06-01

    Full Text Available This paper describes an advanced tool for turbocharger rotor dynamics analysis and its development. The hydrodynamic model of the journal bearing based on Reynolds equation is presented. The paper also describes assembly of the turbocharger rotor model. At the end the basic results are presented and analyzed.

  2. Rotordynamics of automotive turbochargers

    CERN Document Server

    Nguyen-Schäfer, Hung

    2015-01-01

    Rotordynamics of automotive turbochargers is dealt with in this book encompassing the widely working field of small turbomachines under real operating conditions at the very high rotor speeds up to 300000 rpm. The broadly interdisciplinary field of turbocharger rotordynamics involves 1) Thermodynamics and Turbo-Matching of Turbochargers 2) Dynamics of Turbomachinery 3) Stability Analysis of Linear Rotordynamics with the Eigenvalue Theory 4) Stability Analysis of Nonlinear Rotordynamics with the Bifurcation Theory 5) Bearing Dynamics of the Oil Film using the Two-Phase Reynolds Equation 6) Computation of Nonlinear Responses of a Turbocharger Rotor 7) Aero and Vibroacoustics of Turbochargers 8) Shop and Trim Balancing at Two Planes of the Rotor 9) Tribology of the Bearing Surface Roughness 10) Design of Turbocharger Platforms using the Similarity Laws The rotor response of an automotive turbocharger at high rotor speeds is studied analytically, computationally, and experimentally. Due to the nonlinear character...

  3. Effects of bearing outer clearance on the dynamic behaviours of the full floating ring bearing supported turbocharger rotor

    Science.gov (United States)

    Tian, L.; Wang, W. J.; Peng, Z. J.

    2012-08-01

    As a high speed rotating device, the modern turbocharger rotor is commonly supported by floating ring bearings (FRBs). The high nonlinearity there can always lead to quite complex and interesting phenomena rarely observed in other rotating applications. Using the run-up and run-down simulation method, this paper originally and systematically discusses the effect of bearing outer clearance on the rotordynamic characteristics of a realistic turbocharger rotor over the speed range up to 3000 Hz. The rotor is discretized by the Finite Element Method and supported by analytically calculated bearing forces. The linear analysis is proved to be effective in predicting the first two nonlinear jumps but inadequate to study the rotordynamic characteristics at higher rotor speeds. The nonlinearly simulated results show the appearances of distinct and interesting phenomena within the considered range of FRB outer clearance, which can be further divided into four groups. Within the same group, the simulation results are qualitatively similar to each other but quite dissimilar from the results from different groups. Moreover, the unwelcome Critical Limit Cycle Oscillation can be avoided by increasing the outer clearance size. Additionally, in some cases, the run-down simulations reveal distinct frequency maps as compared to the corresponding run-ups. Furthermore, it is seen that ring speed ratios can be considerably affected by the nonlinear jumps. Therefore, FRB outer clearance should be thoroughly examined to achieve the best rotordynamic performance.

  4. Aero and vibroacoustics of automotive turbochargers

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen-Schaefer, Hung [Bosch Mahle Turbo Systems GmbH, Stuttgart (Germany)

    2013-02-01

    First book about the aeroacoustics of automotive turbochargers. Author of the book ''Rotordynamics of Automotive Turbochargers'', Springer, 2012. Written by an R and D expert in the turbocharger industry. Aero and Vibroacoustics of Automotive Turbochargers is a topic involving aspects from the working fields of thermodynamics of turbomachinery, aerodynamics, rotordynamics, and noise propagation computation. In this broadly interdisciplinary subject, thermodynamics of turbomachinery is used to design the turbocharger and to determine its operating conditions. Aerodynamics is needed to study the compressor flow dynamics and flow instabilities of rotating stall and surge, which can produce growling and whining-type noises. Rotordynamics is necessary to study rotor unbalance and self-excited oil-whirl instabilities, which lead to whistling and constant tone-type noises in rotating floating oil-film type bearings. For the special case of turbochargers using ball bearings, some high-order harmonic and wear noises also manifest in the rotor operating range. Lastly, noise propagation computation, based on Lighthill's analogy, is required to investigate airborne noises produced by turbochargers in passenger vehicles. The content of this book is intended for advanced undergraduates, graduates in mechanical engineering, research scientists and practicing engineers who want to better understand the interactions between these working fields and the resulting impact on the interesting topic of Aero and Vibroacoustics of Automotive Turbochargers.

  5. Model Development and Stability Analysis for a Turbocharger Rotor System under Multi-Field Coupled Forces

    OpenAIRE

    Zhang, Hao

    2012-01-01

    Automotive turbochargers have been widely applied in vehicles in order to increase the power output of internal combustion engines by increasing the air to fuel ratio entering the piston cylinders. Turbochargers use the exhaust flow to spin a turbine at speeds of up to 140,000 r/min. Under such extreme working conditions, even a weak vibration can lead to the bearing failure and the whole turbocharger destroyed. In order to guarantee a safe operation, it is necessary to carry out a theoretica...

  6. Advanced disk-type LP turbine rotors

    International Nuclear Information System (INIS)

    This paper addresses the application of these design considerations. After twenty years experience with disk-type rotors, the Siemens/KWU ten-disk rotor for low-speed nuclear LP turbines was developed in 1969. Full volumetric disk hub inspections after 83,000 service hours did not reveal any stress corrosion cracking. In the meantime, this rotor design has been further improved. In 1987, two advanced eight-disk rotors went into operation at the Connecticut Yankee station. This rotor design together with the advanced LP turbine blading has been delivered to the Unterweser station. First test results indicated a remarkably improved thermodynamic performance. Avoidance of stress corrosion cracking can be accomplished by a combination of various measures: Proper keyway design; Low metal temperature; Low tensile stressing (by design); Low yield strength; High fracture toughness; Low surface stresses (by manufacturing); Proper steam/water cycle chemistry

  7. Recent developments in the dynamics of advanced rotor systems

    Science.gov (United States)

    Johnson, W.

    1985-01-01

    The problems that were encountered in the dynamics of advanced rotor systems are described. The methods for analyzing these problems are discussed, as are past solutions of the problems. To begin, the basic dynamic problems of rotors are discussed: aeroelastic stability, rotor and airframe loads, and aircraft vibration. Next, advanced topics that are the subject of current research are described: vibration control, dynamic upflow, finite element analyses, and composite materials. Finally, the dynamics of various rotorcraft configurations are considered: hingeless rotors, bearingless rotors, rotors with circulation control, coupled rotor/engine dynamics, articulated rotors, and tilting proprotor aircraft.

  8. 球轴承涡轮增压器轴承-转子系统动力学分析与应用∗%Analysis and Application of Rotor Dynamics of Bearing-rotor System of Ball Bearing Turbocharger

    Institute of Scientific and Technical Information of China (English)

    刘大诚; 史立伟

    2014-01-01

    相比于普遍使用的浮动轴承,在涡轮增压器中使用球轴承具有机械效率高和加速响应快的优势。以车用球轴承涡轮增压器为研究对象,用有限元法对轴承-转子系统进行了转子动力学特性的研究,对轴承-转子系统的临界转速进行了计算与分析,这是判断转子工作转速是否稳定和涡轮增压器工作是否可靠的重要依据;建立了增压器模型,并对比了计算结果和试验结果,证明了方法的可行性。通过整机试验表明,球轴承涡轮增压器能够满足当前车用发动机的需求,能够提高发动机的工作性能。%Turbochargers in ball bearings have much advantage than floating busing bearings,such as high mechanical efficiency and fast accelerate response.The paper studied obj ect that was ball bearing turbocharger of vehicle,researched on rotor dynamic characteristics of bearing-rotor system,and used finite element method to analyze the critical speed of bearing-rotor system which is the very important basis to j udging whether the rotor work is stable and turbocharger work is reliable. Comparing and analyzing the computing and experimental results,it proves the feasibility and accuracy of setting up model on bearing-rotor system of ball bearing turbocharger.After the test of prototype,it was proved that ball bearing turbo-charger can meet the current needs of vehicle engine and improve the working performance of the engine.

  9. Advanced Gasoline Turbocharged Direction Injection (GTDI) Engine Development

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Terrance [Ford Motor Co., Dearborn, MI (United States)

    2015-12-31

    This program was undertaken in response to US Department of Energy Solicitation DE-FOA-0000079, resulting in a cooperative agreement with Ford and MTU to demonstrate improvement of fuel efficiency in a vehicle equipped with an advanced GTDI engine. Ford Motor Company has invested significantly in GTDI engine technology as a cost effective, high volume, fuel economy solution, marketed globally as EcoBoost technology. Ford envisions additional fuel economy improvement in the medium and long term by further advancing EcoBoost technology. The approach for the project was to engineer a comprehensive suite of gasoline engine systems technologies to achieve the project objectives, and to progressively demonstrate the objectives via concept analysis / computer modeling, single-cylinder and multi-cylinder engine testing on engine dynamometer, and vehicle level testing on chassis rolls.

  10. HARP model rotor test at the DNW. [Hughes Advanced Rotor Program

    Science.gov (United States)

    Dawson, Seth; Jordan, David; Smith, Charles; Ekins, James; Silverthorn, Lou

    1989-01-01

    Data from a test of a dynamically scaled model of the Hughes Advanced Rotor Program (HARP) bearingless model main rotor and 369K tail rotor are reported. The history of the HARP program and its goals are reviewed, and the main and tail rotor models are described. The test facilities and instrumentation are described, and wind tunnel test data are presented on hover, forward flight performance, and blade-vortex interaction. Performance data, acoustic data, and dynamic data from near field/far field and shear layer studies are presented.

  11. Advances in tilt rotor noise prediction

    Science.gov (United States)

    George, A. R.; Coffen, C. D.; Ringler, T. D.

    The two most serious tilt rotor external noise problems, hover noise and blade-vortex interaction noise, are studied. The results of flow visualization and inflow velocity measurements document a complex, recirculating highly unsteady and turbulent flow due to the rotor-wing-body interactions characteristic of tilt rotors. The wing under the rotor is found to obstruct the inflow, causing a deficit in the inflow velocities over the inboard region of the rotor. Discrete frequency harmonic thickness and loading noise mechanisms in hover are examined by first modeling tilt rotor hover aerodynamics and then applying various noise prediction methods using the WOPWOP code. The analysis indicates that the partial ground plane created by the wing below the rotor results in a primary sound source for hover.

  12. The application of advanced rotor (performance) methods for design calculations

    Energy Technology Data Exchange (ETDEWEB)

    Bussel, G.J.W. van [Delft Univ. of Technology, Inst. for Wind Energy, Delft (Netherlands)

    1997-08-01

    The calculation of loads and performance of wind turbine rotors has been a topic for research over the last century. The principles for the calculation of loads on rotor blades with a given specific geometry, as well as the development of optimal shaped rotor blades have been published in the decades that significant aircraft development took place. Nowadays advanced computer codes are used for specific problems regarding modern aircraft, and application to wind turbine rotors has also been performed occasionally. The engineers designing rotor blades for wind turbines still use methods based upon global principles developed in the beginning of the century. The question what to expect in terms of the type of methods to be applied in a design environment for the near future is addressed here. (EG) 14 refs.

  13. Modelling for a Turbocharger in Rotordynamics

    OpenAIRE

    Zhang, Hongyu; Shi, John Z.

    2009-01-01

    Turbochargers are widely used on commercial automotive vehicles, power generation and marine applications. A comprehensive model for a turbocharger would be an effective tool for fault detection. In this paper, research focus on mathematical modelling of turbochargers supported on floating ring bearings in rotordynamics. Nonlinear hydrodynamic forces are considered in order to describe the dynamic behaviour of the rotor system. Following model development, a numerical simulation is implemente...

  14. Tests of Full-Scale Helicopter Rotors at High Advancing Tip Mach Numbers and Advance Ratios

    Science.gov (United States)

    Biggers, James C.; McCloud, John L., III; Stroub, Robert H.

    2015-01-01

    As a continuation of the studies of reference 1, three full-scale helicopter rotors have been tested in the Ames Research Center 40- by SO-foot wind tunnel. All three of them were two-bladed, teetering rotors. One of the rotors incorporated the NACA 0012 airfoil section over the entire length of the blade. This rotor was tested at advance ratios up to 1.05. Both of the other rotors were tapered in thickness and incorporated leading-edge camber over the outer 20 percent of the blade radius. The larger of these rotors was tested at advancing tip Mach numbers up to 1.02. Data were obtained for a wide range of lift and propulsive force, and are presented without discussion.

  15. Performance and Weight Estimates for an Advanced Open Rotor Engine

    Science.gov (United States)

    Hendricks, Eric S.; Tong, Michael T.

    2012-01-01

    NASA s Environmentally Responsible Aviation Project and Subsonic Fixed Wing Project are focused on developing concepts and technologies which may enable dramatic reductions to the environmental impact of future generation subsonic aircraft. The open rotor concept (also historically referred to an unducted fan or advanced turboprop) may allow for the achievement of this objective by reducing engine fuel consumption. To evaluate the potential impact of open rotor engines, cycle modeling and engine weight estimation capabilities have been developed. The initial development of the cycle modeling capabilities in the Numerical Propulsion System Simulation (NPSS) tool was presented in a previous paper. Following that initial development, further advancements have been made to the cycle modeling and weight estimation capabilities for open rotor engines and are presented in this paper. The developed modeling capabilities are used to predict the performance of an advanced open rotor concept using modern counter-rotating propeller designs. Finally, performance and weight estimates for this engine are presented and compared to results from a previous NASA study of advanced geared and direct-drive turbofans.

  16. Stability Analysis of a Turbocharger for Marine Diesel Engine Service

    OpenAIRE

    Adams, Michael

    2012-01-01

    Rotor stability is essential to the life span of any piece of rotating machinery; it becomes increasingly critical in high-speed machinery such as turbochargers. Large turbochargers, such as those found in marine diesel propulsion engines where the rotor alone often exceeds forty pounds, require careful consideration regarding stability as well as load support during the bearing selection process. Logarithmic Decrement is the primary consideration for rotor stability. Commercial software is...

  17. CRADA Final Report for CRADA Number NFE-08-01671 Materials for Advanced Turbocharger Designs

    Energy Technology Data Exchange (ETDEWEB)

    Maziasz, P. J. [ORNL; Wilson, M. [Honeywell

    2014-11-28

    Results were obtained on residual stresses in the weld of the steel shaft to the Ni-based superalloy turbine wheel for turbochargers. Neutron diffraction studies at the HFIR Residual Stress Facility showed asymmetric tensile stresses after electron-beam welding of the wheel and shaft. A post-weld heat-treatment was found to relieve and reduce the residual stresses. Results were also obtained on cast CF8C-Plus steel as an upgrade alternative to cast irons (SiMo, Ni-resist) for higher temperature capability and performance for the turbocharger housing. CF8C-Plus steel has demonstrated creep-rupture resistance at 600-950oC, and is more creep-resistant than HK30Nb, but lacks oxidation-resistance at 800oC and above in 10% water vapor. New modified CF8C-Plus Cu/W steels with Cr and Ni additions show better oxidation resistance at 800oC in 10% water vapor, and have capability to higher temperatures. For automotive gasoline engine turbocharger applications, higher temperatures are required, so at the end of this project, testing began at 1000oC and above.

  18. Aero and vibroacoustics of automotive turbochargers

    CERN Document Server

    Nguyen-Schäfer, Hung

    2013-01-01

    Aero and Vibroacoustics of Automotive Turbochargers is a topic involving aspects from the working fields of thermodynamics of turbomachinery, aerodynamics, rotordynamics, and noise propagation computation.   In this broadly interdisciplinary subject, thermodynamics of turbomachinery is used to design the turbocharger and to determine its operating conditions.  Aerodynamics is needed to study the compressor flow dynamics and flow instabilities of rotating stall and surge, which can produce growling and whining-type noises. Rotordynamics is necessary to study rotor unbalance and self-excited oil-whirl instabilities, which lead to whistling and constant tone-type noises in rotating floating oil-film type bearings. For the special case of turbochargers using ball bearings, some high-order harmonic and wear noises also manifest in the rotor operating range. Lastly, noise propagation computation, based on Lighthill’s analogy, is required to investigate airborne noises produced by turbochargers in passenger vehi...

  19. Rotordynamics and Design Methods of an Oil-Free Turbocharger

    Science.gov (United States)

    Howard, Samuel A.

    1999-01-01

    The feasibility of supporting a turbocharger rotor on air foil bearings is investigated based upon predicted rotordynamic stability, load accommodations, and stress considerations. It is demonstrated that foil bearings offer a plausible replacement for oil-lubricated bearings in diesel truck turbochargers. Also, two different rotor configurations are analyzed and the design is chosen which best optimizes the desired performance characteristics. The method of designing machinery for foil bearing use and the assumptions made are discussed.

  20. Advanced radial inflow turbine rotor program: Design and dynamic testing

    Science.gov (United States)

    Rodgers, C.

    1976-01-01

    The advancement of small, cooled, radial inflow turbine technology in the area of operation at higher turbine inlet temperature is discussed. The first step was accomplished by designing, fabricating, and subjecting to limited mechanical testing an advanced gas generator rotating assembly comprising a radial inflow turbine and two-stage centrifugal compressor. The radial inflow turbine and second-stage compressor were designed as an integrally machined monorotor with turbine cooling taking place basically by conduction to the compressor. Design turbine inlet rotor gas temperature, rotational speed, and overall gas generator compressor pressure ratio were 1422 K (2560 R), 71,222 rpm, and 10/1 respectively. Mechanical testing on a fabricated rotating assembly and bearing system covered 1,000 cold start/stop cycles and three spins to 120 percent design speed (85,466 rpm).

  1. Induced Unbalance as a Method for Improving the Dynamic Stability of High-Speed Turbochargers

    OpenAIRE

    R. Gordon Kirk; Ali A. Alsaeed

    2011-01-01

    The high-speed diesel engine turbocharger is known to have subsynchronous vibrations for a wide speed range. The bearing fluid-film instability is the main source of the vibration. The nonlinear forces inside the bearings are causing the rotor to whirl in a limit cycle. This study presents a new method for improving the dynamic stability by inducing the turbocharger rotor unbalance in order to suppress the subsynchronous vibration. The finite-element model of the turbocharger with floating-ri...

  2. Stability and control issues associated with lightly loaded rotors autorotating in high advance ratio flight

    Science.gov (United States)

    Rigsby, James Michael

    Interest in high speed rotorcraft has directed attention toward the slowed-rotor, high advance ratio compound autogyro concept as evidenced by the current DARPA Heliplane project. The behavior of partially unloaded rotors, autorotating at high advance ratio is not well understood and numerous technical issues must be resolved before the vehicle can be realized. Autorotation in helicopters usually indicates an emergency loss of power. For the concept vehicle autorotation is the normal working state of the rotor. The necessity for a reduction in rotor speed with increasing flight speed results in high advance ratio operation where the retreating side of the rotor is dominated by the reverse flow region. Further, rotor speed changes also affect the rotor dynamics and the associated hub moments generated by cyclic flapping. The result is rotor characteristics that vary widely depending on advance ratio. In the present work, rotor behavior is characterized in terms of issues relevant to the control system conceptual design and the rotor impact on the intrinsic vehicle flight dynamics characteristics. A series of trim, stability, and control analyses, based on features inherent in the concept vehicle, are performed. Trends are identified through parametric variation of rotor operating conditions, augmented by inclusion of the sensitivities to blade mass and blade stiffness properties. In this research, non-linear models, including the rotor speed degree of freedom, were created and analyzed with FLIGHTLAB(TM) rotorcraft modeling software. Performance analysis for rotors trimmed to autorotate with zero average hub pitching and rolling moments indicates reduced rotor thrust is achieved primarily through rotor speed reduction at lower shaft incidence angle, and imposing hub moment trim constraints results in a thrust increment sign reversal with collective pitch angle above advance ratio mu ˜ 1.0. Swashplate control perturbations from trim indicate an increase in control

  3. Synchrotron X-ray CT characterization of friction-welded joints in tial turbocharger components

    Science.gov (United States)

    Sun, J. G.; Kropf, A. J.; Vissers, D. R.; Sun, W. M.; Katsoudas, J.; Yang, N.; Fei, D.

    2012-05-01

    Titanium aluminide (TiAl) is an advanced intermetallic material and is being investigated for application in turbocharger components for diesel engines. A TiAl turbocharger rotor consists of a cast TiAl turbine wheel and a Ti-alloy shaft that are joined by friction welding. Although friction welding is an established industrial process, it is still challenging to join dissimilar materials especially for brittle intermetallics. These joints are therefore required to be inspected using a nondestructive evaluation (NDE) method. In this study, synchrotron X-ray computed tomography (CT) developed at the Advanced Photon Source at Argonne National Laboratory was used for NDE characterization of friction-welded joint in three TiAl turbocharger rotors. The filtered synchrotron X-ray source has high peak energies to penetrate thick metallic materials, and the detector (imager) has high spatial resolutions to resolve small flaws. The CT inspections revealed detailed 3D crack distributions within poorly welded joints. The crack detection sensitivity and resolution was calibrated and found to be correlated well with destructive examination.

  4. Optimising the turbocharging of large engines in the future

    Energy Technology Data Exchange (ETDEWEB)

    Codan, E. [ABB Turbo Systems, Ltd., R and D Turbocharging, Baden (Switzerland)

    1998-12-31

    The new ABB turbocharger generations TPL and TPS were developed to match the most advanced turbocharged engines over 500 kW of the coming years. High performance in terms of pressure ratio and turbocharging efficiency no longer guarantees an efficient engine operation over the whole operating field. Therefore matched turbocharger characteristics for different applications are increasingly important. This paper shows the influence of the turbocharging system characteristics on the steady state and transient behaviour of a turbocharged engine for different applications. Basis for the study is the well proven simulation system SiSy, which is widely used for the performance prediction of the turbocharging engine. Some simple parameters were developed that numerically describe the correlation between the characteristic of the turbocharging system and the engine operation. The limits of the commonly used turbocharging systems are shown together with an overview of future possibilities, e.g. two-stage turbocharging and turbocompound. A joint optimisation of the turbocharging system and of the engine will be of paramount importance in the future, to exploit the improvement potential. (au)

  5. Reduction and Maintance of Turbochargers by Applying Valid Tribological Constructing

    Directory of Open Access Journals (Sweden)

    V. Marušić

    2016-06-01

    Full Text Available Condition recordings and turbochargers test results indicate that during the long driving at higher speeds may cause turbochargers overheat. Lubricate termination after shutting generator can cause damage to the sliding surface bearings. As a result, eventually comes to unbalance of rotating parts, turbine rotor and the compressor impeller. One of the solutions is application of sensor which would not allow shutting generator down until the temperature is lowered to an acceptable value.

  6. Updated Assessment of an Open Rotor Airplane Using an Advanced Blade Design

    Science.gov (United States)

    Hendricks, Eric S.; Berton, Jeffrey J.; Haller, William J.; Tong, Michael T.; Guynn, Mark D.

    2013-01-01

    Application of open rotor propulsion systems (historically referred to as "advanced turboprops" or "propfans") to subsonic transport aircraft received significant attention and research in the 1970s and 1980s when fuel efficiency was the driving focus of aeronautical research. Recent volatility in fuel prices and concern for aviation's environmental impact have renewed interest in open rotor propulsion, and revived research by NASA and a number of engine manufacturers. Over the last few years, NASA has revived and developed analysis capabilities to assess aircraft designs with open rotor propulsion systems. These efforts have been described in several previous papers along with initial results from applying these capabilities. The initial results indicated that open rotor engines have the potential to provide large reductions in fuel consumption and emissions. Initial noise analysis indicated that current noise regulations can be met with modern baseline blade designs. Improved blades incorporating low-noise features are expected to result in even lower noise levels. This paper describes improvements to the initial assessment, plus a follow-on study using a more advanced open rotor blade design to power the advanced singleaisle transport. The predicted performance and environmental results of these two advanced open rotor concepts are presented and compared.

  7. Performance and Environmental Assessment of an Advanced Aircraft with Open Rotor Propulsion

    Science.gov (United States)

    Guynn, Mark D.; Berton, Jeffrey J.; Haller, William J.; Hendricks, Eric S.; Tong, Michael T.

    2012-01-01

    Application of high speed, advanced turboprops, or "propfans," to transonic transport aircraft received significant attention during the 1970s and 1980s when fuel efficiency was the driving focus of aeronautical research. Unfortunately, after fuel prices declined sharply there was no longer sufficient motivation to continue maturing this technology. Recent volatility in fuel prices and increasing concern for aviation s environmental impact, however, have renewed interest in unducted, open rotor propulsion. Because of the renewed interest in open rotor propulsion, the lack of publicly available up-to-date studies assessing its benefits, and NASA s focus on reducing fuel consumption, a preliminary aircraft system level study on open rotor propulsion was initiated to inform decisions concerning research in this area. New analysis processes were established to assess the characteristics of open rotor aircraft. These processes were then used to assess the performance, noise, and emissions characteristics of an advanced, single-aisle aircraft using open rotor propulsion. The results of this initial study indicate open rotor engines have the potential to provide significant reductions in fuel consumption and landing-takeoff cycle NOX emissions. Noise analysis of the study configuration indicates that an open rotor aircraft in the single-aisle class would be able to meet current noise regulations with margin.

  8. Development and application of steam turbines with advanced HLP single-cylinder rotors

    Energy Technology Data Exchange (ETDEWEB)

    Sakuma, A.; Tsuda, Y.; Suzuki, M. [Toshiba Corp. (Japan)

    1996-12-31

    Recently, the Gas Turbine capacity has been increased step by step to improve initial cost of the Gas turbine and plant efficiency as well as to improve cycle conditions that is, temperature, pressure and cycle. In accordance with this improvement, the steam turbine capacity has been increased gradually in combined-cycle plants. In this application, the steam turbine became larger and the steam turbine is generally equipped with multiple rotors. When the rotor forging with a good combination of creep rupture strength in the HP section and toughness in the LP section is available, the steam turbine can be designed as a single rotor, instead of multiple rotors, which makes the steam turbine to be compact and to be simple. The authors have already developed an HLP rotor forging (first generation), which has been applied to turbine rotors of units having capacities up to around 100 MW with a last stage blade (LSB) of a maximum 26 inch (660 mm) class. Recently, the advanced HLP rotor forging has been developed, which can be applied to longer LSBs of 42 inch (1070 mm) for 50 Hz machines, and 40 inch (1016 mm) for 60 Hz machines. As a result of the development, the steam turbines of 100 to 250 MW capacity in thermal power plants and advanced combined-cycle plants can be made more compact through this single-cylinder design. This paper describes development and application of the steam turbine with the advanced HLP rotor for advanced combined-cycle plants as well as for conventional thermal plants.

  9. Turbocharger Structural Integrity

    OpenAIRE

    Barrans, Simon; Allport, John; Khodabakhshi, Goodarz

    2014-01-01

    Since the introduction of Euro VI in January 2014, all new diesel powered commercial vehicles have been equipped with turbocharged engines. It is virtually impossible to meet these emission regulations without using a turbocharger. Similarly, in the passenger car sector both on diesel and petrol (gasoline) powered vehicles, legislative pressure to reduce emissions of carbon dioxide are seeing the introduction of turbochargers across almost all new power units. Future legislation will continue...

  10. Research on the Critical Speed of a Mixed-Flow Turbocharger with Hybrid Ceramic Ball Bearing

    Institute of Scientific and Technical Information of China (English)

    HUANG Ruo; GE Xin-bin; MA Chao-chen

    2009-01-01

    The critical speeds for a vehicle turbocharger with hybrid ceramic ball bearing are researched. The ball bearing-rotor system produces resonance when it working in critical speed and that makes the turbocharger injury working for a long time. The calculation and analysis methods of the critical speed for the vehicle turbocharger are described. The critical speed is computed by two methods including Riccati transfer matrix and DyRoBeS finite element method for a vehicle turbocharger with hybrid ceramic ball bearing. The vibration experiment had been taken to validate the calculating result. Comparison between the results by two calculation methods and the test results show that the first critical speed differences are 6.47% and 5.66%, the second critical speed differences are 2.87% and 2.94% respectively. And then, the primary factors which influence the critical speed are analyzed, the conclusions will be helpful for the vehicle turbocharger bearing-rotor system design.

  11. AVATAR: AdVanced Aerodynamic Tools for lArge Rotors

    DEFF Research Database (Denmark)

    Schepers, J.C.; Ceyhan, O.; Savenije, F.J.;

    2015-01-01

    An EERA (European Energy Research Alliance) consortium started an ambitious EU FP7 project AVATAR (AdVanced Aerodynamic Tools of lArge Rotors) in November 2013. The project lasts 4 years and is carried out in a consortium with 11 research institutes and two industry partners. The motivation for t...

  12. THERMODYNAMIC DESIGN OF RADIAL TURBINE FOR TURBO-CHARGER

    OpenAIRE

    Sondkar Pratik *, Siddiqui Qasim, Sonawane Shubham, Phirke Indraneel.

    2016-01-01

    This is a report for design process of radial turbine used in turbocharger. Input for design requirements are power, mass flow rate, inlet temperature, pressure and rotation speed. The design variables include rotor radius ratios, stator-exit angle and rotor-exit tangential velocity distribution. The geometry was tested using Computational Fluid Dynamics (CFD) where some modifications were introduced on the preliminary design to satisfy the design requirements. The turbine’s design poin...

  13. Stress analysis of advanced attack helicopter composite main rotor blade root end lug

    Science.gov (United States)

    Baker, D. J.

    1982-01-01

    Stress analysis of the Advanced Attack Helicopter (AAH) composite main rotor blade root end lug is described. The stress concentration factor determined from a finite element analysis is compared to an empirical value used in the lug design. The analysis and test data indicate that the stress concentration is primarily a function of configuration and independent of the range of material properties typical of Kevlar-49/epoxy and glass epoxy.

  14. Development of a rotor alloy for advanced ultra super critical turbine power generation system

    Energy Technology Data Exchange (ETDEWEB)

    Miyashita, Shigekazu; Yamada, Masayuki; Suga, Takeo; Imai, Kiyoshi; Nemoto, Kuniyoshi; Yoshioka, Youmei [Toshiba Corporation, Yokohama (Japan)

    2008-07-01

    A Ni-based superalloy ''TOS1X'', for the rotor material of the 700 class advanced ultra super critical (A-USC) turbine power generation system was developed. TOS1X is an alloy that is improved in the creep rupture strength of Inconel trademark 617 maintaining both forgeability and weldability. The 7 t weight model rotor made of TOS1X was manufactured by double melt process, vacuum induction melting and electro slag remelting, and forging. During forging process, forging cracks and any other abnormalities were not detected on the ingots. The metallurgical and the mechanical properties in this rotor were investigated. Macro and micro structure observation, and some mechanical tests were conducted. According to the metallurgical structure investigation, there was no remarkable segregation in whole area and the forging effect was reached in the center part of the rotor ingot. The results of tensile test and creep rupture test proved that proof stress and tensile stress of the TOS1X are higher than those of Inconel trademark 617 and creep rupture strength of TOS1X is much superior than that of Inconel trademark 617. (orig.)

  15. Effects of Unbalance Location on Dynamic Characteristics of High-speed Gasoline Engine Turbocharger with Floating Ring Bearings

    Institute of Scientific and Technical Information of China (English)

    WANG Longkai; BIN Guangfu; LI Xuejun; LIU Dingqu

    2016-01-01

    For the high-speed gasoline engine turbocharger rotor, due to the heterogeneity of multiple parts material, manufacturing and assembly errors, running wear in impeller and uneven carbon of turbine, the random unbalance usually can be developed which will induce excessive rotor vibration, and even lead to nonlinear vibration accidents. However, the investigation of unbalance location on the nonlinear high-speed turbocharger rotordynamic characteristics is less. In order to discuss the rotor unbalance location effects of turbocharger with nonlinear floating ring bearings(FRBs), the realistic turbocharger of gasoline engine is taken as a research object. The rotordynamic equations of motion under the condition of unbalance are derived by applied unbalance force and nonlinear oil film force of FRBs. The FE model of turbocharger rotor-bearing system is modeled which includes the unbalance excitation and nonlinear FRBs. Under the conditions of four different applied locations of unbalance, the nonlinear transient analyses are performed based on the rotor FEM. The differences of dynamic behavior are obvious to the turbocharger rotor systems for four conditions, and the bifurcation phenomena are different. From the results of waterfall and transient response analysis, the speed for the appearance of fractional frequency is not identical and the amplitude magnitude is different from the different unbalance locations, and the non-synchronous vibration does not occur in the turbocharger and the amplitude is relative stable and minimum under the condition 4. The turbocharger vibration and non-synchronous components could be reduced or suppressed by controlling the applied location of unbalance, which is helpful for the dynamic design, fault diagnosis and vibration control of the high-speed gasoline engine turbochargers.

  16. Effects of unbalance location on dynamic characteristics of high-speed gasoline engine turbocharger with floating ring bearings

    Science.gov (United States)

    Wang, Longkai; Bin, Guangfu; Li, Xuejun; Liu, Dingqu

    2016-03-01

    For the high-speed gasoline engine turbocharger rotor, due to the heterogeneity of multiple parts material, manufacturing and assembly errors, running wear in impeller and uneven carbon of turbine, the random unbalance usually can be developed which will induce excessive rotor vibration, and even lead to nonlinear vibration accidents. However, the investigation of unbalance location on the nonlinear high-speed turbocharger rotordynamic characteristics is less. In order to discuss the rotor unbalance location effects of turbocharger with nonlinear floating ring bearings(FRBs), the realistic turbocharger of gasoline engine is taken as a research object. The rotordynamic equations of motion under the condition of unbalance are derived by applied unbalance force and nonlinear oil film force of FRBs. The FE model of turbocharger rotor-bearing system is modeled which includes the unbalance excitation and nonlinear FRBs. Under the conditions of four different applied locations of unbalance, the nonlinear transient analyses are performed based on the rotor FEM. The differences of dynamic behavior are obvious to the turbocharger rotor systems for four conditions, and the bifurcation phenomena are different. From the results of waterfall and transient response analysis, the speed for the appearance of fractional frequency is not identical and the amplitude magnitude is different from the different unbalance locations, and the non-synchronous vibration does not occur in the turbocharger and the amplitude is relative stable and minimum under the condition 4. The turbocharger vibration and non-synchronous components could be reduced or suppressed by controlling the applied location of unbalance, which is helpful for the dynamic design, fault diagnosis and vibration control of the high-speed gasoline engine turbochargers.

  17. Review of Recent Advances in the Application of the Wavelet Transform to Diagnose Cracked Rotors

    Directory of Open Access Journals (Sweden)

    María J. Gómez

    2016-03-01

    Full Text Available Wavelet transform (WT has been used in the diagnosis of cracked rotors since the 1990s. At present, WT is one of the most commonly used tools to treat signals in several fields. Understandably, this has been an area of extensive scientific research, which is why this paper aims to summarize briefly the major advances in the field since 2008. The present review considers advances in the use and application of WT, the selection of the parameters used, and the key achievements in using WT for crack diagnosis.

  18. Simulation of the Performance of a Variable Geometry Turbocharger for Diesel Engine Road Propulsion

    Directory of Open Access Journals (Sweden)

    J. Jullien

    2002-09-01

    Full Text Available Advanced research work has lead to the development of a new simulation program and the thermodynamic parameters at engine inlet and exhaust of an engine-mounted variable-geometry turbine can thus be evaluated. The machine is divided into characteristic sub-blocks and resolution of thermomechanical flow equations is carried out using the necessary geometrical parameters. A detailed study of losses is conducted experimentally and numerically into the scroll, the vaned nozzle and the rotor in relation to nozzle opening angles. Simulation results made on the variable geometry turbine are analyzed in relation to main flow entry parameters and are compared systematically with experimental data gathered on turbocharger test equipment, and on a Diesel engine used for industrial applications.

  19. Noise Radiation from Automotive Turbochargers

    OpenAIRE

    Zhenrui, Wang

    2011-01-01

    Turbochargers are now commonly used in modern automotive engines, which increase the density of air entering the engine to produce more power. This device not only greatly improves the degree of engine efficiency, but also reduces the pollutant emissions. However, one of the important issues which must be considered is the noise from turbochargers. This noise can radiate either after propagation through the intake and exhaust ducts or via induced vibrations in the turbocharger housing. Here t...

  20. Causes of automotive turbocharger faults

    OpenAIRE

    Jan FILIPCZYK

    2013-01-01

    This paper presents the results of examinations of turbocharger damages. The analysis of the causes of faults in 100 engines with turbochargers of cars, buses and trucks has been carried out. The incidence and structure of turbocharged engine faults has been compared to the causes of faults of naturally aspirated engines. The cause of damage, the possibility of early detection, the time between overhaul and the impact on engine operation for each case of fault was carried out as well. The re...

  1. Induced Unbalance as a Method for Improving the Dynamic Stability of High-Speed Turbochargers

    KAUST Repository

    Gordon Kirk, R.

    2011-01-01

    The high-speed diesel engine turbocharger is known to have subsynchronous vibrations for a wide speed range. The bearing fluid-film instability is the main source of the vibration. The nonlinear forces inside the bearings are causing the rotor to whirl in a limit cycle. This study presents a new method for improving the dynamic stability by inducing the turbocharger rotor unbalance in order to suppress the subsynchronous vibration. The finite-element model of the turbocharger with floating-ring bearings is numerically solved for the nonlinear time-transient response. Both compressor and turbine added unbalance are induced and the dynamic stability is computed. The turbocharger model with linearized floating-ring bearings is also solved for eigenvalues to predict the modes of instability. The linear analysis demonstrates that the forward whirling mode of the floating-ring at the compressor end also becomes unstable at the higher turbocharger speeds, in addition to the unstable forward conical and cylindrical modes. The numerical predictions are also compared to the former experimental results of a similar turbocharger. The results of the study show that the subsynchronous frequency amplitude of the dominant first mode is reduced when inducing either the compressor or the turbine unbalance at a certain level. © 2011 R. Gordon Kirk and Ali A. Alsaeed.

  2. Induced Unbalance as a Method for Improving the Dynamic Stability of High-Speed Turbochargers

    Directory of Open Access Journals (Sweden)

    R. Gordon Kirk

    2011-01-01

    Full Text Available The high-speed diesel engine turbocharger is known to have subsynchronous vibrations for a wide speed range. The bearing fluid-film instability is the main source of the vibration. The nonlinear forces inside the bearings are causing the rotor to whirl in a limit cycle. This study presents a new method for improving the dynamic stability by inducing the turbocharger rotor unbalance in order to suppress the subsynchronous vibration. The finite-element model of the turbocharger with floating-ring bearings is numerically solved for the nonlinear time-transient response. Both compressor and turbine added unbalance are induced and the dynamic stability is computed. The turbocharger model with linearized floating-ring bearings is also solved for eigenvalues to predict the modes of instability. The linear analysis demonstrates that the forward whirling mode of the floating-ring at the compressor end also becomes unstable at the higher turbocharger speeds, in addition to the unstable forward conical and cylindrical modes. The numerical predictions are also compared to the former experimental results of a similar turbocharger. The results of the study show that the subsynchronous frequency amplitude of the dominant first mode is reduced when inducing either the compressor or the turbine unbalance at a certain level.

  3. Measured and predicted rotor performance for the SERI advanced wind turbine blades

    Science.gov (United States)

    Tangler, J.; Smith, B.; Kelley, N.; Jager, D.

    1992-02-01

    Measured and predicted rotor performance for the Solar Energy Research Institute (SERI) advanced wind turbine blades were compared to assess the accuracy of predictions and to identify the sources of error affecting both predictions and measurements. An awareness of these sources of error contributes to improved prediction and measurement methods that will ultimately benefit future rotor design efforts. Propeller/vane anemometers were found to underestimate the wind speed in turbulent environments such as the San Gorgonio Pass wind farm area. Using sonic or cup anemometers, good agreement was achieved between predicted and measured power output for wind speeds up to 8 m/sec. At higher wind speeds an optimistic predicted power output and the occurrence of peak power at wind speeds lower than measurements resulted from the omission of turbulence and yaw error. In addition, accurate two-dimensional (2-D) airfoil data prior to stall and a post stall airfoil data synthesization method that reflects three-dimensional (3-D) effects were found to be essential for accurate performance prediction.

  4. Modeling Creep-Fatigue-Environment Interactions in Steam Turbine Rotor Materials for Advanced Ultra-supercritical Coal Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Chen [General Electric Global Research, Niskayuna, NY (United States)

    2014-04-01

    The goal of this project is to model creep-fatigue-environment interactions in steam turbine rotor materials for advanced ultra-supercritical (A-USC) coal power Alloy 282 plants, to develop and demonstrate computational algorithms for alloy property predictions, and to determine and model key mechanisms that contribute to the damages caused by creep-fatigue-environment interactions.

  5. 14 CFR 23.909 - Turbocharger systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Turbocharger systems. 23.909 Section 23.909... Turbocharger systems. (a) Each turbocharger must be approved under the engine type certificate or it must be shown that the turbocharger system, while in its normal engine installation and operating in the...

  6. Advanced pulp screen rotor technology provides electrical energy savings at Canfor-Northwood

    Energy Technology Data Exchange (ETDEWEB)

    Dylke, E.; Fowler, L. [Cantor Pulp Ltd., Prince George, BC (Canada); Pflueger, C. [Fransen Engineering Ltd., Richmond, BC (Canada); Olson, J.A. [British Columbia Univ., Vancouver, BC (Canada)

    2008-02-15

    Narrow slotted cylinders are traditionally used in pulp screening processes to ensure high debris removal efficiency. Screens are required to operate at higher speeds in order to maintain high capacity, which typically results in higher power and electricity costs. This article described the AFT Gladiator HC{sup TM} rotor and provided details of pilot and mill test trials conducted to compare the rotor with conventional rotor technologies. The hydrodynamic rotor elements of the rotor were segmented along the length to ensure that large debris were able to pass freely down the screening zone and into the reject stream. Angled elements were also used to distribute the pressure pulse evenly across the cylinder's surface. Screen rotor trials were conducted at a kraft mill on brown stock with 1.6 to 2 per cent feed pulp consistency. The tests demonstrated that power consumption of the GHC rotor was lower than other rotors, and was able to operate at lower speeds. Total savings were estimated at 52 per cent, which resulted in a payback period of 12 months. Small increases in rotor speed result in large changes in consumed power and reduced operating costs. When combined with narrow slotted screen technology, the GHC provided shive removal efficiencies equal to competitor rotors over a wide range of slot velocities. It was concluded that the increased capacity of the rotor increased debris removal efficiency. 4 refs., 9 figs.

  7. Assessment of Structural Design for Turbocharger Impeller

    International Nuclear Information System (INIS)

    The impeller in a turbocharger is a key component and is subject to the various loads as well as centrifugal force over 10,000rpm. The high structural reliability and stability are required to the impeller which is assembled with a rotor shaft, bearings and thrust collar. In this paper, the structural assessment of the impeller which is made of the aluminium alloy was presented. In order to confirm it, structural and dynamic evaluation using FE analyses were performed. In FE analyses, centrifugal force, thermal load, working pressure and mechanical contact between neighboring components were taken into account. Structural contribution for each loading was compared. Additionally, the characteristics of deformation and vibration under each loading were also investigated

  8. Turbocharging the Financial Markets

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Introduction of new financial instruments may not put China’s markets in the fast lane just yet, a market analyst warns China has introduced new sources of leverage into the financial system, which will enable participants to have "new opportunities both to hedge their bets and lever them up using futures, options and margin trading," according to Mark A DeWeaver, a research analyst in Shenzhen who now manages a fund investing in Asian equities called Quantrarian Asia Hedge. He compares these measures to "turbocharging a car," which he says can damage it if the engine’s basic structure cannot handle the pressure. His main ideas follow:

  9. Causes of automotive turbocharger faults

    Directory of Open Access Journals (Sweden)

    Jan FILIPCZYK

    2013-01-01

    Full Text Available This paper presents the results of examinations of turbocharger damages. The analysis of the causes of faults in 100 engines with turbochargers of cars, buses and trucks has been carried out. The incidence and structure of turbocharged engine faults has been compared to the causes of faults of naturally aspirated engines. The cause of damage, the possibility of early detection, the time between overhaul and the impact on engine operation for each case of fault was carried out as well. The results of examinations allowed to determine the most common causes of damages and how to prevent them.

  10. Effects of Floating Ring Bearing Manufacturing Tolerance Clearances on the Dynamic Characteristics for Turbocharger

    Institute of Scientific and Technical Information of China (English)

    WANG Longkai; BIN Guangfu; LI Xuejun; ZHANG Xuefeng

    2015-01-01

    The inner and outer oil film dynamic characteristic coefficients of floating ring bearings(FRBs) change due to the manufacturing tolerance of the floating ring, journal and intermediate, which leads to high-speed turbocharger’s vibration too large and even causes nonlinear vibration accident. However, the investigation of floating ring bearing manufacturing tolerance clearance on the rotordynamic characteristics is less at present. In order to study the influence law of inner and outer clearance on turbocharger vibration, the rotor dynamic motion equations of turbocharger supported in FRBs are derived by analyzing the size relations between floating ring, journal and intermediate for the inner and outer oil film clearances, the time transient response analysis for combination of FRBs clearance are developed. A realistic turbocharger is taken as a research object, the FE model of the turbocharger with FRBs is modeled. Under the conditions of four kinds of limit state bearing clearances for inner and outer oil film, the nonlinear transient analyses are performed based on the established FE dynamic models of the nonlinear rotor-FRBs system applied incentive combinations of gravity and unbalance force, respectively. From the waterfall, the simulation results show that the speed for the appearance of fractional frequency is not identical and the amplitude magnitude is different under the four kinds of bearing manufacturing tolerance limit clearances, and fractional frequency does not appear in the turbocharger and the amplitude is minimum under the ODMin/IDMax bearing manufacturing tolerance clearances. The turbocharger vibration is reduced by controlling the manufacturing tolerance clearance combinations of FRBs, which is helpful for the dynamic design and production-manufacturing of high-speed turbocharger.

  11. Two operating modes for turbocharger system

    International Nuclear Information System (INIS)

    Highlights: ► A turbocharger system that operates in power assisted mode is introduced. ► The parameters affecting performance of the turbocharger is presented. ► Different operational charts for turbocharger are presented. ► The parametric study is helpful guide to determine turbocharger dimensioning. - Abstract: The present paper introduces a turbocharger system that operates in two different modes according to turbocharging requirements. In the first mode, the turbocharger is operating with power assistance at lower engine speeds where the power of the exhaust gases is insufficient. Thereafter, the second mode is switched leading the compressor and the turbine of the turbocharger to rotate separately for best performance. Analysis is presented to find out the parameters affecting the operation of the turbocharger and their values to achieve enhanced turbocharger performance with high efficient impellers. The parameters studied are based on data of the turbocharger operating conditions and the operational requirements of the engine. The analysis considers the turbocharger system, its turbine and its compressor. The operational charts demonstrate the simulated results for two operating modes. This study is helpful as a guide to determine the turbocharger dimensioning and blade profile assignment without using any given blade dimensional value.

  12. Mean Value Modelling of Turbocharged SI Engines

    DEFF Research Database (Denmark)

    Müller, Martin; Hendricks, Elbert; Sorenson, Spencer C.

    1998-01-01

    The development of a computer simulation to predict the performance of a turbocharged spark ignition engine during transient operation. New models have been developed for the turbocharged and the intercooling system. An adiabatic model for the intake manifold is presented....

  13. Dynamics of High-Speed Rotors Supported in Sliding Bearings

    Science.gov (United States)

    Šimek, J.; Svoboda, R.

    The higher the operating speed, the more serious are problems with rotor stability. Three basic groups of rotors are analyzed and some methods of suppressing instability are shown. In the first group are classical elastic rotors supported in hydrodynamic bearings. Practically all high-speed rotors now run in tilting pad bearings, which are inherently stable, but in specific conditions even tiling pad bearings may not ensure rotor stability. The second group is composed of combustion engines turbocharger rotors, which are characteristic by heavy impellers at both overhung ends of elastic shaft. These rotors are in most cases supported in floating ring bearings, which bring special features to rotor behaviour. The third group of rotors with gas bearings exhibits special features.

  14. Research and development on transonic compressor of high pressure ratio turbocharger for vehicle internal combustion engines

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The pressure ratio required for a turbocharger centrifugal compressor increases with internal combustion engine power density. High pressure ratio causes a transonic flow field at the impeller inducer. Transonic flow narrows the stable flow range and de-teriorates stage efficiency. In this work, an advanced high pressure ratio transonic compressor was designed. The experimental results show that the maximum pressure ratio of this turbocharger is about 4.2, the maximum efficiency is above 80% and the stable flow range at the designed rotating speed is up to 34%. A turbocharger with this transonic compressor has been applied to some vehicle research actually, and improved power density by 40%.

  15. Turbocharging the DA465 gasoline engine

    Institute of Scientific and Technical Information of China (English)

    ZHANG Peng-qi; ZONG Li-jun; WANG Yin-yan

    2008-01-01

    In order to improve performance of the DA465Q gasoline engine,a substantial amount of research was done to optimize its turbocharging system.The research led to the GT12 turbocharger being selected and its turbocharging parameters being settled.Based on these tests,rational matching was worked out for respective components of the turbocharging system.Results show that this turbocharger allows the engine to easily meet the proposed requirements for power and economic performance,giving insight into further performance improvements for gasoline engines.

  16. Advanced Vibration Analysis Tools and New Strategies for Robust Design of Turbine Engine Rotors

    Science.gov (United States)

    Min, James B.

    2002-01-01

    The adverse effects of small, random structural irregularities among the blades, called mistuning, can result in blade forced-response amplitudes and stresses that are much larger than those predicted for a perfectly tuned rotor. Manufacturing tolerances, deviations in material properties, or nonuniform operational wear causes mistuning; therefore, mistuning is unavoidable. Furthermore, even a small mistuning can have a dramatic effect on the vibratory behavior of a rotor because it can lead to spatial localization of the vibration energy (see the following photographs). As a result, certain blades may experience forced response amplitudes and stresses that are substantially larger than those predicted by an analysis of the nominal (tuned) design. Unfortunately, these random uncertainties in blade properties, and the immense computational effort involved in obtaining statistically reliable design data, combine to make this aspect of rotor design cumbersome.

  17. Influence of Induced Unbalance on Subsynchronous Vibrations of an Automotive Turbocharger

    OpenAIRE

    Sterling, John Anthony

    2009-01-01

    Rotordynamic instability is present in most or all automotive turbochargers. High subsynchronous amplitudes can cause a variety of problems in areas such as mechanical failures, emissions regulations and rotor design. Self-excited vibrations from sources of damping can lock in at lateral natural frequencies causing dangerously high vibration levels. The resulting high-amplitude conical and bending modes can be reduced in order to achieve a more robust system. This rese...

  18. ANALISA TURBOCHARGER PADA MOTOR BENSIN DAIHATSU TIPE CB-23

    OpenAIRE

    Rully Hartadi; Willyanto Anggono; Philip Kristanto

    2001-01-01

    Turbocharger is one of component that used to improve performance of vehicle by increasing density of air. Turbocharger consists of turbin and compressor. Many people hope that their vehicle has better performance and faster acceleration by applaying some component. In this case turbocharger can do that. By applaying turbocharger, air and fuel will homogeneously mixed that can give a better combustion. Turbocharger has many advantages. Turbocharger powered by pressure of exhaust gas. Abstract...

  19. Turbine adapted maps for turbocharger engine matching

    Energy Technology Data Exchange (ETDEWEB)

    Tancrez, M. [PSA - Peugeot Citroen, 18 rue des fauvelles, La Garenne-Colombes (France); Galindo, J.; Guardiola, C.; Fajardo, P.; Varnier, O. [CMT - Motores Termicos, Universidad Politecnica de Valencia (Spain)

    2011-01-15

    This paper presents a new representation of the turbine performance maps oriented for turbocharger characterization. The aim of this plot is to provide a more compact and suited form to implement in engine simulation models and to interpolate data from turbocharger test bench. The new map is based on the use of conservative parameters as turbocharger power and turbine mass flow to describe the turbine performance in all VGT positions. The curves obtained are accurately fitted with quadratic polynomials and simple interpolation techniques give reliable results. Two turbochargers characterized in an steady flow rig were used for illustrating the representation. After being implemented in a turbocharger submodel, the results obtained with the model have been compared with success against turbine performance evaluated in engine tests cells. A practical application in turbocharger matching is also provided to show how this new map can be directly employed in engine design. (author)

  20. Advanced grid-stiffened composite shells for applications in heavy-lift helicopter rotor blade spars

    Science.gov (United States)

    Narayanan Nampy, Sreenivas

    Modern rotor blades are constructed using composite materials to exploit their superior structural performance compared to metals. Helicopter rotor blade spars are conventionally designed as monocoque structures. Blades of the proposed Heavy Lift Helicopter are envisioned to be as heavy as 800 lbs when designed using the monocoque spar design. A new and innovative design is proposed to replace the conventional spar designs with light weight grid-stiffened composite shell. Composite stiffened shells have been known to provide excellent strength to weight ratio and damage tolerance with an excellent potential to reduce weight. Conventional stringer--rib stiffened construction is not suitable for rotor blade spars since they are limited in generating high torsion stiffness that is required for aeroelastic stability of the rotor. As a result, off-axis (helical) stiffeners must be provided. This is a new design space where innovative modeling techniques are needed. The structural behavior of grid-stiffened structures under axial, bending, and torsion loads, typically experienced by rotor blades need to be accurately predicted. The overall objective of the present research is to develop and integrate the necessary design analysis tools to conduct a feasibility study in employing grid-stiffened shells for heavy-lift rotor blade spars. Upon evaluating the limitations in state-of-the-art analytical models in predicting the axial, bending, and torsion stiffness coefficients of grid and grid-stiffened structures, a new analytical model was developed. The new analytical model based on the smeared stiffness approach was developed employing the stiffness matrices of the constituent members of the grid structure such as an arch, helical, or straight beam representing circumferential, helical, and longitudinal stiffeners. This analysis has the capability to model various stiffening configurations such as angle-grid, ortho-grid, and general-grid. Analyses were performed using an

  1. On Mixed Flow Turbines for Automotive Turbocharger Applications

    Directory of Open Access Journals (Sweden)

    Bernhardt Lüddecke

    2012-01-01

    Full Text Available Due to increased demands for improved fuel economy of passenger cars, low-end and part-load performance is of key importance for the design of automotive turbocharger turbines. In an automotive drive cycle, a turbine which can extract more energy at high pressure ratios and lower rotational speeds is desirable. In the literature it is typically found that radial turbines provide peak efficiency at speed ratios of 0.7, but at high pressure ratios and low rotational speeds the blade speed ratio will be low and the rotor will experience high values of positive incidence at the inlet. Based on fundamental considerations, it is shown that mixed flow turbines offer substantial advantages for such applications. Moreover, to prove these considerations an experimental assessment of mixed flow turbine efficiency and optimal blade speed ratio is presented. This has been achieved using a new semi-unsteady measurement approach. Finally, evidence of the benefits of mixed flow turbine behaviour in engine operation is given. Regarding turbocharged engine simulation, the benefit of wide-ranging turbine map measurement data as well as the need for reasonable turbine map extrapolation is illustrated.

  2. Thermal Efficiency of a Combined Turbocharger Set with Gasoline Engine

    OpenAIRE

    Jarut Kunanoppadon

    2010-01-01

    Problem statement: The technology of turbocharger has been used with internal combustion engines since 1905 to increase intake air pressure prior to putting it into the cylinders to increase thermal efficiency of the engine. Based on previous researches and uses of turbochargers, the pattern of turbocharger installation remains the same, either in series or in parallel. Therefore, this research aims to study installation of the combined turbocharger. The combined turbocharger set comprised tw...

  3. Rotordynamics and bearing design of turbochargers

    Science.gov (United States)

    Chen, Wen Jeng

    2012-05-01

    Turbochargers have gained significant attention in recent years. They are already widely used in automotive, locomotive, and marine applications with diesel engines. They are also applied in the aerospace application to increase the engine performance now. The turbochargers used in automotive and aerospace industry are very light-weight with operating speeds above 100,000 rpm. The turbochargers used in locomotive and marine applications are relatively heavy in size and power compared to the automotive and aerospace applications, and the maximum continuous operating speeds are around 30,000 rpm depending on the diesel engine power rating. Floating ring bushings, semi-floating dampers, ball bearings, and ball bearings with dampers are commonly used in automotive applications for small turbochargers. However, these bearings may not be appropriate for large turbochargers in locomotive and marine applications. Instead, multi-lobed bearings with and without squeeze film dampers are commonly used in these heavy-duty turbochargers. This paper deals with the rotordynamic characteristics of larger turbochargers in locomotive and marine applications. Various bearing designs are discussed. Bearing design parameters are studied and optimal values are suggested. Test results are also presented to support the analytical simulation.

  4. Optimization of wind turbine rotors - using advanced aerodynamic and aeroelastic models and numerical optimization

    Energy Technology Data Exchange (ETDEWEB)

    Doessing, M.

    2011-05-15

    During the last decades the annual energy produced by wind turbines has increased dramatically and wind turbines are now available in the 5MW range. Turbines in this range are constantly being developed and it is also being investigated whether turbines as large as 10-20MW are feasible. The design of very large machines introduces new problems in the practical design, and optimization tools are necessary. These must combine the dynamic effects of both aerodynamics and structure in an integrated optimization environment. This is referred to as aeroelastic optimization. The Risoe DTU optimization software HAWTOPT has been used in this project. The quasi-steady aerodynamic module have been improved with a corrected blade element momentum method. A structure module has also been developed which lays out the blade structural properties. This is done in a simplified way allowing fast conceptual design studies and with focus on the overall properties relevant for the aeroelastic properties. Aeroelastic simulations in the time domain were carried out using the aeroelastic code HAWC2. With these modules coupled to HAWTOPT, optimizations have been made. In parallel with the developments of the mentioned numerical modules, focus has been on analysis and a fundamental understanding of the key parameters in wind turbine design. This has resulted in insight and an effective design methodology is presented. Using the optimization environment a 5MW wind turbine rotor has been optimized for reduced fatigue loads due to apwise bending moments. Among other things this has indicated that airfoils for wind turbine blades should have a high lift coefficient. The design methodology proved to be stable and a help in the otherwise challenging task of numerical aeroelastic optimization. (Author)

  5. An integrated turbocharger design approach to improve engine performance

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Turbocharging technology is today considered as a promising way for internal combustion engine energy saving and CO2 reduction.Turbocharger design is a major challenge for turbocharged engine performance improvement.The turbocharger designer must draw upon the information of engine operation conditions,and an appropriate link between the engine requirements and design features must be carefully developed to generate the most suitable design recommendation.The objective of this research is to develop a turbocharger design approach for better turbocharger matching to an internal combustion engine.The development of the approach is based on the concept of turbocharger design and interaction links between engine cycle requirements and design parameter values.A turbocharger through flow model is then used to generate the design alternatives.This integrated method has been applied with success to a gasoline engine turbocharger assembly.

  6. The Role of Tribology in the Development of an Oil-Free Turbocharger

    Science.gov (United States)

    Dellacorte, Christopher

    1997-01-01

    Gas-turbine-based aeropropulsion engines are technologically mature. Thus, as with any mature technology, revolutionary approaches will be needed to achieve the significant performance gains that will keep the U.S. propulsion manufacturers well ahead of foreign competition. One such approach is the development of oil-free turbomachinery utilizing advanced foil air bearings, seals, and solid lubricants. By eliminating oil-lubricated bearings and seals and supporting an engine rotor on an air film, significant improvements can be realized. For example, the entire oil system including pipes, lines, filters, cooler, and tanks could be removed, thereby saving considerable weight. Since air has no thermal decomposition temperature, engine systems could operate without excessive cooling. Also, since air bearings have no diameter-rpm fatigue limits (D-N limits), engines could be designed to operate at much higher speeds and higher density, which would result in a smaller aeropropulsion package. Because of recent advances in compliant foil air bearings and high temperature solid lubricants, these technologies can be applied to oil-free turbomachinery. In an effort to develop these technologies and to demonstrate a project along the path to an oil-free gas turbine engine, NASA has undertaken the development of an oil-free turbocharger for a heavy duty diesel engine. This turbomachine can reach 120000 rpm at a bearing temperature of 540 C (1000 F) and, in comparison to oil-lubricated bearings, can increase efficiency by 10 to 15 percent because of reduced friction. In addition, because there are no oil lubricants, there are no seal-leakage-induced emissions.

  7. Super long-term creep tests of advanced HP and IP rotor steels

    Energy Technology Data Exchange (ETDEWEB)

    Tchizhik, A.A. [The Polzunov Central Boiler and Turbine Institute, Department the Fatigue Life of Materials for Power Plans Equipment, St. Petersburg (Russian Federation)

    1998-12-31

    A creep model has been developed for predicting the long-term creep behavior, in excess of 200,000 h for advanced materials.The new creep theory is based on a continuum microdamage model and is used to calculate the fields of stress and strain and wedge and cavities damage in critical components of steam and gas turbines. The application of this new model increases the reliability and service life of modern turbines. The accuracy of the model to predict long - term creep behavior, creep ductility was verified using the data bank of super long-term creep tests of advanced materials. (orig.) 12 refs.

  8. Design space exploration and performance modelling of advanced turbofan and open-rotor engines

    OpenAIRE

    Giannakakis, Panagiotis

    2013-01-01

    This work focuses on the current civil engine design practice of increasing overall pressure ratio, turbine entry temperature and bypass ratio, and on the technologies required in order to sustain it. In this context, this thesis contributes towards clarifying the following gray aspects of future civil engine development: the connection between an aircraft application, the engine thermodynamic cycle and the advanced technologies of variable area fan nozzle and fan drive gearb...

  9. ANALISA TURBOCHARGER PADA MOTOR BENSIN DAIHATSU TIPE CB-23

    Directory of Open Access Journals (Sweden)

    Rully Hartadi

    2001-01-01

    Full Text Available Turbocharger is one of component that used to improve performance of vehicle by increasing density of air. Turbocharger consists of turbin and compressor. Many people hope that their vehicle has better performance and faster acceleration by applaying some component. In this case turbocharger can do that. By applaying turbocharger, air and fuel will homogeneously mixed that can give a better combustion. Turbocharger has many advantages. Turbocharger powered by pressure of exhaust gas. Abstract in Bahasa Indonesia : Turbocharger adalah suatu komponen yang dipasang pada kendaraan bermotor yang bertujuan untuk meningkatkan daya dari motor dengan melakukan penambahan rapat massa udara yang lebih banyak dibandingkan dengan cara pengisian biasa. Turbocharger terdiri dari sebuah turbin dan sebuah kompresor. Banyak yang mengharapkan daya dari kendaraannya dapat meningkat dengan memasang perangkat. Diharapkan dengan memasang perangkat tersebut, daya dari motor akan meningkat dan juga akselerasinya. perangkat yang dipakai dalam hal ini adalah turbocharger. Dengan penambahan turbocharger, akan membuat campuran udara dengan bahan bakar semakin sempurna atau semakin homogen sehingga pembakaran akan semakin sempurna. Perangkat turbocharger ini mempunyai kelebihan dariperangkat lain yang bertujuan untuk meningkatkan daya. Turbocharger ini digerakkan oleh tekanan gas buang, yang pada umumnya tekanan gas buang dan panas dari gas buang ini tidak dimanfaatkan atau langsung dibuang begitu saja. Kata kunci: turbocharger, turbin, kompresor dan knocking.

  10. Evaluation of different heat transfer conditions on an automotive turbocharger

    OpenAIRE

    Aghaali, Habib; Angström, Hans-Erik; Serrano Cruz, José Ramón

    2015-01-01

    This paper presents a combination of theoretical and experimental investigations for determining the main heat fluxes within a turbocharger. These investigations consider several engine speeds and loads as well as different methods of conduction, convection, and radiation heat transfer on the turbocharger. A one-dimensional heat transfer model of the turbocharger has been developed in combination with simulation of a turbocharged engine that includes the heat transfer of the turbo...

  11. Unsteady Interaction Of Turbocharger Compressor With IC Engine

    OpenAIRE

    Gilkes, Oliver S.; Mishra, Rakesh; John D. Fieldhouse; Rao, Vasu

    2009-01-01

    Growing global concern pertaining to climate change has meant that engine development has become more focused on engine emissions. A method of reducing the emissions of an internal combustion (IC) engine is to use smaller engines but recover power lost due to reduction in size by using a turbocharger or supercharger. To ensure that a turbocharger is appropriate for a given engine it has to be matched correctly. This process is called turbocharger matching. Turbocharger...

  12. Turbocharger in Regional Production Organization and Quality Control

    OpenAIRE

    Jia Yang; Lijun Qiu

    2013-01-01

    Exhaust gas turbocharger parts manufacturing is composed of multiple enterprises. Turbocharger product quality and turbocharger parts manufacturing requirement is the main content of the research. The regional production organization form, which is a kind of production mode, has been developed in recent years. Turbocharger's manufacturing fully describes the geographical concentration of production and it is the product of dimensions and it breeds a basis expansion. Parts of the specialized p...

  13. Nonlinear dynamics of a support-excited flexible rotor with hydrodynamic journal bearings.

    OpenAIRE

    Dakel, M. Zaki; Baguet, Sébastien; Dufour, Régis

    2014-01-01

    The major purpose of this study is to predict the dynamic behavior of an on-board rotor mounted on hydrodynamic journal bearings in the presence of rigid support movements, the target application being turbochargers of vehicles or rotating machines subject to seismic excitation. The proposed on-board rotor model is based on Timoshenko beam finite elements. The dynamic modeling takes into account the geometric asymmetry of shaft and/or rigid disk as well as the six deterministic translations a...

  14. 77 FR 34206 - Airworthiness Directives; Hartzell Engine Technologies Turbochargers

    Science.gov (United States)

    2012-06-11

    ... 12866, (2) Is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034... was prompted by a report of an HET turbocharger causing an engine in-flight power rollback. We are issuing this AD to prevent turbocharger bearing seizure, failed turbocharger components, and damage to...

  15. 14 CFR 23.1109 - Turbocharger bleed air system.

    Science.gov (United States)

    2010-01-01

    ... Induction System § 23.1109 Turbocharger bleed air system. The following applies to turbocharged bleed air systems used for cabin pressurization: (a) The cabin air system may not be subject to hazardous... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Turbocharger bleed air system....

  16. Influence of speed and frequency towards the automotive turbocharger turbine performance under pulsating flow conditions

    International Nuclear Information System (INIS)

    Highlights: • 3D CFD modeling of a turbocharger turbine with pulsating flow. • Characterization based on turbine speed and frequency. • Speed has higher influence on turbine performance compared to frequency. • Detailed localized flow behavior are shown for better understanding. - Abstract: The ever-increasing demand for low carbon applications in automotive industry has intensified the development of highly efficient engines and energy recovery devices. Even though there are significant developments in the alternative powertrains such as full electric, their full deployment is hindered by high costing and unattractive life-cycle energy and emission balance. Thus powertrain based on highly efficient internal combustion engines are still considered to be the mainstream for years to come. Traditionally, turbocharger has been an essential tool to boost the engine power, however in recent years it is seen as an enabling technology for engine downsizing. It is a well-known fact that a turbocharger turbine in an internal combustion engine operates in a highly pulsating exhaust flow. There are numerous studies looking into the complex interaction of the pulsating exhaust gas within the turbocharger turbine, however the phenomena is still not fully integrated into the design stage. Industry practice is still to design and match the turbine to an engine based on steady performance maps. The current work is undertaken with the mind to move one step closer towards fully integrating the pulsating flow performance into the turbocharger turbine design. This paper presents the development efforts and results from a full 3-D CFD model of a turbocharger turbine stage. The simulations were conducted at 30,000 rpm and 48,000 rpm (50% and 80% design speed respectively) for both 20 Hz and 80 Hz pulsating flow inlet conditions. Complete validation procedure using cold-flow experimental data is also described. The temporal and spatial resolutions of the incidence angle at the

  17. Thermal Efficiency of a Combined Turbocharger Set with Gasoline Engine

    Directory of Open Access Journals (Sweden)

    Jarut Kunanoppadon

    2010-01-01

    Full Text Available Problem statement: The technology of turbocharger has been used with internal combustion engines since 1905 to increase intake air pressure prior to putting it into the cylinders to increase thermal efficiency of the engine. Based on previous researches and uses of turbochargers, the pattern of turbocharger installation remains the same, either in series or in parallel. Therefore, this research aims to study installation of the combined turbocharger. The combined turbocharger set comprised two turbochargers of the same size having exhaust turbine connected in parallel to let both turbochargers work simultaneously and having intake air compressor connected in series for two stage compress. Approach: This research aimed to study the thermal efficiency of a combined turbocharger set with gasoline engine. The study was done by comparing the thermal efficiency between the combined turbocharger set and the parallel turbocharger set. The variation of both temperature and pressure of the intake air and exhaust gas were also investigated. The engine used in the study was TOYOTA engine model 1JZ-GTE with six cylinders and a total displacement volume of 2,491 cc. The engine was already installed with parallel turbocharger from the factory, therefore, the thermal efficiency test of the parallel turbocharger case was conducted first. Then, the engine was modified to be a combined turbocharger set and tested by the same procedure. The test was run under the speed of 2,000-5,000 rpm. Results: According to the test, the combined turbocharger set gave higher thermal efficiency than the parallel turbocharger set in all range of speed. At the speed of 2,500, 3,000, 3,500, 4,000, 4,500 and 5,000 rpm, the thermal efficiency of the combined turbocharger set was equal to 39.37, 57.73, 79.30, 67.66, 60.63 and 55.05%, respectively. Meanwhile, the thermal efficiency of the parallel turbocharger set was equal to 15.40, 22.61, 44.96, 55.21, 56.38 and 52.24%, respectively

  18. 减重涡轮增压器试验研究%Experimental investigation on turbocharger with lighting turbine wheel

    Institute of Scientific and Technical Information of China (English)

    赵俊生; 马朝臣; 胡辽平

    2011-01-01

    Based on the optimum design result,the lightening turbine wheel is casted adopting lost wax casting with rapid prototyping technology (RPT).And three turbochargers are assembled with the lightening turbine wheels. Overspeed burst tests and self-circulation overall service tests are carried out in the turbocharger test bench, and dynamic balancing test is finished in the TURBO TECHNICS. The test results shown it meet the necessity of the strength of the lightening turbine wheel. Compared with original turbocharger,the second-order critical speed of lightening rotor decreased. And the working speed of turbocharger still between the first-order critical speed and the second-order critical speed. The lighting turbine wheel is no influence nearly on the general efficiency of turbocharger.%以某型号车用增压器涡轮叶轮为研究对象,采用快速成型技术加工了蜡模,浇铸了减重优化的涡轮叶轮,在增压器试验台架上对三台增压器进行了超速破坏试验和整机性能试验,以及转子高速动平衡试验.试验结果表明,减重优化厚度涡轮叶轮满足强度要求,转子的第二阶临界转速降低,但增压器工作转速仍介于二阶和三阶临界转速之间,减重涡轮对增压器效率几乎没有影响.

  19. On-Engine Turbocharger Performance Considering Heat Transfer

    Energy Technology Data Exchange (ETDEWEB)

    Aghaali, Habib

    2012-07-01

    Heat transfer plays an important role in affecting an on-engine turbocharger performance. However, it is normally not taken into account for turbocharged engine simulations. Generally, an engine simulation based on one-dimensional gas dynamics uses turbocharger performance maps which are measured without quantifying and qualifying the heat transfer, regardless of the fact that they are measured on the hot-flow or cold-flow gas-stand. Since heat transfer situations vary for on-engine turbochargers, the maps have to be shifted and corrected in the 1-D engine simulation, which mass and efficiency multipliers usually do for both the turbine and the compressor. The multipliers change the maps and are often different for every load point. Particularly, the efficiency multiplier is different for every heat transfer situation on the turbocharger. The heat transfer leads to a deviation from turbocharger performance maps, and increased complexity of the turbocharged engine simulation. Turbochargers operate under different heat transfer situations while they are installed on the engines. The main objectives of this thesis are: 1. Heat transfer modeling of a turbocharger to quantify and qualify heat transfer mechanisms. 2. Improving turbocharged engine simulation by including heat transfer in the turbocharger. 3. Assessing the use of two different turbocharger performance maps concerning the heat transfer situation (cold-measured and hot-measured turbocharger performance maps) in the simulation of a measured turbocharged engine. 4. Prediction of turbocharger walls' temperatures and their effects on the turbocharger performance on different heat transfer situations. Experimental investigation has been performed on a water-oil-cooled turbocharger, which was installed on a 2-liter GDI engine for different load points of the engine and different heat transfer situations on the turbocharger by using insulators, an extra cooling fan, radiation shields and water-cooling settings

  20. Implementation of Turbocharger in Petrol Engines and its Thermal Analysis

    Directory of Open Access Journals (Sweden)

    Swapnil Bhurat, Amit Yadav , Atreya pathak

    2012-12-01

    Full Text Available In this paper we have discussed about turbocharging of four stroke petrol engine, difference between turbocharging of diesel and gasoline engine and possibilities to reduce losses in Exhaust system are highlighted. However, it omits to discuss two stroke engines due to their different gas exchange processes. Designing of different components involved in turbocharging is done and thermal analysis of turbocharger’s connector pipehas been done along with different kind of stress analysis.

  1. On-Engine Turbocharger Performance Considering Heat Transfer

    OpenAIRE

    Aghaali, Habib

    2012-01-01

    Heat transfer plays an important role in affecting an on-engine turbocharger performance. However, it is normally not taken into account for turbocharged engine simulations. Generally, an engine simulation based on one-dimensional gas dynamics uses turbocharger performance maps which are measured without quantifying and qualifying the heat transfer, regardless of the fact that they are measured on the hot-flow or cold-flow gas-stand. Since heat transfer situations vary for on-engine turbochar...

  2. Implementation of Turbocharger in Petrol Engines and its Thermal Analysis

    OpenAIRE

    Swapnil Bhurat, Amit Yadav , Atreya pathak

    2012-01-01

    In this paper we have discussed about turbocharging of four stroke petrol engine, difference between turbocharging of diesel and gasoline engine and possibilities to reduce losses in Exhaust system are highlighted. However, it omits to discuss two stroke engines due to their different gas exchange processes. Designing of different components involved in turbocharging is done and thermal analysis of turbocharger’s connector pipehas been done along with different kind of stress analysis.

  3. Fabrication of a mechanically aligned single-wafer MEMS turbine with turbocharger

    Science.gov (United States)

    Pelekies, S. O.; Schuhmann, T.; Gardner, W. G.; Camacho, A.; Protz, J. M.

    2010-10-01

    We describe the fabrication of a turbocharged, microelectromechanical system (MEMS) turbine. The turbine will be part of a standalone power unit and includes extra layers to connect the turbine to a generator. The project goal is to demonstrate the successful combination of several features, namely: silicon fusion bonding (SFB), a micro turbocharger [2], two rotors, mechanical alignment between two wafers [1], and the use of only one 5" silicon wafer. The dimension of the actual turbine casing will be 14mm. The turbine rotor will have a diameter of 8mm. Given these dimensions, MEMS processes are an adequate way to fabricate the device, but it will be necessary to stack up seven different layers to build the turbine, as it is not possible to construct it out of one thick wafer. SFB will be used for bonding because it permits the great precision necessary for high quality alignment. Yet a more precise alignment will be necessary between the layers that contain the turbine rotor, to decrease imbalance and guarantee operation at a very high rpm. To achieve these tight tolerances, a mechanical alignment feature announced by Liudi Jiang [1] is used. The alignment accuracy is expected to be around 200nm. Despite the fact that the turbine consists of multiple layers, it will be fabricated on only one silicon-on-insulator (SOI) wafer. As a result, all layers are exposed to the same process flow. The fabrication process includes MEMS technology as photolithography, nine deep reactive ion etching (DRIE) steps, and six SFB operations. A total of 14 masks are necessary for the fabrication.

  4. Separators for flywheel rotors

    Science.gov (United States)

    Bender, Donald A.; Kuklo, Thomas C.

    1998-01-01

    A separator forms a connection between the rotors of a concentric rotor assembly. This separator allows for the relatively free expansion of outer rotors away from inner rotors while providing a connection between the rotors that is strong enough to prevent disassembly. The rotor assembly includes at least two rotors referred to as inner and outer flywheel rings or rotors. This combination of inner flywheel ring, separator, and outer flywheel ring may be nested to include an arbitrary number of concentric rings. The separator may be a segmented or continuous ring that abuts the ends of the inner rotor and the inner bore of the outer rotor. It is supported against centrifugal loads by the outer rotor and is affixed to the outer rotor. The separator is allowed to slide with respect to the inner rotor. It is made of a material that has a modulus of elasticity that is lower than that of the rotors.

  5. Compact and Accurate Turbocharger Modelling for Engine Control

    DEFF Research Database (Denmark)

    Sorenson, Spencer C; Hendricks, Elbert; Magnússon, Sigurjón;

    2005-01-01

    With the current trend towards engine downsizing, the use of turbochargers to obtain extra engine power has become common. A great díffuculty in the use of turbochargers is in the modelling of the compressor map. In general this is done by inserting the compressor map directly into the engine ECU...

  6. Production of Diesel Engine Turbocharger Turbine from Low Cost Titanium Powder

    Energy Technology Data Exchange (ETDEWEB)

    Muth, T. R.; Mayer, R. (Queen City Forging)

    2012-05-04

    Turbochargers in commercial turbo-diesel engines are multi-material systems where usually the compressor rotor is made of aluminum or titanium based material and the turbine rotor is made of either a nickel based superalloy or titanium, designed to operate under the harsh exhaust gas conditions. The use of cast titanium in the turbine section has been used by Cummins Turbo Technologies since 1997. Having the benefit of a lower mass than the superalloy based turbines; higher turbine speeds in a more compact design can be achieved with titanium. In an effort to improve the cost model, and develop an industrial supply of titanium componentry that is more stable than the traditional aerospace based supply chain, the Contractor has developed component manufacturing schemes that use economical Armstrong titanium and titanium alloy powders and MgR-HDH powders. Those manufacturing schemes can be applied to compressor and turbine rotor components for diesel engine applications with the potential of providing a reliable supply of titanium componentry with a cost and performance advantage over cast titanium.

  7. Turbocharger in Regional Production Organization and Quality Control

    Directory of Open Access Journals (Sweden)

    Jia Yang

    2013-05-01

    Full Text Available Exhaust gas turbocharger parts manufacturing is composed of multiple enterprises. Turbocharger product quality and turbocharger parts manufacturing requirement is the main content of the research. The regional production organization form, which is a kind of production mode, has been developed in recent years. Turbocharger's manufacturing fully describes the geographical concentration of production and it is the product of dimensions and it breeds a basis expansion. Parts of the specialized production enterprises enjoyed the rapid expansion and development. Their producing ability and quality have reached a higher level. The parts and components manufacturing advantages into product advantages of quality. The development trend for product brand manufacturers no longer need to invest a lot of energy to the various parts of the production. As for the product design, the processing and material of the key parts is the main content for this study. Turbocharger product quality requires the precision of the parts and the accuracy of components assembly.

  8. THERMODYNAMIC DESIGN OF CENTRIFUGAL COMPRESSOR FOR TURBOCHARGER

    OpenAIRE

    Sonawane Shubham*, Sondkar Pratik, Qasim Siddiqui, Phirke Indraneel, Prof. R. P. Kakde

    2016-01-01

    The purpose of a turbocharger is to increase the power output of an engine by supplying compressed air to the engine intake manifold so that fuel can be burnt efficiently. In this work, thermodynamic design of a high pressure ratio centrifugal compressor, for 75 kW class engines, was carried out. A pressure ratio of 2.8 was considered with a compressor rotational speed of 60,000 RPM. The compressor was designed for vane less diffuser. The impeller designs were obtained using ci...

  9. Turbocharger Heat Transfer Modeling Under Steady and Transient Conditions

    Directory of Open Access Journals (Sweden)

    Jean-François Hetet

    2009-12-01

    Full Text Available In the field of automotive propulsion, environmental issues (need for drastic reduction of greenhouse gases and diminishing fossil fuels supplies enhance the need to reduce fuel consumption. To reach this goal, a possible solution is downsizing. Unfortunately, the degradation of the transient performance of the engine limits the expected benefits of downsizing. Engine manufacturers try to improve turbocharger matching using simulation. However, the literature and experiments on a turbocharger test bench show that, contrary to general opinions, heat transfer can influence the turbocharger performance. Thus it seems essential to determine and correlate the different types of heat transfer phenomena occurring in a turbocharger. First a complete experimental characterization of turbocharger heat transfer is performed in steady and transient conditions. The experimental results are used to correlate turbocharger heat transfer coefficients. Then, the equivalent heat transfer resistance method is explained. The correlations obtained are then used in this method to calculate all heat transfer interactions within the turbocharger and transferred to the surroundings in steady and transient conditions. In each case, comparisons between numerical and experimental results are performed to verify the quality of the method proposed.

  10. Prediction of the Aero-Acoustic Performance of Open Rotors

    Science.gov (United States)

    VanZante, Dale; Envia, Edmane

    2014-01-01

    The rising cost of jet fuel has renewed interest in contrarotating open rotor propulsion systems. Contemporary design methods offer the potential to maintain the inherently high aerodynamic efficiency of open rotors while greatly reducing their noise output, something that was not feasible in the 1980's designs. The primary source mechanisms of open rotor noise generation are thought to be the front rotor wake and tip vortex interacting with the aft rotor. In this paper, advanced measurement techniques and high-fidelity prediction tools are used to gain insight into the relative importance of the contributions to the open rotor noise signature of the front rotor wake and rotor tip vortex. The measurements include three-dimensional particle image velocimetry of the intra-rotor flowfield and the acoustic field of a model-scale open rotor. The predictions provide the unsteady flowfield and the associated acoustic field. The results suggest that while the front rotor tip vortex can have a significant influence on the blade passing tone noise produced by the aft rotor, the front rotor wake plays the decisive role in the generation of the interaction noise produced as a result of the unsteady aerodynamic interaction of the two rotors. At operating conditions typical of takeoff and landing operations, the interaction noise level is easily on par with that generated by the individual rotors, and in some cases is even higher. This suggests that a comprehensive approach to reducing open rotor noise should include techniques for mitigating the wake of the front rotor as well as eliminating the interaction of the front rotor tip vortex with the aft rotor blade tip.

  11. Helicopter Rotor Blade Monitoring using Autonomous Wireless Sensor Network

    OpenAIRE

    Sanchez Ramirez, Andrea; Loendersloot, Richard; Tinga, Tiedo; Basu, B

    2013-01-01

    The advancement on Wireless Sensor Networks for vibration monitoring presents important possibilities for helicopter rotor health and usage monitoring. While main rotor blades account for the main source of lift for helicopters, rotor induced vibration establishes an important source for understanding the rotor performance and blade condition. A discussion on the dual character of blades as rotating structures results in two different interrogation strategies for external and internal dynamic...

  12. Eddy current turbocharger blade speed detection

    Energy Technology Data Exchange (ETDEWEB)

    Rickman, J. Jr.

    1982-09-01

    A commercially available magnetic reluctance sensor is used to determine the angular velocity of turbocharger impeller blades from outside the aluminum housing. Eddy currents are induced in the aluminum blades by blade motion through the magnetic field projected by an externally mounted samarium-cobalt permanent magnet. Experiments show that secondary eddy currents and associated ac magnetic fields generated in the aluminum housing provide the prime excitation for a sensor coil located outside the housing. The coil output voltage spectrum shows a strongly peaked structure with peak locations at multiples of the blade passage frequency in the range 1-10 kHz. The sensor output signal decreases with increasing frequency above 2 kHz because of increasingly effective attenuation by the housing. Test results show that a circuit designed to track the blade signal gives an analog voltage output proportional to the frequency of blade passage over the operating range of the Cummins VT-903 and Detroit 8V-71T turbocharged diesel engines. Suggestions are made for the design of a sensor appropriate for both magnetic reluctance and eddy current sensing applications.

  13. Research on the technology of vehicular turbocharger test bench%车用涡轮增压器试验台技术研究

    Institute of Scientific and Technical Information of China (English)

    张卫波; 吴星

    2015-01-01

    In order to enroll the performance parameters of the turbocharger accurately and test the design level of rotor , a turbocharger test bench is designed and set up , a test system which has the function of data acquisition , processing , display and save , is developed based on the LabVIEW software graphical environment .The compressor performance test of a certain type prototype has conducted , the test results showed that:the turbocharger test bench works normally and can enroll the performance parameters of the turbocharger accurately; the design level of rotor is up tothe design requirements;the test system has high precision and the testing process automation is improved .%为准确采集涡轮增压器的各性能参数并检测转子的设计水平,设计并搭建涡轮增压器测试台架。基于LabVIEW软件图形化环境开发一套具有数据采集、处理、显示及保存等功能的测试系统。对某型号性能样机进行压气机性能试验,试验结果表明:涡轮增压器性能测试台架工作稳定,能够准确采集增压器的各性能参数;转子设计水平符合要求;设计开发的测试系统具有较高的测试精度、测试过程自动化程度提高。

  14. Flywheel Rotor Safe-Life Technology

    Science.gov (United States)

    Ratner, J. K. H.; Chang, J. B.; Christopher, D. A.; McLallin, Kerry L. (Technical Monitor)

    2002-01-01

    Since the 1960s, research has been conducted into the use of flywheels as energy storage systems. The-proposed applications include energy storage for hybrid and electric automobiles, attitude control and energy storage for satellites, and uninterruptible power supplies for hospitals and computer centers. For many years, however, the use of flywheels for space applications was restricted by the total weight of a system employing a metal rotor. With recent technological advances in the manufacturing of composite materials, however, lightweight composite rotors have begun to be proposed for such applications. Flywheels with composite rotors provide much higher power and energy storage capabilities than conventional chemical batteries. However, the failure of a high speed flywheel rotor could be a catastrophic event. For this reason, flywheel rotors are classified by the NASA Fracture Control Requirements Standard as fracture critical parts. Currently, there is no industry standard to certify a composite rotor for safe and reliable operation forth( required lifetime of the flywheel. Technical problems hindering the development of this standard include composite manufacturing inconsistencies, insufficient nondestructive evaluation (NDE) techniques for detecting defects and/or impact damage, lack of standard material test methods for characterizing composite rotor design allowables, and no unified proof (over-spin) test for flight rotors. As part of a flywheel rotor safe-life certification pro-ram funded b the government, a review of the state of the art in composite rotors is in progress. The goal of the review is to provide a clear picture of composite flywheel rotor technologies. The literature review has concentrated on the following topics concerning composites and composite rotors: durability (fatigue) and damage tolerance (safe-life) analysis/test methods, in-service NDE and health monitoring techniques, spin test methods/ procedures, and containment options

  15. Oil-whirl instability in an automotive turbocharger

    OpenAIRE

    Kamesh, P.

    2011-01-01

    This thesis is concerned with a theoretical investigation into the nonlinear dynamic behaviour of a turbocharger. Specifically the instabilities due to oil-whirl are examined. These are self-excited vibrations existing in the form of an in-phase whirl mode and a conical whirl mode. Waterfall plots were provided by Cummins Turbo-Technologies Ltd., Huddersfield, UK, based on test data using two different unbalance levels on a turbocharger. The test with the high unbalance indicated that there w...

  16. Analiza vibracij gonilnika turbopuhala: An analysis of turbocharger impeller vibrations:

    OpenAIRE

    Sekavčnik, Mihael

    2000-01-01

    The paper presents the results of experimental studies of natural vibrations of turbocharger blades. In order to excite the structure of a turbocharger impeller (composite blade-disc system), impulse disturbance and acoustic harmonic excitation were used. The response of the system was measured using accelerometers attached to the impeller blades. The logaritmic decrement method was used to determine the damping ratio. Measurements showed that the blades are most responsive (the largest ampli...

  17. Turbocharger Heat Transfer Modeling Under Steady and Transient Conditions

    OpenAIRE

    Jean-François Hetet; Pascal Chesse; Mickaël Cormerais

    2009-01-01

    In the field of automotive propulsion, environmental issues (need for drastic reduction of greenhouse gases) and diminishing fossil fuels supplies enhance the need to reduce fuel consumption. To reach this goal, a possible solution is downsizing. Unfortunately, the degradation of the transient performance of the engine limits the expected benefits of downsizing. Engine manufacturers try to improve turbocharger matching using simulation. However, the literature and experiments on a turbocharge...

  18. Steady and unsteady experimental analysis of a turbocharger for automotive applications

    International Nuclear Information System (INIS)

    a 5–10% relative error. The improved experimental set up also allows for higher precision transient analysis both on the cold and hot side branch of the test article. While the steady-state performance maps of the turbocharger are readily obtained with the semi-automated testing procedure, the detailed analysis of the unsteady phenomena related for instance to the occurrence of mild and deep compressor surge events, are reproduced and thoroughly analysed using the rig in more advanced operating modes

  19. Compressor performance of two-stage turbocharging system

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To study the performance of high and low stage compressors and that of the system as a whole,a two-stage turbocharging system was matched,and a special two-stage turbocharging system test bench was built.For each test curve,the speeds of the two stage turbochargers were adjusted to the fixed data,and a compressor performance experiment was performed.The results showed many differences between the corrected mass flow and the actual mass flow of the high pressure (HP) stage compressor.To find out the actual supercharging effect of the two-stage turbocharging system,it is better to adopt the actual mass flow.The two-stage turbocharging system in this paper has much higher efficiency under most operating conditions if the pressure ratio assignment is 1:1.The system can get very high supercharging pressure when the speeds of the two stage turbochargers are rather low,which ensures the system's security and reliability.

  20. Rotordynamic Design Analysis of an Oil-Free Turbocharger

    Science.gov (United States)

    Howard, Samuel A.

    1997-01-01

    Modern heavy duty diesel engines utilize turbochargers for increased power output. Also, a wide range of power levels can be achieved with one engine displacement through the use of different turbocharger configurations, eliminating the need for several different sized engines. These are the reasons that virtually all diesel truck engines currently marketed use turbochargers. However, because these turbochargers rely on ring seals and oil-lubricated floating sleeve bearings, they often suffer breakdowns. These turbochargers operate at elevated temperatures which often causes the oil to degrade and even coke to the bearing surfaces. This can lead to catastrophic failure, increased particulate emissions from oil leaks, and, in extreme cases, engine fires. Replacing the oil lubricated bearings from these turbochargers with some other device is desirable to eliminate these inherent problems. Foil bearings are compliant selecting bearings lubricated by air and are well suited to high speed, light load applications. Thus, foil bearings present one potential replacement for oil-lubricated sleeve bearings. Their use as such is investigated in this work.

  1. Non-adiabatic pressure loss boundary condition for modelling turbocharger turbine pulsating flow

    International Nuclear Information System (INIS)

    Highlights: • Bespoke non-adiabatic pressure loss boundary for pulse flow turbine modelling. • Predictions show convincing results against experimental and literature data. • Predicted pulse pressure propagation is in good agreement with literature data. • New methodology is time efficient and requires minimal geometrical inputs. - Abstract: This paper presents a simplified methodology of pulse flow turbine modelling, as an alternative over the meanline integrated methodology outlined in previous work, in order to make its application to engine cycle simulation codes much more straight forward. This is enabled through the development of a bespoke non-adiabatic pressure loss boundary to represent the turbine rotor. In this paper, turbocharger turbine pulse flow performance predictions are presented along with a comparison of computation duration against the previously established integrated meanline method. Plots of prediction deviation indicate that the mass flow rate and actual power predictions from both methods are highly comparable and are reasonably close to experimental data. However, the new boundary condition required significantly lower computational time and rotor geometrical inputs. In addition, the pressure wave propagation in this simplified unsteady turbine model at different pulse frequencies has also been found to be in agreement with data from the literature, thereby supporting the confidence in its ability to simulate the wave action encountered in turbine pulse flow operation

  2. 1D engine simulation of a turbocharged SI engine with CFD computation on components

    OpenAIRE

    Renberg, Ulrica

    2008-01-01

    Techniques that can increase the SI- engine efficiency while keeping the emissions very low is to reduce the engine displacement volume combined with a charging system. Advanced systems are needed for an effective boosting of the engine and today 1D engine simulation tools are often used for their optimization. This thesis concerns 1D engine simulation of a turbocharged SI engine and the introduction of CFD computations on components as a way to assess inaccuracies in the 1D model. 1D engine ...

  3. Materials for Advanced Ultrasupercritical Steam Turbines Task 3: Materials for Non-Welded Rotors, Buckets, and BoltingMaterials for Advanced Ultrasupercritical Steam Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Deepak

    2015-09-15

    The primary objective of the task was to characterize the materials suitable for mechanically coupled rotor, buckets and bolting operating with an inlet temperature of 760°C (1400°F). A previous study DOE-FC26-05NT42442, identified alloys such as Haynes®282®, Nimonic 105, Inconel 740, Waspaloy, Nimonic 263, and Inconel 617 as potential alloys that met the requirements for the necessary operating conditions. Of all the identified materials, Waspaloy has been widely utilized in the aviation industry in the form of disk and other smaller forgings, and sufficient material properties and vendor experience exist, for the design and manufacture of large components. The European program characterizing materials for A-USC conditions are evaluating Nimonic 263 and Inconel 617 for large components. Inconel 740 has been studied extensively as a part of the boiler consortium and is code approved. Therefore, the consortium focused efforts in the development of material properties for Haynes®282® and Nimonic 105 to avoid replicative efforts and provide material choices/trade off during the detailed design of large components. Commercially available Nimonic 105 and Haynes®282® were evaluated for microstructural stability by long term thermal exposure studies. Material properties requisite for design such as tensile, creep / rupture, low cycle fatigue, high cycle fatigue, fatigue crack growth rate, hold-time fatigue, fracture toughness, and stress relaxation are documented in this report. A key requisite for the success of the program was a need demonstrate the successful scale up of the down-selected alloys, to large components. All property evaluations in the past were performed on commercially available bar/billet forms. Components in power plant equipment such as rotors and castings are several orders in magnitude larger and there is a real need to resolve the scalability issue. Nimonic 105 contains high volume fraction y’ [>50%], and hence the alloy is best suited

  4. Importance of Heat Transfer Phenomena in Small Turbochargers for Passenger Car Applications

    OpenAIRE

    Serrano Cruz, José Ramón; Olmeda González, Pablo Cesar; Arnau Martínez, Francisco José; Reyes Belmonte, Miguel Angel; Lefebvre, Alain

    2013-01-01

    Nowadays turbocharging the internal combustion engine has become a key point in the reduction on pollutant emissions and the improvement on engine performance. The matching between the turbocharger and the engine is vital due to the highly unsteady flow the turbocharger works with. In the present paper the importance of the heat transfer phenomena inside small automotive turbochargers will be analyzed. This phenomenon will be studied from the point of view of both the ...

  5. Cummins/Tacom advanced adiabatic engine

    Energy Technology Data Exchange (ETDEWEB)

    Kamo, R.; Bryzik, W.

    1984-01-01

    Cummins Engine Company, Inc. and the U.S. Army have been jointly developing an adiabatic turbocompound engine during the last nine years. Although progress in the early years was slow, recent developments in the field of advanced ceramics have made it possible to make steady progress. It is now possible to reconsider the temperature limitation imposed on current heat engines and its subsequent influence on higher engine efficiency when using an exhaust energy utilization system. This paper presents an adiabatic turbocompound diesel engine concept in which high-performance ceramics are used in its design. The adiabatic turbocompound engine will enable higher operating temperatures, reduced heat loss, and higher exhaust energy recovery, resulting in higher thermal engine efficiency. This paper indicates that the careful selection of ceramics in engine design is essential. Adiabatic engine materials requirements are defined and the possible ceramic materials which will satisfy these requirements are identified. Examples in design considerations of engine components are illustrated. In addition to these important points, the use of ceramic coatings in the design of engine components. The first generation adiabatic engine with ceramic coatings is described. The advanced adiabatic engine with minimum friction features utilizaing ceramics is also presented. The advanced ceramic turbocharger turbine rotor as well as the oilless ceramic bearing design is described. Finally, the current status of the advanced adiabatic engine program culminating in the AA750 V-8 adiabatic engine is presented.

  6. Pulsating flow performance of a turbocharger compressor for automotive application

    International Nuclear Information System (INIS)

    Highlights: • The behavior of a turbocharger for automotive application was studied. • A broad experimental activity was developed under steady and unsteady flow. • Compressor performance was analyzed under unsteady flow. • Compressor unsteady flow performance deviates from the corresponding steady state. • The surge line position proved to be affected by unsteady flow operation. -- Abstract: Downsizing with turbocharging is the most promising way, especially in terms of cost, to get reduced fuel consumption and CO2 emissions particularly in the case of Spark Ignition engines. In automotive applications the turbocharger turbine usually operates under heavy unsteady flow conditions due to the opening and closing of engine valves. However, in the case of extremely downsized engines with a reduced number of cylinders and a small intake circuit volume also the compressor performance can be affected by the unsteady flow generated by the engine intake valves. To make simulation models able to accurately predict engine performance, a better understanding of compressor and turbine pulsating flow performance can be accomplished through measurements performed on specialized test facilities, using suitable measuring equipment. As regards the turbocharger compressor, the surge line position under pulsating flow conditions is another important aspect to be considered. In the paper the results of a broad experimental investigation performed on a small turbocharger compressor matched to a downsized gasoline engine are presented. Measurements were developed on the test facility operating at the University of Genoa, which allows investigations on automotive turbochargers both under steady and unsteady flow conditions. Tested turbocharger compressor was coupled to the automotive engine intake circuit and the pulsating flow was generated by a motor-driven cylinder head fitted with a variable valve actuation system. Different levels of turbocharger rotational speed and

  7. The rotor systems research aircraft - A flying wind tunnel

    Science.gov (United States)

    Linden, A. W.; Hellyar, M. W.

    1974-01-01

    The Sikorsky Aircraft division of United Aircraft Corporation is constructing two uniquely designed Rotor Systems Research Aircraft (RSRA). These aircraft will be used through the 1980's to comparatively test many different types of rotors - articulated, hingeless, teetering, and gimballed, as well as advanced rotor concepts, such as reverse velocity and variable diameter rotors. The RSRA combines a new airframe with existing Sikorsky H-3 (S-61) dynamic components. A force measurement system is incorporated to permit accurate evaluation of significant rotor characteristics. Both rotor and fixed-wing control systems are provided, appropriately integrated for operation in the pure helicopter mode, compound helicopter mode, and fixed-wing mode. The RSRA is the first rotary wing aircraft designed with a crew escape system, including a pyrotechnic system to sever the main rotor blades.

  8. Providing Eligibility Criteria On Turbocharger Filter Silencer Design Processes

    Directory of Open Access Journals (Sweden)

    Adem GÜLERYÜZ

    2013-06-01

    Full Text Available Supply of ventilation air to either the engine room or diesel engine directly affects engine performances. Main criteria is supply of air volume and pressure into the cylinder. When Air starts to come until the cylinders, there many points which behave as restrictions. These are ventilation grills. ventilation fans, ventilation casings, misteliminators, manual or pneumatically adjusted fan dampers, number of bending of ventilation casing, cleanness of casings, air flow speed, air filters, turbocharger filter and silencers, engine’s scavenge air cooler restrictions. Here, we focused on optimum required air need through turbocharger for local diesel engine. While researching actual need, new turbocharger filter were designed and manufactured for engine manufacturer.

  9. Carbon-Carbon Turbocharger Housing Unit for Intermittent Combustion Engines

    Science.gov (United States)

    Northam, G. Burton (Inventor); Ransone, Philip O. (Inventor); Rivers, H. Kevin (Inventor)

    1998-01-01

    An improved, lightweight, turbine housing unit for an intermittent combustion reciprocating internal combustion engine turbocharger is prepared from a lay-up or molding of carbon-carbon composite materials in a single-piece or two-piece process. When compared to conventional steel or cast iron, the use of carbon-carbon composite materials in a turbine housing unit reduces the overall weight of the engine and reduces the heat energy loss used in the turbocharging process. This reduction in heat energy loss and weight reduction provides for more efficient engine operation.

  10. Solid oxide fuel cell power plant with an anode recycle loop turbocharger

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Kazuo; Skiba, Tommy; Patel, Kirtikumar H.

    2016-09-27

    An anode exhaust recycle turbocharger (100) has a turbocharger turbine (102) secured in fluid communication with a compressed oxidant stream within an oxidant inlet line (218) downstream from a compressed oxidant supply (104), and the anode exhaust recycle turbocharger (100) also includes a turbocharger compressor (106) mechanically linked to the turbocharger turbine (102) and secured in fluid communication with a flow of anode exhaust passing through an anode exhaust recycle loop (238) of the solid oxide fuel cell power plant (200). All or a portion of compressed oxidant within an oxidant inlet line (218) drives the turbocharger turbine (102) to thereby compress the anode exhaust stream in the recycle loop (238). A high-temperature, automotive-type turbocharger (100) replaces a recycle loop blower-compressor (52).

  11. Solid oxide fuel cell power plant with an anode recycle loop turbocharger

    Science.gov (United States)

    Saito, Kazuo; Skiba, Tommy; Patel, Kirtikumar H.

    2015-07-14

    An anode exhaust recycle turbocharger (100) has a turbocharger turbine (102) secured in fluid communication with a compressed oxidant stream within an oxidant inlet line (218) downstream from a compressed oxidant supply (104), and the anode exhaust recycle turbocharger (100) also includes a turbocharger compressor (106) mechanically linked to the turbocharger turbine (102) and secured in fluid communication with a flow of anode exhaust passing through an anode exhaust recycle loop (238) of the solid oxide fuel cell power plant (200). All or a portion of compressed oxidant within an oxidant inlet line (218) drives the turbocharger turbine (102) to thereby compress the anode exhaust stream in the recycle loop (238). A high-temperature, automotive-type turbocharger (100) replaces a recycle loop blower-compressor (52).

  12. Numerical analysis of flow interaction of turbine system in two-stage turbocharger of internal combustion engine

    Science.gov (United States)

    Liu, Y. B.; Zhuge, W. L.; Zhang, Y. J.; Zhang, S. Y.

    2016-05-01

    To reach the goal of energy conservation and emission reduction, high intake pressure is needed to meet the demand of high power density and high EGR rate for internal combustion engine. Present power density of diesel engine has reached 90KW/L and intake pressure ratio needed is over 5. Two-stage turbocharging system is an effective way to realize high compression ratio. Because turbocharging system compression work derives from exhaust gas energy. Efficiency of exhaust gas energy influenced by design and matching of turbine system is important to performance of high supercharging engine. Conventional turbine system is assembled by single-stage turbocharger turbines and turbine matching is based on turbine MAP measured on test rig. Flow between turbine system is assumed uniform and value of outlet physical quantities of turbine are regarded as the same as ambient value. However, there are three-dimension flow field distortion and outlet physical quantities value change which will influence performance of turbine system as were demonstrated by some studies. For engine equipped with two-stage turbocharging system, optimization of turbine system design will increase efficiency of exhaust gas energy and thereby increase engine power density. However flow interaction of turbine system will change flow in turbine and influence turbine performance. To recognize the interaction characteristics between high pressure turbine and low pressure turbine, flow in turbine system is modeled and simulated numerically. The calculation results suggested that static pressure field at inlet to low pressure turbine increases back pressure of high pressure turbine, however efficiency of high pressure turbine changes little; distorted velocity field at outlet to high pressure turbine results in swirl at inlet to low pressure turbine. Clockwise swirl results in large negative angle of attack at inlet to rotor which causes flow loss in turbine impeller passages and decreases turbine

  13. Computational Study of Flow Interactions in Coaxial Rotors

    Science.gov (United States)

    Yoon, Seokkwan; Lee, Henry C.; Pulliam, Thomas H.

    2016-01-01

    Although the first idea of coaxial rotors appeared more than 150 years ago, most helicopters have used single main-rotor/tail-rotor combination. Since reactive moments of coaxial rotors are canceled by contra-rotation, no tail rotor is required to counter the torque generated by the main rotor. Unlike the single main rotor design that distributes power to both main and tail rotors, all of the power for coaxial rotors is used for vertical thrust. Thus, no power is wasted for anti-torque or directional control. The saved power helps coaxial rotors reach a higher hover ceiling than single rotor helicopters. Another advantage of coaxial rotors is that the overall rotor diameter can be reduced for a given vehicle gross weight because each rotor provides a maximum contribution to vertical thrust to overcome vehicle weight. However, increased mechanical complexity of the hub has been one of the challenges for manufacturing coaxial rotorcraft. Only the Kamov Design Bureau of Russia had been notably successful in production of coaxial helicopters until Sikorsky built X2, an experimental compound helicopter. Recent developments in unmanned aircraft systems and high-speed rotorcraft have renewed interest in the coaxial configuration. Multi-rotors are frequently used for small electric unmanned rotorcraft partly due to mechanical simplicity. The use of multiple motors provides redundancy as well as cost-efficiency. The multi-rotor concept has rarely been used until recently because of its inherent stability and control problems. However, advances in inexpensive electronic flight control systems have opened the floodgates for small drones using multirotors. Coaxial rotors have started to appear in some multi-rotor configurations. Small coaxial rotors have often been designed using a hundred year old approach that is "sketch, build, fly, and iterate." In that approach, there is no systematic way to explore trade-offs or determine logical next steps. It is neither possible to

  14. New turbocharger concept for gasoline engines; Neues Turboladerkonzept fuer Ottomotoren

    Energy Technology Data Exchange (ETDEWEB)

    Lotterman, Jeff [Honeywell Turbo Technologies, Torrance, CA (United States); Kares, Vaclav; Di Martino, Paolo [Honeywell Turbo Technologies, Bruenn (Czech Republic); Jeckel, Denis [Honeywell Turbo Technologies, Thaon-les-Vosges (France)

    2012-06-15

    Honeywell has developed a new turbocharging concept for gasoline engines which uses an axial turbine. The new system increases the engine speed around 25 % faster than conventional radial turbines, when accelerating from low revs. By using an existing turbine design and only conventional materials, it has been possible to keep costs low. (orig.)

  15. Review of Some Methods for Improving Transient Response in Automotive Diesel Engines through Various Turbocharging Configurations

    Directory of Open Access Journals (Sweden)

    Evangelos G. Giakoumis

    2016-05-01

    Full Text Available Turbocharged diesel engines suffer from poor drivability, mostly at low loads and speeds, leading also to overshoot in exhaust emissions (primarily PM/soot and NOx during the transient operation after a speed or load increase. The main cause for this problematic behavior is located in the turbocharger in the form of high moment of inertia and unfavorable aerodynamic-type compressor flow characteristics. In the present work, various alternative turbocharging configurations are reviewed that have proven successful in improving the dynamic diesel engine operation. The configurations studied are: combined supercharging, variable geometry turbine, electrically assisted turbocharging, two stage series and sequential turbocharging, as well as lower turbine moment of inertia. It is shown that significant improvement in the engine’s transient response can be realized through reduction in the turbocharger mass moment of inertia (using lighter materials and/or more than one units. Increasing the available turbine torque (e.g. through elevated turbine back pressure in a variable-geometry turbine is another successful option, as well as enhancement of the compressor boost pressure (e.g. through the use of a positive displacement compressor upstream of the turbocharger. Finally, the use of external energy (e.g. in the form of electrical assistance on the turbocharger shaft during the critical turbocharger lag phase is another recently developed and highly promising measure to mitigate the drawbacks of the poor transient performance of turbocharged diesel-engined vehicles and limit their exhaust emissions.

  16. Large Wind Turbine Rotor Design using an Aero-Elastic / Free-Wake Panel Coupling Code

    DEFF Research Database (Denmark)

    Sessarego, Matias; Ramos García, Néstor; Shen, Wen Zhong;

    2016-01-01

    Despite the advances in computing resources in the recent years, the majority of large wind-turbine rotor design problems still rely on aero-elastic codes that use blade element momentum (BEM) approaches to model the rotor aerodynamics. The present work describes an approach to wind-turbine rotor...

  17. Genetics Home Reference: Rotor syndrome

    Science.gov (United States)

    ... Me Understand Genetics Home Health Conditions Rotor syndrome Rotor syndrome Enable Javascript to view the expand/collapse boxes. Print All Open All Close All Description Rotor syndrome is a relatively mild condition characterized by ...

  18. Investigation of rotor control system loads

    Institute of Scientific and Technical Information of China (English)

    Sun Tao; Tan Jianfeng; Wang Haowen

    2013-01-01

    This paper concentrates on the aeroelasticity analysis of rotor blade and rotor control systems. A new multi-body dynamics model is established to predict both rotor pitch link loads and swashplate servo loads. Two helicopter rotors of UH-60A and SA349/2, both operating in two critical flight conditions, high-speed flight and high-thrust flight, are studied. The analysis shows good agreements with the flight test data and the calculation results using CAMRAD II. The mechanisms of rotor control loads are then analyzed in details based on the present predictions and the flight test data. In high-speed conditions, the pitch link loads are dominated by the integral of blade pitching moments, which are generated by cyclic pitch control. In high-thrust conditions, the positive pitching loads in the advancing side are caused by high collective pitch angle, and dynamic stall in the retreating side excites high-frequency responses. The swashplate servo loads are predominated by the rotor pitch link loads, and the inertia of the swashplate has significant effects on high-frequency harmonics of the servo loads.

  19. Stress corrosion cracking of steam turbine rotors

    International Nuclear Information System (INIS)

    In the wake of the catastrophic failure of a low-pressure (LP) turbine disk at the Hinkley Point Nuclear Station in 1969, considerable research and development has been devoted to the problem of stress corrosion cracking (SCC) in steam turbine rotors. Principle factors affecting the susceptibility of rotors to SCC have been identified as disk yield strength, applied stress level, and surface film/crevice chemistry. Microstructure and cleanliness of the steel have been found to have relatively little effect. Advances in steel making and forging over the last 20 years have provided manufacturers with additional design and material options to mitigate the problem. Increases in forging size capabilities of steel companies and the welded construction of rotors now permit designing with integral and partial integral rotors that use materials with lower yield strength (more SCC resistant) as well as eliminating the SCC problem in bores and keyways. However, a recent survey of US utilities has shown that SCC in the blade attachment legion of LP rotors is an increasing concern. This problem has led to development of repair and refurbishment methods for rim attachments, especially weld buildup of rims with corrosion-resistant alloys. Life prediction of rotors under SCC conditions currently involves estimating crack growth time from assumed defects to critical size. Factors that govern the location and time of crack initiation are not understood adequately. 50 refs., 23 figs., 1 tab

  20. Determination of heat flows inside turbochargers by means of a one dimensional lumped model

    OpenAIRE

    Olmeda González, Pablo Cesar; Dolz Ruiz, Vicente; Arnau Martínez, Francisco José; Reyes Belmonte, Miguel Angel

    2013-01-01

    In the present paper, a methodology to calculate the heat fluxes inside a turbocharger from diesel passenger car is presented. The heat transfer phenomenon is solved by using a one dimensional lumped model that takes into account both the heat fluxes between the different turbocharger elements, as well as the heat fluxes between the working fluids and the turbocharger elements. This heat transfer study is supported by the high temperature differences between the working fluids passing thr...

  1. Impact of Turbocharger Non-Adiabatic Operation on Engine Volumetric Efficiency and Turbo Lag

    OpenAIRE

    Shaaban, S; Seume, J.

    2012-01-01

    Turbocharger performance significantly affects the thermodynamic properties of the working fluid at engine boundaries and hence engine performance. Heat transfer takes place under all circumstances during turbocharger operation. This heat transfer affects the power produced by the turbine, the power consumed by the compressor, and the engine volumetric efficiency. Therefore, non-adiabatic turbocharger performance can restrict the engine charging process and hence engine performance. The prese...

  2. Turbocharger efficiencies in pulsating exhaust gas flow; Turboladerwirkungsgrade in pulsierender Abgasstroemung

    Energy Technology Data Exchange (ETDEWEB)

    Aymanns, Richard; Scharf, Johannes; Uhlmann, Tolga [FEV GmbH, Aachen (Germany). Business Unit Gasoline Engines; Pischinger, Stefan [RWTH Aachen (Germany). Lehrstuhl fuer Verbrennungskraftmaschinen

    2012-07-15

    The exhaust pressure pulse amplitudes in downsizing engines challenge the quasi steady modelling of turbocharger turbines in engine process simulation. An early selection of a well matching turbocharger is the key to time efficiency in the concept development phase of engines with ambitious performance and fuel economy targets. This article from FEV and RWTH Aachen assesses the turbocharger efficiencies in pulsating exhaust gas flow and gives a handling recommendation to minimise matching errors. (orig.)

  3. Effect of a curved duct upstream on performance of small centrifugal compressors for automobile turbochargers

    Science.gov (United States)

    Kikuchi, Shigeta; Yamasaki, Nobuhiko; Yamagata, Akihiro

    2013-02-01

    Since the automobile turbochargers are installed in an engine compartment with limited space, the ducts upstream of the turbocharger compressor may be curved in a complex manner. In the present paper, the effect of a curved duct upstream on performance of small centrifugal compressors for automobile turbochargers is discussed. The computational fluid dynamics (CFD) analysis of a turbocharger compressor validated for the compressor model with the straight pipe applied to the compressor with the curved pipe are executed, and the deterioration of the performance for the curved pipe is confirmed. It is also found that the deterioration of compressor performance is caused by the interaction of the secondary flow and the impeller.

  4. Flexible rotor dynamics analysis

    Science.gov (United States)

    Shen, F. A.

    1973-01-01

    A digital computer program was developed to analyze the general nonaxisymmetric and nonsynchronous transient and steady-state rotor dynamic performance of a bending- and shear-wise flexible rotor-bearing system under various operating conditions. The effects of rotor material mechanical hysteresis, rotor torsion flexibility, transverse effects of rotor axial and torsional loading and the anisotropic, in-phase and out-of-phase bearing stiffness and damping force and moment coefficients were included in the program to broaden its capability. An optimum solution method was found and incorporated in the computer program. Computer simulation of experimental data was made and qualitative agreements observed. The mathematical formulations, computer program verification, test data simulation, and user instruction was presented and discussed.

  5. Flight Adaptive Blade for Optimum Rotor Response (FABFORR) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — While past research has demonstrated the utility and benefits to be gained with the application of advanced rotor system control concepts, none have been...

  6. Combustion mode switching with a turbocharged/supercharged engine

    Energy Technology Data Exchange (ETDEWEB)

    Mond, Alan; Jiang, Li

    2015-09-22

    A method for switching between low- and high-dilution combustion modes in an internal combustion engine having an intake passage with an exhaust-driven turbocharger, a crankshaft-driven positive displacement supercharger downstream of the turbocharger and having variable boost controllable with a supercharger bypass valve, and a throttle valve downstream of the supercharger. The current combustion mode and mass air flow are determined. A switch to the target combustion mode is commanded when an operating condition falls within a range of predetermined operating conditions. A target mass air flow to achieve a target air-fuel ratio corresponding to the current operating condition and the target combustion mode is determined. The degree of opening of the supercharger bypass valve and the throttle valve are controlled to achieve the target mass air flow. The amount of residual exhaust gas is manipulated.

  7. Mean Value Modelling of a Turbocharged SI Engine

    DEFF Research Database (Denmark)

    Müller, Martin; Hendricks, Elbert; Sorenson, Spencer C.

    1998-01-01

    An important paradigm for the modelling of naturallly aspirated (NA) spark ignition (SI) engines for control purposes is the Mean Value Engine Model (MVEM). Such models have a time resolution which is just sufficient to capture the main details of the dynamic performance of NA SI engines...... but not the cycle-by-cycle behavior. In principle such models are also physically based,are very compact in a mathematical sense but nevertheless can have reasonable prediction accuracy. Presently no MVEMs have been constructed for intercooled turbocharged SI engines because their complexity confounds the simple...... physical understanding and description of such engines. This paper presents a newly constructed MVEM for a turbocharged SI engine which contains the details of the compressor and turbine characteristics in a compact way. The model has been tested against the responses of an experimental engine and has...

  8. Effect of AFT Rotor on the Inter-Rotor Flow of an Open Rotor Propulsion System

    Science.gov (United States)

    Slaboch, Paul E.; Stephens, David B.; Van Zante, Dale E.

    2016-01-01

    The effects of the aft rotor on the inter-rotor flow field of an open rotor propulsion rig were examined. A Particle Image Velocimetry (PIV) dataset that was acquired phase locked to the front rotor position has been phase averaged based on the relative phase angle between the forward and aft rotors. The aft rotor phase was determined by feature tracking in raw PIV images through an image processing algorithm. The effect of the aft rotor potential field on the inter-rotor flow were analyzed and shown to be in good agreement with Computational Fluid Dynamics (CFD) simulations. It was shown that the aft rotor had no substantial effect on the position of the forward rotor tip vortex but did have a small effect on the circulation strength of the vortex when the rotors were highly loaded.

  9. Nonstationary heat flow in the piston of the turbocharged engine

    Directory of Open Access Journals (Sweden)

    Piotr GUSTOF

    2010-01-01

    Full Text Available In this study the numeric computations of nonstationary heat flow in form of temperature distribution on characteristic surfaces of the piston of the turbocharged engine at the beginning phase its work was presented. The computations were performed for fragmentary load engine by means of the two-zone combustion model, the boundary conditions of III kind and the finite elements method (FEM by using of COSMOS/M program.

  10. Numerical Investigation: Effect of Stator Vanes on Turbocharger Turbine Performance

    OpenAIRE

    Ganesh Yadagiri Rapolu; Siddharth Swaminathan Balachandar; Keerthi Vallarasu Kamaraj

    2014-01-01

    With reduced turbo lag and better transient response, the introduction of VTG stator guide vanes improved turbocharger performance at all the engine operating conditions. The VTG system accelerates and maneuvers exhaust gas flow to the turbine. Favorable flow conditions at turbine inlet created by vane shape improve turbine performance. At lower engine speed, it is observed that the pressure drop across vane system influences overall efficiency. Whereas at higher speed, the pressure drop and ...

  11. Structure Analysis of a Turbocharger Compressor Wheel Using FEA

    Directory of Open Access Journals (Sweden)

    Shaik Mohammad Rafi

    2014-10-01

    Full Text Available When people talk about race cars or high-performance sports cars, the topic of turbochargers usually comes up. Turbochargers also appear on large diesel engines. A turbo can significantly boost an engine's horsepower without significantly increasing its weight, which is the huge benefit that makes turbos so popular. Turbochargers are a type of forced induction system. They compress the air flowing into the engine. The advantage of compressing the air is that it lets the engine squeeze more air into a cylinder, and more air means that more fuel can be added. Therefore, you get more power from each explosion in each cylinder. Here in this project we are designing the compressor wheel by using Pro-E and doing analysis by using FEA package. The main aim of the project is to increase the performance of the compressor wheel for this we are changing the material and also we are changing the existing design. By comparing the results we will get the best model from this data we suggests the design modifications to the company to improve the performance of the compressor wheel.

  12. Intake Manifold Boosting of Turbocharged Spark-Ignited Engines

    Directory of Open Access Journals (Sweden)

    Lino Guzzella

    2013-03-01

    Full Text Available Downsizing and turbocharging is a widely used approach to reduce the fuel consumption of spark ignited engines while retaining the maximum power output. However, a substantial loss in drivability must be expected due to the occurrence of the so-called turbo lag. The turbo lag results from the additional inertia that the turbocharger adds to the system. Supplying air by an additional valve, the boost valve, to the intake manifold can be used to overcome the turbo lag. This turbo lag compensationmethod is referred to as intakemanifold boosting. The aims of this study are to show the effectiveness of intake manifold boosting on a turbocharged spark-ignited engine and to show that intake manifold boosting can be used as an enabler of strong downsizing. Guidelines for the dimensioning of the boost valve are given and a control strategy is presented. The trade-off between additional fuel consumption and the consumption of pressurized air during the turbo lag compensation is discussed. For a load step at 2000 rpm the rise time can be reduced from 2.8 s to 124ms, requiring 11.8 g of pressurized air. The transient performance is verified experimentally by means of load steps at various engine speeds to various engine loads.

  13. Open Rotor Aeroacoustic Modelling

    Science.gov (United States)

    Envia, Edmane

    2012-01-01

    Owing to their inherent fuel efficiency, there is renewed interest in developing open rotor propulsion systems that are both efficient and quiet. The major contributor to the overall noise of an open rotor system is the propulsor noise, which is produced as a result of the interaction of the airstream with the counter-rotating blades. As such, robust aeroacoustic prediction methods are an essential ingredient in any approach to designing low-noise open rotor systems. To that end, an effort has been underway at NASA to assess current open rotor noise prediction tools and develop new capabilities. Under this effort, high-fidelity aerodynamic simulations of a benchmark open rotor blade set were carried out and used to make noise predictions via existing NASA open rotor noise prediction codes. The results have been compared with the aerodynamic and acoustic data that were acquired for this benchmark open rotor blade set. The emphasis of this paper is on providing a summary of recent results from a NASA Glenn effort to validate an in-house open noise prediction code called LINPROP which is based on a high-blade-count asymptotic approximation to the Ffowcs-Williams Hawkings Equation. The results suggest that while predicting the absolute levels may be difficult, the noise trends are reasonably well predicted by this approach.

  14. Open Rotor Aeroacoustic Modeling

    Science.gov (United States)

    Envia, Edmane

    2012-01-01

    Owing to their inherent fuel efficiency, there is renewed interest in developing open rotor propulsion systems that are both efficient and quiet. The major contributor to the overall noise of an open rotor system is the propulsor noise, which is produced as a result of the interaction of the airstream with the counter-rotating blades. As such, robust aeroacoustic prediction methods are an essential ingredient in any approach to designing low-noise open rotor systems. To that end, an effort has been underway at NASA to assess current open rotor noise prediction tools and develop new capabilities. Under this effort, high-fidelity aerodynamic simulations of a benchmark open rotor blade set were carried out and used to make noise predictions via existing NASA open rotor noise prediction codes. The results have been compared with the aerodynamic and acoustic data that were acquired for this benchmark open rotor blade set. The emphasis of this paper is on providing a summary of recent results from a NASA Glenn effort to validate an in-house open noise prediction code called LINPROP which is based on a high-blade-count asymptotic approximation to the Ffowcs-Williams Hawkings Equation. The results suggest that while predicting the absolute levels may be difficult, the noise trends are reasonably well predicted by this approach.

  15. Study of Flow Patterns in Radial and Back Swept Turbine Rotor under Design and Off-Design Conditions

    Directory of Open Access Journals (Sweden)

    Samip Shah

    2016-01-01

    Full Text Available Paper details the numerical investigation of flow patterns in a conventional radial turbine compared with a back swept design for same application. The blade geometry of a designed turbine from a 25kW micro gas turbine was used as a baseline. A back swept blade was subsequently designed for the rotor, which departed from the conventional radial inlet blade angle to incorporate up to 25° inlet blade angle. A comparative numerical analysis between the two geometries is presented. While operating at lower than optimum velocity ratios (U/C, the 25° back swept blade offers significant increases in efficiency. In turbocharger since the turbine typically experiences lower than optimum velocity ratios, this improvement in the efficiency at off-design condition could significantly improve turbocharger performance. The numerical predictions show off-design performance gains of the order of 4.61% can be achieved, while maintaining design point efficiency.

  16. Improved silicon carbide for advanced heat engines

    Science.gov (United States)

    Whalen, Thomas J.

    1989-01-01

    The development of high strength, high reliability silicon carbide parts with complex shapes suitable for use in advanced heat engines is studied. Injection molding was the forming method selected for the program because it is capable of forming complex parts adaptable for mass production on an economically sound basis. The goals were to reach a Weibull characteristic strength of 550 MPa (80 ksi) and a Weibull modulus of 16 for bars tested in four-point loading. Statistically designed experiments were performed throughout the program and a fluid mixing process employing an attritor mixer was developed. Compositional improvements in the amounts and sources of boron and carbon used and a pressureless sintering cycle were developed which provided samples of about 99 percent of theoretical density. Strengths were found to improve significantly by annealing in air. Strengths in excess of 550 MPa (80 ksi) with Weibull modulus of about 9 were obtained. Further improvements in Weibull modulus to about 16 were realized by proof testing. This is an increase of 86 percent in strength and 100 percent in Weibull modulus over the baseline data generated at the beginning of the program. Molding yields were improved and flaw distributions were observed to follow a Poisson process. Magic angle spinning nuclear magnetic resonance spectra were found to be useful in characterizing the SiC powder and the sintered samples. Turbocharger rotors were molded and examined as an indication of the moldability of the mixes which were developed in this program.

  17. 混合增压柴油机增压系统参数模拟计算研究%Numerical Simulation on Parameters of Hybrid Turbocharging System in Hybrid Turbocharged Diesel Engine

    Institute of Scientific and Technical Information of China (English)

    赵付舟; 常思勤; 韩国强

    2009-01-01

    该文优化调整模拟计算时确定的混合增压系统的参数,扩大了增压系统涡轮的流量,减小了高速电机功率,电机功率下降直接带来发动机的轻量化和增压器转动惯量的大幅减小.同时,涡轮流量的增加还提高了车用发动机在常用工况下的经济性和低速高负荷工况下的潜在动力性.与原废气旁通增压柴油机相比,参数调整后的混合增压柴油机减小了排气提前角调整不当对发动机燃油经济性的扰动.%The parameters of the hybrid turbocharging system are adjusted and optimised after simulation. The method is to magnify the flow rate of a turbine and decrease the power of a high-speed motor. Downsizing the motor can directly make the engine lightweight and greatly reduce the moment of inertia for the turbocharging system. Magnifying the flow rate of a turbine can not only reduce the BSFC (Brake specific fuel consumption ) in the frequent engine conditions , but also boost the potential of engine drivability in the low-speed and high-load condition. Compared with the original wastegated diesel engine, the adjusted hybrid turbocharged engine can minish the BSFC disturbance from the inappropriate advanced exhaust angle.

  18. Analysis of the dynamic response improvement of a turbocharged diesel engine driven alternating current generating set

    International Nuclear Information System (INIS)

    Reliability of electric supply systems is among the most required necessities of modern society. Turbocharged diesel engine driven alternating current generating sets are often used to prevent electric black outs and/or as prime electric energy suppliers. It is well known that turbocharged diesel engines suffer from an inadequate response to a sudden load increase, this being a consequence of the nature of the energy exchange between the engine and the turbocharger. The dynamic response of turbocharged diesel engines could be improved by electric assisting systems, either by direct energy supply with an integrated starter-generator-booster (ISG) mounted on the engine flywheel, or by an indirect energy supply with an electrically assisted turbocharger. An experimentally verified zero dimensional computer simulation method was used for the analysis of both types of electrical assistance. The paper offers an analysis of the interaction between a turbocharged diesel engine and different electric assisting systems, as well as the requirements for the supporting electric motors that could improve the dynamic response of a diesel engine while driving an AC generating set. When performance class compliance is a concern, it is evident that an integrated starter-generator-booster outperforms an electrically assisted turbocharger for the investigated generating set. However, the electric energy consumption and frequency recovery times are smaller when an electrically assisted turbocharger is applied

  19. Experimental Evaluation of a Method for Turbocharging Four-Stroke, Single Cylinder, Internal Combustion Engines

    Science.gov (United States)

    Buchman, Michael; Winter, Amos

    2015-11-01

    Turbocharging an engine increases specific power, improves fuel economy, reduces emissions, and lowers cost compared to a naturally aspirated engine of the same power output. These advantages make turbocharging commonplace for multi-cylinder engines. Single cylinder engineers are not commonly turbocharged due to the phase lag between the exhaust stroke, which powers the turbocharger, and the intake stroke, when air is pumped into the engine. Our proposed method of turbocharging single cylinder engines is to add an ``air capacitor'' to the intake manifold, an additional volume that acts as a buffer to store compressed air between the exhaust and intake strokes, and smooth out the pressure pulses from the turbocharger. This talk presents experimental results from a single cylinder, turbocharged diesel engine fit with various sized air capacitors. Power output from the engine was measured using a dynamometer made from a generator, with the electrical power dissipated with resistive heating elements. We found that intake air density increases with capacitor size as theoretically predicted, ranging from 40 to 60 percent depending on heat transfer. Our experiment was able to produce 29 percent more power compared to using natural aspiration. These results validated that an air capacitor and turbocharger may be a simple, cost effective means of increasing the power density of single cylinder engines.

  20. Reducing rotor weight

    Energy Technology Data Exchange (ETDEWEB)

    Cheney, M.C. [PS Enterprises, Inc., Glastonbury, CT (United States)

    1997-12-31

    The cost of energy for renewables has gained greater significance in recent years due to the drop in price in some competing energy sources, particularly natural gas. In pursuit of lower manufacturing costs for wind turbine systems, work was conducted to explore an innovative rotor designed to reduce weight and cost over conventional rotor systems. Trade-off studies were conducted to measure the influence of number of blades, stiffness, and manufacturing method on COE. The study showed that increasing number of blades at constant solidity significantly reduced rotor weight and that manufacturing the blades using pultrusion technology produced the lowest cost per pound. Under contracts with the National Renewable Energy Laboratory and the California Energy Commission, a 400 kW (33m diameter) turbine was designed employing this technology. The project included tests of an 80 kW (15.5m diameter) dynamically scaled rotor which demonstrated the viability of the design.

  1. Advanced Boost System Developing for High EGR Applications

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Harold

    2012-09-30

    To support industry efforts of clean and efficient internal combustion engine development for passenger and commercial applications • This program focuses on turbocharger improvement for medium and light duty diesel applications, from complete system optimization percepective to enable commercialization of advanced diesel combustion technologies, such as HCCI/LTC. • Improve combined turbocharger efficiency up to 10% or fuel economy by 3% on FTP cycle at Tier II Bin 5 emission level.

  2. Rotor internal friction instability

    Science.gov (United States)

    Bently, D. E.; Muszynska, A.

    1985-01-01

    Two aspects of internal friction affecting stability of rotating machines are discussed. The first role of internal friction consists of decreasing the level of effective damping during rotor subsynchronous and backward precessional vibrations caused by some other instability mechanisms. The second role of internal frication consists of creating rotor instability, i.e., causing self-excited subsynchronous vibrations. Experimental test results document both of these aspects.

  3. Study of turbocharger shaft motion by means of non-invasive optical techniques: Application to the behaviour analysis in turbocharger lubrication failures

    Science.gov (United States)

    Pastor, J. V.; Serrano, J. R.; Dolz, V.; López, M. A.; Bouffaud, F.

    2012-10-01

    This paper presents a novel non-invasive technique to estimate the turbocharger shaft whirl motion. The aim of this article is to present a system for monitoring the shaft motion of a turbocharger, which will be used in turbocharger destructive testing. To achieve this, a camera and a light source were installed in a turbocharger test bench with a controlled lubrication circuit. An image recording methodology and a process algorithm have been developed, in order to estimate the shaft motion. This processing consists on differentiating specific zones of the image, in order to obtain their coordinates. Two reference points have been configured on the compressor side, which help to calculate the relative position of the shaft, avoiding the errors due to structural vibrations. Maximum eccentricity of the turbocharger has been determined and it has been compared with shaft motion when it is spinning in different conditions. A luminosity study has been also done, in order to improve the process and to obtain locus of shaft position in a picture exposition time period. The technique has been applied to diagnosis of a lubrication failure test and the main results will be presented in this article: like shaft motion figures; thermodynamic variables and pictures of the shaft while it is spinning at abnormal lubrication conditions. The measuring components used in this technique have the ability to withstand the catastrophic failure of the turbocharger in this type of test.

  4. Simulation of the Performance of a Variable Geometry Turbocharger for Diesel Engine Road Propulsion

    OpenAIRE

    G. Decombes; Pichouron, J. F.; F. Maroteaux; Moreno, N.; Jullien, J.

    2002-01-01

    Advanced research work has lead to the development of a new simulation program and the thermodynamic parameters at engine inlet and exhaust of an engine-mounted variable-geometry turbine can thus be evaluated. The machine is divided into characteristic sub-blocks and resolution of thermomechanical flow equations is carried out using the necessary geometrical parameters. A detailed study of losses is conducted experimentally and numerically into the scroll, the vaned nozzle and the rotor in re...

  5. Performance and loads data from a wind tunnel test of a full-scale, coaxial, hingeless rotor helicopter

    Science.gov (United States)

    Felker, F. F., III

    1981-01-01

    A full-scale XH-59A advancing blade concept helicopter was tested in Ames Research Center's 40 by 80 foot wind tunnel. The helicopter was tested with the rotor on and off, rotor hub fairings on and off, interrotor shaft fairing on and off, rotor instrumentation module on and off, and auxiliary propulsion thrust on and off. An advance ratio range of 0.25 and 0.45 with the rotor on and from 60 to 180 knots with the rotor off was investigated. Data on aerodynamic forces and moments, rotor loads, rotor control positions and vibration for the XH-59A as well as the aerodynamic performance of the isolated rotor are presented.

  6. Lifecycle optimized ethanol-gasoline blends for turbocharged engines

    KAUST Repository

    Zhang, Bo

    2016-08-16

    This study presents a lifecycle (well-to-wheel) analysis to determine the CO2 emissions associated with ethanol blended gasoline in optimized turbocharged engines. This study provides a more accurate assessment on the best-achievable CO2 emission of ethanol blended gasoline mixtures in future engines. The optimal fuel blend (lowest CO2 emitting fuel) is identified. A range of gasoline fuels is studied, containing different ethanol volume percentages (E0–E40), research octane numbers (RON, 92–105), and octane sensitivities (8.5–15.5). Sugarcane-based and cellulosic ethanol-blended gasolines are shown to be effective in reducing lifecycle CO2 emission, while corn-based ethanol is not as effective. A refinery simulation of production emission was utilized, and combined with vehicle fuel consumption modeling to determine the lifecycle CO2 emissions associated with ethanol-blended gasoline in turbocharged engines. The critical parameters studied, and related to blended fuel lifecycle CO2 emissions, are ethanol content, research octane number, and octane sensitivity. The lowest-emitting blended fuel had an ethanol content of 32 vol%, RON of 105, and octane sensitivity of 15.5; resulting in a CO2 reduction of 7.1%, compared to the reference gasoline fuel and engine technology. The advantage of ethanol addition is greatest on a per unit basis at low concentrations. Finally, this study shows that engine-downsizing technology can yield an additional CO2 reduction of up to 25.5% in a two-stage downsized turbocharged engine burning the optimum sugarcane-based fuel blend. The social cost savings in the USA, from the CO2 reduction, is estimated to be as much as $187 billion/year. © 2016 Elsevier Ltd

  7. Emission of a Dual-Fuel Turbocharged Compression Ignition Engine

    Science.gov (United States)

    Rózycki, Andrzej

    2012-02-01

    The paper describes the results of a four-cylinder dual fuel turbocharged compression ignition engine. The aim of the study was to determine the maximum CNG share in thefuel mixture delivered into the cylinder. Analysis of the investigation results showed that the CNG energy share in the fuel charge delivered into the cylinder can reach 45%. At that level of CNG energy share a 15% reduction in maximum torque is achieved in comparison with the standard fuelling. The unburnt hydrocarbon emission increases significantly. Emissions of other principal pollutants reach values comparable with those obtained at standard fuelling.

  8. On-Engine Measurement of Turbocharger Surge Limit

    OpenAIRE

    Galindo, José; Tiseira Izaguirre, Andrés Omar; Arnau Martínez, Francisco José; Lang ., Ricardo Hector

    2013-01-01

    In this article a new experimental technique is presented to measure the turbocharger surge limit in a regular engine test bench. It is known that the surge margin on engine tests may be very different from that obtained in a steady-flow gas-stand. In particular, surge is very dependent on the flow pattern produced by the compressor inlet duct and also on the piping upstream and downstream the compressor. The proposed technique that is based on the injection of pressurized a...

  9. On Mixed Flow Turbines for Automotive Turbocharger Applications

    OpenAIRE

    Bernhardt Lüddecke; Dietmar Filsinger; Jan Ehrhard

    2012-01-01

    Due to increased demands for improved fuel economy of passenger cars, low-end and part-load performance is of key importance for the design of automotive turbocharger turbines. In an automotive drive cycle, a turbine which can extract more energy at high pressure ratios and lower rotational speeds is desirable. In the literature it is typically found that radial turbines provide peak efficiency at speed ratios of 0.7, but at high pressure ratios and low rotational speeds the blade speed ratio...

  10. Impact of Turbocharger Non-Adiabatic Operation on Engine Volumetric Efficiency and Turbo Lag

    Directory of Open Access Journals (Sweden)

    S. Shaaban

    2012-01-01

    Full Text Available Turbocharger performance significantly affects the thermodynamic properties of the working fluid at engine boundaries and hence engine performance. Heat transfer takes place under all circumstances during turbocharger operation. This heat transfer affects the power produced by the turbine, the power consumed by the compressor, and the engine volumetric efficiency. Therefore, non-adiabatic turbocharger performance can restrict the engine charging process and hence engine performance. The present research work investigates the effect of turbocharger non-adiabatic performance on the engine charging process and turbo lag. Two passenger car turbochargers are experimentally and theoretically investigated. The effect of turbine casing insulation is also explored. The present investigation shows that thermal energy is transferred to the compressor under all circumstances. At high rotational speeds, thermal energy is first transferred to the compressor and latter from the compressor to the ambient. Therefore, the compressor appears to be “adiabatic” at high rotational speeds despite the complex heat transfer processes inside the compressor. A tangible effect of turbocharger non-adiabatic performance on the charging process is identified at turbocharger part load operation. The turbine power is the most affected operating parameter, followed by the engine volumetric efficiency. Insulating the turbine is recommended for reducing the turbine size and the turbo lag.

  11. A Method for Turbocharging Four-Stroke Single Cylinder Engines

    Science.gov (United States)

    Buchman, Michael; Winter, Amos

    2014-11-01

    Turbocharging is not conventionally used with single cylinder engines due to the timing mismatch between when the turbo is powered and when it can deliver air to the cylinder. The proposed solution involves a fixed, pressurized volume - which we call an air capacitor - on the intake side of the engine between the turbocharger and intake valves. The capacitor acts as a buffer and would be implemented as a new style of intake manifold with a larger volume than traditional systems. This talk will present the flow analysis used to determine the optimal size for the capacitor, which was found to be four to five times the engine capacity, as well as its anticipated contributions to engine performance. For a capacitor sized for a one-liter engine, the time to reach operating pressure was found to be approximately two seconds, which would be acceptable for slowly accelerating applications and steady state applications. The air density increase that could be achieved, compared to ambient air, was found to vary between fifty percent for adiabatic compression and no heat transfer from the capacitor, to eighty percent for perfect heat transfer. These increases in density are proportional to, to first order, the anticipated power increases that could be realized. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. 1122374.

  12. Mach number scaling of helicopter rotor blade/vortex interaction noise

    Science.gov (United States)

    Leighton, Kenneth P.; Harris, Wesley L.

    1985-01-01

    A parametric study of model helicopter rotor blade slap due to blade vortex interaction (BVI) was conducted in a 5 by 7.5-foot anechoic wind tunnel using model helicopter rotors with two, three, and four blades. The results were compared with a previously developed Mach number scaling theory. Three- and four-bladed rotor configurations were found to show very good agreement with the Mach number to the sixth power law for all conditions tested. A reduction of conditions for which BVI blade slap is detected was observed for three-bladed rotors when compared to the two-bladed baseline. The advance ratio boundaries of the four-bladed rotor exhibited an angular dependence not present for the two-bladed configuration. The upper limits for the advance ratio boundaries of the four-bladed rotors increased with increasing rotational speed.

  13. Investigation of the influence coefficient method for balancing of flexible rotors systems

    OpenAIRE

    Hanish, Giuma Ramadan

    2005-01-01

    Abstract Several sophisticated procedures for balancing flexible rotors have been developed during the past two decades. For a variety of reasons, none of these methods has gained general acceptance by practicing balancing engineers. Some of these balancing techniques require a great deal of expertise from the operator. This thesis is dedicated to the research of flexible rotor balancing techniques, and aims to apply some advanced techniques to the field of high-speed rotor balancing. Signifi...

  14. Simulation of realistic rotor blade-vortex interactions using a finite-difference technique

    Science.gov (United States)

    Hassan, Ahmed A.; Charles, Bruce D.

    1989-01-01

    A numerical finite-difference code has been used to predict helicopter blade loads during realistic self-generated three-dimensional blade-vortex interactions. The velocity field is determined via a nonlinear superposition of the rotor flowfield. Data obtained from a lifting-line helicopter/rotor trim code are used to determine the instantaneous position of the interaction vortex elements with respect to the blade. Data obtained for three rotor advance ratios show a reasonable correlation with wind tunnel data.

  15. Probabilistic analysis of manufacturing uncertainties for an automotive turbocharger centrifugal compressor using numerical and experimental methods

    NARCIS (Netherlands)

    Javed, A.; Kamphues, E.; Hartuc, T.; Pecnik, R.; Van Buijtenen, J.P.

    2015-01-01

    The compressor impellers for mass-produced turbochargers are generally die-casted and machined to their final configuration. Manufacturing uncertainties are inherently introduced as stochastic dimensional deviations in the impeller geometry. These deviations eventually propagate into the compressor

  16. Turbocharger blade vibration: Measurement and validation through laser tip-timing

    OpenAIRE

    Allport, John; Jupp, Martyn

    2012-01-01

    High Cycle Fatigue (HCF) of turbine blades is a major cause of failure in turbochargers. In order to validate changes to blades intended to reduce fatigue failure, accurate measurement of blade dynamics is necessary. Strain gauging has limitations, so an alternative method is investigated. A description of the tip-timing method is given, applied to turbocharger testing. The advantages and disadvantages of laser probes are assessed. Examples of output data and interpretation are presented and ...

  17. A Study of Methods for Improving the Dynamic Stability of High-Speed Turbochargers

    OpenAIRE

    Ali A. Alsaeed

    2010-01-01

    The turbocharger industry is booming recently, and there is an urgent need for new evaluations of the overall design. As the oil prices continue to rise, along with the new emissions regulations strictly enforced for the in-road as well as the off-road vehicles, the transition to turbocharged engines, and especially for diesel engines, has become irresistible. Higher power, smaller engines, reduced emissions, and overall better efficiency are the main concerns. By means of the recent developm...

  18. CFD Prediction and Experimental Measurement of Blade Water Coverage in a Diesel Turbocharger

    OpenAIRE

    Jun Yao; Yufeng Yao

    2012-01-01

    A turbocharger unit for diesel engine is often equipped with a built-in online water washing system and its performance is not always satisfactory because of efficiency declination due to deposit accumulated on blade surfaces not being washed away. In this study, a systematic approach of using experimental measurements and computational fluid dynamics (CFD) is adopted to analyse liquid/gas two-phase flow associated with a turbocharger water washing system, in order to understand the underlyin...

  19. HCCI Heat Release Data for Combustion Simulation, based on Results from a Turbocharged Multi Cylinder Engine

    OpenAIRE

    Johansson, Thomas; Borgqvist, Patrick; Johansson, Bengt; Tunestål, Per; Aulin, Hans

    2010-01-01

    When simulating homogenous charge compression ignition or HCCI using one-dimensional models it is important to have the right combustion parameters. When operating in HCCI the heat release parameters will have a high influence on the simulation result due to the rapid combustion rate, especially if the engine is turbocharged. In this paper an extensive testing data base is used for showing the combustion data from a turbocharged engine operating in HCCI mode. The experimental data cover a wid...

  20. Integral rotor design for large nuclear low pressure turbine

    International Nuclear Information System (INIS)

    Considering corrosion assisted incidents of shrunk-on discs in nuclear low pressure turbines experienced in foreign utilities and recent progress of large forging manufacturing capability, the integral rotor have been developed and will be applied to 870 MW nuclear turbines as the first application in the world. The present nuclear integral rotor eliminating shrunk-on disc construction for the area of upstream discs where stress corrosion crackings have been experienced and will be potentially estimated due to dry and wet steam condition is considered to be the most reliable and advanced design at present from the view points of design and manufacturing. Design features and forging material properties of present nuclear integral rotors including monoblock rotor development as a future design, are presented in this paper. (author)

  1. Evaluation of Performance and Emission characteristics of Turbocharged Diesel Engine with Mullite as Thermal Barrier Coating

    Directory of Open Access Journals (Sweden)

    P. N. Shrirao

    2011-06-01

    Full Text Available Tests were performed on a single cylinder, four stroke, direct injection, diesel engine whose piston crown, cylinder head and valves were coated with a 0.5 mm thickness of 3Al2O3 .2SiO2 (mullite (Al2O3= 60%, SiO2= 40% over a 150 μm thickness of NiCrAlY bond coat. Tests were carried out on standard engine (uncoated and low heatrejection (LHR engine with and without turbocharger. This paper is intended to emphasis on energy balance and emission characteristic for standard engine (uncoated and low heat rejection (LHR engine with and without turbocharger. Tests were carried out at different engine load and engine speed conditions for standard and low heatrejection engine with and without turbocharger. The results showed that there was 2.18% decreasing on specific fuel consumption value of low heat rejection (LHR engine with turbocharger compared to standard engine at full load. There was as much as 12% increasing on exhaust gas temperature of LHR engine with turbocharger compared tostandard engine at full load. There was as much as 20.64% increasing on NOx emission of exhaust gas, 22.05% decreasing on CO emission of exhaust gas and 28.20% decreasing on HC emission of exhaust gas of LHR engine with turbocharger compared to standard engine at full load.

  2. Turbocharger with sliding piston, and having vanes and leakage dams

    Science.gov (United States)

    Roberts, Quentin; Alnega, Ahmed

    2011-12-06

    A turbocharger having a sliding piston for regulating exhaust gas flow into the turbine wheel includes a set of first vanes mounted on a fixed first wall of the turbine nozzle and projecting axially toward an opposite second wall of the nozzle, and/or a set of second vanes mounted on the end of the piston and projecting in an opposite axial direction toward the first wall of the nozzle. For the/each set of vanes, there are leakage dams formed on the wall that is adjacent the vane tips when the piston is closed. The leakage dams are closely adjacent the vane tips and discourage exhaust gas from leaking in a generally radial direction past the vane tips as the piston just begins to open from its fully closed position.

  3. Lightening structure optimization on turbine wheel of vehicular turbocharger

    Institute of Scientific and Technical Information of China (English)

    Junsheng ZHAO; Chaochen MA; Liaoping HU

    2008-01-01

    Based on basic principle of optimization design, structure optimization of turbine is conducted using optimization module of ANSYS and APDL in order to get the minimum turbine weight. Meanwhile, the original blade profile and flow passage are main-tained, and the structural strength of the turbine are guar-anteed. Considering assembly technique and cast requirement, the structure of the modified turbine is deter-mined which can save 6.91 percent of the material com-pared with the original one. The modified turbine not only saved material, but also gained better effect of mass dis-tribution between the turbine and the compressor impel-ler. The result can provide useful reference to engineering application of turbocharger.

  4. Turbocharger with variable nozzle having vane sealing surfaces

    Science.gov (United States)

    Arnold, Philippe; Petitjean, Dominique; Ruquart, Anthony; Dupont, Guillaume; Jeckel, Denis

    2011-11-15

    A variable nozzle for a turbocharger includes a plurality of vanes rotatably mounted on a nozzle ring and disposed in a nozzle flow path defined between the nozzle ring and an opposite nozzle wall. Either or both of the faces of the nozzle ring and nozzle wall include(s) at least one step that defines sealing surfaces positioned to be substantially abutted by airfoil surfaces of the vanes in the closed position of the vanes and to be spaced from the airfoil surfaces in positions other than the closed position. This substantial abutment between the airfoil surfaces and the sealing surfaces serves to substantially prevent exhaust gas from leaking past the ends of the airfoil portions. At the same time, clearances between the nozzle ring face and the end faces of the airfoil portions can be sufficiently large to prevent binding of the vanes under all operating conditions.

  5. Turbocharger design for electrical wastegate actuation to minimize leakage; Turboladerdesign fuer elektrische Waste-Gate-Betaetigung minimiert Leckage

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Achim; Herfurth, Roland [Continental, Regensburg (Germany); Claus, Hartmut; Frankenstein, Dirk [Continental, Gruenstadt (Germany)

    2010-10-15

    Exhaust gas turbochargers are a major part of current strategies for reducing CO{sub 2} emissions - especially in the gasoline engine. To optimally support downsizing and downspeeding, turbochargers must react as fast as possible, and the exhaust gas volumetric flow to the turbine must be exactly adjustable with a wastegate. Electric motor actuation is advantageous here. However, it places specific requirements on the wastegate which Continental has taken into account in its new generation of turbochargers. (orig.)

  6. Rotor for a pyrolysis centrifuge reactor

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a rotor for a pyrolysis centrifuge reactor, said rotor comprising a rotor body having a longitudinal centre axis, and at least one pivotally mounted blade being adapted to pivot around a pivot axis under rotation of the rotor body around the longitudinal centre axis....... Moreover, the present invention relates to a pyrolysis centrifuge reactor applying such a rotor....

  7. Vibratory Loads Data from a Wind-Tunnel Test of Structurally Tailored Model Helicopter Rotors

    Science.gov (United States)

    Yeager, William T., Jr.; Hamouda, M-Nabil H.; Idol, Robert F.; Mirick, Paul H.; Singleton, Jeffrey D.; Wilbur, Matthew L.

    1991-01-01

    An experimental study was conducted in the Langley Transonic Dynamics Tunnel to investigate the use of a Bell Helicopter Textron (BHT) rotor structural tailoring concept, known as rotor nodalization, in conjunction with advanced blade aerodynamics as well as to evaluate rotor blade aerodynamic design methodologies. A 1/5-size, four-bladed bearingless hub, three sets of Mach-scaled model rotor blades were tested in forward flight from transition up to an advance ratio of 0.35. The data presented pertain only to the evaluation of the structural tailoring concept and consist of fixed-system and rotating system vibratory loads. These data will be useful for evaluating the effects of tailoring blade structural properties on fixed-system vibratory loads, as well as validating analyses used in the design of advanced rotor systems.

  8. Rotor blade dynamic design

    Science.gov (United States)

    Pritchard, Jocelyn I.; Adelman, Howard M.; Mantay, Wayne R.

    1989-01-01

    The rotor dynamic design considerations are essentially limitations on the vibratory response of the blades which in turn limit the dynamic excitation of the fuselage by forces and moments transmitted to the hub. Quantities which are associated with the blade response and which are subject to design constraints are discussed. These include blade frequencies, vertical and inplane hub shear, rolling and pitching moments, and aeroelastic stability margin.

  9. Lessons from Rotor 37

    Institute of Scientific and Technical Information of China (English)

    J.D.Denton

    1997-01-01

    NASA rotor 37 was used as a blind test case for turbomachinery CFD by the Turbomachinery Committee of the IGTI.The rotor is a transonic compressor with a tip speed of 454 m/s(1500ft/s)and a relatively high pressure ratio of 2.1.It was tested in isolation with a circumferentially uniform inlet flow so that the flow through it should be steady apart from and effects of passage to passage geometry variation and mechanical vibration.As such it represents the simplest possible type of test for three-dimensional turbomachinery flow solvers.Howerver,the rotor still presents a real challenge to 3D viscous flow solvers because the shock wave-boudary layer interaction is strong and the effects of viscosity are dominant in determining the flow deviation and hence the pressure ration.Eleven blind solutions were submittewd and in addition a non-blind solution was used to prepare for the exercies.This paper reviews the flow in the test case and the comparisons of the CFD solutions with the test data.Lessons for both the Flow physics in transonic fans and for the application of CFD to such machines are pointed out.

  10. Development of turbo-viscous pump with ceramic rotor assembly and oil-free driving unit

    International Nuclear Information System (INIS)

    In order to establish a dynamic pumping system for fusion reactors and other advanced vacuum devices, a new type of roughing pump named turbo-viscous pump has been developed. The construction of the pump features a multistage ceramic (silicon nitride) rotor assembly and an oil-free driving unit. The rotor assembly has parallel rotor disks, between which project stator disks from the outer casing with rotor-stator clearances -3 Pa. The pumping speed and ultimate pressure attained so far are 0.28 m3/min (at inlet pressures between 10-1 and 102 Pa) and 1x10-3 Pa, respectively

  11. Dynamics of Anisotropically Supported Rotors

    OpenAIRE

    Agnes Muszynska; Hatch, Charles T.; Donald E. Bently

    1997-01-01

    The paper discusses dynamic effects occurring in machinery rotors supported in bearings and pedestals with laterally different characteristics. In the considered rotor model the anisotropy of radial stiffness and tangential (“cross”) stiffness components are included. Within certain ranges of the rotative speed the support anisotropy leads to the specific, excited-by-unbalance rotor lateral synchronous vibrations in a form of backward (reverse) precession. In addition, one section of the roto...

  12. Dynamical properties of granular rotors

    OpenAIRE

    Cleuren, Bart; Eichhorn, Ralf

    2008-01-01

    The stochastic motion of an arbitrarily shaped rotor, free to rotate around a fixed axis as a result of dissipative collisions with a surrounding thermalized gas, is investigated. A Boltzmann master equation is derived, starting from the elementary gas–rotor collisions. Analytical expressions for the moments of the rotational speed and the rotational temperature are obtained in the form of a series expansion, using the mass ratio of the gas particle and the rotor as the expansion parameter. W...

  13. Performance of Double-step Savonius Rotor for Environmentally Friendly Hydraulic Turbine

    Science.gov (United States)

    Nakajima, Miyoshi; Iio, Shouichiro; Ikeda, Toshihiko

    The aim of this investigation is to develop an environmentally friendly nano-hydraulic turbine. Three type models of Savonius rotor are constructed and tested in a water tunnel to improve and clarify the power performance. Flow field around the rotor is examined visually to reveal the enhancement mechanisms of power coefficient using the double-step rotor. Flow visualization showed the difference of flow patterns at the central section between the standard (single-step) rotor and the double-step one. A meandering flow in the axial direction of the rotor was observed only for the double-step rotor. This flow had the pressure restoration effect at the returning blade's concave side and the torque strengthened effect at the advancing blade's convex side. As a consequence, the power coefficient was 10% improved.

  14. Rotor/body aerodynamic interactions

    Science.gov (United States)

    Betzina, M. D.; Smith, C. A.; Shinoda, P.

    1985-01-01

    A wind tunnel investigation was conducted in which independent, steady state aerodynamic forces and moments were measured on a 2.24 m diam. two bladed helicopter rotor and on several different bodies. The mutual interaction effects for variations in velocity, thrust, tip-path-plane angle of attack, body angle of attack, rotor/body position, and body geometry were determined. The results show that the body longitudinal aerodynamic characteristics are significantly affected by the presence of a rotor and hub, and that the hub interference may be a major part of such interaction. The effects of the body on the rotor performance are presented.

  15. Homopolar motor with dual rotors

    Science.gov (United States)

    Hsu, John S.

    1998-01-01

    A homopolar motor (10) has a field rotor (15) mounted on a frame (11) for rotation in a first rotational direction and for producing an electromagnetic field, and an armature rotor (17) mounted for rotation on said frame (11) within said electromagnetic field and in a second rotational direction counter to said first rotational direction of said field rotor (15). The two rotors (15, 17) are coupled through a 1:1 gearing mechanism (19), so as to travel at the same speed but in opposite directions. This doubles the output voltage and output power, as compared to a motor in which only the armature is rotated. Several embodiments are disclosed.

  16. Variable Speed Rotor System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Variable speed rotors will give helicopters several advantages: higher top speed, greater fuel efficiency, momentary emergency over-power, resonance detuning...

  17. Experimental study of combustion noise radiation during transient turbocharged diesel engine operation

    International Nuclear Information System (INIS)

    Diesel engine noise radiation has drawn increased attention in recent years since it is associated with the passengers' and pedestrians' discomfort, a fact that has been acknowledged by the manufacturers and the legislation in many countries. In the current study, experimental tests were conducted on a truck, turbocharged diesel engine in order to investigate the mechanism of combustion noise emission under various transient schedules experienced during daily driving conditions, namely acceleration and load increase. To this aim, a fully instrumented test bed was set up in order to capture the development of key engine and turbocharger variables during the transient events. Analytical diagrams are provided to explain the behavior of combustion noise radiation in conjunction with cylinder pressure (spectrum), turbocharger and governor/fuel pump response. Turbocharger lag was found to be the main cause for the noise spikes during all test cases examined, with the engine injection timing calibration and the slow adjustment of cylinder wall temperature to the new fueling conditions playing a vital role. The analysis was extended with a quasi-steady approximation of transient combustion noise using steady-state maps, in order to better highlight the effect of dynamic engine operation on combustion noise emissions. -- Highlights: → Studying the effects of acceleration and load increase on the combustion noise radiation from a turbocharged diesel engine. → Turbocharger lag was the most notable contributor for the behavior of combustion noise radiation. → Turbocharged diesel engine behaves noisier at acceleration compared with the steady-state operation. → Fuel limiter, governing and engine injection timing calibration play a decisive role on the emission of combustion noise. → Transient noise radiation was smoothed the slower the acceleration and the smaller the demanded speed increase.

  18. Internal rotor friction instability

    Science.gov (United States)

    Walton, J.; Artiles, A.; Lund, J.; Dill, J.; Zorzi, E.

    1990-01-01

    The analytical developments and experimental investigations performed in assessing the effect of internal friction on rotor systems dynamic performance are documented. Analytical component models for axial splines, Curvic splines, and interference fit joints commonly found in modern high speed turbomachinery were developed. Rotor systems operating above a bending critical speed were shown to exhibit unstable subsynchronous vibrations at the first natural frequency. The effect of speed, bearing stiffness, joint stiffness, external damping, torque, and coefficient of friction, was evaluated. Testing included material coefficient of friction evaluations, component joint quantity and form of damping determinations, and rotordynamic stability assessments. Under conditions similar to those in the SSME turbopumps, material interfaces experienced a coefficient of friction of approx. 0.2 for lubricated and 0.8 for unlubricated conditions. The damping observed in the component joints displayed nearly linear behavior with increasing amplitude. Thus, the measured damping, as a function of amplitude, is not represented by either linear or Coulomb friction damper models. Rotordynamic testing of an axial spline joint under 5000 in.-lb of static torque, demonstrated the presence of an extremely severe instability when the rotor was operated above its first flexible natural frequency. The presence of this instability was predicted by nonlinear rotordynamic time-transient analysis using the nonlinear component model developed under this program. Corresponding rotordynamic testing of a shaft with an interference fit joint demonstrated the presence of subsynchronous vibrations at the first natural frequency. While subsynchronous vibrations were observed, they were bounded and significantly lower in amplitude than the synchronous vibrations.

  19. Aeromechanical Evaluation of Smart-Twisting Active Rotor

    Science.gov (United States)

    Lim, Joon W.; Boyd, D. Douglas, Jr.; Hoffman, Frauke; van der Wall, Berend G.; Kim, Do-Hyung; Jung, Sung N.; You, Young H.; Tanabe, Yasutada; Bailly, Joelle; Lienard, Caroline; Delrieux, Yves

    2014-01-01

    An investigation of Smart-Twisting Active Rotor (STAR) was made to assess potential benefits of the current active twist rotor concept for performance improvement, vibration reduction, and noise alleviation. The STAR rotor is a 40% Mach-scaled, Bo105 rotor with an articulated flap-lag hinge at 3.5%R and no pre-cone. The 0-5 per rev active twist harmonic inputs were applied for various flight conditions including hover, descent, moderate to high speed level flights, and slowed rotor high advance ratio. For the analysis, the STAR partners used multiple codes including CAMRAD II, S4, HOST, rFlow3D, elsA, and their associated software. At the high thrust level in hover, the 0 per rev active twist with 80% amplitude increased figure of merit (FM) by 0.01-0.02 relative to the baseline. In descent, the largest BVI noise reduction was on the order of 2 to 5 dB at the 3 per rev active twist. In the high speed case (mu = 0.35), the 2 per rev actuation was found to be the most effective in achieving a power reduction as well as a vibration reduction. At the 2 per rev active twist, total power was reduced by 0.65% at the 60 deg active twist phase, and vibration was reduced by 47.6% at the 45 deg active twist phase. The use of the 2 per rev active twist appears effective for vibration reduction. In the high advance ratio case (mu = 0.70), the 0 per rev actuation appeared to have negligible impact on performance improvement. In summary, computational simulations successfully demonstrated that the current active twist concept provided a significant reduction of the maximum BVI noise in descent, a significant reduction of the vibration in the high speed case, a small improvement on rotor performance in hover, and a negligible impact on rotor performance in forward flight.

  20. Molecular Rotors as Switches

    Directory of Open Access Journals (Sweden)

    Kang L. Wang

    2012-08-01

    Full Text Available The use of a functional molecular unit acting as a state variable provides an attractive alternative for the next generations of nanoscale electronics. It may help overcome the limits of conventional MOSFETd due to their potential scalability, low-cost, low variability, and highly integratable characteristics as well as the capability to exploit bottom-up self-assembly processes. This bottom-up construction and the operation of nanoscale machines/devices, in which the molecular motion can be controlled to perform functions, have been studied for their functionalities. Being triggered by external stimuli such as light, electricity or chemical reagents, these devices have shown various functions including those of diodes, rectifiers, memories, resonant tunnel junctions and single settable molecular switches that can be electronically configured for logic gates. Molecule-specific electronic switching has also been reported for several of these device structures, including nanopores containing oligo(phenylene ethynylene monolayers, and planar junctions incorporating rotaxane and catenane monolayers for the construction and operation of complex molecular machines. A specific electrically driven surface mounted molecular rotor is described in detail in this review. The rotor is comprised of a monolayer of redox-active ligated copper compounds sandwiched between a gold electrode and a highly-doped P+ Si. This electrically driven sandwich-type monolayer molecular rotor device showed an on/off ratio of approximately 104, a read window of about 2.5 V, and a retention time of greater than 104 s. The rotation speed of this type of molecular rotor has been reported to be in the picosecond timescale, which provides a potential of high switching speed applications. Current-voltage spectroscopy (I-V revealed a temperature-dependent negative differential resistance (NDR associated with the device. The analysis of the device

  1. MACROSCOPIC ROTORS AND GRAVITATIONAL EFFECTS

    OpenAIRE

    Ritter, R.

    1981-01-01

    Astronomical bodies have, in the past, provided essentially the only macroscopic basis for studies of gravitation by means of rotations. Now new technology provides the possibility that laboratory rotors may be made more precise than astronomical ones. This article surveys the properties of some of both types of rotors and describes several laboratory experiments for tests of General Relativity.

  2. Experimental investigation of thermal balance of a turbocharged SI engine operating on natural gas

    International Nuclear Information System (INIS)

    This paper experimentally investigates the thermal balance and performance of a turbocharged gas spark ignition engine. The First Law of Thermodynamics was used for control volume around the engine to compute the output power, transferred energy to the cooling fluid, exhaust gases and also unaccounted losses through convection and radiation heat transfer. Thermal balance tests were performed for various operational conditions including full and half loads and different cooling fluid temperatures. Results indicate that by increasing engine load and coolant temperature, the percentage of transferred energy to the exhaust gases increased while the percentage of coolant energy decreased. Also, experimental data reveals that using gaseous fuel and a turbocharger (TC) in the engine leads to 4.5% and 4% more thermal efficiency than gasoline and natural aspirated (NA), respectively. Also, second law analysis reveals that using a turbocharger leads to a 3.6% increase in exergetic efficiency of the engine, averagely. Based on experimental results, an empirical correlation was suggested for computing the energy of exhaust gases which shows good agreement with the experimental data for the majority of operating conditions. -- Highlights: • Thermal balance of a turbocharged gas SI engine was investigated experimentally. • By increasing load and coolant temperature, transferred energy to exhaust increased. • Coolant energy percentage decreased by increasing the load and coolant temperature. • Gaseous fuel and a turbocharger (TC) lead to 4.5% and 4% more thermal efficiency. • An empirical correlation was suggested for computing the energy of exhaust gases

  3. Active control for performance enhancement of electrically controlled rotor

    Institute of Scientific and Technical Information of China (English)

    Lu Yang; Wang Chao

    2015-01-01

    Electrically controlled rotor (ECR) system has the potential to enhance the rotor perfor-mance by applying higher harmonic flap inputs. In order to explore the feasibility and effectiveness for ECR performance enhancement using closed-loop control method, firstly, an ECR rotor perfor-mance analysis model based on helicopter flight dynamic model is established, which can reflect the performance characteristics of ECR helicopter at high advance ratio. Based on the simulation platform, an active control method named adaptive T-matrix algorithm is adopted to explore the feasibility and effectiveness for ECR performance enhancement. The simulation results verify the effectiveness of this closed-loop control method. For the sample ECR helicopter, about 3%rotor power reduction is obtained with the optimum 2/rev flap inputs at the advance ratio of 0.34. And through analyzing the distributions of attack of angle and drag in rotor disk, the underlying physical essence of ECR power reduction is cleared. Furthermore, the influence of the key control parameters, including convergence factor and weighting matrix, on the effectiveness of closed-loop control for ECR performance enhancement is explored. Some useful results are summarized, which can be used to direct the future active control law design of ECR performance enhancement.

  4. Active control for performance enhancement of electrically controlled rotor

    Directory of Open Access Journals (Sweden)

    Lu Yang

    2015-10-01

    Full Text Available Electrically controlled rotor (ECR system has the potential to enhance the rotor performance by applying higher harmonic flap inputs. In order to explore the feasibility and effectiveness for ECR performance enhancement using closed-loop control method, firstly, an ECR rotor performance analysis model based on helicopter flight dynamic model is established, which can reflect the performance characteristics of ECR helicopter at high advance ratio. Based on the simulation platform, an active control method named adaptive T-matrix algorithm is adopted to explore the feasibility and effectiveness for ECR performance enhancement. The simulation results verify the effectiveness of this closed-loop control method. For the sample ECR helicopter, about 3% rotor power reduction is obtained with the optimum 2/rev flap inputs at the advance ratio of 0.34. And through analyzing the distributions of attack of angle and drag in rotor disk, the underlying physical essence of ECR power reduction is cleared. Furthermore, the influence of the key control parameters, including convergence factor and weighting matrix, on the effectiveness of closed-loop control for ECR performance enhancement is explored. Some useful results are summarized, which can be used to direct the future active control law design of ECR performance enhancement.

  5. Fan Noise Screening Rig for New Open Rotor and Propeller Concepts Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Recent advancements in open rotor engine concepts warrant continued research, however the cost of wind tunnel tests is not insignificant. Because the jet noise of...

  6. Several rotor noise sources and treatments

    Energy Technology Data Exchange (ETDEWEB)

    Tangler, J. [National Renewable Energy Laboratory, Golden, CO (United States)

    1997-12-31

    Noise has been a design consideration in the development of advanced blades and turbines at the National Renewable Energy Laboratory. During atmospheric testing associated with these efforts various types of aeroacoustic noise have been encountered. This presentation discusses several of these noise sources and treatments used to mitigate or eliminate the noise. Tonal noise resulting from tip-vortex/trailing-edge interaction and laminar separation bubbles was found to be easily eliminated. Impulsive noise resulting from blade/vortex interaction for rotors that furl and that due to tower shadow can be mitigated by various means. (au)

  7. Numerical Investigation: Effect of Stator Vanes on Turbocharger Turbine Performance

    Directory of Open Access Journals (Sweden)

    Ganesh Yadagiri Rapolu

    2014-01-01

    Full Text Available With reduced turbo lag and better transient response, the introduction of VTG stator guide vanes improved turbocharger performance at all the engine operating conditions. The VTG system accelerates and maneuvers exhaust gas flow to the turbine. Favorable flow conditions at turbine inlet created by vane shape improve turbine performance. At lower engine speed, it is observed that the pressure drop across vane system influences overall efficiency. Whereas at higher speed, the pressure drop and guide vane exit flow angle are found to determine the turbine efficiency. Successful practical operation of VTG system also depends on its ability to smoothly open and close the vanes at different gas loads. Stator vane shape greatly influences the smooth operability/controllability of vane system. In the present work, 3 symmetric vanes with different T/C ratios and 2 asymmetric vanes are analyzed. The effect of geometric changes is studied from overall turbine performance as well as VTG system performance perspective. It is observed that symmetric vanes cause higher pressure drop at lower speeds leading to lower efficiency irrespective of the vane width. It is also observed that the pressure drop characteristics and vane exit flow angle are better with the asymmetric vanes, whereas the controllability of symmetric vanes is found to be superior. Analysis methodology is presented for achieving the best compromise between performance and controllability by the modification of vane geometric parameters through CFD simulations.

  8. Boeing Smart Rotor Full-scale Wind Tunnel Test Data Report

    Science.gov (United States)

    Kottapalli, Sesi; Hagerty, Brandon; Salazar, Denise

    2016-01-01

    A full-scale helicopter smart material actuated rotor technology (SMART) rotor test was conducted in the USAF National Full-Scale Aerodynamics Complex 40- by 80-Foot Wind Tunnel at NASA Ames. The SMART rotor system is a five-bladed MD 902 bearingless rotor with active trailing-edge flaps. The flaps are actuated using piezoelectric actuators. Rotor performance, structural loads, and acoustic data were obtained over a wide range of rotor shaft angles of attack, thrust, and airspeeds. The primary test objective was to acquire unique validation data for the high-performance computing analyses developed under the Defense Advanced Research Project Agency (DARPA) Helicopter Quieting Program (HQP). Other research objectives included quantifying the ability of the on-blade flaps to achieve vibration reduction, rotor smoothing, and performance improvements. This data set of rotor performance and structural loads can be used for analytical and experimental comparison studies with other full-scale rotor systems and for analytical validation of computer simulation models. The purpose of this final data report is to document a comprehensive, highquality data set that includes only data points where the flap was actively controlled and each of the five flaps behaved in a similar manner.

  9. Investigation of Maximum Blade Loading Capability of Lift-Offset Rotors

    Science.gov (United States)

    Yeo, Hyeonsoo; Johnson, Wayne

    2013-01-01

    Maximum blade loading capability of a coaxial, lift-offset rotor is investigated using a rotorcraft configuration designed in the context of short-haul, medium-size civil and military missions. The aircraft was sized for a 6600-lb payload and a range of 300 nm. The rotor planform and twist were optimized for hover and cruise performance. For the present rotor performance calculations, the collective pitch angle is progressively increased up to and through stall with the shaft angle set to zero. The effects of lift offset on rotor lift, power, controls, and blade airloads and structural loads are examined. The maximum lift capability of the coaxial rotor increases as lift offset increases and extends well beyond the McHugh lift boundary as the lift potential of the advancing blades are fully realized. A parametric study is conducted to examine the differences between the present coaxial rotor and the McHugh rotor in terms of maximum lift capabilities and to identify important design parameters that define the maximum lift capability of the rotor. The effects of lift offset on rotor blade airloads and structural loads are also investigated. Flap bending moment increases substantially as lift offset increases to carry the hub roll moment even at low collective values. The magnitude of flap bending moment is dictated by the lift-offset value (hub roll moment) but is less sensitive to collective and speed.

  10. Blade lock for a rotor disk and rotor blade assembly

    Science.gov (United States)

    Moore, Jerry H. (Inventor)

    1992-01-01

    A rotor disk 18 and rotor blade 26 assembly is disclosed having a blade lock 66 which retains the rotor blade against axial movement in an axially extending blade retention slot 58. Various construction details are developed which shield the dead rim region D.sub.d and shift at least a portion of the loads associated with the locking device from the dead rim. In one detailed embodiment, a projection 68 from the live rim D.sub.1 of the disk 18 is adapted by slots 86 to receive blade locks 66.

  11. Exhaust Gas Temperature Measurements in Diagnostics of Turbocharged Marine Internal Combustion Engines Part I Standard Measurements

    Directory of Open Access Journals (Sweden)

    Korczewski Zbigniew

    2015-01-01

    Full Text Available The article discusses the problem of diagnostic informativeness of exhaust gas temperature measurements in turbocharged marine internal combustion engines. Theoretical principles of the process of exhaust gas flow in turbocharger inlet channels are analysed in its dynamic and energetic aspects. Diagnostic parameters are defined which enable to formulate general evaluation of technical condition of the engine based on standard online measurements of the exhaust gas temperature. A proposal is made to extend the parametric methods of diagnosing workspaces in turbocharged marine engines by analysing time-histories of enthalpy changes of the exhaust gas flowing to the turbocompressor turbine. Such a time-history can be worked out based on dynamic measurements of the exhaust gas temperature, performed using a specially designed sheathed thermocouple.

  12. Variable-geometry turbocharger with asymmetric divided volute for engine exhaust gas pulse optimization

    Science.gov (United States)

    Serres, Nicolas

    2010-11-09

    A turbine assembly for a variable-geometry turbocharger includes a turbine housing defining a divided volute having first and second scrolls, wherein the first scroll has a substantially smaller volume than the second scroll. The first scroll feeds exhaust gas to a first portion of a turbine wheel upstream of the throat of the wheel, while the second scroll feeds gas to a second portion of the wheel at least part of which is downstream of the throat. Flow from the second scroll is regulated by a sliding piston. The first scroll can be optimized for low-flow conditions such that the turbocharger can operate effectively like a small fixed-geometry turbocharger when the piston is closed. The turbine housing defines an inlet that is divided by a dividing wall into two portions respectively feeding gas to the two scrolls, a leading edge of the dividing wall being downstream of the inlet mouth.

  13. 14 CFR 27.1509 - Rotor speed.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor speed. 27.1509 Section 27.1509... Rotor speed. (a) Maximum power-off (autorotation). The maximum power-off rotor speed must be established... minimum power-off rotor speed must be established so that it is not less than 105 percent of the...

  14. 14 CFR 29.1509 - Rotor speed.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor speed. 29.1509 Section 29.1509....1509 Rotor speed. (a) Maximum power-off (autorotation). The maximum power-off rotor speed must be... minimum power-off rotor speed must be established so that it is not less than 105 percent of the...

  15. 14 CFR 27.921 - Rotor brake.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor brake. 27.921 Section 27.921... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 27.921 Rotor brake. If there is a means to control the rotation of the rotor drive system independently of the engine, any limitations...

  16. 14 CFR 29.921 - Rotor brake.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor brake. 29.921 Section 29.921... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 29.921 Rotor brake. If there is a means to control the rotation of the rotor drive system independently of the engine, any limitations...

  17. Performance tests on helical Savonius rotors

    Energy Technology Data Exchange (ETDEWEB)

    Kamoji, M.A.; Kedare, S.B. [Department of Energy Science and Engineering, Indian Institute of Technology, Bombay (India); Prabhu, S.V. [Department of Mechanical Engineering, Indian Institute of Technology, Bombay (India)

    2009-03-15

    Conventional Savonius rotors have high coefficient of static torque at certain rotor angles and a negative coefficient of static torque from 135 to 165 and from 315 to 345 in one cycle of 360 . In order to decrease this variation in static torque from 0 to 360 , a helical Savonius rotor with a twist of 90 is proposed. In this study, tests on helical Savonius rotors are conducted in an open jet wind tunnel. Coefficient of static torque, coefficient of torque and coefficient of power for each helical Savonius rotor are measured. The performance of helical rotor with shaft between the end plates and helical rotor without shaft between the end plates at different overlap ratios namely 0.0, 0.1 and 0.16 is compared. Helical Savonius rotor without shaft is also compared with the performance of the conventional Savonius rotor. The results indicate that all the helical Savonius rotors have positive coefficient of static torque at all the rotor angles. The helical rotors with shaft have lower coefficient of power than the helical rotors without shaft. Helical rotor without shaft at an overlap ratio of 0.0 and an aspect ratio of 0.88 is found to have almost the same coefficient of power when compared with the conventional Savonius rotor. Correlation for coefficient of torque and power is developed for helical Savonius rotor for a range of Reynolds numbers studied. (author)

  18. Determination of Number of Broken Rotor Bars in Squirrel-Cage Induction Motors Using Adaptive Neuro-Fuzzy Interface System

    OpenAIRE

    Mehran Amani Juneghani; Babak Keyvani Boroujeni; Mostafa Abdollahi

    2012-01-01

    For determination the number of broken rotor bars in squirrel-cage induction motors when these motors are working, this study presents a new method based on an intelligent processing of the stator transient starting current. In light load condition, distinguishing between safe and faulty rotors is difficult, because the characteristic frequencies of rotor with broken bars are very close to the fundamental component and their amplitudes are small in comparison. In this study, an advanced techn...

  19. FUN3D Airload Predictions for the Full-Scale UH-60A Airloads Rotor in a Wind Tunnel

    Science.gov (United States)

    Lee-Rausch, Elizabeth M.; Biedron, Robert T.

    2013-01-01

    An unsteady Reynolds-Averaged Navier-Stokes solver for unstructured grids, FUN3D, is used to compute the rotor performance and airloads of the UH-60A Airloads Rotor in the National Full-Scale Aerodynamic Complex (NFAC) 40- by 80-foot Wind Tunnel. The flow solver is loosely coupled to a rotorcraft comprehensive code, CAMRAD-II, to account for trim and aeroelastic deflections. Computations are made for the 1-g level flight speed-sweep test conditions with the airloads rotor installed on the NFAC Large Rotor Test Apparatus (LRTA) and in the 40- by 80-ft wind tunnel to determine the influence of the test stand and wind-tunnel walls on the rotor performance and airloads. Detailed comparisons are made between the results of the CFD/CSD simulations and the wind tunnel measurements. The computed trends in solidity-weighted propulsive force and power coefficient match the experimental trends over the range of advance ratios and are comparable to previously published results. Rotor performance and sectional airloads show little sensitivity to the modeling of the wind-tunnel walls, which indicates that the rotor shaft-angle correction adequately compensates for the wall influence up to an advance ratio of 0.37. Sensitivity of the rotor performance and sectional airloads to the modeling of the rotor with the LRTA body/hub increases with advance ratio. The inclusion of the LRTA in the simulation slightly improves the comparison of rotor propulsive force between the computation and wind tunnel data but does not resolve the difference in the rotor power predictions at mu = 0.37. Despite a more precise knowledge of the rotor trim loads and flight condition, the level of comparison between the computed and measured sectional airloads/pressures at an advance ratio of 0.37 is comparable to the results previously published for the high-speed flight test condition.

  20. IDENTIFICATION OF CRACKED ROTOR BY WAVELET TRANSFORM

    Institute of Scientific and Technical Information of China (English)

    邹剑; 陈进; 蒲亚鹏

    2002-01-01

    The dynamic equation of cracked rotor in rotational frame was modelled, the numerical simulation solutions of the cracked rotor and the uncracked rotor were obtained. By the wavelet transform, the time-frequency properties of the cracked rotor and the uncracked rotor were discussed, the difference of the time-frequency properties between the cracked rotor and the uncracked rotor was compared. A new detection algorithm using wavelet transform to identify crack was proposed. The experiments verify the availability and validity of the wavelet transform in identification of crack.

  1. Process for Making Carbon-Carbon Turbocharger Housing Unit for Intermittent Combustion Engines

    Science.gov (United States)

    Northam, G. Burton (Inventor); Ransone, Philip O. (Inventor); Rivers, H. Kevin (Inventor)

    1999-01-01

    An improved. lightweight, turbine housing unit for an intermittent combustion reciprocating internal combustion engine turbocharger is prepared from a lay-up or molding of carbon-carbon composite materials in a single-piece or two-piece process. When compared to conventional steel or cast iron, the use of carbon-carbon composite materials in a turbine housing unit reduces the overall weight of the engine and reduces the heat energy loss used in the turbo-charging process. This reduction in heat energy loss and weight reduction provides for more efficient engine operation.

  2. Turbocharger Lubrication - Lubricant Behavior and Factors That Cause Turbocharger Failure / Turboşarj Yağlama - Yağlama Davranışı ve Turboşarj Arızasına Neden Olan Faktörler

    OpenAIRE

    Dellis, Polychronis; Retzios, Evaggelos; Geralis, Alcibiades; Gasparakis, Elias; Pesiridis, Apostolos

    2013-01-01

    This paper is a review of the turbocharger lubrication system and at the same time an attempt to point out and analyze the factors responsible for turbocharger wear, damage and failures. In particular, the conditions under which the lubricant works are presented, from its entrance up to its exit from the turbocharger bearing housing. Additionally, the consequences of failure to comply with the instructions for appropriate turbocharger operation, are provided by the various manufacturers....

  3. A new approach to helicopter rotor blade research instrumentation

    Science.gov (United States)

    Knight, V. H., Jr.

    1978-01-01

    A rotor-blade-mounted telemetry instrumentation system developed and used in flight tests by the NASA/Langley Research Center is described. The system uses high-speed digital techniques to acquire research data from miniature pressure transducers on advanced rotor airfoils which are flight tested using an AH-1G helicopter. The system employs microelectronic PCM multiplexer-digitizer stations located remotely on the blade and in a hub-mounted metal canister. The electronics contained in the canister digitizes up to 16 sensors, formats this data with serial PCM data from the remote stations, and transmits the data from the canister which is above the plane of the rotor. Data is transmitted over an RF link to the ground for real-time monitoring and to the helicopter fuselage for tape recording.

  4. Computation of transonic potential flow on helicopter rotor blades

    Science.gov (United States)

    Costes, M.; Jones, H. E.

    1987-01-01

    Two computer codes, the full-potential three-dimensional (FP3D) code and the full-potential rotor (FPR) code have recently been developed. Both of these codes solve the three-dimensional conservative formulation of the full potential equation. The FPR code was developed at the U.S. Army Aeroflightdynamics Directorate (AFDD) while the FP3D code was a joint development by ONERA and AFDD. Both of these codes were used to predict the nonlifting, unsteady flow over a rotor operating at high advance ratio and tip speed. Three different rotor tip planform shapes were studied: a rectangular tip, a 30 deg aft swept tip and a 30 deg forward swept tip. Results of these computations are compared to results obtained using an earlier small-disturbances code. Also, the lifting flow over a rectangular tip operating at a slightly different condition was computed. These results are also compared with the small disturbances computations and with experimental results.

  5. Design of composite flywheel rotor

    Institute of Scientific and Technical Information of China (English)

    Yue BAI; Qingjia GAO; Haiwen LI; Yihui WU; Ming XUAN

    2008-01-01

    A design method for a flywheel rotor com-posed of a composite rim and a metal hub is proposed by studying the connection between the rotor and the driving machine. The influence of some factors such as the rotor material, configuration, connection, and frac-ture techniques on energy density is analyzed. The results show that the ratio of the inner radius to outer radius of the rim is the key factor, and is determined by the rim material. Optimizing the hub can further efficiently improve energy density. The composite flywheel rotor is produced and its rotation stress has been tested at the speed of 20 krpm. The emulation results are consistent with testing results, which proves that the introduced design method is useful.

  6. LAVA Applications to Open Rotors

    Science.gov (United States)

    Kiris, Cetin C.; Housman, Jeff; Barad, Mike; Brehm, Christoph

    2015-01-01

    Outline: LAVA (Launch Ascent Vehicle Aerodynamics); Introduction; Acoustics Related Applications; LAVA Applications to Open Rotor; Structured Overset Grids; Cartesian Grid with Immersed Boundary; High Speed Case; High Speed Case with Plate Low Speed Case.

  7. Rotor disk cooling and rim sealing to prevent hot gas ingestion. Rotor reikyaku to hot gas no seal

    Energy Technology Data Exchange (ETDEWEB)

    Hamabe, K. (Kawasaki Heavy Industries, Ltd., Tokyo (Japan))

    1993-03-01

    In designing a high-temperature gas turbine disc, it is necessary to know pressure distribution around a disc, which correlates with flows inside and outside the disc. With design conditions becoming very stringent for efficiency improvement as a background, this paper describes latest trends in technologies on heat transfer around a disc and hot gas sealing while introducing reports on various studies. Generally speaking, fundamental researches on rotors without mainstreams have conventionally been carried out mainly in Europe and the U.S.A. Researches have become active recently on entrainment of mainstream gas where there is a mainstream that renders practical problems. The number of research papers is increasing sharply that relate to rotor shapes closer to those used in practical turbines incorporating moving and static blades, and high rotation Reynolds numbers. Further, studies using numerical analysis are on the increase, and rotor cooling studies are advancing remarkably in recent years. 36 refs., 10 figs.

  8. Prediction and measurement of low-frequency harmonic noise of a hovering model helicopter rotor

    Science.gov (United States)

    Aggarawal, H. R.; Schmitz, F. H.; Boxwell, D. A.

    Far-field acoustic data for a model helicopter rotor have been gathered in a large open-jet, acoustically treated wind tunnel with the rotor operating in hover and out of ground-effect. The four-bladed Boeing 360 model rotor with advanced airfoils, planform, and tip shape was run over a range of conditions typical of today's modern helicopter main rotor. Near in-plane acoustic measurements were compared with two independent implementations of classical linear theory. Measured steady thrust and torque were used together with a free-wake analysis (to predict the thrust and drag distributions along the rotor radius) as input to this first-principles theoretical approach. Good agreement between theory and experiment was shown for both amplitude and phase for measurements made in those positions that minimized distortion of the radiated acoustic signature at low-frequencies.

  9. Quantum rotor in nanostructured superconductors

    OpenAIRE

    Lin, Shi-Hsin; Milošević, M. V.; Covaci, L.; Jankó, B.; Peeters, F.M.

    2014-01-01

    Despite its apparent simplicity, the idealized model of a particle constrained to move on a circle has intriguing dynamic properties and immediate experimental relevance. While a rotor is rather easy to set up classically, the quantum regime is harder to realize and investigate. Here we demonstrate that the quantum dynamics of quasiparticles in certain classes of nanostructured superconductors can be mapped onto a quantum rotor. Furthermore, we provide a straightforward experimental procedure...

  10. Evaluation of combustion, performance, and emissions of optimum palm–coconut blend in turbocharged and non-turbocharged conditions of a diesel engine

    International Nuclear Information System (INIS)

    Highlights: • Properties limitation of biodiesel has been overcome using multiple biodiesel blends. • New biodiesel was developed using biodiesel–biodiesel optimum blend. • Engine performance and emission was tested with the newly developed biodiesels. • New biodiesels showed better engine performance than other tested fuels. - Abstract: Fossil fuel depletion, global warming with rapid changes in climate, and increases in oil prices have motivated scientists to search for alternative fuel. Biodiesel can be an effective solution despite some limitations, such as poor fuel properties and engine performance. From this perspective, experiments were carried out to improve fuel properties and engine performance by using a binary blend of palm and coconut biodiesel at an optimized ratio. MATLAB optimization tool was used to determine this blend ratio. A new biodiesel was developed and represented by PC (optimum blend of palm and coconut biodiesel). Engine performance and emission were tested under a full load at variable speed condition by using a 20% blend of each biodiesel with petroleum diesel, and the results were compared with petroleum diesel under both turbocharged and non-turbocharged conditions. PC20 (blend of 20% PC biodiesel and 80% petroleum diesel) showed the highest engine power with lower brake-specific fuel consumption than the other tested fuels in the presence of a turbocharger. The emissions of PC20 were lower than those of all other tested fuels. The experimental analysis reveals that PC showed superior performance and emission over palm biodiesel blend

  11. Development of a heavy-duty diesel engine with two-stage turbocharging

    NARCIS (Netherlands)

    Sturm, L.; Kruithof, J.

    2001-01-01

    A mean value model was developed by using Matrixx/ Systembuild simulation tool for designing real-time control algorithms for the two-stage engine. All desired characteristics are achieved, apart from lower A/F ratio at lower engine speeds and Turbocharger matches calculations. The CANbus is used to

  12. Internal combustion engine supercharging: turbocharger vs. pressure wave compressor. Performance comparison

    Science.gov (United States)

    George, Atanasiu; Chiru, Anghel

    2014-06-01

    This paper aims on comparison between a turbocharged engine and a pressure wave charged engine. The comparison was accomplished using the engine simulation software AVL Boost, version 2010. The grahps were extracted using AVL Impress, version 2010. The performance increase is limited by the mechanical side of the simulated engine.

  13. The Outlook of Electrically-assisted Turbocharger%EAT技术发展前瞻

    Institute of Scientific and Technical Information of China (English)

    张俊红; 王铁宁

    2007-01-01

    本文介绍了电辅助涡轮增压器(Electrically-Assisted Turbocharger-EAT)的发展前景及技术优势.列举一些EAT方案并对其进行了分类,分析了优缺点,归纳了研发过程中需要解决的问题.

  14. 75 FR 16662 - Airworthiness Directives; Kelly Aerospace Energy Systems, LLC Rebuilt Turbochargers

    Science.gov (United States)

    2010-04-02

    ... in the Federal Register published on April 11, 2000 (65 FR 19477-78). Examining the AD Docket You may... rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and 3. Will... are issuing this AD to prevent separation or seizure of the turbocharger turbine, which could...

  15. Influence of the rotor slit depth on the performance of the solid-rotor induction motor

    Energy Technology Data Exchange (ETDEWEB)

    Aho, T.; Nerg, J.; Pyrhoenen, J. [Lappeenranta Univ. of Tech., Dept. of Electrical Engineering (Finland)

    2005-07-01

    The polyphase induction motor with solid iron rotor offers undoubted advantages in terms of construction simplicity and strength over conventional induction motors when the elevated rotation speed is needed. In this paper a three-phase induction motor with slitted solid-rotor is analyzed using two-dimensional finite-element method. Different rotor designs are studied in order to find out the influence of the rotor slit depth on the motor performance characteristics. It was found that the rotor slits should reach very deep inside the rotor. The depth of the rotor slitting is restricted by the saturation of the rotor material between the slits. Also the mechanical strength of the rotor material limits the depth of the rotor slitting. It is shown that in order to reduce the mechanical stress and the saturation of the rotor material between the slits the slitting should be made in such a way that every second slit is deeper than the other. (orig.)

  16. The range of a rotor walk

    OpenAIRE

    Florescu, Laura; Levine, Lionel; Peres, Yuval

    2014-01-01

    In a \\emph{rotor walk} the exits from each vertex follow a prescribed periodic sequence. On an infinite Eulerian graph embedded periodically in $\\R^d$, we show that any simple rotor walk, regardless of rotor mechanism or initial rotor configuration, visits at least on the order of $t^{d/(d+1)}$ distinct sites in $t$ steps. We prove a shape theorem for the rotor walk on the comb graph with i.i.d.\\ uniform initial rotors, showing that the range is of order $t^{2/3}$ and the asymptotic shape of ...

  17. Engine turbocharger performance prediction: One-dimensional modeling of a twin entry turbine

    International Nuclear Information System (INIS)

    Highlights: ► Paper presents the geometrical effects in 1D twin entry turbocharger turbine model. ► Twin entry turbine investigation under full admission pulsating flow conditions. ► Pressure wave propagation, reflection and superposition in the system are examined. ► Varying cross-sectional area model shows higher secondary fluctuation prediction. ► Two inlet constant cross-sectional model with junction tongue gives best compromise. - Abstract: As the automotive industry develops technology strategies to meet increasingly stringent vehicle emission regulations, turbocharging has become the primary enabler for engine downsizing, a building block for improving fuel consumption and reduced CO2 emissions. Engine manufacturers routinely use one-dimensional engine cycle simulation for performance and emissions prediction, and accurate engine-turbocharger matching is a key aspect. Turbocharger turbines are subject to the highly unsteady, pulsating flow inherent to reciprocating engines, however standard 1D turbine models rely on steady state test measurements. Simplification of turbine geometry is unavoidable, especially in 1D performance studies, yet this must not be taken so far that it prohibits acceptable prediction accuracy. This paper presents the geometrical effects of 1D numerical models of a twin entry turbocharger turbine under full admission pulsating flow conditions. Several turbine volute models of increasing complexity were developed and the corresponding performance predicted using a 1D compressible flow solver. The predicted mass flow rate is strongly dependent on local total state flow parameters, and higher secondary mass flow rate fluctuation was noticed as model complexity increased. Finally, a two-inlet constant cross-section model with junction tongue gave the best compromise of flow prediction accuracy and geometrical complexity.

  18. An approach for exhaust gas energy recovery of internal combustion engine: Steam-assisted turbocharging

    International Nuclear Information System (INIS)

    Highlights: • The calculation method for SAT engine was developed and introduced. • SAT can effectively promote the low-speed performances of IC engine. • At 1500 r/min, intake pressure reaches target value and torque is increased by 25%. • The thermal efficiency of SAT engine only has a slight increase. - Abstract: An approach for IC engine exhaust gas energy recovery, named as steam-assisted turbocharging (SAT), is developed to assist the exhaust turbocharger. A steam generating plant is coupled to the exhaust turbocharged engine’s exhaust pipe, which uses the high-temperature exhaust gas to generate steam. The steam is injected into turbine inlet and used as the supplementary working medium for turbine. By this means, turbine output power and then boosting pressure can be promoted due to the increase of turbine working medium. To reveal the advantages and energy saving potentials of SAT, this concept was applied to an exhaust turbocharging engine, and a parameter analysis was carried out. Research results show that, SAT can effectively promote the low-speed performances of IC engine, and make the peak torque shift to low-speed area. At 1500 r/min, the intake gas pressure can reach the desired value and the torque can be increased by 25.0% over the exhaust turbocharging engine, while the pumping mean effective pressure (PMEP) and thermal efficiency only have a slight increase. At 1000 r/min, the improvement of IC engine performances is very limited due to the low exhaust gas energy

  19. Rotorcraft technology at Boeing Vertol: Recent advances

    Science.gov (United States)

    Shaw, John; Dadone, Leo; Wiesner, Robert

    1988-01-01

    An overview is presented of key accomplishments in the rotorcraft development at Boeing Vertol. Projects of particular significance: high speed rotor development and the Model 360 Advanced Technology Helicopter. Areas addressed in the overview are: advanced rotors with reduced noise and vibration, 3-D aerodynamic modeling, flight control and avionics, active control, automated diagnostics and prognostics, composite structures, and drive systems.

  20. CALCULATION OF HELICOPTER ROTOR FLAPPING ANGLES AND COMPARISON WITH MEASURED DATA

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Helicopter rotor flapping angles from hover to low-speed forward flight are calculated and compared with the measured data in this paper. The analytical method is based on a second order lifting-line/full-span free wake model as well as a fully coupled rotor trim model. It is shown that, in order to accurately predict the lateral flapping angle at low advance ratio, it is necessary to use free wake analysis to account for the highly non-uniform inflow induced by the distorted wake geometry at rotor disc plane.

  1. WindPACT Turbine Rotor Design Study: June 2000--June 2002 (Revised)

    Energy Technology Data Exchange (ETDEWEB)

    Malcolm, D. J.; Hansen, A. C.

    2006-04-01

    This report presents the results of the turbine rotor study completed by Global Energy Concepts (GEC) as part of the U.S. Department of Energy's WindPACT (Wind Partnership for Advanced Component Technologies) project. The purpose of the WindPACT project is to identify technology improvements that will enable the cost of energy from wind turbines to fall to a target of 3.0 cents/kilowatt-hour in low wind speed sites. The study focused on different rotor configurations and the effect of scale on those rotors.

  2. Design of composite flywheel rotors with soft cores

    Science.gov (United States)

    Kim, Taehan

    A flywheel is an inertial energy storage system in which the energy or momentum is stored in a rotating mass. Over the last twenty years, high-performance flywheels have been developed with significant improvements, showing potential as energy storage systems in a wide range of applications. Despite the great advances in fundamental knowledge and technology, the current successful rotors depend mainly on the recent developments of high-stiffness and high-strength carbon composites. These composites are expensive and the cost of flywheels made of them is high. The ultimate goal of the study presented here is the development of a cost-effective composite rotor made of a hybrid material. In this study, two-dimensional and three-dimensional analysis tools were developed and utilized in the design of the composite rim, and extensive spin tests were performed to validate the designed rotors and give a sound basis for large-scale rotor design. Hybrid rims made of several different composite materials can effectively reduce the radial stress in the composite rim, which is critical in the design of composite rims. Since the hybrid composite rims we studied employ low-cost glass fiber for the inside of the rim, and the result is large radial growth of the hybrid rim, conventional metallic hubs cannot be used in this design. A soft core developed in this study was successfully able to accommodate the large radial growth of the rim. High bonding strength at the shaft-to-core interface was achieved by the soft core being molded directly onto the steel shaft, and a tapered geometry was used to avoid stress concentrations at the shaft-to-core interface. Extensive spin tests were utilized for reverse engineering of the design of composite rotors, and there was good correlation between tests and analysis. A large-scale composite rotor for ground transportation is presented with the performance levels predicted for it.

  3. An evaluation of 1D loss model collections for the off-design performance prediction of automotive turbocharger compressors

    Science.gov (United States)

    Harley, P.; Spence, S.; Early, J.; Filsinger, D.; Dietrich, M.

    2013-12-01

    Single-zone modelling is used to assess different collections of impeller 1D loss models. Three collections of loss models have been identified in literature, and the background to each of these collections is discussed. Each collection is evaluated using three modern automotive turbocharger style centrifugal compressors; comparisons of performance for each of the collections are made. An empirical data set taken from standard hot gas stand tests for each turbocharger is used as a baseline for comparison. Compressor range is predicted in this study; impeller diffusion ratio is shown to be a useful method of predicting compressor surge in 1D, and choke is predicted using basic compressible flow theory. The compressor designer can use this as a guide to identify the most compatible collection of losses for turbocharger compressor design applications. The analysis indicates the most appropriate collection for the design of automotive turbocharger centrifugal compressors.

  4. Rotor-to-stator Partial Rubbing and Its Effects on Rotor Dynamic Response

    Science.gov (United States)

    Muszynska, Agnes; Franklin, Wesley D.; Hayashida, Robert D.

    1991-01-01

    Results from experimental and analytical studies on rotor to stationary element partial rubbings at several locations and their effects on rotor dynamic responses are presented. The mathematical model of a rubbing rotor is given. The computer program provides numerical results which agree with experimentally obtained rotor responses.

  5. The Diver with a Rotor

    CERN Document Server

    Bharadwaj, Sudarsh; Dullin, Holger R; Leung, Karen; Tong, William

    2015-01-01

    We present and analyse a simple model for the twisting somersault. The model is a rigid body with a rotor attached which can be switched on and off. This makes it simple enough to devise explicit analytical formulas whilst still maintaining sufficient complexity to preserve the shape-changing dynamics essential for twisting somersaults in springboard and platform diving. With `rotor on' and with `rotor off' the corresponding Euler-type equations can be solved, and the essential quantities characterising the dynamics, such as the periods and rotation numbers, can be computed in terms of complete elliptic integrals. Thus we arrive at explicit formulas for how to achieve a dive with m somersaults and n twists in a given total time. This can be thought of as a special case of a geometric phase formula due to Cabrera 2007.

  6. Quantum rotor in nanostructured superconductors

    Science.gov (United States)

    Lin, Shi-Hsin; Milošević, M. V.; Covaci, L.; Jankó, B.; Peeters, F. M.

    2014-01-01

    Despite its apparent simplicity, the idealized model of a particle constrained to move on a circle has intriguing dynamic properties and immediate experimental relevance. While a rotor is rather easy to set up classically, the quantum regime is harder to realize and investigate. Here we demonstrate that the quantum dynamics of quasiparticles in certain classes of nanostructured superconductors can be mapped onto a quantum rotor. Furthermore, we provide a straightforward experimental procedure to convert this nanoscale superconducting rotor into a regular or inverted quantum pendulum with tunable gravitational field, inertia, and drive. We detail how these novel states can be detected via scanning tunneling spectroscopy. The proposed experiments will provide insights into quantum dynamics and quantum chaos. PMID:24686241

  7. Computer program for flexible rotor dynamics analysis

    Science.gov (United States)

    Shen, F. A.

    1974-01-01

    Program analyzes general nonaxisymmetric and nonsynchronous transient and steady-state rotor dynamic performance of bending- and shear-wise flexible rotor-bearing system under various operating conditions. Program can be used as analytical study tool for general transient spin-speed and/or non-axisymmetric rotor motion.

  8. Dielectric anomaly in coupled rotor systems

    OpenAIRE

    Shima, Hiroyuki; Nakayama, Tsuneyoshi

    2004-01-01

    The correlated dynamics of coupled quantum rotors carrying electric dipole moment is theoretically investigated. The energy spectra of coupled rotors as a function of dipolar interaction energy is analytically solved. The calculated dielectric susceptibilities of the system show the peculiar temperature dependence different from that of isolated rotors.

  9. 14 CFR 29.1565 - Tail rotor.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Tail rotor. 29.1565 Section 29.1565 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS....1565 Tail rotor. Each tail rotor must be marked so that its disc is conspicuous under normal...

  10. Dielectric anomaly in coupled rotor systems

    OpenAIRE

    Shima, Hiroyuki; Nakayama, Tsuneyoshi

    2004-01-01

    The correlated dynamics of coupled quantum rotors carrying electric dipole moment is theoretically investigated. The energy spectra of coupled rotors as a function of dipolar interaction energy are analytically solved. The calculated dielectric susceptibilities of the system show a peculiar temperature dependence different from that of isolated rotors.

  11. 14 CFR 27.1565 - Tail rotor.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Tail rotor. 27.1565 Section 27.1565 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... Tail rotor. Each tail rotor must be marked so that its disc is conspicuous under normal daylight...

  12. Blade Displacement Measurement Technique Applied to a Full-Scale Rotor Test

    Science.gov (United States)

    Abrego, Anita I.; Olson, Lawrence E.; Romander, Ethan A.; Barrows, Danny A.; Burner, Alpheus W.

    2012-01-01

    Blade displacement measurements using multi-camera photogrammetry were acquired during the full-scale wind tunnel test of the UH-60A Airloads rotor, conducted in the National Full-Scale Aerodynamics Complex 40- by 80-Foot Wind Tunnel. The objectives were to measure the blade displacement and deformation of the four rotor blades as they rotated through the entire rotor azimuth. These measurements are expected to provide a unique dataset to aid in the development and validation of rotorcraft prediction techniques. They are used to resolve the blade shape and position, including pitch, flap, lag and elastic deformation. Photogrammetric data encompass advance ratios from 0.15 to slowed rotor simulations of 1.0, thrust coefficient to rotor solidity ratios from 0.01 to 0.13, and rotor shaft angles from -10.0 to 8.0 degrees. An overview of the blade displacement measurement methodology and system development, descriptions of image processing, uncertainty considerations, preliminary results covering static and moderate advance ratio test conditions and future considerations are presented. Comparisons of experimental and computational results for a moderate advance ratio forward flight condition show good trend agreements, but also indicate significant mean discrepancies in lag and elastic twist. Blade displacement pitch measurements agree well with both the wind tunnel commanded and measured values.

  13. Analysis of Ignition Behavior in a Turbocharged Direct Injection Dual Fuel Engine Using Propane and Methane as Primary Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Polk, A. C.; Gibson, C. M.; Shoemaker, N. T.; Srinivasan, K. K.; Krishnan, S. R.

    2013-05-24

    This paper presents experimental analyses of the ignition delay (ID) behavior for diesel-ignited propane and diesel-ignited methane dual fuel combustion. Two sets of experiments were performed at a constant speed (1800 rev/min) using a 4-cylinder direct injection diesel engine with the stock ECU and a wastegated turbocharger. First, the effects of fuel-air equivalence ratios (© pilot ¼ 0.2-0.6 and © overall ¼ 0.2-0.9) on IDs were quantified. Second, the effects of gaseous fuel percent energy substitution (PES) and brake mean effective pressure (BMEP) (from 2.5 to 10 bar) on IDs were investigated. With constant © pilot (> 0.5), increasing © overall with propane initially decreased ID but eventually led to premature propane autoignition; however, the corresponding effects with methane were relatively minor. Cyclic variations in the start of combustion (SOC) increased with increasing © overall (at constant © pilot), more significantly for propane than for methane. With increasing PES at constant BMEP, the ID showed a nonlinear (initially increasing and later decreasing) trend at low BMEPs for propane but a linearly decreasing trend at high BMEPs. For methane, increasing PES only increased IDs at all BMEPs. At low BMEPs, increasing PES led to significantly higher cyclic SOC variations and SOC advancement for both propane and methane. Finally, the engine ignition delay (EID) was also shown to be a useful metric to understand the influence of ID on dual fuel combustion.

  14. Turbocharging and variable valve trains. Fuel reducing technologies for worldwide use; Aufladung und variable Ventiltriebe. Verbrauchstechnologien fuer den weltweiten Einsatz

    Energy Technology Data Exchange (ETDEWEB)

    Klauer, Norbert; Klueting, Manfred; Steinparzer, Fritz; Unger, Harald [BMW Group, Muenchen (Germany)

    2009-07-01

    Strongly increasing prices of crude oil terrify the fear around energy shortage and result in a distinct increase of the fuel prices. The customers react to it with a changed behaviour of purchase. The national regularization increases beyond Europe strongly. With the holistic approach BMW EfficientDynamics years ago, BMW Group already began to react to these changed requirements adequately in order to secure a sustainable mobility. Electrification, energy recovery, engine start/stop and efficient propulsion technologies thereby are the substantial components of this approach. In the near future, the combustion engine plays the leading role with the vehicle drives and thus is in the focus of further reductions of consumption. With the introduction of Valvetronic 2001 at BMW Ottomotoren, a significant reduction of consumption sinking in serial production had been presented for the first time. With the direct injection and the turbocharging, further milestones could be established for the reduction of consumption by means of the engine technology. Their consistent advancement and its intelligent combination in new engine concepts and concepts of powertrain can be a main part of innovative new drives for the world-wide employment in future.

  15. Development of an exhaust-gas turbocharger for HD Daimler CV engines; Entwicklung eines Abgas-Turboladers fuer die schweren NFZ-Motoren von Daimler

    Energy Technology Data Exchange (ETDEWEB)

    Chebli, Elias; Mueller, Markus; Leweux, Johannes; Gorbach, Andreas [Daimler AG, Stuttgart (Germany)

    2013-02-01

    The matching of a turbocharging system to the specific requirements of an entire engine with regard to fuel consumption, emissions and service life is a key element of engine development. This is the reason for taking the decision to initiate in-house turbocharger component development as the New Engine Generation (NEG) engine series of Daimler AG was being developed. The aim of this in-house turbocharger development is to produce the best possible turbocharging system for the entire engine with regard to fuel consumption, emissions and economy. (orig.)

  16. Rotor Vortex Filaments: Living on the Slipstream's Edge

    Science.gov (United States)

    Young, Larry A.

    1997-01-01

    The purpose of this paper is to gain a better understanding of rotor wake evolution in hover and axial flow by deriving an analytical solution for the time dependent behavior of vortex filament circulation and core size. This solution is applicable only for vortex filaments in the rotor far-wake. A primarily inviscid vortex/shear layer interaction (where the slipstream boundary is modeled as a shear layer) has been identified in this analytical treatment. This vortex/shear layer interaction results in decreasing, vortex filament circulation and core size with time. The inviscid vortex/shear layer interaction is shown, in a first-order treatment, to be of greater magnitude than viscous diffusion effects. The rate of contraction, and ultimate collapse, of the vortex filament core is found to be directly proportional to the rotor inflow velocity. This new insight into vortex filament decay promises to help reconcile several disparate observations made in the literature and will, hopefully, promote new advances in theoretical modeling of rotor wakes.

  17. 232Th, a rigid rotor

    International Nuclear Information System (INIS)

    We undertake the present work to treat 232Th with a soft rotor formula used recently by C. Bihari et. al for γ-band and modified by J.B. Gupta et. al. It describes energy in terms of moment of inertia and softness parameter

  18. Topological dynamics in supramolecular rotors.

    Science.gov (United States)

    Palma, Carlos-Andres; Björk, Jonas; Rao, Francesco; Kühne, Dirk; Klappenberger, Florian; Barth, Johannes V

    2014-08-13

    Artificial molecular switches, rotors, and machines are set to establish design rules and applications beyond their biological counterparts. Herein we exemplify the role of noncovalent interactions and transient rearrangements in the complex behavior of supramolecular rotors caged in a 2D metal-organic coordination network. Combined scanning tunneling microscopy experiments and molecular dynamics modeling of a supramolecular rotor with respective rotation rates matching with 0.2 kcal mol(-1) (9 meV) precision, identify key steps in collective rotation events and reconfigurations. We notably reveal that stereoisomerization of the chiral trimeric units entails topological isomerization whereas rotation occurs in a topology conserving, two-step asynchronous process. In supramolecular constructs, distinct displacements of subunits occur inducing a markedly lower rotation barrier as compared to synchronous mechanisms of rigid rotors. Moreover, the chemical environment can be instructed to control the system dynamics. Our observations allow for a definition of mechanical cooperativity based on a significant reduction of free energy barriers in supramolecules compared to rigid molecules. PMID:25078022

  19. Emission characteristics of a turbocharged diesel engine fueled with gas-to-liquids

    Institute of Scientific and Technical Information of China (English)

    WU Tao; ZHANG Wugao; FANG Junhua; HUANG Zhen

    2007-01-01

    Emission characteristics of a turbocharged,intercooled,heavy-duty diesel engine operating on neat gas-toliquids (GTL) and blends of GTL with conventional diesel were investigated and a comparison was made with those of diesel fuel.The results show that nitrogen oxides (NOx),smoke,and particulate matter (PM) emissions can be decreased when operating on GTL and diesel-GTL blends.Engine emissions decrease with an increase of GTL fraction in the blends.Compared with diesel fuel,an engine operatingon GTL can reduce NOx,PM,carbon monoxide (CO),and hydrocarbon (HC) by 23.7%,27.6%,16.6% and 12.9% in ECE R49 13-mode procedure,respectively.Engine speed and load have great influences on emissions when operating on diesel-GTL blends and diesel fuel in the turbocharged diesel engine.The study indicates that GTL is a promisingalternative fuel for diesel engines to reduce emissions.

  20. Oil Coking Prevention Using Electric Water Pump for Turbo-Charge Spark-Ignition Engines

    Directory of Open Access Journals (Sweden)

    Han-Ching Lin

    2014-01-01

    Full Text Available Turbocharger has been widely implemented for internal combustion engine to increase an engine's power output and reduce fuel consumption. However, its operating temperature would rise to 340°C when engine stalls. This higher temperature may results in bearing wear, run-out, and stick, due to oil coking and insufficient lubrication. In order to overcome these problems, this paper employs Electric Water Pump (EWP to supply cool liquid to turbocharger actively when the engine stalls. The system layout, operating timing, and duration of EWP are investigated for obtaining optimal performance. The primarily experimental results show that the proposed layout and control strategy have a lower temperature of 100°C than the conventional temperature 225°C.

  1. Experiment and surge analysis of centrifugal two-stage turbocharging system

    Institute of Scientific and Technical Information of China (English)

    Yituan HE; Chaochen MA

    2008-01-01

    To study a centrifugal two-stage turbocharging system's surge and influencing factors, a special test bench was set up and the system surge test was performed. The test results indicate that the measured parameters such as air mass flow and rotation speed of a high pressure (HP) stage compressor can be converted into corrected para-meters under a standard condition according to the Mach number similarity criterion, because the air flow in a HP stage compressor has entered the Reynolds number (Re) auto-modeling range. Accordingly, the reasons leading to a two-stage turbocharging system's surge can be analyzed according to the corrected mass flow characteristic maps and actual operating conditions of HP and low pressure (LP) stage compressors.

  2. Rotor damage detection by using piezoelectric impedance

    Science.gov (United States)

    Qin, Y.; Tao, Y.; Mao, Y. F.

    2016-04-01

    Rotor is a core component of rotary machinery. Once the rotor has the damage, it may lead to a major accident. Thus the quantitative rotor damage detection method based on piezoelectric impedance is studied in this paper. With the governing equation of piezoelectric transducer (PZT) in a cylindrical coordinate, the displacement along the radius direction is derived. The charge of PZT is calculated by the electric displacement. Then, by the use of the obtained displacement and charge, an analytic piezoelectric impedance model of the rotor is built. Given the circular boundary condition of a rotor, annular elements are used as the analyzed objects and spectral element method is used to set up the damage detection model. The Electro-Mechanical (E/M) coupled impedance expression of an undamaged rotor is deduced with the application of a low-cost impedance test circuit. A Taylor expansion method is used to obtain the approximate E/M coupled impedance expression for the damaged rotor. After obtaining the difference between the undamaged and damaged rotor impedance, a rotor damage detection method is proposed. This method can directly calculate the change of bending stiffness of the structural elements, it follows that the rotor damage can be effectively detected. Finally, a preset damage configuration is used for the numerical simulation. The result shows that the quantitative damage detection algorithm based on spectral element method and piezoelectric impedance proposed in this paper can identify the location and the severity of the damaged rotor accurately.

  3. Contribution to the Experimental Characterization and 1-D Modelling of Turbochargers for IC Engines

    OpenAIRE

    Reyes Belmonte, Miguel Angel

    2014-01-01

    At the end of the 19th Century, the invention of the Internal Combustion Engine (ICE) marked the beginning of our current lifestyle. Soon after the first ICE patent, the importance of increasing air pressure upstream the engine cylinders was revealed. At the beginning of the 20th Century turbo-machinery developments (which had started time before), met the ICE what represented the beginning of turbocharged engines. Since that time, the working principle has not fundamentally ch...

  4. Aftertreatment in a pre-turbocharger position. Size and fuel consumption advantage for Tier 4

    Energy Technology Data Exchange (ETDEWEB)

    Bruestle, Claus [Emitec, Inc., Rochester Hills, MI (United States); Tomazic, Dean; Franke, Michael [FEV, Inc., Auburn Hills, MI (United States)

    2013-05-15

    As the 2014 implementation of EPA Tier 4 fast approaches in the US A, manufacturers of large bore diesel engines face a dilemma. The stringent limits set by Tier 4 legislation require large, heavy and expensive emissions control systems but severe constraints on installation space, weight and cost exist for these systems. A viable solution is to place catalysts and filters upstream of the turbocharger. (orig.)

  5. A Control-Oriented 0D Model of a Turbocharger Gas Stand Including Heat Transfer

    OpenAIRE

    Bengtsson, Mikael

    2015-01-01

    A turbocharger’s performance is measured in a gas stand in order to provide information of the components characteristics. The measurement procedure is a very time consuming process and it is thus desired to make it more time-efficient. To allow for development of an enhanced control strategy used during the measurements, a 0D model of a gas stand is developed. The physical gas stand components are modeled and validated against measurements, all showing a reasonable result. Turbocharger heat ...

  6. Behavior of an IC Engine Turbocharger in Critical Conditions of Lubrication

    OpenAIRE

    Galindo, José; Serrano Cruz, José Ramón; Dolz Ruiz, Vicente; LÓPEZ HIDALGO, MIGUEL ANDRÉS; Bouffaud, F.

    2013-01-01

    Problems in the turbocharger lubrication system can cause serious deterioration in their overall performance and even their complete destruction. The paper describes several tests with different critical lubrication conditions, in order to determine the thresholds at which the operation may be appropriate. In an IC engine, these problems can be produced mainly by several factors: the decreasing in the supply pressure of the oil, a delay in the lubrication oil pressure and...

  7. Magnetorheological valve based actuator for improvement of passively controlled turbocharger system

    Science.gov (United States)

    Bahiuddin, I.; Mazlan, S. A.; Imaduddin, F.; Ubaidillah, Ichwan, B.

    2016-03-01

    Variable geometry turbochargers have been widely researched to fulfil the current engine stringent regulations. The passively controlled turbocharger (PCT) concept has been proposed to reduce energy consumption by utilizing the emission energy to move the actuator. However, it only covered a small range operating condition. Therefore, a magnetorheological(MR) Valve device, as typical smart material devices to enhance a passive device, is proposed to improve the PCT. Even though the benefits have been considered for the compactness and easiness to connect to an electrical system, the number of publications regarding the MR application within engine system is hard to be found. Therefore, this paper introduces a design of an MR Valve in a turbocharger. The main challenge is to make sure its capability to produce a sufficient total pressure drop. To overcome the challenge, its material properties, shape and pressure drop calculation has been analyzed to fulfil the requirement. Finally, to get a more understanding of actuator performance, the actuator response was simulated by treating the exhaust gas pressure as an input. It shows that the new MR actuator has a potential dynamic to improve the PCT controllability.

  8. Modeling and extrapolating mass flow characteristics of a radial turbocharger turbine

    International Nuclear Information System (INIS)

    Since the turbocharger turbine plays an important role in determining the engine performance, how to model and extrapolate mass flow characteristics of the turbocharger turbine is very important especially when only a narrow range of turbine data is provided by manufacturers. In this paper, a new mass flow model is proposed based on the physical model of a radial turbine simplified as two nozzles in series. With the ideal nozzle flow equation applied on the turbine stator, the mass flow rate through the turbine can be expressed with three fitted coefficients which have clear physical meanings. Existing empirical and partly empirical models of turbine mass flow characteristics are reviewed and compared with the deduced model in the Matlab software. The results show that considering the number of fitted coefficients and the modeling accuracy, the deduced model performs well in regression analyses conducted with experimental data tested from three radial turbines of different sizes. Also interpolating and extrapolating performances of this new model can match the turbine model in the GT-Power commercial software. Thus this new model is sufficiently robust to model and extrapolate mass flow characteristics of the radial turbocharger turbine at off design operating conditions. - Highlights: • A physical based turbine model of mass flow characteristics is proposed. • Existing turbine mass flow models are reviewed and summarized. • Comparative analyses of the deduced model and existing models are conducted. • Interpolating and extrapolating abilities of the deduced model are evaluated

  9. CFD Prediction and Experimental Measurement of Blade Water Coverage in a Diesel Turbocharger

    Directory of Open Access Journals (Sweden)

    Jun Yao

    2012-01-01

    Full Text Available A turbocharger unit for diesel engine is often equipped with a built-in online water washing system and its performance is not always satisfactory because of efficiency declination due to deposit accumulated on blade surfaces not being washed away. In this study, a systematic approach of using experimental measurements and computational fluid dynamics (CFD is adopted to analyse liquid/gas two-phase flow associated with a turbocharger water washing system, in order to understand the underlying flow physics. A medium-sized diesel engine turbocharger configuration is chosen for this purpose. Experiments are focussed on blade surface temperature measurements, while CFD modelling with a coupled Eulerian/Lagrangian method is used for capturing the complex gas/liquid two-phase flow behaviours inside the induction duct and the blade passage. It was found that numerical predictions are in a good agreement with experimental data in terms of temperature distributions of the blade leading edge region and water coverage over the blade ring. Other flow features such as the water droplet trajectories and the particle size distributions are also explored and analysed in further details, and they are useful for understanding the deposit removal mechanism.

  10. Study of the turbocharger shaft motion by means of infrared sensors

    Science.gov (United States)

    Serrano, J. R.; Guardiola, C.; Dolz, V.; López, M. A.; Bouffaud, F.

    2015-05-01

    This work describes a technique for measuring the precession movement of the shaft of small automotive turbochargers. The main novelty is that the technique is based on infrared light diode sensors. With presented technique it is possible to perform secure mounting of electronics and also to measure, with good accuracy, far enough from the turbocharger shaft. Both advantages allow applying it even in critical lubrication conditions and when blade contact occurs. The technique's main difficulties arise from the small size of the turbocharger shaft and the high precession movement in critical conditions. In order to generate the optimum albedo reflection for infrared measurement, a special cylindrical nut with larger diameter than the original one is assembled at the shaft tip in the compressor side. Following, shaft balancing, the calibration of the sensors and the compensation of errors from different sources are needed steps before the method is able to identify the main frequencies of shaft motion. Once synchronous and sub-synchronous frequencies have been obtained it is possible to reconstruct the instantaneous position of the shaft to determine its precession movement.

  11. A nonlinear Kalman filtering approach to embedded control of turbocharged diesel engines

    Science.gov (United States)

    Rigatos, Gerasimos; Siano, Pierluigi; Arsie, Ivan

    2014-10-01

    The development of efficient embedded control for turbocharged Diesel engines, requires the programming of elaborated nonlinear control and filtering methods. To this end, in this paper nonlinear control for turbocharged Diesel engines is developed with the use of Differential flatness theory and the Derivative-free nonlinear Kalman Filter. It is shown that the dynamic model of the turbocharged Diesel engine is differentially flat and admits dynamic feedback linearization. It is also shown that the dynamic model can be written in the linear Brunovsky canonical form for which a state feedback controller can be easily designed. To compensate for modeling errors and external disturbances the Derivative-free nonlinear Kalman Filter is used and redesigned as a disturbance observer. The filter consists of the Kalman Filter recursion on the linearized equivalent of the Diesel engine model and of an inverse transformation based on differential flatness theory which enables to obtain estimates for the state variables of the initial nonlinear model. Once the disturbances variables are identified it is possible to compensate them by including an additional control term in the feedback loop. The efficiency of the proposed control method is tested through simulation experiments.

  12. On the use of first order rotor dynamics in multiblade coordinates. [for compound helicopter

    Science.gov (United States)

    Hohenemser, K. H.; Yin, S. K.

    1974-01-01

    This paper is directed to the question of how to represent most efficiently rotor/body coupling in a linear flight dynamics analysis. Rigid body pitch, roll and vertical motions are considered for the rotor/body coupling studies. Flapping stability limits, eigenvalues, transient responses to control step inputs, to step gusts and to random gusts are determined for a hypothetical hingeless compound helicopter operating up to .8 advance ratio. Data are obtained for the basic helicopter and for the craft with two simple control feedback systems. While complete periodic system modeling is necessary for determining flapping stability limits and vibrations, constant system modeling using first order dynamics in each of the multiblade rotor coordinates was found to be adequate for rotor-craft stability and response computations.

  13. Dynamic Calibration of the NASA Ames Rotor Test Apparatus Steady/Dynamic Rotor Balance

    Science.gov (United States)

    Peterson, Randall L.; vanAken, Johannes M.

    1996-01-01

    The NASA Ames Rotor Test Apparatus was modified to include a Steady/Dynamic Rotor Balance. The dynamic calibration procedures and configurations are discussed. Random excitation was applied at the rotor hub, and vibratory force and moment responses were measured on the steady/dynamic rotor balance. Transfer functions were computed using the load cell data and the vibratory force and moment responses from the rotor balance. Calibration results showing the influence of frequency bandwidth, hub mass, rotor RPM, thrust preload, and dynamic loads through the stationary push rods are presented and discussed.

  14. Darmstadt Rotor No. 2, II: Design of Leaning Rotor Blades

    OpenAIRE

    Jörg Bergner; Dietmar K. Hennecke; Martin Hoeger; Karl Engel

    2003-01-01

    For Darmstadt University of Technology's axial singlestage transonic compressor rig, a new three-dimensional aft-swept rotor was designed and manufactured at MTU Aero Engines in Munich, Germany. The application of carbon fiber–reinforced plastic made it possible to overcome structural constraints and therefore to further increase the amount of lean and sweep of the blade. The aim of the design was to improve the mechanical stability at operation that is close to stall.

  15. Darmstadt Rotor No. 2, II: Design of Leaning Rotor Blades

    Directory of Open Access Journals (Sweden)

    Jörg Bergner

    2003-01-01

    Full Text Available For Darmstadt University of Technology's axial singlestage transonic compressor rig, a new three-dimensional aft-swept rotor was designed and manufactured at MTU Aero Engines in Munich, Germany. The application of carbon fiber–reinforced plastic made it possible to overcome structural constraints and therefore to further increase the amount of lean and sweep of the blade. The aim of the design was to improve the mechanical stability at operation that is close to stall.

  16. Application of system identification to analytic rotor modeling from simulated and wind tunnel dynamic test data, part 2

    Science.gov (United States)

    Hohenemser, K. H.; Banerjee, D.

    1977-01-01

    An introduction to aircraft state and parameter identification methods is presented. A simplified form of the maximum likelihood method is selected to extract analytical aeroelastic rotor models from simulated and dynamic wind tunnel test results for accelerated cyclic pitch stirring excitation. The dynamic inflow characteristics for forward flight conditions from the blade flapping responses without direct inflow measurements were examined. The rotor blades are essentially rigid for inplane bending and for torsion within the frequency range of study, but flexible in out-of-plane bending. Reverse flow effects are considered for high rotor advance ratios. Two inflow models are studied; the first is based on an equivalent blade Lock number, the second is based on a time delayed momentum inflow. In addition to the inflow parameters, basic rotor parameters like the blade natural frequency and the actual blade Lock number are identified together with measurement bias values. The effect of the theoretical dynamic inflow on the rotor eigenvalues is evaluated.

  17. Analytical aeroelastic stability considerations and conversion loads for an XV-15 tilt-rotor in a wind tunnel simulation

    Science.gov (United States)

    Kottapalli, Sesi; Meza, Victor

    1992-01-01

    A rotorcraft analysis is conducted to assess tilt-rotor stability and conversion loads for the XV-15 rotor with metal blades within its specified test envelope. A 38-DOF flutter analysis based on the code by Johnson (1988) is developed to simulate a wind-tunnel test in which the rotor torque is constant and thereby study stability. The same analytical model provides the simulated loads including hub loads, blade loads, and oscillatory pitch-link loads with attention given to the nonuniform inflow through the proprotor in the presence of the wing. Tilt-rotor stability during the cruise mode is found to be sensitive to coupling effects in the control system stiffness, and a stability problem is identified in the XV-15 Advanced Technology Blades. The present analysis demonstrates that the tilt-rotor is stable within the specified test envelope of the NASA 40 x 80-ft wind tunnel.

  18. Computer-aided ultrasonic inspection of steam turbine rotors

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, K.H.; Weber, M.; Weiss, M. [GEC ALSTHOM Energie GmbH, Nuremberg (Germany)

    1998-12-31

    As the output and economic value of power plants increase, the detection and sizing of the type of flaws liable to occur in the rotors of turbines using ultrasonic methods assumes increasing importance. An ultrasonic inspection carried out at considerable expense is expected to bring to light all safety-relevant flaws and to enable their size to be determined so as to permit a fracture-mechanics analysis to assess the reliability of the rotor under all possible stresses arising in operation with a high degree of accuracy. The advanced computer-aided ultrasonic inspection of steam turbine rotors have improved reliability, accuracy and reproducibility of ultrasonic inspection. Further, there has been an improvement in the resolution of resolvable group indications by applying reconstruction and imagine methods. In general, it is also true for the advanced computer-aided ultrasonic inspection methods that, in the case of flaw-affected forgings, automated data acquisition provides a substantial rationalization and a significant documentation of the results for the fracture mechanics assessment compared to manual inspection. (orig.) 8 refs.

  19. Research on the Power Recovery of Diesel Engines with Regulated Two-Stage Turbocharging System at Different Altitudes

    Directory of Open Access Journals (Sweden)

    Hualei Li

    2014-01-01

    Full Text Available Recovering the boost pressure is very important in improving the dynamic performance of diesel engines at high altitudes. A regulated two-stage turbocharging system is an adequate solution for power recovery of diesel engines. In the present study, the change of boost pressure and engine power at different altitudes was investigated, and a regulated two-stage turbocharging system was constructed with an original turbocharger and a matched low pressure turbocharger. The valve control strategies for boost pressure recovery, which formed the basis of the power recovery method, are presented here. The simulation results showed that this system was effective in recovering the boost pressure at different speeds and various altitudes. The turbine bypass valve and compressor bypass valve had different modes to adapt to changes in operating conditions. The boost pressure recovery could not ensure power recovery over the entire operating range of the diesel engine, because of variation in overall turbocharger efficiency. The fuel-injection compensation method along with the valve control strategies for boost pressure recovery was able to reach the power recovery target.

  20. Material sampling for rotor evaluation

    International Nuclear Information System (INIS)

    Decisions regarding continued operation of aging rotating machinery must often be made without adequate knowledge of rotor material conditions. Physical specimens of the material are not generally available due to lack of an appropriate sampling technique or the high cost and inconvenience of obtaining such samples. This is despite the fact that examination of such samples may be critical to effectively assess the degradation of mechanical properties of the components in service or to permit detailed examination of microstructure and surface flaws. Such information permits a reduction in the uncertainty of remaining life estimates for turbine rotors to avoid unnecessarily premature and costly rotor retirement decisions. This paper describes the operation and use of a recently developed material sampling device which machines and recovers an undeformed specimen from the surface of rotor bores or other components for metallurgical analysis. The removal of the thin, wafer-like sample has a negligible effect on the structural integrity of these components, due to the geometry and smooth surface finish of the resulting shallow depression. Samples measuring approximately 0.03 to 0.1 inches (0.76 to 2.5 mm) thick by 0.5 to 1.0 inch (1.3 to 2.5 cm) in diameter can be removed without mechanical deformation or thermal degradation of the sample or the remaining component material. The device is operated remotely from a control console and can be used externally or internally on any surface for which there is at least a three inch (7.6 cm) working clearance. Application of the device in two case studies of turbine-generator evaluations are presented

  1. The fractional symmetric rigid rotor

    OpenAIRE

    Herrmann, Richard

    2006-01-01

    Based on the Riemann fractional derivative the Casimir operators and multipletts for the fractional extension of the rotation group SO(n) are calculated algebraically. The spectrum of the corresponding fractional symmetric rigid rotor is discussed. It is shown, that the rotational, vibrational and $\\gamma$-unstable limits of the standard geometric collective models are particular limits of this spectrum. A comparison with the ground state band spectra of nuclei shows an agreement with experim...

  2. Design of plywood and paper flywheel rotors

    Science.gov (United States)

    Hagen, D. L.

    Technical and economic design factors of cellulosic rotors are compared with conventional materials for stationary flywheel energy storage systems. Wood species, operation in a vacuum, assembly and costs of plywood rotors are evaluated. Wound kraft paper, twine and veneer rotors are examined. Two bulb attachments are designed. Support stiffness is shown to be constrained by the material strength, rotor configuration and speed ratio. Plywood moisture equilibrium during manufacture and assembly is critical. Disk shaping and rotor assembly are described. Potential self-centering dynamic balancing methods and equipment are described. Detailed measurements of the distribution of strengths, densities and specific energy of conventional Finnish Birch plywood and of custom made hexagonal Birch plywood are detailed. High resolution tensile tests were performed while monitoring the acoustic emissions with micoprocessor controlled data acquisition. Preliminary duration of load tests were performed on vacuum dried hexagonal birch plywood. Economics of cellulosic and conventional rotors were examined.

  3. Tone and Broadband Noise Separation from Acoustic Data of a Scale-Model Counter-Rotating Open Rotor

    Science.gov (United States)

    Sree, David; Stephens, David B.

    2014-01-01

    Renewed interest in contra-rotating open rotor technology for aircraft propulsion application has prompted the development of advanced diagnostic tools for better design and improved acoustical performance. In particular, the determination of tonal and broadband components of open rotor acoustic spectra is essential for properly assessing the noise control parameters and also for validating the open rotor noise simulation codes. The technique of phase averaging has been employed to separate the tone and broadband components from a single rotor, but this method does not work for the two-shaft contra-rotating open rotor. A new signal processing technique was recently developed to process the contra-rotating open rotor acoustic data. The technique was first tested using acoustic data taken of a hobby aircraft open rotor propeller, and reported previously. The intent of the present work is to verify and validate the applicability of the new technique to a realistic one-fifth scale open rotor model which has 12 forward and 10 aft contra-rotating blades operating at realistic forward flight Mach numbers and tip speeds. The results and discussions of that study are presented in this paper.

  4. Tone and Broadband Noise Separation from Acoustic Data of a Scale-Model Contra-Rotating Open Rotor

    Science.gov (United States)

    Sree, Dave; Stephens, David B.

    2014-01-01

    Renewed interest in contra-rotating open rotor technology for aircraft propulsion application has prompted the development of advanced diagnostic tools for better design and improved acoustical performance. In particular, the determination of tonal and broadband components of open rotor acoustic spectra is essential for properly assessing the noise control parameters and also for validating the open rotor noise simulation codes. The technique of phase averaging has been employed to separate the tone and broadband components from a single rotor, but this method does not work for the two-shaft contra-rotating open rotor. A new signal processing technique was recently developed to process the contra-rotating open rotor acoustic data. The technique was first tested using acoustic data taken of a hobby aircraft open rotor propeller, and reported previously. The intent of the present work is to verify and validate the applicability of the new technique to a realistic one-fifth scale open rotor model which has 12 forward and 10 aft contra-rotating blades operating at realistic forward flight Mach numbers and tip speeds. The results and discussions of that study are presented in this paper.

  5. Vibration Analysis of Hollow Tapered Shaft Rotor

    OpenAIRE

    P. M. G. Bashir Asdaque; Behera, R. K.

    2014-01-01

    Shafts or circular cross-section beams are important parts of rotating systems and their geometries play important role in rotor dynamics. Hollow tapered shaft rotors with uniform thickness and uniform bore are considered. Critical speeds or whirling frequency conditions are computed using transfer matrix method and then the results were compared using finite element method. For particular shaft lengths and rotating speeds, response of the hollow tapered shaft-rotor system is determined for t...

  6. The Dynamics of Rotor with Rubbing

    OpenAIRE

    Jerzy T. Sawicki; Joe Padovan; Rabih Al-Khatib

    1999-01-01

    This paper presents the description of some phenomena associated with dynamic behavior of rotors interacting with stationary components. Numerical simulations show rotor vibration spectrum rich in subharmonic, quasi-periodic, and chaotic vibrations. The nonlinear calculation techniques are applied to demonstrate the changes of the vibration patterns for different operating conditions. Some conclusions are discussed with regard to unique characteristics of rub-induced rotor response, initial c...

  7. Rotor fatigue monitoring data acquisition system

    Science.gov (United States)

    Smith, Scott M.

    1993-01-01

    The 40 by 80 Foot Wind Tunnel of the National Full Scale Aerodynamics Complex (NFAC) had a requirement to monitor rotor fatigue during a test. This test subjected various rotor components to stress levels higher than their structural fatigue limits. A data acquisition system was developed to monitor the cumulative fatigue damage of rotor components using National Instruments hardware and LabVIEW software. A full description of the data acquisition system including its configuration and salient features, is presented in this paper.

  8. Optimization of wind turbine rotors

    Energy Technology Data Exchange (ETDEWEB)

    Nygaard, Tor Anders

    1999-07-01

    The Constrained Steepest Descent method has been applied to the optimization of wind turbine rotors through the development of a numerical model. The model consists of an optimization kernel, an aerodynamic model, a structural dynamic model of a rotating beam, and a cost model for the wind turbine. The cost of energy is minimized directly by varying the blade design, the rotational speed and the resulting design of the drive-train and tower. The aerodynamic model is a combination of a fast engineering model based on strip-theory and two and three-dimensional Euler solvers. The two-dimensional Euler solver is used for generation of pre-stall airfoil data. Comparisons with experimental data verify that the engineering model effectively approximates non-stalled flow, except at the blade tip. The three-dimensional Euler solver is in good agreement with the experimental data at the tip, and is therefore a useful supplement for corrections of the tip-loss model, and evaluation of an optimized design. The structural dynamic model evaluates stresses and deformations for the blade. It is based on constitutive relations for a slender beam that are solved with the equations of motions using a finite-difference method. The cost model evaluates the design change of the wind turbine and the resulting costs that occur when a change in blade design modifies the blade mass and the overall forces. The cost model is based on engineering design rules for the drive-train and tower. The model was applied using a Danish 600 kW wind turbine as a reference. Two rotors were optimized using traditional NACA airfoils and a new low-lift airfoil family developed specifically for wind turbine purposes. The cost of energy decreased four percent for the NACA rotor, and seven percent for the low-lift rotor. Optimizations with a high number of degrees of freedom show that a designer has considerable flexibility in choosing some primary parameters such as rated power and rotor diameter, if the rest

  9. Unsteady Flow Variability Driven by Rotor-stator Interaction at Rotor Exit

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ben; YANG Ce; CHEN Shan; QI Mingxu; ZHOU Mi

    2012-01-01

    Numerical investigation of the unsteady flow variability driven by rotor-stator interaction in a transonic axial compressor is performed.Two models with close and far axial gap between rotor and stator rows are studied in the simulation.Particular attention is attached to the analysis of mechanisms involved in driving rotor wake oscillation,rotor wake skewing and flow angle fluctuation at rotor exit.The results show that smaller axial gap is favorable to enhance the interaction in the region between two adjacent rows,and the fluctuation of the static pressure difference between two sides of rotor wake is improved by potential field from down stator,which is the driving force for rotor wake oscillation.The interaction between rotor and stator is weakened by increasing axial distance,rotor wake shifts to suction side of rotor blade with 5%-10% of rotor pitch,the absolute value of flow angle at rotor exit is less than that in the case of close interspace for every time step,and the fluctuation amplitude is also decreased.

  10. Bifurcation analysis of a preloaded Jeffcott rotor

    International Nuclear Information System (INIS)

    A model of two-degrees-of-freedom Jeffcott rotor system with bearing clearance subjected of an out-of-balance excitation is considered. The influence of preloading and viscous damping of the snubber ring is introduced in the mathematical description. A programme of numerical simulations is conducted to show how the preloading and viscous damping change the dynamics of the rotor system. Bifurcation diagrams and Lyapunov exponents are constructed to explore stability. It is shown that dynamics of the rotor system can be effectively controlled by varying the preloading and the damping both of the rotor and the snubber ring. In the most considered cases preloading stabilises the dynamic responses

  11. Bifurcation analysis of a preloaded Jeffcott rotor

    Energy Technology Data Exchange (ETDEWEB)

    Karpenko, Evgueni V.; Pavlovskaia, Ekaterina E.; Wiercigroch, Marian E-mail: m.wiercigroch@eng.abdn.ac.uk

    2003-01-01

    A model of two-degrees-of-freedom Jeffcott rotor system with bearing clearance subjected of an out-of-balance excitation is considered. The influence of preloading and viscous damping of the snubber ring is introduced in the mathematical description. A programme of numerical simulations is conducted to show how the preloading and viscous damping change the dynamics of the rotor system. Bifurcation diagrams and Lyapunov exponents are constructed to explore stability. It is shown that dynamics of the rotor system can be effectively controlled by varying the preloading and the damping both of the rotor and the snubber ring. In the most considered cases preloading stabilises the dynamic responses.

  12. Energy from Swastika-Shaped Rotors

    Directory of Open Access Journals (Sweden)

    McCulloch M. E.

    2015-04-01

    Full Text Available It is suggested here that a swastika-shaped rotor exposed to waves will rotate in the di- rection its arms are pointing (towards the arm-tips due to a sheltering effect. A formula is derived to predict the motion obtainable from swastika rotors of different sizes given the ocean wave height and phase speed and it is suggested that the rotor could provide a new, simpler method of wave energy generation. It is also proposed that the swastika rotor could generate energy on a smaller scale from sound waves and Brownian motion, and potentially the zero point field.

  13. Concepts for a theoretical and experimental study of lifting rotor random loads and vibrations (the effects of some rotor feedback systems on rotor-body dynamics), Phase 7-A

    Science.gov (United States)

    Hohenemser, K. H.; Yin, S. K.

    1973-01-01

    The effects of three gyroless rotor feedback systems: (1) coning feedback, (2) proportional tilting feedback, and (3) a combination of these on the rotor-body dynamics of hingeless rotorcraft are studied with a simplified analytical model in the advance ratio range from 0 to .8. Combinations of feedback phase angles and control phase angles are selected to minimize control cross coupling and control sensitivity changes between low and high speed flight. For the feedback systems thus selected the effects of feedback gain and control actuator time lag on the stability both with fixed hub and in free flight is studied, whereby the rotorcraft is free in pitch, roll and vertical motion but otherwise restrained. For the free flight is studied, whereby the rotorcraft is free in pitch, roll and vertical motion but otherwise restrained. For the free flight conditions the effects of a horizontal tail are also determined in itself and in combination with the rotor feedback systems.

  14. Aerodynamic and acoustic integral characteristics of porous rotors

    OpenAIRE

    Benedik, Gašper; Eberlinc, Matjaž; Hočevar, Marko; Širok, Brane

    2015-01-01

    This paper describes porous rotors manufactured from open cell aluminium foam. Rotor construction and theoretical description of fluid flow through rotating porous material are presented. Nine porous rotors made of materials with three different average pore sizes, with or without inducer, three rotor heights and two inlet diameters were selected and compared to a classical rotor with blades. Measurements involved two parts, measurement of pressure drop on non-rotating rotors while integral f...

  15. Orienting coupled quantum rotors by ultrashort laser pulses

    OpenAIRE

    Shima, Hiroyuki; Nakayama, Tsuneyoshi

    2004-01-01

    We point out that the non-adiabatic orientation of quantum rotors, produced by ultrashort laser pulses, is remarkably enhanced by introducing dipolar interaction between the rotors. This enhanced orientation of quantum rotors is in contrast with the behavior of classical paired rotors, in which dipolar interactions prevent the orientation of the rotors. We demonstrate also that a specially designed sequence of pulses can most efficiently enhances the orientation of quantum paired rotors.

  16. Cooperative Self-Propulsion of Active and Passive Rotors

    OpenAIRE

    Fily, Yaouen; Baskaran, Aparna; Marchetti, M. Cristina

    2011-01-01

    Using minimal models for low Reynolds number passive and active rotors in a fluid, we characterize the hydrodynamic interactions among rotors and the resulting dynamics of a pair of interacting rotors. This allows us to treat in a common framework passive or externally driven rotors, such as magnetic colloids driven by a rotating magnetic field, and active or internally driven rotors, such as sperm cells confined at boundaries. The hydrodynamic interaction of passive rotors is known to contai...

  17. Orienting coupled quantum rotors by ultrashort laser pulses

    OpenAIRE

    Shima, Hiroyuki; Nakayama, Tsuneyoshi

    2004-01-01

    We pointed out that the nonadiabatic orientation of quantum rotors, produced by ultrashort laser pulses, is remarkably enhanced by introducing dipolar interaction between the rotors. This enhanced orientation of quantum rotors is in contrast with the behavior of classical paired rotors, in which dipolar interactions prevent the orientation of the rotors. We demonstrate also that a specially designed sequence of pulses can most efficiently enhance the orientation of quantum paired rotors.

  18. Darmstadt Rotor No. 2, II: Design of Leaning Rotor Blades

    OpenAIRE

    Bergner J.; Hennecke K. D.; Hoeger M.; Engel K.

    2003-01-01

    For Darmstadt University of Technology's axial singlestage transonic compressor rig, a new three-dimensional aft-swept rotor was designed and manufactured at MTU Aero Engines in Munich, Germany. The application of carbon fiber–reinforced plastic made it possible to overcome structural constraints and therefore to further increase the amount of lean and sweep of the blade. The aim of the design was to improve the mechanical stability at operation that is close to stall.To avoid the hazard of r...

  19. Open Rotor Tone Shielding Methods for System Noise Assessments Using Multiple Databases

    Science.gov (United States)

    Bahr, Christopher J.; Thomas, Russell H.; Lopes, Leonard V.; Burley, Casey L.; Van Zante, Dale E.

    2014-01-01

    Advanced aircraft designs such as the hybrid wing body, in conjunction with open rotor engines, may allow for significant improvements in the environmental impact of aviation. System noise assessments allow for the prediction of the aircraft noise of such designs while they are still in the conceptual phase. Due to significant requirements of computational methods, these predictions still rely on experimental data to account for the interaction of the open rotor tones with the hybrid wing body airframe. Recently, multiple aircraft system noise assessments have been conducted for hybrid wing body designs with open rotor engines. These assessments utilized measured benchmark data from a Propulsion Airframe Aeroacoustic interaction effects test. The measured data demonstrated airframe shielding of open rotor tonal and broadband noise with legacy F7/A7 open rotor blades. Two methods are proposed for improving the use of these data on general open rotor designs in a system noise assessment. The first, direct difference, is a simple octave band subtraction which does not account for tone distribution within the rotor acoustic signal. The second, tone matching, is a higher-fidelity process incorporating additional physical aspects of the problem, where isolated rotor tones are matched by their directivity to determine tone-by-tone shielding. A case study is conducted with the two methods to assess how well each reproduces the measured data and identify the merits of each. Both methods perform similarly for system level results and successfully approach the experimental data for the case study. The tone matching method provides additional tools for assessing the quality of the match to the data set. Additionally, a potential path to improve the tone matching method is provided.

  20. A study of autogiro rotor-blade oscillations in the plane of the rotor disk

    Science.gov (United States)

    Wheatley, John B

    1936-01-01

    An analysis of the factors governing the oscillation of an autogiro rotor blade in the plane of the rotor disk showed that the contribution of the air forces to the resultant motion was small and that the oscillation is essentially a direct effect of the rotor-blade flapping motion. A comparison of calculated oscillations with those measured in flight on three different rotors disclosed that the calculations gave satisfactory agreement with experiment. The calculated air forces on the rotor blade appear to be larger than the experimental ones, but this discrepancy can be attributed to the deficiencies in the strip analysis.

  1. Analysis of ignition behavior in a turbocharged direct injection dual fuel engine using propane and methane as primary fuels

    Energy Technology Data Exchange (ETDEWEB)

    Polk, A. C.; Gibson, C. M.; Shoemaker, N. T.; Srinivasan, K. K.; Krishnan, S. R.

    2011-10-05

    This paper presents experimental analyses of the ignition delay (ID) behavior for diesel-ignited propane and diesel-ignited methane dual fuel combustion. Two sets of experiments were performed at a constant speed (1800 rev/min) using a 4-cylinder direct injection diesel engine with the stock ECU and a wastegated turbocharger. First, the effects of fuel-air equivalence ratios (Ω pilot ∼ 0.2-0.6 and Ω overall ∼ 0.2-0.9) on IDs were quantified. Second, the effects of gaseous fuel percent energy substitution (PES) and brake mean effective pressure (BMEP) (from 2.5 to 10 bar) on IDs were investigated. With constant Ω pilot (> 0.5), increasing Ω overall with propane initially decreased ID but eventually led to premature propane autoignition; however, the corresponding effects with methane were relatively minor. Cyclic variations in the start of combustion (SOC) increased with increasing Ω overall (at constant Ω pilot), more significantly for propane than for methane. With increasing PES at constant BMEP, the ID showed a nonlinear (initially increasing and later decreasing) trend at low BMEPs for propane but a linearly decreasing trend at high BMEPs. For methane, increasing PES only increased IDs at all BMEPs. At low BMEPs, increasing PES led to significantly higher cyclic SOC variations and SOC advancement for both propane and methane. Finally, the engine ignition delay (EID) was also shown to be a useful metric to understand the influence of ID on dual fuel combustion.

  2. Super-knock Suppression Using Split Injection in a Turbo-Charged GDI Engine

    Directory of Open Access Journals (Sweden)

    Lv Meng

    2016-01-01

    Full Text Available Super-knock, which occurs under low-speed and big load operate condition in turbo-charged gasoline direct injection (TGDI engine, is an abnormal combustion phenomenon. Due to its potential to cause degradation of the engine, super knock has become the main obstacle for increasing specific power and lowing fuel consumption of engine. In order to investigate suppress strategies of super-knock, split injection is applied on a high boosted GDI engine. The results shows that: super knock correlates to some extent with split injection; further study shows that appropriate split injection duty ratio and the end of second injection time could reduce super knock effectively.

  3. Computation of the Matching Performance of Diesel Engine with Variable Geometry Turbocharger

    Institute of Scientific and Technical Information of China (English)

    SHI Xin; MA Chao-chen

    2006-01-01

    To compute the matching performance of diesel engine with variable geometry turbocharger(VGT), the formerly used program is improved through adjustment of turbine mass flow rate and efficiency characteristics. The calculation result is applied to forecast the performance of J6110Z diesel engine with rotary-vaned VGT70, and to guide the improvement of engine fuel supply. The computed engine performance curve coincides with the experiment result well: the low-speed torque, fuel economy, exhaust temperature and boost pressure of the VGT engine are all improved.

  4. Air mass flow estimation in turbocharged diesel engines from in-cylinder pressure measurement

    Energy Technology Data Exchange (ETDEWEB)

    Desantes, J.M.; Galindo, J.; Guardiola, C.; Dolz, V. [CMT - Motores Termicos, Universidad Politecnica de Valencia (Spain)

    2010-01-15

    Air mass flow determination is needed for the control of current internal combustion engines. Current methods are based on specific sensors (as hot wire anemometers) or indirect estimation through manifold pressure. With the availability of cylinder pressure sensors for engine control, methods based on them can be used for replacing or complementing standard methods. Present paper uses in cylinder pressure increase during the intake stroke for inferring the trapped air mass. The method is validated on two different turbocharged diesel engines and compared with the standard methods. (author)

  5. Evaluation of Performance and Emission characteristics of Turbocharged Diesel Engine with Mullite as Thermal Barrier Coating

    OpenAIRE

    P. N. Shrirao; A. N. Pawar

    2011-01-01

    Tests were performed on a single cylinder, four stroke, direct injection, diesel engine whose piston crown, cylinder head and valves were coated with a 0.5 mm thickness of 3Al2O3 .2SiO2 (mullite) (Al2O3= 60%, SiO2= 40%) over a 150 μm thickness of NiCrAlY bond coat. Tests were carried out on standard engine (uncoated) and low heatrejection (LHR) engine with and without turbocharger. This paper is intended to emphasis on energy balance and emission characteristic for standard engine (uncoated) ...

  6. Application of feal intermetallic phase matrix based alloys in the turbine components of a turbocharger

    OpenAIRE

    J. Cebulski

    2015-01-01

    This paper presents a possible application of the state-of-the-art alloys based on the FeAl intermetallic phases as materials for the manufacture of heat-proof turbine components in an automobile turbocharger. The research was aimed at determining the resistance to corrosion of Fe40Al5CrTiB alloy in a gaseous environment containing 9 % O2 + 0,2 % HCl + 0,08 % SO2 + N2. First the kinetics of corrosion processes for the considered alloy were determined at the temperatures of 900 °C, 1 000 °C an...

  7. Study on rotational frequency noise in a centrifugal compressor for automobile turbochargers

    Science.gov (United States)

    Wakaki, Daichi; Sakuka, Yuta; Yamasaki, Nobuhiko; Yamagata, Akihiro

    2014-02-01

    The rotational frequency noise (also known as the pulsation noise) due to the mistuning of impeller blade rows introduced at the manufacturing stage of the impellers is observed in the small-sized centrifugal compressor for automobile turbochargers. The present paper addresses the elucidation of the generating mechanism and parameter dependency such as the kind and degree of mistuning. In order to analyze numerically the rotational frequency noise due to mistuning, the unsteady computational fluid dynamics (CFD) of the whole compressor including volute is executed, and the resultant time history of the pressure is fed into the spectral analysis.

  8. ERA's Open Rotor Studies Including Shielding for Noise Reduction

    Science.gov (United States)

    Van Zante, Dale; Thomas, Russell

    2012-01-01

    The Open Rotor is a modern version of the UnDucted Fan (UDF) that was flight tested in the late 1980's through a partnership between NASA and General Electric (GE). Tests were conducted in the 9' x 15' Low Speed Wind Tunnel and the 8' x 6' Supersonic Wind Tunnel starting in late 2009 and completed in early 2012. Aerodynamic and acoustic data were obtained for takeoff, approach and cruise simulations. GE was the primary partner, but other organizations were involved such as Boeing and Airbus who provided additional hardware for fuselage simulations. This test campaign provided the acoustic and performance characteristics for modern open rotor blades designs." NASA and GE conducted joint systems analysis to evaluate how well new blade designs would perform on a B737 class aircraft, and compared the results to an advanced higher bypass ratio turbofan." Acoustic shielding experiments were performed at NASA GRC and Boeing LSAF facilities to provide data for noise estimates of unconventional aircraft configurations with Open Rotor propulsion systems." The work was sponsored by NASA's aeronautics programs, including the Subsonic Fixed Wing (SFW) and the Environmentally Responsible Aviation (ERA) projects."

  9. Multiple piece turbine rotor blade

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Russell B; Fedock, John A

    2013-05-21

    A multiple piece turbine rotor blade with a shell having an airfoil shape and secured between a spar and a platform with the spar including a tip end piece. a snap ring fits around the spar and abuts against the spar tip end piece on a top side and abuts against a shell on the bottom side so that the centrifugal loads from the shell is passed through the snap ring and into the spar and not through a tip cap dovetail slot and projection structure.

  10. Nonlinear Analysis Of Rotor Dynamics

    Science.gov (United States)

    Day, William B.; Zalik, Richard

    1988-01-01

    Study explores analytical consequences of nonlinear Jeffcott equations of rotor dynamics. Section 1: Summary of previous studies. Section 2: Jeffcott Equations. Section 3: Proves two theorems that provide inequalities on coefficients of differential equations and magnitude of forcing function in absence of side force. Section 4: Numerical investigation of multiple-forcing-function problem by introducing both side force and mass imbalance. Section 5: Examples of numberical solutions of complex generalized Jeffcott equation with two forcing functions of different frequencies f1 and f2. Section 6: Boundedness and stability of solutions.Section 7: Concludes report reviewing analytical results and significance.

  11. Innovative multi rotor wind turbine designs

    Energy Technology Data Exchange (ETDEWEB)

    Kale, S.A.; Sapali, S.N. [College of Engineering. Mechanical Engineering Dept, Pune (India)

    2012-07-01

    Among the renewable energy sources, today wind energy is the most recognized and cost effective. Developers and researchers in this sector are optimistic and continuously working innovatively to improve the technology. The wind power obtained is proportional to the swept area of wind turbine. The swept area is increased by using a single rotor of large diameter or multi rotors in array. The rotor size is growing continuously with mature technology. Multi rotor technology has a long history and the multi rotor concept persists in a variety of modern innovative systems but the concept has fallen out of consideration in mainstream design from the perception that is complex and unnecessary as very large single rotor units are now technically feasible. This work addresses the evaluation of different multi rotor wind turbine systems. These innovative wind turbines are evaluated on the basis of feasibility, technological advantages, security of expected power performance, cost, reliability, impact of innovative system, comparison with existing wind turbine design. The findings of this work will provide guidelines for the practical and economical ways for further research on the multi rotor wind turbines. (Author)

  12. Blood Pump Having a Magnetically Suspended Rotor

    Science.gov (United States)

    Antaki, James F. (Inventor); Paden, Bradley (Inventor); Burgreen, Gregory (Inventor); Groom, Nelson J. (Inventor)

    2002-01-01

    A blood pump preferably has a magnetically suspended rotor that rotates within a housing. The rotor may rotate about a stator disposed within the housing. Radial magnetic bearings may be defined within the stator and the rotor in order to suspend the rotor. The radial magnetic bearings may be passive magnetic bearings that include permanent magnets disposed within the stator and the rotor or active magnetic bearings. The pump may further include an axial magnetic bearing that may be either a passive or an active magnetic bearing. A motor that drives the rotor may be disposed within the housing in order to more easily dissipate heat generated by the motor. A primary flow path is defined between the rotor and the stator, and a secondary flow path is defined between the stator and the rotor. Preferably, a substantial majority of blood passes through the primary flow path. The secondary flow path is large enough so that it provides adequate flushing of the secondary flow path while being small enough to permit efficient operation of the radial magnet bearings across the secondary flow path.

  13. Computational Analysis of Multi-Rotor Flows

    Science.gov (United States)

    Yoon, Seokkwan; Lee, Henry C.; Pulliam, Thomas H.

    2016-01-01

    Interactional aerodynamics of multi-rotor flows has been studied for a quadcopter representing a generic quad tilt-rotor aircraft in hover. The objective of the present study is to investigate the effects of the separation distances between rotors, and also fuselage and wings on the performance and efficiency of multirotor systems. Three-dimensional unsteady Navier-Stokes equations are solved using a spatially 5th order accurate scheme, dual-time stepping, and the Detached Eddy Simulation turbulence model. The results show that the separation distances as well as the wings have significant effects on the vertical forces of quadroror systems in hover. Understanding interactions in multi-rotor flows would help improve the design of next generation multi-rotor drones.

  14. Open Rotor - Analysis of Diagnostic Data

    Science.gov (United States)

    Envia, Edmane

    2011-01-01

    NASA is researching open rotor propulsion as part of its technology research and development plan for addressing the subsonic transport aircraft noise, emission and fuel burn goals. The low-speed wind tunnel test for investigating the aerodynamic and acoustic performance of a benchmark blade set at the approach and takeoff conditions has recently concluded. A high-speed wind tunnel diagnostic test campaign has begun to investigate the performance of this benchmark open rotor blade set at the cruise condition. Databases from both speed regimes will comprise a comprehensive collection of benchmark open rotor data for use in assessing/validating aerodynamic and noise prediction tools (component & system level) as well as providing insights into the physics of open rotors to help guide the development of quieter open rotors.

  15. Substantially parallel flux uncluttered rotor machines

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, John S.

    2012-12-11

    A permanent magnet-less and brushless synchronous system includes a stator that generates a magnetic rotating field when sourced by polyphase alternating currents. An uncluttered rotor is positioned within the magnetic rotating field and is spaced apart from the stator. An excitation core is spaced apart from the stator and the uncluttered rotor and magnetically couples the uncluttered rotor. The brushless excitation source generates a magnet torque by inducing magnetic poles near an outer peripheral surface of the uncluttered rotor, and the stator currents also generate a reluctance torque by a reaction of the difference between the direct and quadrature magnetic paths of the uncluttered rotor. The system can be used either as a motor or a generator

  16. Auto-ignition control in turbocharged internal combustion engines operating with gaseous fuels

    International Nuclear Information System (INIS)

    Control strategies for auto-ignition control in turbocharged internal combustion engines operating with gaseous fuels are presented. Ambient temperature and ambient pressure are considered as the disturbing variables. A thermodynamic model for predicting temperature at the ignition point is developed, adjusted and validated with a large experimental data-set from high power turbocharged engines. Based on this model, the performance of feedback and feedforward auto-ignition control strategies is explored. A robustness and fragility analysis for the Feedback control strategies is presented. The feedforward control strategy showed the best performance however its implementation entails adding a sensor and new control logic. The proposed control strategies and the proposed thermodynamic model are useful tools for increasing the range of application of gaseous fuels with low methane number while ensuring a safe running in internal combustion engines. - Highlights: • A model for predicting temperature at the ignition point. • Robust PID, modified PID, and feedforward strategies for auto-ignition control. • λ′ were the best set of tuning equations for calculating controller parameters. • Robust PID showed significant improvements in auto-ignition control. • Feedforward control showed the best performance

  17. Flatness-based embedded adaptive fuzzy control of turbocharged diesel engines

    Science.gov (United States)

    Rigatos, Gerasimos; Siano, Pierluigi; Arsie, Ivan

    2014-10-01

    In this paper nonlinear embedded control for turbocharged Diesel engines is developed with the use of Differential flatness theory and adaptive fuzzy control. It is shown that the dynamic model of the turbocharged Diesel engine is differentially flat and admits dynamic feedback linearization. It is also shown that the dynamic model can be written in the linear Brunovsky canonical form for which a state feedback controller can be easily designed. To compensate for modeling errors and external disturbances an adaptive fuzzy control scheme is implemanted making use of the transformed dynamical system of the diesel engine that is obtained through the application of differential flatness theory. Since only the system's output is measurable the complete state vector has to be reconstructed with the use of a state observer. It is shown that a suitable learning law can be defined for neuro-fuzzy approximators, which are part of the controller, so as to preserve the closed-loop system stability. With the use of Lyapunov stability analysis it is proven that the proposed observer-based adaptive fuzzy control scheme results in H∞ tracking performance.

  18. Analysis of Two Stroke Marine Diesel Engine Operation Including Turbocharger Cut-Out by Using a Zero-Dimensional Model

    Directory of Open Access Journals (Sweden)

    Cong Guan

    2015-06-01

    Full Text Available In this article, the operation of a large two-stroke marine diesel engine including various cases with turbocharger cut-out was thoroughly investigated by using a modular zero-dimensional engine model built in MATLAB/Simulink environment. The model was developed by using as a basis an in-house modular mean value engine model, in which the existing cylinder block was replaced by a more detailed one that is capable of representing the scavenging ports-cylinder-exhaust valve processes. Simulation of the engine operation at steady state conditions was performed and the derived engine performance parameters were compared with the respective values obtained by the engine shop trials. The investigation of engine operation under turbocharger cut-out conditions in the region from 10% to 50% load was carried out and the influence of turbocharger cut-out on engine performance including the in-cylinder parameters was comprehensively studied. The recommended schedule for the combination of the turbocharger cut-out and blower activation was discussed for the engine operation under part load conditions. Finally, the influence of engine operating strategies on the annual fuel savings, CO2 emissions reduction and blower operating hours for a Panamax container ship operating at slow steaming conditions is presented and discussed.

  19. 1-dimensional simulation of the radial compressor of a waste gas turbocharger; 1-dimensionale Simulation des Radialverdichters eines Abgasturboladers

    Energy Technology Data Exchange (ETDEWEB)

    Marques Gomes, Andre; Schmidt, Sebastian; Neumann, Jens [BMW Group, Muenchen (Germany)

    2011-07-01

    The simulation fo the thermodynamical properties of turbochargers in IC engines is mostly done with 1D gas exchange simulation tools, in which the turbocharger is represented by maps, or with 3D-CFD tools, in which a more precise geometrical detail of the charger can be considered. The present work aims for a modeling depth which lies between these 2 variants. This approach (''1D gas exchange simulation with 1D modeling of the turbocharger'') is not only motivated by enabling a better interaction, when compared to the map-based approach, between an IC engine and the turbocharger, but by distinctly reducing the modeling efforts and computing time when compared to the 3D-CFD approach. Within the study, a coarsely discretized model of a centrifugal compressor is built using only the model library of the commercial software GT-Power. For the validation regarding total pressure ratio and isentropic efficiency, the results of the stationary simulations of two different compressors are compared to CFD and measurement results. Differences can be seen only close to the choking limit of the compressor. The model was further used to demonstrate its applicability in extrapolated regions of the compressor map and in the instable operating range near the surge limit. (orig.)

  20. 废气涡轮增压器故障诊断浅谈%Fault Diagnosis of Exhaust Gas Turbochargers

    Institute of Scientific and Technical Information of China (English)

    谷伟

    2014-01-01

    废气涡轮增压器被广泛应用于采油平台发电机组中。描述了废气涡轮增压器的构造、原理及作用,提出采用正确的使用和保养方法。针对影响增压器使用寿命因素加以诊断分析,并说明使用中的注意事项,意在减少增压器故障,延长其使用寿命,降低维护费用。%Exhaust gas turbochargers are widely applied in the generator sets of oil platforms. In the paper,the struc-ture,principle and functions of gas turbochargers were described and proper usage and maintenance methods were proposed. Moreover,factors affecting the service life of the turbochargers were diagnosed and analyzed and precau-tions were explained,aiming to reduce turbocharger failures,prolong their service life and reduce maintenance costs.

  1. Stability of Rotor Systems: A Complex Modelling Approach

    DEFF Research Database (Denmark)

    Kliem, Wolfhard; Pommer, Christian; Stoustrup, Jakob

    1996-01-01

    with the results of the classical approach using Rayleighquotients. Several rotor systems are tested: a simple Laval rotor, a Laval rotor with additional elasticity and damping in thr bearings, and a number of rotor systems with complex symmetric 4x4 randomly generated matrices....

  2. 14 CFR 27.1461 - Equipment containing high energy rotors.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Equipment containing high energy rotors. 27... Equipment containing high energy rotors. (a) Equipment containing high energy rotors must meet paragraph (b), (c), or (d) of this section. (b) High energy rotors contained in equipment must be able to...

  3. 14 CFR 29.1461 - Equipment containing high energy rotors.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Equipment containing high energy rotors. 29... § 29.1461 Equipment containing high energy rotors. (a) Equipment containing high energy rotors must meet paragraph (b), (c), or (d) of this section. (b) High energy rotors contained in equipment must...

  4. 14 CFR 25.1461 - Equipment containing high energy rotors.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Equipment containing high energy rotors. 25... § 25.1461 Equipment containing high energy rotors. (a) Equipment containing high energy rotors must meet paragraph (b), (c), or (d) of this section. (b) High energy rotors contained in equipment must...

  5. 14 CFR 27.661 - Rotor blade clearance.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor blade clearance. 27.661 Section 27... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Rotors § 27.661 Rotor blade clearance. There must be enough clearance between the rotor blades and other parts of the structure...

  6. 14 CFR 29.411 - Ground clearance: tail rotor guard.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground clearance: tail rotor guard. 29.411... System Loads § 29.411 Ground clearance: tail rotor guard. (a) It must be impossible for the tail rotor to contact the landing surface during a normal landing. (b) If a tail rotor guard is required to...

  7. 14 CFR 29.547 - Main and tail rotor structure.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main and tail rotor structure. 29.547... Requirements § 29.547 Main and tail rotor structure. (a) A rotor is an assembly of rotating components, which includes the rotor hub, blades, blade dampers, the pitch control mechanisms, and all other parts...

  8. 14 CFR 29.661 - Rotor blade clearance.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor blade clearance. 29.661 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Rotors § 29.661 Rotor blade clearance. There must be enough clearance between the rotor blades and other parts of the structure...

  9. 14 CFR 27.411 - Ground clearance: tail rotor guard.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground clearance: tail rotor guard. 27.411... System Loads § 27.411 Ground clearance: tail rotor guard. (a) It must be impossible for the tail rotor to contact the landing surface during a normal landing. (b) If a tail rotor guard is required to...

  10. 14 CFR 27.547 - Main rotor structure.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main rotor structure. 27.547 Section 27.547... structure. (a) Each main rotor assembly (including rotor hubs and blades) must be designed as prescribed in this section. (b) (c) The main rotor structure must be designed to withstand the following...

  11. State of the art and prospectives of smart rotor control for wind turbines

    Science.gov (United States)

    Barlas, T. K.; van Kuik, G. A. M.

    2007-07-01

    The continued reduction in cost of energy of wind turbines, especially with the increasingly upscaling of the rotor, will require contribution from technology advances in many areas. Reducing loads on the rotor can offer great reduction to the total cost of wind turbines. With the increasing size of wind turbine blades, the need for more sophisticated load control techniques has induced the interest for locally distributed aerodynamic control systems with built-in intelligence on the blades. Such concepts are often named in popular terms "smart structures" or "smart rotor control". This paper focuses on research regarding active rotor control and smart structures for load reduction. It presents an overview of available knowledge and future concepts on the application of active aerodynamic control and smart structures for wind turbine applications. The goal of the paper is to provide a perspective on the current status and future directions of the specific area of research. It comprises a novel attempt to summarize and analyze possible advanced control systems for future wind turbines. The overview builds on existing research on helicopter rotors and expands similar concepts for wind turbine applications, based on ongoing research in the field. Research work has been analyzed through UPWIND project's work package on Smart Rotor Blades and Rotor Control. First, the specifications of unsteady loads, the state of the art of modern control for load reduction and the need for more advanced and detailed active aerodynamic control are analyzed. Also, overview of available knowledge in application of active aerodynamic control on rotating blades, from helicopter research, is provided. Concepts, methods, and achieved results are presented. Furthermore, R&D so far and up-to-date ongoing progress of similar applications for wind turbines are presented. Feasibility studies for wind turbine applications, preliminary performance evaluation and novel computational and experimental

  12. Cyclic Control Optimization for a Smart Rotor

    DEFF Research Database (Denmark)

    Bergami, Leonardo; Henriksen, Lars Christian

    2012-01-01

    The paper presents a method to determine cyclic control trajectories for a smart rotor undergoing periodic-deterministic load variations. The control trajectories result from a constrained optimization problem, where the cost function to minimize is given by the variation of the blade root flapwise...... bending moment within a rotor revolution. The method is applied to a rotor equipped with trailing edge flaps, and capable of individual blade pitching. Results show that the optimized cyclic control significantly alleviates the load variations from periodic disturbances; the combination of both cyclic...

  13. Smart helicopter rotor with active blade tips

    Science.gov (United States)

    Bernhard, Andreas Paul Friedrich

    2000-10-01

    The smart active blade tip (SABT) rotor is an on-blade rotor vibration reduction system, incorporating active blade tips that can be independently pitched with respect to the main blade. The active blade tip rotor development included an experimental test program culminating in a Mach scale hover test, and a parallel development of a coupled, elastic actuator and rotor blade analysis for preliminary design studies and hover performance prediction. The experimental testing focussed on a small scale rotor on a bearingless Bell-412 hub. The fabricated Mach-scale active-tip rotor has a diameter of 1.524 m, a blade chord of 76.2 mm and incorporated a 10% span active tip. The nominal operating speed is 2000 rpm, giving a tip Mach number of 0.47. The blade tips are driven by a novel piezo-induced bending-torsion coupled actuator beam, located spanwise in the hollow mid-cell of the main rotor blade. In hover at 2000 rpm, at 2 deg collective, and for an actuation of 125 Vrms, the measured blade tip deflection at the first four rotor harmonics is between +/-1.7 and +/-2.8 deg, increasing to +/-5.3 deg at 5/rev with resonant amplification. The corresponding oscillatory amplitude of the rotor thrust coefficient is between 0.7 · 10-3 and 1.3 · 10-1 at the first four rotor harmonics, increasing to 2.1 · 10-3 at 5/rev. In general, the experimental blade tip frequency response and corresponding rotor thrust response are well captured by the analysis. The flexbeam root flap bending moment is predicted in trend, but is significantly over-estimated. The blade tips did not deflect as expected at high collective settings, because of the blade tip shaft locking up in the bearing. This is caused by the high flap bending moment on the blade tip shaft. Redesign of the blade tip shaft assembly and bearing support is identified as the primary design improvement for future research. The active blade tip rotor was also used as a testbed for the evaluation of an adaptive neural-network based

  14. Study on wave rotor refrigerators

    Institute of Scientific and Technical Information of China (English)

    Yuqiang DAI; Dapeng HU; Meixia DING

    2009-01-01

    As a novel generation of a rotational gas wave machine, the wave rotor refrigerator (WRR) is an unsteady flow device used for refrigeration, in whose passages pressured streams directly contact and exchange energy due to the movement of pressure waves. In this paper, the working mechanism and refrigeration principle are inves-tigated based on the one-dimensional unsteady flow theory.A basic limitation on main structural parameters and operating parameters is deduced and the wave diagram of WRR to guide designing is sketched. The main influential factors are studied through an experiment. In the DUT Gas Wave Refrigeration Studying and Development Center (GWRSDC) lab, the isentropic efficiency can now reach about 65%. The results show that the WRR is a feasible and promising technology in pressured gas refrigeration cases.

  15. Multiple piece turbine rotor blade

    Energy Technology Data Exchange (ETDEWEB)

    Kimmel, Keith D.; Plank, William L.

    2016-07-19

    A spar and shell turbine rotor blade with a spar and a tip cap formed as a single piece, the spar includes a bottom end with dovetail or fir tree slots that engage with slots on a top end of a root section, and a platform includes an opening on a top surface for insertion of the spar in which a shell made from an exotic high temperature resistant material is secured between the tip cap and the platform. The spar is tapered to form thinner walls at the tip end to further reduce the weight and therefore a pulling force due to blade rotation. The spar and tip cap piece is made from a NiAL material to further reduce the weight and the pulling force.

  16. Control of molecular rotor rotational frequencies in porous coordination polymers using a solid-solution approach.

    Science.gov (United States)

    Inukai, Munehiro; Fukushima, Tomohiro; Hijikata, Yuh; Ogiwara, Naoki; Horike, Satoshi; Kitagawa, Susumu

    2015-09-30

    Rational design to control the dynamics of molecular rotors in crystalline solids is of interest because it offers advanced materials with precisely tuned functionality. Herein, we describe the control of the rotational frequency of rotors in flexible porous coordination polymers (PCPs) using a solid-solution approach. Solid-solutions of the flexible PCPs [{Zn(5-nitroisophthalate)x(5-methoxyisophthalate)1-x(deuterated 4,4'-bipyridyl)}(DMF·MeOH)]n allow continuous modulation of cell volume by changing the solid-solution ratio x. Variation of the isostructures provides continuous changes in the local environment around the molecular rotors (pyridyl rings of the 4,4'-bipyridyl group), leading to the control of the rotational frequency without the need to vary the temperature. PMID:26368067

  17. Loads and Performance Data from a Wind-Tunnel Test of Generic Model Helicopter Rotor Blades

    Science.gov (United States)

    Yeager, William T., Jr.; Wilbur, Matthew L.

    2005-01-01

    An investigation was conducted in the NASA Langley Transonic Dynamics Tunnel to acquire data for use in assessing the ability of current and future comprehensive analyses to predict helicopter rotating-system and fixed-system vibratory loads. The investigation was conducted with a generic model helicopter rotor system using blades with rectangular planform, no built-in twist, uniform radial distribution of mass and stiffnesses, and a NACA 0012 airfoil section. Rotor performance data, as well as mean and vibratory components of blade bending and torsion moments, fixed-system forces and moments, and pitch link loads were obtained at advance ratios up to 0.35 for various combinations of rotor shaft angle-of-attack and collective pitch. The data are presented without analysis.

  18. The Savonius rotor. A construction guide. 11. ed.; Der Savonius-Rotor. Eine Bauanleitung

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Heinz

    2009-07-01

    The Savonius rotor is particularly suited for medium and low wind velocities and low capacities (up to 500 W). It can be constructed of commercial components and using simple techniques. It requires little wind to start, and the useful energy is transmitted via a shaft. In this lavishly illustrated book, the author describes the construction and operation of a robust Savonius rotor. He also shows how this rotor can be developed into a flow-through rotor for bigger plants, and he presents recommendations for appropriate machinery like pumps and slow generators.

  19. Wind-tunnel investigation of the effects of blade tip geometry on the interaction of torsional loads and performance for an articulated helicopter rotor

    Science.gov (United States)

    Yeager, W. T.; Mantay, W. R.

    1981-01-01

    The Langley transonic dynamics tunnel was used to determine the degree of correlation between rotor performance and the dynamic twist generated by changes in blade tip geometry using an articulated rotor with four different tip geometries at advance ratios of 0.20, 0.30 and 0.35. Based on the data obtained, it is concluded that: (1) there appears to be no strong correlation between blade torsion loads and rotor performance prediction; (2) for a given rotor task at each advance ratio investigated, both the azimuthal variation of torsional moment and the mean torsional moment at 81% radius are configuration dependent; (3) reducing the nose down twist on the advancing blade appears to be more important to forward flight performance than increasing the nose down twist on the retreating blade; (4) the rotor inflow model used was important in predicting the performance of the adaptive rotor; and (5) neither rigid blade solidity effects, inflow environment, nor blade torsion loads can be used alone to accurately predict active rotor performance.

  20. Summary of Full-Scale Blade Displacement Measurements of the UH- 60A Airloads Rotor

    Science.gov (United States)

    Abrego, Anita I.; Meyn, Larry; Burner, Alpheus W.; Barrows, Danny A.

    2016-01-01

    Blade displacement measurements using multi-camera photogrammetry techniques were acquired for a full-scale UH-60A rotor, tested in the National Full-Scale Aerodynamic Complex 40-Foot by 80-Foot Wind Tunnel. The measurements, acquired over the full rotor azimuth, encompass a range of test conditions that include advance ratios from 0.15 to 1.0, thrust coefficient to rotor solidity ratios from 0.01 to 0.13, and rotor shaft angles from -10.0 to 8.0 degrees. The objective was to measure the blade displacements and deformations of the four rotor blades and provide a benchmark blade displacement database to be utilized in the development and validation of rotorcraft prediction techniques. An overview of the blade displacement measurement methodology, system development, and data analysis techniques are presented. Sample results based on the final set of camera calibrations, data reduction procedures and estimated corrections that account for registration errors due to blade elasticity are shown. Differences in blade root pitch, flap and lag between the previously reported results and the current results are small. However, even small changes in estimated root flap and pitch can lead to significant differences in the blade elasticity values.

  1. Nonlinear dynamic behavior of rubbing rotor under interaction between bending and torsional vibrations

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The nonlinear dynamic behavior of a rubbing rotor system was studied with a mathematical model established with the eccentricity and interaction between bending and torsional vibrations taken into consideration.The nonlinear vibrational response of a rubbing rotor was analyzed using numerical integral,spectroscopic analysis and Poince mapping method,which made it possible to have better understanding of the vibrational characteristics of partial rubbing and complete circular rubbing rotors.The numerical results reveal the response of torsional vibration mainly takes a form of suporchronous motion,and its frequency decreases as the rotational speed increases when partial rubbing occurs,and the response of torsional vibration is synchronous when complete circular rubbing occurs.The comparison of the dynamics of rubbing rotors with and without the interaction between bending and torsional vibrations shows the interaction between bending and torsional vibrations advances the rotational speed,at which the response of bending vibration changes from a synchronous motion into a quasi-periodic motion,and the interaction between bending and torsional vibrations reduces stability of the rubbing rotor.

  2. Interlayer toughening of fiber composite flywheel rotors

    Science.gov (United States)

    Groves, Scott E.; Deteresa, Steven J.

    1998-01-01

    An interlayer toughening mechanism to mitigate the growth of damage in fiber composite flywheel rotors for long application. The interlayer toughening mechanism may comprise one or more tough layers composed of high-elongation fibers, high-strength fibers arranged in a woven pattern at a range from 0.degree. to 90.degree. to the rotor axis and bound by a ductile matrix material which adheres to and is compatible with the materials used for the bulk of the rotor. The number and spacing of the tough interlayers is a function of the design requirements and expected lifetime of the rotor. The mechanism has particular application in uninterruptable power supplies, electrical power grid reservoirs, and compulsators for electric guns, as well as electromechanical batteries for vehicles.

  3. Superconducting motor with multiple winding rotor

    International Nuclear Information System (INIS)

    This patent describes a poly-phase, self- energizing, air-core superconducting motor. It comprises a stator having three sets of windings; a rotor including a large rotor winding and a small rotor winding, the windings being installed so their axes are orthogonal to each other and connected to form a current loop which is exposed to a magnetic field, the stator and rotor each being made from a superconductive material, and the ratio of turns of the large winding to the small winding being between 5:1 and 10:1; and, means for trapping a maximum number of magnetic flux lines in the loop when the magnetic field is impressed thereon and for thereafter transferring the trapped flux between the large and small winding to run the motor, the loop acting as a perfect conductor whereby no flux change occurs within the loop after the flux lines are trapped

  4. Valve-aided twisted Savonius rotor

    Energy Technology Data Exchange (ETDEWEB)

    Jaya Rajkumar, M.; Saha, U.K.

    2006-05-15

    Accessories, such as end plates, deflecting plates, shielding and guide vanes, may increase the power of a Savonius rotor, but make the system structurally complex. In such cases, the rotor can develop a relatively large torque at small rotational speeds and is cheap to build, however it harnesses only a small fraction of the incident wind energy. Another proposition for increasing specific output is to place non-return valves inside the concave side of the blades. Such methods have been studied experimentally with a twisted-blade Thus improving a Savonius rotor's energy capture. This new concept has been named as the 'Valve-Aided Twisted Savonius'rotor. Tests were conducted in a low-speed wind tunnel to evaluate performance. This mechanism is found to be independent of flow direction, and shows potential for large machines. [Author].

  5. Direct integration of transient rotor dynamics

    Science.gov (United States)

    Kascak, A. F.

    1980-01-01

    An implicit method was developed for integrating the equations of motion for a lumped mass model of a rotor dynamics system. As an aside, a closed form solution to the short bearing theory was also developed for a damper with arbitrary motion. The major conclusions are that the method is numerically stable and that the computation time is proportional to the number of elements in the rotor dynamics model rather than to the cube of the number. This computer code allowed the simulation of a complex rotor bearing system experiencing nonlinear transient motion and displayed the vast amount of results in an easily understood motion picture format - a 10 minute, 16 millimeter, color, sound motion picture supplement. An example problem with 19 mass elements in the rotor dynamics model took 0.7 second of central processing unit time per time step on an IBM 360-67 computer in a time sharing mode.

  6. Aerodynamics of Rotor Blades for Quadrotors

    CERN Document Server

    Bangura, Moses; Naldi, Roberto; Mahony, Robert

    2016-01-01

    In this report, we present the theory on aerodynamics of quadrotors using the well established momentum and blade element theories. From a robotics perspective, the theoretical development of the models for thrust and horizontal forces and torque (therefore power) are carried out in the body fixed frame of the quadrotor. Using momentum theory, we propose and model the existence of a horizontal force along with its associated power. Given the limitations associated with momentum theory and the inadequacy of the theory to account for the different powers represented in a proposed bond graph lead to the use of blade element theory. Using this theory, models are then developed for the different quadrotor rotor geometries and aerodynamic properties including the optimum hovering rotor used on the majority of quadrotors. Though this rotor is proven to be the most optimum rotor, we show that geometric variations are necessary for manufacturing of the blades. The geometric variations are also dictated by a desired th...

  7. What can be done differently with a super turbo? 2013 Formula 1 engine modeling of a super turbocharged engine in two configurations vs. a base turbocharged F1 engine

    Energy Technology Data Exchange (ETDEWEB)

    VanDyne, Ed; Schumacher, Volker; Brown, Jared [VanDyne SuperTurbo, Inc., Fort Collins, CO (United States)

    2011-07-01

    A 10% increase in power for the same fuel flow is huge in a Formula 1 engine. But an 18% increase in power for the same fuel flow, that is out of this world. Yes, 90 horsepower on top of 500 for the base already turbocharged engine, is the potential for the Bypass configuration of a super Turbocharger. Especially, given the rumored fuel flow limitation rule for a Formula 1 in the future. This result is better than we even expected when we started this modeling exercise. This is the value of using a catalytic converter on a racing car??? Who would have thought that a catalytic converter would be a horsepower device? With a SuperTurbocharger it is. The turbocompounding potential in a SuperTurbocharged F1 engine is great because of the high in cylinder pressures. Running the engine rich makes the most power in the engines cylinders. Burning the extra fuel in a catalyst provides added thermal energy to the turbine. The ability to burn that extra fuel in a catalyst in the exhaust comes from adding more mass flow across the turbine. More mass flow across the turbine provides more turbocompound power. Air is a lousy coolant therefore it adds more mass to the mass flow across the turbine. More mass flow at a given temperature equals more power from the turbine. If you have an unlimited temperature turbine material the plain SuperTurbocharger would make the best choice for its simplicity. If there were not limit to instantaneous fuel flow the results would show a higher output for all three cases at 12,000 rpm, but the bypass approach might require a bigger turbine and compressor to achieve its optimum output. In any case, with the proper turbine design, a SuperTurbocharger can add a great deal of extra power to any engine without any added stress to the base engine. This extra power from exhaust waste heat energy recovery is essentially for free. (orig.)

  8. Edge states of periodically kicked quantum rotors

    CERN Document Server

    Floß, Johannes

    2015-01-01

    We present a quantum localization phenomenon that exists in periodically kicked 3D rotors, but is absent in the commonly studied 2D ones: edge localization. We show that under the condition of a fractional quantum resonance there are states of the kicked rotor that are strongly localized near the edge of the angular momentum space at $J=0$. These states are analogs of surface states in crystalline solids, and they significantly affect resonant excitation of molecular rotation by laser pulse trains.

  9. Thermomechanical Behavior of Rotor with Rubbing

    OpenAIRE

    Jerzy T. Sawicki; Alberto Montilla-Bravo; Zdzislaw Gosiewski

    2003-01-01

    This article presents an analytical study of the dynamics and stability of rotors subjected to rubbing due to contact with seals, taking account of associated thermal effects. The seal interaction force acting on the shaft gives rise to a friction force, which is a source of heating and can induce so-called spiral vibrations. A mathematical model that has been developed couples the heat-conduction equation with the equations for motion of the rotor. Numerical simulations have been conducted t...

  10. Dynamic Gust Load Analysis for Rotors

    Directory of Open Access Journals (Sweden)

    Yuting Dai

    2016-01-01

    Full Text Available Dynamic load of helicopter rotors due to gust directly affects the structural stress and flight performance for helicopters. Based on a large deflection beam theory, an aeroelastic model for isolated helicopter rotors in the time domain is constructed. The dynamic response and structural load for a rotor under the impulse gust and slope-shape gust are calculated, respectively. First, a nonlinear Euler beam model with 36 degrees-of-freedoms per element is applied to depict the structural dynamics for an isolated rotor. The generalized dynamic wake model and Leishman-Beddoes dynamic stall model are applied to calculate the nonlinear unsteady aerodynamic forces on rotors. Then, we transformed the differential aeroelastic governing equation to an algebraic one. Hence, the widely used Newton-Raphson iteration algorithm is employed to simulate the dynamic gust load. An isolated helicopter rotor with four blades is studied to validate the structural model and the aeroelastic model. The modal frequencies based on the Euler beam model agree well with published ones by CAMRAD. The flap deflection due to impulse gust with the speed of 2m/s increases twice to the one without gust. In this numerical example, results indicate that the bending moment at the blade root is alleviated due to elastic effect.

  11. Study of combustion and emission characteristics of turbocharged diesel engine fuelled with dimethylether

    Institute of Scientific and Technical Information of China (English)

    Junhua WU; Zhen HUANG; Xinqi QIAO; Jun LU; Junjun ZHANG; Liang ZHANG

    2008-01-01

    An experimental study of a turbocharged diesel engine operating on dimethyl ether (DME) was conducted. The combustion and emission characteristics of the DME engine were investigated. The results show that the maximum torque and power of DME are greater than those of diesel, particularly at low speeds; the brake specific fuel consum-ption of DME is lower than that of diesel at low and middle engine speeds, and the injection delay of DME is longer than that of diesel. However, the maximum cylinder pressure, maximum pressure rise rate and combustion noises of the DME engine are lower than those of diesel. The combustion velocity of DME is faster than that of diesel, resulting in a shorter combustion duration of DME. Compared with the diesel engine, NOx emission of the DME engine is reduced by 41.6% on ESC data. In addition, the DME engine is smoke free at any operating condition.

  12. Aspects of the bioethanol use at the turbocharged spark ignition engine

    Directory of Open Access Journals (Sweden)

    Obeid Zuhair

    2015-01-01

    Full Text Available In the actual content of pollution regulations for the automotives, the use of alternative fuels becomes a priority of the thermal engine scientific research domain. From this point of view bioethanol can represents a viable alternative fuel for spark ignition engines offering the perspective of pollutant emissions reduction and combustion improvement. The paper presents results of the experimental investigations of a turbo-supercharged spark ignition engine (developed from a natural admission spark ignition engine fuelled with gasoline fuelled with bioethanol-gasoline blends. The engine is equipped with a turbocharger for low pressure supercharging, up till 1.4 bar. An correlation between air supercharging pressure-compression ratio-dosage-spark ignition timing-brake power is establish to avoid knocking phenomena at the engine operate regime of full load and 3000 min-1. The influences of the bioethanol on pollutant emissions level are presented.

  13. Neural control of fast nonlinear systems--application to a turbocharged SI engine with VCT.

    Science.gov (United States)

    Colin, Guillaume; Chamaillard, Yann; Bloch, Gérard; Corde, Gilles

    2007-07-01

    Today, (engine) downsizing using turbocharging appears as a major way in reducing fuel consumption and pollutant emissions of spark ignition (SI) engines. In this context, an efficient control of the air actuators [throttle, turbo wastegate, and variable camshaft timing (VCT)] is needed for engine torque control. This paper proposes a nonlinear model-based control scheme which combines separate, but coordinated, control modules. Theses modules are based on different control strategies: internal model control (IMC), model predictive control (MPC), and optimal control. It is shown how neural models can be used at different levels and included in the control modules to replace physical models, which are too complex to be online embedded, or to estimate nonmeasured variables. The results obtained from two different test benches show the real-time applicability and good control performance of the proposed methods.

  14. Application of feal intermetallic phase matrix based alloys in the turbine components of a turbocharger

    Directory of Open Access Journals (Sweden)

    J. Cebulski

    2015-01-01

    Full Text Available This paper presents a possible application of the state-of-the-art alloys based on the FeAl intermetallic phases as materials for the manufacture of heat-proof turbine components in an automobile turbocharger. The research was aimed at determining the resistance to corrosion of Fe40Al5CrTiB alloy in a gaseous environment containing 9 % O2 + 0,2 % HCl + 0,08 % SO2 + N2. First the kinetics of corrosion processes for the considered alloy were determined at the temperatures of 900 °C, 1 000 °C and 1 100 °C, which was followed by validation under operating conditions. To do so, the tests were carried out over a distance of 20 000 km. The last stage involved examination of the surfaces after the test drive. The obtained results are the basis for further research in this field.

  15. Numerical Simulation of the Thermoelectric Model on Vehicle Turbocharged Diesel Engine Intercooler

    Directory of Open Access Journals (Sweden)

    Zhou Minfeng

    2013-09-01

    Full Text Available A thermoelectric gas-solid heat transfer numerical model was established between an air-cooling tube-fin intercooler’s intake and cooling air passage channel on vehicle turbocharged diesel engine. The outlet temperature of intake air, the output power of the thermoelectric components and the thermal conversion efficiency are considered as the research objectives. When load value is constant, the outlet temperature of intake air decreases with the number of thermocouples increases and there exist maximum values for output power and thermal conversion efficiency; when the number of thermocouples is constant, there is little effect on the outlet temperature of intake air with the load value increases. When the load was been optimal designed, set the load value throughout equals to the value of thermoelectric component total internal resistance, the values of the maximum output power was increased by 20.3% and the thermal conversion efficiency was increased from 1.78 to 3.48%.

  16. Heat transfer in turbocharger turbines under steady, pulsating and transient conditions

    International Nuclear Information System (INIS)

    Highlights: • Compare turbine heat transfer correlations from different studies. • Compare heat transfer for a same turbine on-engine and on gas-stand. • Analyse heat transfer under steady and transient operating conditions. • Gas stand heat transfer correlations are transferrable to engine conditions. • Heat flows can be reversed compared to steady conditions during transients. - Abstract: Heat transfer is significant in turbochargers and a number of mathematical models have been proposed to account for the heat transfer, however these have predominantly been validated under steady flow conditions. A variable geometry turbocharger from a 2.2 L Diesel engine was studied, both on gas stand and on-engine, under steady and transient conditions. The results showed that heat transfer accounts for at least 20% of total enthalpy change in the turbine and significantly more at lower mechanical powers. A convective heat transfer correlation was derived from experimental measurements to account for heat transfer between the gases and the turbine housing and proved consistent with those published from other researchers. This relationship was subsequently shown to be consistent between engine and gas stand operation: using this correlation in a 1D gas dynamics simulation reduced the turbine outlet temperature error from 33 °C to 3 °C. Using the model under transient conditions highlighted the effect of housing thermal inertia. The peak transient heat flow was strongly linked to the dynamics of the turbine inlet temperature: for all increases, the peak heat flow was higher than under thermally stable conditions due to colder housing. For all decreases in gas temperature, the peak heat flow was lower and for temperature drops of more than 100 °C the heat flow was reversed during the transient

  17. Equations of motion for a rotor blade, including gravity, pitch action and rotor speed variations

    DEFF Research Database (Denmark)

    Kallesøe, Bjarne Skovmose

    2007-01-01

    This paper extends Hodges-Dowell's partial differential equations of blade motion, by including the effects from gravity, pitch action and varying rotor speed. New equations describing the pitch action and rotor speeds are also derived. The physical interpretation of the individual terms...

  18. THE DESIGN OF AXIAL PUMP ROTORS USING THE NUMERICAL METHODS

    Directory of Open Access Journals (Sweden)

    Ali BEAZIT

    2010-06-01

    Full Text Available The researches in rotor theory, the increasing use of computers and the connection between design and manufacturing of rotors, have determined the revaluation and completion of classical rotor geometry. This paper presents practical applications of mathematical description of rotor geometry. A program has been created to describe the rotor geometry for arbitrary shape of the blade. The results can be imported by GAMBIT - a processor for geometry with modeling and mesh generations, to create a mesh needed in hydrodynamics analysis of rotor CFD. The results obtained are applicable in numerical methods and are functionally convenient for CAD/CAM systems.

  19. Optimum blade loading for a powered rotor in descent

    Institute of Scientific and Technical Information of China (English)

    Ramin Modarres; David A. Peters

    2016-01-01

    The optimum loading for rotors has previously been found for hover, climb and wind turbine conditions;but, up to now, no one has determined the optimum rotor loading in descent. This could be an important design consideration for rotary-wing parachutes and low-speed des-cents. In this paper, the optimal loading for a powered rotor in descent is found from momentum theory based on a variational principle. This loading is compared with the optimal loading for a rotor in hover or climb and with the Betz rotor loading (which is optimum for a lightly-loaded rotor). Wake contraction for each of the various loadings is also presented.

  20. Electric Drive Control with Rotor Resistance and Rotor Speed Observers Based on Fuzzy Logic

    Directory of Open Access Journals (Sweden)

    C. Ben Regaya

    2014-01-01

    Full Text Available Many scientific researchers have proposed the control of the induction motor without speed sensor. These methods have the disadvantage that the variation of the rotor resistance causes an error of estimating the motor speed. Thus, simultaneous estimation of the rotor resistance and the motor speed is required. In this paper, a scheme for estimating simultaneously the rotor resistance and the rotor speed of an induction motor using fuzzy logic has been developed. We present a method which is based on two adaptive observers using fuzzy logic without affecting each other and a simple algorithm in order to facilitate the determination of the optimal values of the controller gains. The control algorithm is proved by the simulation tests. The results analysis shows the characteristic robustness of the two observers of the proposed method even in the case of variation of the rotor resistance.

  1. Coupled rotor/fuselage dynamic analysis of the AH-1G helicopter and correlation with flight vibrations data

    Science.gov (United States)

    Corrigan, J. C.; Cronkhite, J. D.; Dompka, R. V.; Perry, K. S.; Rogers, J. P.; Sadler, S. G.

    1989-01-01

    Under a research program designated Design Analysis Methods for VIBrationS (DAMVIBS), existing analytical methods are used for calculating coupled rotor-fuselage vibrations of the AH-1G helicopter for correlation with flight test data from an AH-1G Operational Load Survey (OLS) test program. The analytical representation of the fuselage structure is based on a NASTRAN finite element model (FEM), which has been developed, extensively documented, and correlated with ground vibration test. One procedure that was used for predicting coupled rotor-fuselage vibrations using the advanced Rotorcraft Flight Simulation Program C81 and NASTRAN is summarized. Detailed descriptions of the analytical formulation of rotor dynamics equations, fuselage dynamic equations, coupling between the rotor and fuselage, and solutions to the total system of equations in C81 are included. Analytical predictions of hub shears for main rotor harmonics 2p, 4p, and 6p generated by C81 are used in conjunction with 2p OLS measured control loads and a 2p lateral tail rotor gearbox force, representing downwash impingement on the vertical fin, to excite the NASTRAN model. NASTRAN is then used to correlate with measured OLS flight test vibrations. Blade load comparisons predicted by C81 showed good agreement. In general, the fuselage vibration correlations show good agreement between anslysis and test in vibration response through 15 to 20 Hz.

  2. Smart rotor modeling aero-servo-elastic modeling of a smart rotor with adaptive trailing edge flaps

    CERN Document Server

    Bergami, Leonardo

    2014-01-01

    A smart rotor is a wind turbine rotor that, through a combination of sensors, control units and actuators actively reduces the variation of the aerodynamic loads it has to withstand. Smart rotors feature?promising load alleviation potential and might provide the technological breakthrough required by the next generation of large wind turbine rotors.The book presents the aero-servo-elastic model of a smart rotor with Adaptive Trailing Edge Flaps for active load alleviation and provides an insight on the rotor aerodynamic, structural and control modeling. A novel model for the unsteady aerodynam

  3. New Physics-Based Turbocharger Data-Maps Extrapolation Algorithms: Validation on a Spark-Ignited Engine

    OpenAIRE

    El Hadef, Jamil; Colin, Guillaume; Talon, Vincent; Chamaillard, Yann

    2012-01-01

    Objectives in terms of pollutant emissions and fuel consumption reduction, as well as development costs and time to market reduction, has led car manufacturers to use more and more system simulation. However, among all the fields in which it has enabled to achieve these goals, the control development stage is one of those, in which major improvements can still be achieved. In this context and with the increasing penetration of downsized engines, turbocharger modeling has become one of the big...

  4. Investigation into the thermodynamic suitability of a commercial turbocharger for use in a micro gas-turbine / David Tertius Landsberg

    OpenAIRE

    Landsberg, David Tertius

    2006-01-01

    Micro gas-turbines are expanding to be much more prevalent in the power generating market. They are merely scaled down versions of their larger siblings, gas-turbines powering commercial airplanes on generating megawatts of electrical energy throughout the world. The basic components of a micro gas-turbine and that of a turbocharger unit on internal combustion engines are quite similar. Both have a compressor, a heat source and a turbine. This study investigates the possibility...

  5. Smart dynamic rotor control using active flaps on a small-scale wind turbine: aeroelastic modeling and comparison with wind tunnel measurements

    DEFF Research Database (Denmark)

    Barlas, Thanasis K.; van Wingerden, W.; Hulskamp, A.W.;

    2013-01-01

    using the aeroelastic tool, load predictions are compared with the wind tunnel measurements, and similar control concepts are compared and evaluated in the numerical environment. Conclusions regarding evaluation of the performance of smart rotor concepts for wind turbines are drawn from this threefold......In this paper, the proof of concept of a smart rotor is illustrated by aeroelastic simulations on a small-scale rotor and comparison with wind tunnel experiments. The application of advanced feedback controllers using actively deformed flaps in the wind tunnel measurements is shown to alleviate...

  6. Performance and Vibratory Loads Data From a Wind-Tunnel Test of a Model Helicopter Main-Rotor Blade With a Paddle-Type Tip

    Science.gov (United States)

    Yeager, William T., Jr.; Noonan, Kevin W.; Singleton, Jeffrey D.; Wilbur, Matthew L.; Mirick, Paul H.

    1997-01-01

    An investigation was conducted in the Langley Transonic Dynamics Tunnel to obtain data to permit evaluation of paddle-type tip technology for possible use in future U.S. advanced rotor designs. Data was obtained for both a baseline main-rotor blade and a main-rotor blade with a paddle-type tip. The baseline and paddle-type tip blades were compared with regard to rotor performance, oscillatory pitch-link loads, and 4-per-rev vertical fixed-system loads. Data was obtained in hover and forward flight over a nominal range of advance ratios from 0.15 to 0.425. Results indicate that the paddle-type tip offers no performance improvements in either hover or forward flight. Pitch-link oscillatory loads for the paddle-type tip are higher than for the baseline blade, whereas 4-per-rev vertical fixed-system loads are generally lower.

  7. Impact of two-stage turbocharging architectures on pumping losses of automotive engines based on an analytical model

    International Nuclear Information System (INIS)

    Present work presents an analytical study of two-stage turbocharging configuration performance. The aim of this work is to understand the influence of different two-stage-architecture parameters to optimize the use of exhaust manifold gases energy and to aid decision making process. An analytical model giving the relationship between global compression ratio and global expansion ratio is developed as a function of basic engine and turbocharging system parameters. Having an analytical solution, the influence of different variables, such as expansion ratio between HP and LP turbine, intercooler efficiency, turbochargers efficiency, cooling fluid temperature and exhaust temperature are studied independently. Engine simulations with proposed analytical model have been performed to analyze the influence of these different parameters on brake thermal efficiency and pumping mean effective pressure. The results obtained show the overall performance of the two-stage system for the whole operative range and characterize the optimum control of the elements for each operative condition. The model was also used to compare single-stage and two-stage architectures performance for the same engine operative conditions. Benefits and limits in terms of breathing capabilities and brake thermal efficiency of each type of system have been presented and analyzed.

  8. Impact of two-stage turbocharging architectures on pumping losses of automotive engines based on an analytical model

    Energy Technology Data Exchange (ETDEWEB)

    Galindo, J. [Universidad Politecnica de Valencia, CMT - Motores Termicos (Spain); Serrano, J.R., E-mail: jrserran@mot.upv.e [Universidad Politecnica de Valencia, CMT - Motores Termicos (Spain); Climent, H.; Varnier, O. [Universidad Politecnica de Valencia, CMT - Motores Termicos (Spain)

    2010-10-15

    Present work presents an analytical study of two-stage turbocharging configuration performance. The aim of this work is to understand the influence of different two-stage-architecture parameters to optimize the use of exhaust manifold gases energy and to aid decision making process. An analytical model giving the relationship between global compression ratio and global expansion ratio is developed as a function of basic engine and turbocharging system parameters. Having an analytical solution, the influence of different variables, such as expansion ratio between HP and LP turbine, intercooler efficiency, turbochargers efficiency, cooling fluid temperature and exhaust temperature are studied independently. Engine simulations with proposed analytical model have been performed to analyze the influence of these different parameters on brake thermal efficiency and pumping mean effective pressure. The results obtained show the overall performance of the two-stage system for the whole operative range and characterize the optimum control of the elements for each operative condition. The model was also used to compare single-stage and two-stage architectures performance for the same engine operative conditions. Benefits and limits in terms of breathing capabilities and brake thermal efficiency of each type of system have been presented and analyzed.

  9. Inlet Guide Vane Wakes Including Rotor Effects

    Science.gov (United States)

    Johnston, R. T.; Fleeter, S.

    2001-02-01

    Fundamental experiments are described directed at the investigation of forcing functions generated by an inlet guide vane (IGV) row, including interactions with the downstream rotor, for application to turbomachine forced response design systems. The experiments are performed in a high-speed research fan facility comprised of an IGV row upstream of a rotor. IGV-rotor axial spacing is variable, with the IGV row able to be indexed circumferentially, thereby allowing measurements to be made across several IGV wakes. With an IGV relative Mach number of 0.29, measurements include the IGV wake pressure and velocity fields for three IGV-rotor axial spacings. The decay characteristics of the IGV wakes are compared to the Majjigi and Gliebe empirical correlations. After Fourier decomposition, a vortical-potential gust splitting analysis is implemented to determine the vortical and potential harmonic wake gust forcing functions both upstream and downstream of the rotor. Higher harmonics of the vortical gust component of the IGV wakes are found to decay at a uniform rate due to viscous diffusion.

  10. Rotor instability due to loose rotating part

    Science.gov (United States)

    Muszynska, A.

    1985-01-01

    Loosening of a rotating part from its fixed position on the shaft or a part of the stator which comes loose and begins to turn with the rotor very frequently represents machinery malfunction. The loose part becomes involved in rotative motion mostly due to dry or fluid friction, and thus its motion is very erratic. The loose part can also move axially along the shaft. Detachment of the rotating part causes changes in the rotor balance state. Most often this results in higher unbalance. During steady-state operation the effect of a loose rotating part can manifest itself through heat vibration. It can be diagnosed by observing periodic changes of amplitude and phase of the synchronous response. During start-up (or shutdown) a loose rotating part carrying some amount of unbalance may manifest its dynamic action in the form of subsynchronous vibrations, very similar to those of other instabilities. The objective of this demonstration is to observe the effect of a loose rotating part (fixed, however, in the axial direction) under both steady-state (rotor constant speed) and transient (rotor start-up or shutdown) operation. The dynamic response depends very much on the amount of damping in the system: lubrication of the loose part/shaft surfaces and addition/elimination of aerodynamic drag blades, mounted on the loose disk, significantly change the rotor response.

  11. Performance investigation of the S-Rotors

    Science.gov (United States)

    Bhayo, B. A.; Al-Kayiem, H. H.; Yahaya, N. Z.

    2015-12-01

    This paper presents and discusses results from an experimental investigation of three models of wind S-rotors. Models 1 is modified from conventional Savonius rotor with a single stage and zero offsets zero overlaps; model 2 is three blade single stage wind rotor; and model 3 is double stage conventional Savonius rotor. The three models were designed, fabricated and characterized in terms of their coefficient of performance and dynamic torque coefficient. A special open wind simulator was designed for the test. The optimum parameters for the models were based on previous studies. The results showed that the model 1, model 2 and model 3 has the maximum power coefficient of 0.26, 0.17, and 0.21 at the correspondence tip speed ratio (TSR) of 0.42, 0.39 and 0.46, respectively. Model 1 is further optimized in terms of the aspect ratio resulting in improved power coefficient by 24%. The maximum dynamic torque coefficient of model 1, model 2 and model 3 was found as 0.81, 0.56 and 0.67 at the correspondence minimum TSR of 0.28, 0.21 and 0.17, respectively. It was noted that the all three models have high torque coefficient because the models were tested at higher applied torque on the rotors.

  12. Dynamics and Efficiency of Brownian Rotors

    CERN Document Server

    Bauer, Wolfgang R

    2008-01-01

    Brownian rotors play an important role in biological systems and in future nano-technological applications. However the mechanisms determining their dynamics, efficiency and performance remain to be characterized. Here the F0 portion of the F-ATP synthase is considered as a paradigm of a Brownian rotor. In a generic analytical model we analyze the stochastic rotation of F0-like motors as a function of the driving free energy difference and of the free energy profile the rotor is subjected to. The latter is composed of the rotor interaction with its surroundings, of the free energy of chemical transitions, and of the workload. The dynamics and mechanical efficiency of the rotor depends on the magnitude of its stochastic motion driven by the free energy energy difference and its rectification on the reaction-diffusion path. We analyze which free energy profiles provide maximum flow and how their arrangement on the underlying reaction-diffusion path affects rectification and -- by this -- the efficiency.

  13. RESEARCH ON KNOWLEDGE-BASED CAPP SYSTEM FOR ROTOR FORGING

    Institute of Scientific and Technical Information of China (English)

    Wang Leigang; Deng Dongrnei; Liu Zhubai

    2000-01-01

    Guided by developing forging technology theory,designing rules on rotor forging process are summed up.Knowledge-based CAPP system for rotor forging is created.The system gives a rational and optimum process.

  14. Tip Vortex and Wake Characteristics of a Counterrotating Open Rotor

    Science.gov (United States)

    VanZante, Dale E.; Wernet, Mark P.

    2012-01-01

    One of the primary noise sources for Open Rotor systems is the interaction of the forward rotor tip vortex and blade wake with the aft rotor. NASA has collaborated with General Electric on the testing of a new generation of low noise, counterrotating Open Rotor systems. Three-dimensional particle image velocimetry measurements were acquired in the intra-rotor gap of the Historical Baseline blade set. The velocity measurements are of sufficient resolution to characterize the tip vortex size and trajectory as well as the rotor wake decay and turbulence character. The tip clearance vortex trajectory is compared to results from previously developed models. Forward rotor wake velocity profiles are shown. Results are presented in a form as to assist numerical modeling of Open Rotor system aerodynamics and acoustics.

  15. Design and Analysis of Delta Wing Tilt Rotor UAV

    Directory of Open Access Journals (Sweden)

    S.Ravikanth

    2015-07-01

    Full Text Available A tilt rotor is an aircraft of a special kind, which possesses the characteristics of a helicopter and a fixed-wing airplane. However, there are a great number of important technical problems waiting for settlements. Of them, the flight control system might be a critical one. A tiltrotor aircraft comprising a pair of contra-rotating co-axial tiltable rotors on the longitudinal center line of the aircraft. The rotors may be tiltable sequentially and independently. They may be moveable between a lift position and a flight position in front of or behind the fuselage.In this paper we present a project aimed for the designing of a small scale Unmanned Aerial Vehicle (UAV with Tiltrotor configuration (that uses two rotating rotors. he current paper describes the adopted design methodology, the mathematical and computational models created to represent the UAV, the physical components that constitute the UAV, and the results obtained so far. An unmanned aerial vehicle (UAV, also known as a remotely piloted aircraft (RPA or unmanned aircraft, is a machine which functions either by the remote control of a navigator or pilot or autonomously. A UAV is defined as a powered, aerial vehicle that does not carry a human operator, uses aerodynamic forces to provide vehicle lift, can fly autonomously or be piloted remotely, can be expendable or recoverable, and can carry payload.India‘s requirement of these unmanned aerial vehicles (UAV has become prior need for fighting in the northeast, against threat of terrorism, tension along the Pakistan border and its emerging role as a regional naval power and subsequent need for surveillance. The military wants to acquire at least 1,500 unmanned systems in the next 3-4 years, ranging from man-portable drones to high-altitude, long-endurance (HALE vehicles.Indian military is using Israeli-built UAVs such as the Heron, Searcher Mk II and Harop from Israel Aerospace Industries (IAI. Till date India has mostly deployed

  16. Estimation of dynamic rotor loads for the rotor systems research aircraft: Methodology development and validation

    Science.gov (United States)

    Duval, R. W.; Bahrami, M.

    1985-01-01

    The Rotor Systems Research Aircraft uses load cells to isolate the rotor/transmission systm from the fuselage. A mathematical model relating applied rotor loads and inertial loads of the rotor/transmission system to the load cell response is required to allow the load cells to be used to estimate rotor loads from flight data. Such a model is derived analytically by applying a force and moment balance to the isolated rotor/transmission system. The model is tested by comparing its estimated values of applied rotor loads with measured values obtained from a ground based shake test. Discrepancies in the comparison are used to isolate sources of unmodeled external loads. Once the structure of the mathematical model has been validated by comparison with experimental data, the parameters must be identified. Since the parameters may vary with flight condition it is desirable to identify the parameters directly from the flight data. A Maximum Likelihood identification algorithm is derived for this purpose and tested using a computer simulation of load cell data. The identification is found to converge within 10 samples. The rapid convergence facilitates tracking of time varying parameters of the load cell model in flight.

  17. System Noise Assessment and the Potential for a Low Noise Hybrid Wing Body Aircraft with Open Rotor Propulsion

    Science.gov (United States)

    Thomas, Russell H.; Burley, Casey L.; Lopes, Leonard V.; Bahr, Christopher J.; Gern, Frank H.; VanZante, Dale E.

    2014-01-01

    An aircraft system noise assessment was conducted for a hybrid wing body freighter aircraft concept configured with three open rotor engines. The primary objective of the study was to determine the aircraft system level noise given the significant impact of installation effects including shielding the open rotor noise by the airframe. The aircraft was designed to carry a payload of 100,000 lbs on a 6,500 nautical mile mission. An experimental database was used to establish the propulsion airframe aeroacoustic installation effects including those from shielding by the airframe planform, interactions with the control surfaces, and additional noise reduction technologies. A second objective of the study applied the impacts of projected low noise airframe technology and a projection of advanced low noise rotors appropriate for the NASA N+2 2025 timeframe. With the projection of low noise rotors and installation effects, the aircraft system level was 26.0 EPNLdB below Stage 4 level with the engine installed at 1.0 rotor diameters upstream of the trailing edge. Moving the engine to 1.5 rotor diameters brought the system level noise to 30.8 EPNLdB below Stage 4. At these locations on the airframe, the integrated level of installation effects including shielding can be as much as 20 EPNLdB cumulative in addition to lower engine source noise from advanced low noise rotors. And finally, an additional set of technology effects were identified and the potential impact at the system level was estimated for noise only without assessing the impact on aircraft performance. If these additional effects were to be included it is estimated that the potential aircraft system noise could reach as low as 38.0 EPNLdB cumulative below Stage 4.

  18. Analysis on structural characteristics of rotors in twin-rotor cylinder-embedded piston engine

    Institute of Scientific and Technical Information of China (English)

    陈虎; 潘存云; 徐海军; 邓豪; 韩晨

    2014-01-01

    Twin-rotor cylinder-embedded piston engine is proposed for dealing with the sealing problems of rotors in twin-rotor piston engine where the existent mature sealing technologies for traditional reciprocating engine can be applied. The quantity and forms of its sealing surfaces are reduced and simplified, and what’s more, the advantages of twin-rotor piston engine are inherited, such as high power density and no valve mechanism. Given the motion law of two rotors, its kinematic model is established, and the general expression for some parameters related to engine performance, such as the trajectory, displacement, velocity and acceleration of the piston and centroid trajectory, angular displacement, velocity and acceleration of the rod are presented. By selecting different variation patterns of relative angle of two rotors, the relevant variables are compared. It can be concluded that by designing the relative angle function of two rotors, the volume variation of working chamber can be changed. However, a comprehensive consideration for friction and vibration is necessary because velocity and acceleration are quite different in the different functions, the swing magnitude of rod is proportional to link ratioλ, and the position of rod swing center is controlled by eccentricitye. In order to reduce the lateral force, a smaller value ofλshould be selected in the case of the structure, and the value ofe should be near 0.95. There is no relationship between the piston stroke and the variation process of relative angle of two rotors, the former is only proportional to the amplitude of relative angle of two rotors.

  19. Algebraic realization of coupled rotor dynamics

    International Nuclear Information System (INIS)

    The relation between shape variables (β,γ) of the collective model and irrep labels (λ,μ) of the SU(3) shell model is generalized to a coupled rotor picture, with one rotor representing protons π and one neutrons (ν).The joint distribution (β,γ) is characterized by the parameters (βπ, γπ), (βν,γν) and three Euler angles describing the relative orientation of proton and neutron sub-systems. It is shown analytically that the rotor construction for a triaxial and an axially symmetric shape corresponds to a (λπ,μπ)direct-product(λν,μν=0) → (λ,μ)ρ=1 coupling in the SU(3) model

  20. Eigenfrequency sensitivity analysis of flexible rotors

    Directory of Open Access Journals (Sweden)

    Šašek J.

    2007-10-01

    Full Text Available This paper deals with sensitivity analysis of eigenfrequencies from the viewpoint of design parameters. The sensitivity analysis is applied to a rotor which consists of a shaft and a disk. The design parameters of sensitivity analysis are the disk radius and the disk width. The shaft is modeled as a 1D continuum using shaft finite elements. The disks of rotating systems are commonly modeled as rigid bodies. The presented approach to the disk modeling is based on a 3D flexible continuum discretized using hexahedral finite elements. The both components of the rotor are connected together by special proposed couplings. The whole rotor is modeled in rotating coordinate system with considering rotation influences (gyroscopic and dynamics stiffness matrices.

  1. Wobbling geometry in simple triaxial rotor

    CERN Document Server

    Shi, W X

    2014-01-01

    The spectroscopy properties and angular momentum geometry for the wobbling motion of a simple triaxial rotor are investigated within the triaxial rotor model up to spin $I=40\\hbar$. The obtained exact solutions of energy spectra and reduced quadrupole transition probabilities are compared to the approximate analytic solutions by harmonic approximation formula and Holstein-Primakoff formula. It is found that the low lying wobbling bands can be well described by the analytic formulas. The evolution of the angular momentum geometry as well as the $K$-distribution with respect to the rotation and the wobbling phonon excitation are studied in detail. It is demonstrated that with the increasing of wobbling phonon number, the triaxial rotor changes its wobbling motions along the axis with the largest moment of inertia to the axis with the smallest moment of inertia. In this process, a specific evolutionary track that can be used to depict the motion of a triaxial rotating nuclei is proposed.

  2. Wind Turbine Rotors with Active Vibration Control

    DEFF Research Database (Denmark)

    Svendsen, Martin Nymann

    This thesis presents a framework for structural modeling, analysis and active vibration damping of rotating wind turbine blades and rotors. A structural rotor model is developed in terms of finite beam elements in a rotating frame of reference. The element comprises a representation of general...... formulation. The element provides an accurate representation of the eigenfrequencies and whirling modes of the gyroscopic system, and identifies lightly damped edge-wise modes. By adoption of a method for active, collocated resonant vibration of multi-degree-of-freedom systems it is demonstrated...... that these are geometrically well separated. For active vibration control in three-bladed wind turbine rotors the present work presents a resonance-based method for groups of one collective and two whirling modes. The controller is based on the existing resonant format and introduces a dual system targeting the collective...

  3. On aerodynamic design of the Savonius windmill rotor

    Science.gov (United States)

    Mojola, O. O.

    This paper examines under field conditions the performance characteristics of the Savonius windmill rotor. Test data were collected on the speed, torque and power of the rotor at a large number of wind speeds for each of seven values of the rotor overlap ratio. Field testing procedures are critically appraised and a unified approach is suggested. The performance data of the Savonius rotor are also fully discussed and design criteria established.

  4. A study of helicopter rotor dynamics and modeling methods

    OpenAIRE

    Hiatt, Daniel S.

    1995-01-01

    The rotor system is the primary source of vibratory forces on a helicopter. Vibratory forces result from the rotor system response to dynamic and aerodynamic loading. This thesis discusses sources of excitation, and investigates rotor system modeling methods. Computer models based on finite element and Mykiestad methods are developed and compared for the free and forced vibration cases of a nniform rotor blade. The modeling assumptions and the effects of non-iniform physical parameters are di...

  5. Multiresolution Wavelet Analysis of the Dynamics of a Cracked Rotor

    OpenAIRE

    Jerzy T. Sawicki; Sen, Asok K.; Grzegorz Litak

    2009-01-01

    We examine the dynamics of a healthy rotor and a rotor with a transverse crack, which opens and closes due to its self weight. Using discrete wavelet transform, we perform a multiresolution analysis of the measured vibration signal from each of these rotors. In particular, the measured vibration signal is decomposed into eight frequency bands, and the rms amplitude values of the healthy and cracked rotors are compared in the three lowest-frequency bands. The results indicate that the rms vibr...

  6. Hybrid algorithm for rotor angle security assessment in power systems

    OpenAIRE

    D. Prasad Wadduwage; Udaya D. Annakkage; Christine Qiong Wu

    2015-01-01

    Transient rotor angle stability assessment and oscillatory rotor angle stability assessment subsequent to a contingency are integral components of dynamic security assessment (DSA) in power systems. This study proposes a hybrid algorithm to determine whether the post-fault power system is secure due to both transient rotor angle stability and oscillatory rotor angle stability subsequent to a set of known contingencies. The hybrid algorithm first uses a new security measure developed based on ...

  7. On the Classification of Universal Rotor-Routers

    CERN Document Server

    He, Xiaoyu

    2011-01-01

    The combinatorial theory of rotor-routers has connections with problems of statistical mechanics, graph theory, chaos theory, and computer science. A rotor-router network defines a deterministic walk on a digraph G in which a particle walks from a source vertex until it reaches one of several target vertices. Motivated by recent results due to Giacaglia et al., we study rotor-router networks in which all non-target vertices have the same type. A rotor type r is universal if every hitting sequence can be achieved by a homogeneous rotor-router network consisting entirely of rotors of type r. We give a conjecture that completely classifies universal rotor types. Then, this problem is simplified by a theorem we call the Reduction Theorem that allows us to consider only two-state rotors. A rotor-router network called the compressor, because it tends to shorten rotor periods, is introduced along with an associated algorithm that determines the universality of almost all rotors. New rotor classes, including boppy ro...

  8. 14 CFR 23.1461 - Equipment containing high energy rotors.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Equipment containing high energy rotors. 23... Equipment Miscellaneous Equipment § 23.1461 Equipment containing high energy rotors. (a) Equipment, such as Auxiliary Power Units (APU) and constant speed drive units, containing high energy rotors must...

  9. 14 CFR 33.92 - Rotor locking tests.

    Science.gov (United States)

    2010-01-01

    ... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.92 Rotor locking tests. If continued rotation is prevented by a means to lock the rotor(s), the engine must be subjected to a test that...

  10. Aeromechanics and Aeroacoustics Predictions of the Boeing-SMART Rotor Using Coupled-CFD/CSD Analyses

    Science.gov (United States)

    Bain, Jeremy; Sim, Ben W.; Sankar, Lakshmi; Brentner, Ken

    2010-01-01

    This paper will highlight helicopter aeromechanics and aeroacoustics prediction capabilities developed by Georgia Institute of Technology, the Pennsylvania State University, and Northern Arizona University under the Helicopter Quieting Program (HQP) sponsored by the Tactical Technology Office of the Defense Advanced Research Projects Agency (DARPA). First initiated in 2004, the goal of the HQP was to develop high fidelity, state-of-the-art computational tools for designing advanced helicopter rotors with reduced acoustic perceptibility and enhanced performance. A critical step towards achieving this objective is the development of rotorcraft prediction codes capable of assessing a wide range of helicopter configurations and operations for future rotorcraft designs. This includes novel next-generation rotor systems that incorporate innovative passive and/or active elements to meet future challenging military performance and survivability goals.

  11. Superballistic wavepacket spreading in double kicked rotors

    Science.gov (United States)

    Fang, Ping; Wang, Jiao

    2016-08-01

    We investigate possible ways in which a quantum wavepacket spreads. We show that in a general class of double kicked rotor system, a wavepacket may undergo superballistic spreading; i.e., its variance increases as the cubic of time. The conditions for the observed superballistic spreading and two related characteristic time scales are studied. Our results suggest that the symmetry of the studied model and whether it is a Kolmogorov-Arnold-Moser system are crucial to its wavepacket spreading behavior. Our study also sheds new light on the exponential wavepacket spreading phenomenon previously observed in the double kicked rotor system.

  12. Edge states of periodically kicked quantum rotors.

    Science.gov (United States)

    Floss, Johannes; Averbukh, Ilya Sh

    2015-05-01

    We present a quantum localization phenomenon that exists in periodically kicked three-dimensional rotors, but is absent in the commonly studied two-dimensional ones: edge localization. We show that under the condition of a fractional quantum resonance there are states of the kicked rotor that are strongly localized near the edge of the angular momentum space at J=0. These states are analogs of surface states in crystalline solids, and they significantly affect resonant excitation of molecular rotation by laser pulse trains.

  13. Component mode synthesis of large rotor systems

    Science.gov (United States)

    Li, D. F.; Gunter, E. J.

    1981-01-01

    A scheme is presented for calculating the vibrations of large multi-component flexible rotor systems based on the component mode synthesis method. It is shown that, by a modal expansion of the elastic interconnecting elements, the system modal equation can be conveniently constructed from the undamped eigen representations of the component subsystems. The capability of the component mode method is demonstrated in two examples: a transient simulation of a two-spool gas turbine engine equipped with a squeeze-film damper; and an unbalance response analysis of the Space Shuttle Main Engine oxygen turbopump in which the dynamics of the rotor and the housing are both considered.

  14. CFD simulations of the MEXICO rotor

    DEFF Research Database (Denmark)

    Bechmann, Andreas; Sørensen, Niels N.; Zahle, Frederik

    2011-01-01

    The wake behind a wind turbine model is investigated using Computational Fluid Dynamics (CFD), and results are compared with measurements. The turbine investigated is the three‐bladed test rotor (D = 4.5 m) used in the Model Experiments in Controlled Conditions (MEXICO) wind tunnel experiment....... During the MEXICO experiment, particle image velocimetry measurements of the induction upstream and downstream of the rotor were performed for different operating conditions, giving a unique dataset to verify theoretical models and CFD models. The present paper first describes the efforts in reproducing...

  15. Rotor/bearing system dynamic stiffness measurements

    Science.gov (United States)

    Muszynska, A.

    1985-01-01

    Sweep perturbation testing as used in Modal Analysis when applied to a rotating machine has to take into consideration the machine dynamic state of equilibrium at its operational rotative speed. This stands in contrasts to a static equilibrium of nonrotating structures. The rotational energy has a significant influence on rotor dynamic characteristics. The best perturbing input for rotating machines is a forward or reverse rotating, circular force applied directly to the shaft. Determination of Dynamic Stiffness Characteristics of the rotor bearing system by nonsynchronous perturbation of a symmetric rotating shaft supported in one relatively rigid and one oil lubricated bearing.

  16. Dynamics and interactions of active rotors

    OpenAIRE

    de Leoni, M. (Massimiliano); Liverpool, T. B.

    2010-01-01

    We consider a simple model of an internally driven self-rotating object; a rotor, confined to two dimensions by a thin film of low Reynolds number fluid. We undertake a detailed study of the hydrodynamic interactions between a pair of rotors and find that their effect on the resulting dynamics is a combination of fast and slow motions. We analyse the slow dynamics using an averaging procedure to take account of the fast degrees of freedom. Analytical results are compared with numerical simula...

  17. Holographic vibration analysis of turbocharger turbine wheel instruction for use and benefit

    Science.gov (United States)

    Chambard, Jean-Pierre; Thouvenin, Denis

    2004-06-01

    Since the early 1990's, holography has been used worldwide to study the vibration of mechanical parts at the design stage. The so-called > technique on holographic plates was able to give accurate information on the vibration modes of structures. TV-Holography has simplified the data capture, and also has the ability to easily produce amplitude and phase maps. This optical method is a powerful tool for vibration analysis but it needs to be used carefully to gain the full benefit of the data recorded. Then several types of analysis of these data may bring to the mechanical designer key information for the future life of the designed mechanical part. In this paper, we present a complete vibration analysis of a turbocharger turbine wheel, including the two main following points: the holographic recording method and the data post-processing that is done by the vibration experts. Concerning the data recording we will emphasize the experimental conditions that lead to data that are useful for the mechanical engineer: wheel preparation, wheel boundary conditions, method of excitation, geometrical conditions, tests complementary to the holographic recording. Experimental results are reported, showing the effect of the experimental conditions on the eigenfrequencies, eigemodes and damping factor. Concerning High Cycle Fatigue (HCF) on turbine blades of turbochargers, Holography is of gret help in two instances, predictive behavior at design stage and field failures analysis. For the first task, Holography confirms/refines the 3 or 4 first modes predicted by FEA models, it gives the high order modes not predictable by models (especially coupled inducer/backdisc modes) and also the damping factors that are not accurately predicted. Those data are then fed into an "Harmonic Analysis" which allows the prediction of a forced response and, subsequently, an answer about robustness with respect to HCF. For the second task, Holography provides accurate nodal lines which can be

  18. How far is smart rotor research and what steps need to be taken to build a full-scale prototype?

    NARCIS (Netherlands)

    Bernhammer, L.O.; Van Kuik, G.A.M.; De Breuker, R.

    2014-01-01

    During the last decade research on the field of smart rotor has advanced significantly. Fundamental aerodynamics, structural and control concepts have been established and simulators created for distributed flaps on wind turbine blades, which are considered the most promising option. Also a proof of

  19. Diesel Engine Turbo-Charger Surge on Large Vessel%大型船用柴油机透平喘振的研究

    Institute of Scientific and Technical Information of China (English)

    高林波

    2011-01-01

    Since the diesel engine turbocharger surge on large vessel becomes a more frequently occurred trouble, this paper explores the inherent reasons of turbocharger surge by means of thermodynamic and hydrodynamics principles: the air through the blower is under the higher pressure and less flow condition. It explores the material reasons in 3 ways; turbocharger matches with engine, propeller and vessel each other, air and gas flow path and components, and engine combustion components. By many representative examples, this work provides analysis and effective methods to remove the turbocharger surge, to protect the main engine and turbocharger, to reduce the components damage and economic loss.%针对大型船用柴油机增压器喘振这一常见故障,采用热力学和流体力学原理阐述了增压器喘振的根本原因是流经压气机的气体形成高被压、小流量;从透平、机、浆、船适配及气体流通部件和柴油机燃烧部件3个方面分析了引起透平喘振的具体原因,并利用实例分析解决透平喘振的有效方法,以保护主机和透平,减少部件和经济损失.

  20. An exploratory investigation of the flight dynamics effects of rotor rpm variations and rotor state feedback in hover

    Science.gov (United States)

    Chen, Robert T. N.

    1992-01-01

    This paper presents the results of an analytical study conducted to investigate airframe/engine interface dynamics, and the influence of rotor speed variations on the flight dynamics of the helicopter in hover, and to explore the potential benefits of using rotor states as additional feedback signals in the flight control system. The analytical investigation required the development of a parametric high-order helicopter hover model, which included heave/yaw body motion, the rotor speed degree of freedom, rotor blade motion in flapping and lead-lag, inflow dynamics, a drive train model with a flexible rotor shaft, and an engine/rpm governor. First, the model was used to gain insight into the engine/drive train/rotor system dynamics and to obtain an improved simple formula for easy estimation of the dominant first torsional mode, which is important in the dynamic integration of the engine and airframe system. Then, a linearized version of the model was used to investigate the effects of rotor speed variations and rotor state feedback on helicopter flight dynamics. Results show that, by including rotor speed variations, the effective vertical damping decreases significantly from that calculated with a constant speed assumption, thereby providing a better correlation with flight test data. Higher closed-loop bandwidths appear to be more readily achievable with rotor state feedback. The results also indicate that both aircraft and rotor flapping responses to gust disturbance are significantly attenuated when rotor state feedback is used.

  1. Characterisation and modelling of the microstructural and mechanical evolution of a steam turbine rotor steel

    International Nuclear Information System (INIS)

    This dissertation deals with the effective mechanical analysis of steam turbine parts which is not only required for the reliable and safe use of newly built steam turbines, but also for the remaining life assessment of components that have been exposed to service duty over long periods of time. This Thesis aims to develop a physically motivated evolutionary constitutive model for a low-alloy bainitic 2CrMoNiWV (23CrMoNiWV8-8) steam turbine rotor steels. A comprehensive experimental characterisation is performed concerning the mechanical and microstructural evolution of 2CrMoNiWV as subjected to low cycle fatigue (LCF) deformation at elevated temperatures, at different strain rates and for various strain amplitudes. This cyclic plastic deformation causes the rearrangement of dislocations in the microstructure of the steels used for such rotor applications. Symmetric, strain controlled LCF experiments have been carried out in the Laboratory of the High Temperature Integrity Group at the Swiss Federal Laboratories for Materials Science and Technology EMPA. These include mechanical tests in the temperature range between 20 °C to 600 °C at strain rates of 0.001%/s to 1.0%/s and strain amplitudes of ±0.25% to ±1.0%. The LCF experiments reported on comprehensively characterise the temperature, strain rate and strain amplitude dependent cyclic elastic-plastic behaviour of 2CrMoNiWV. Both complete single-specimen endurance tests and interrupted multi-specimen tests have been performed. On the basis of this experimental evidence, an evolutionary formulation of the model is further developed that excellently reproduces the strain amplitude dependent mechanical evolution of 2CrMoNiWV when subjected to LCF loading at different constant strain amplitudes but equal temperature and strain rate. The simulation of benchmark experiments introducing increasing or decreasing strain amplitude steps into the LCF deformation history provide promising results. A further important

  2. The evaluation of the power coefficient of a Savonius rotor

    Science.gov (United States)

    Chauvin, A.; Botrini, M.; Brun, R.; Beguier, C.

    1983-03-01

    Measurements of the pressure variations and the blade drag on a Savonius rotor with partially overlapping blades set at different angles of attack are employed to develop a model for the power coefficient. The data were taken in a wind tunnel with probes placed on the interior and exterior surfaces of a blade from the leading edge to the trailing edge in a series of seven trials with each angle of attack. Two rotationary regimes were noted, the first, motoring, which lasted up to an angle of attack of 145 deg, and a resistant mode, which lasted up to 180 deg. A two-dimensional model is developed for a horizontal slice of the Savonius, taking into account the aerodynamic forces on the retreating and advancing blades. It is found that the drag increase with the rotation speed, eventually providing an upper limit to the power available. A maximum power coefficient of 0.17 is projected.

  3. Flap motion of helicopter rotors with novel, dynamic stall model

    Directory of Open Access Journals (Sweden)

    Han Wei

    2016-07-01

    Full Text Available In this paper, a nonlinear flapping equation for large inflow angles and flap angles is established by analyzing the aerodynamics of helicopter blade elements. In order to obtain a generalized flap equation, the Snel stall model was first applied to determine the lift coefficient of the helicopter rotor. A simulation experiment for specific airfoils was then conducted to verify the effectiveness of the Snel stall model as it applies to helicopters. Results show that the model requires no extraneous parameters compared to the traditional stall model and is highly accurate and practically applicable. Based on the model, the relationship between the flapping angle and the angle of attack was analyzed, as well as the advance ratio under the dynamic stall state.

  4. The effect of solidity on the performance of H-rotor Darrieus turbine

    Science.gov (United States)

    Hassan, S. M. Rakibul; Ali, Mohammad; Islam, Md. Quamrul

    2016-07-01

    Utilization of wind energy has been investigated for a long period of time by different researchers in different ways. Out of which, the Horizontal Axis Wind Turbine and the Vertical Axis Wind Turbine have now advanced design, but still there is scope to improve their efficiency. The Vertical Axis Wind Turbine (VAWT) has the advantage over Horizontal Axis Wind Turbine (HAWT) for working on omnidirectional air flow without any extra control system. A modified H-rotor Darrieus type VAWT is analysed in this paper, which is a lift based wind turbine. The effect of solidity (i.e. chord length, no. of blades) on power coefficient (CP) of H-rotor for different tip speed ratios is numerically investigated. The study is conducted using time dependent RANS equations using SST k-ω model. SIMPLE scheme is used as pressure-velocity coupling and in all cases, the second order upwind discretization scheme is chosen for getting more accurate solution. In results, different parameters are compared, which depict the performance of the modified H-rotor Darrieus type VAWT. Double layered H-rotor having inner layer blades with longer chord gives higher power coefficient than those have inner layer blades with smaller chord.

  5. Experimental Investigation of a Forward Swept Rotor in a Multistage Fan with Inlet Distortion

    Directory of Open Access Journals (Sweden)

    Aspi R. Wadia

    2011-01-01

    Full Text Available Previous studies of transonic swept rotors in single stage fans have demonstrated the potential of significant improvements in both efficiency and stall margin with forward swept blading. This paper extends the assessment of the payoff derived from forward sweep to multistage configurations. The experimental investigation compare two builds of an advanced two-stage fan configuration tested alternately with a radial and a forward swept stage 1 blade. In the two-stage evaluations, the testing was extended to include the effect on inlet flow distortion. While the common second stage among the two builds prevented the overall fan from showing clean inlet performance and stability benefits with the forward swept rotor 1, this configuration did demonstrate superior front stage efficiency and tolerance to inlet distortion. Having obtained already low distortion sensitivity with the radial rotor 1 configuration relative to current production military fan standards, the sensitivity to inlet distortion was halved with the forward swept rotor 1 configuration. In the case of the 180-degree one-per-rev distortion pattern, the two-stage configuration was evaluated both with and without inlet guide vanes (IGVs. The presence of the inlet guide vanes had a profound impact in lowering the two-stage fan's sensitivity with inlet distortion.

  6. Rotation-precession and rotor-rotor coupling in 4-methyl- pyridine

    International Nuclear Information System (INIS)

    The low temperature rotational dynamics of methyl groups in 4-methyl-pyridine is explained in terms of rotation-precession and rotor-rotor coupling. Initial estimates of the precession angle and the rotational potentials are obtained from molecular mechanics calculations. Experimental spectra are calculated from these potentials by numerical solution of Schroedinger's equation for clusters of coupled rotors embedded into a greater ensemble of rotors treated in the mean field approximation. The precession angle and the rotational potentials are adjusted to reproduce new high resolution INS spectra of protonated 4-methyl-pyridine measured at well defined spin temperatures. Excellent agreement with the experimental data is obtained for fully protonated 4-methyl-pyridine. Studying methyl group dynamics in 4MP offers the opportunity to measure potential energy changes on experimentally determined trajectories, thus providing valuable information that can be used to test the reliability of ab initio calculations and empirical force fields for the solid state

  7. Airloads Correlation of the UH-60A Rotor inside the 40- by 80-Foot Wind Tunnel

    Directory of Open Access Journals (Sweden)

    I-Chung Chang

    2014-01-01

    Full Text Available The presented research validates the capability of a loosely coupled computational fluid dynamics (CFD and comprehensive rotorcraft analysis (CRA code to calculate the flowfield around a rotor and test stand mounted inside a wind tunnel. The CFD/CRA predictions for the Full-Scale UH-60A Airloads Rotor inside the National Full-Scale Aerodynamics Complex (NFAC 40- by 80-Foot Wind Tunnel at NASA Ames Research Center are compared with the latest measured airloads and performance data. The studied conditions include a speed sweep at constant lift up to an advance ratio of 0.4 and a thrust sweep at constant speed up to and including stall. For the speed sweep, wind tunnel modeling becomes important at advance ratios greater than 0.37 and test stand modeling becomes increasingly important as the advance ratio increases. For the thrust sweep, both the wind tunnel and test stand modeling become important as the rotor approaches stall. Despite the beneficial effects of modeling the wind tunnel and test stand, the new models do not completely resolve the current airload discrepancies between prediction and experiment.

  8. Stability of rotor systems: A complex modelling approach

    DEFF Research Database (Denmark)

    Kliem, Wolfhard; Pommer, Christian; Stoustrup, Jakob

    1998-01-01

    The dynamics of a large class of rotor systems can be modelled by a linearized complex matrix differential equation of second order, Mz + (D + iG)(z) over dot + (K + iN)z = 0, where the system matrices M, D, G, K and N are real symmetric. Moreover M and K are assumed to be positive definite and D...... approach applying bounds of appropriate Rayleigh quotients. The rotor systems tested are: a simple Laval rotor, a Laval rotor with additional elasticity and damping in the bearings, and a number of rotor systems with complex symmetric 4 x 4 randomly generated matrices....

  9. Numerical evaluation of tandem rotor for highly loaded transonic fan

    Institute of Scientific and Technical Information of China (English)

    ZHAO Bin; LIU Bao-jie

    2011-01-01

    Transonic tandem rotor was designed for highly loaded fan at a corrected tip speed of 381 m/s and another conventional rotor was designed as a baseline to evaluate the loading superiority of tandem rotor with three-dimensional (3-D) numerical simulation. The aft blade solidity and its impact on total loading level were studied in depth. The result indicates that tandem rotor has potential to achieve higher loading level and attain favorable aerodynamic performance in a wide range of loading coefficient 0. 55 ~ 0.68, comparing with the conventional rotor which produced a total pressure ratio of 2.0 and loading coefficient of 0. 42.

  10. Time Frequency Features of Rotor Systems with Slowly Varying Mass

    Directory of Open Access Journals (Sweden)

    Tao Yu

    2011-01-01

    Full Text Available With the analytic method and numerical method respectively, the asymptotic solutions and finite element model of rotor system with single slowly varying mass is obtained to investigate the time frequency features of such rotor system; furthermore, with given model of slowly varying mass, the rotor system with dual slowly varying mass is studied. For the first order approximate solution is used, there exists difference between the results with analytic method and numerical method. On the base of common characteristics of rotor system with dual slowly varying mass, the general rules and formula describing the frequency distribution of rotor system with multiple slowly varying mass are proposed.

  11. On the flow field around a Savonius rotor

    Science.gov (United States)

    Bergeles, G.; Athanassiadis, N.

    A model of a two-bucket Savonius rotor windmill was constructed and tested in a wind tunnel. The flow field around the rotor was examined visually and also quantitatively with the use of a hot wire. The flow visualization revealed an upstream influence on the flow field up to 3 rotor diameters away and a strong downwash downstream. Hot wire measurements showed a large velocity deficit behind the rotor and a quick velocity recovery downstream due to strong mixing; the latter was associated with high levels of turbulence. Energy spectra revealed that all turbulence was concentrated in a single harmonic corresponding to twice the rotational speed of the rotor.

  12. Equivalence Between Squirrel Cage and Sheet Rotor Induction Motor

    Science.gov (United States)

    Dwivedi, Ankita; Singh, S. K.; Srivastava, R. K.

    2016-06-01

    Due to topological changes in dual stator induction motor and high cost of its fabrication, it is convenient to replace the squirrel cage rotor with a composite sheet rotor. For an experimental machine, the inner and outer stator stampings are normally available whereas the procurement of rotor stampings is quite cumbersome and is not always cost effective. In this paper, the equivalence between sheet/solid rotor induction motor and squirrel cage induction motor has been investigated using layer theory of electrical machines, so as to enable one to utilize sheet/solid rotor in dual port experimental machines.

  13. Nonlinear Vibration of Rotor Rubbing Stator Caused by Initial Perturbation

    Institute of Scientific and Technical Information of China (English)

    张小章; 隆锦胜; 李正光

    2001-01-01

    The vibration of a rotor rubbing a stator caused by an initial perturbation was studied analytically.The analytical model consists of a simple disc shaft rotor and a fixed stator. The perturbation is aninstantaneous change of the radial velocity when the rotor is operating in its normal steady state. The analysisshowed that the rotor may continue rubbing the stator for small clearance, even if the initial perturbation nolonger exists. For the interest of engineering applications, we investigated various rotating speeds,perturbation amplitudes and clearances between the rotor and the stator. Various friction coefficients on thecontact surface were also considered. The graphical results can be used for the design of rotating machines.``

  14. Eigenvalue assignment strategies in rotor systems

    Science.gov (United States)

    Youngblood, J. N.; Welzyn, K. J.

    1986-01-01

    The work done to establish the control and direction of effective eigenvalue excursions of lightly damped, speed dependent rotor systems using passive control is discussed. Both second order and sixth order bi-axis, quasi-linear, speed dependent generic models were investigated. In every case a single, bi-directional control bearing was used in a passive feedback stabilization loop to resist modal destabilization above the rotor critical speed. Assuming incomplete state measurement, sub-optimal control strategies were used to define the preferred location of the control bearing, the most effective measurement locations, and the best set of control gains to extend the speed range of stable operation. Speed dependent control gains were found by Powell's method to maximize the minimum modal damping ratio for the speed dependent linear model. An increase of 300 percent in stable speed operation was obtained for the sixth order linear system using passive control. Simulations were run to examine the effectiveness of the linear control law on nonlinear rotor models with bearing deadband. The maximum level of control effort (force) required by the control bearing to stabilize the rotor at speeds above the critical was determined for the models with bearing deadband.

  15. Flywheel system using wire-wound rotor

    Science.gov (United States)

    Chiao, Edward Young; Bender, Donald Arthur; Means, Andrew E.; Snyder, Philip K.

    2016-06-07

    A flywheel is described having a rotor constructed of wire wound onto a central form. The wire is prestressed, thus mitigating stresses that occur during operation. In another aspect, the flywheel incorporates a low-loss motor using electrically non-conducting permanent magnets.

  16. Rotor Systems of Aircraft Jet Engines

    Directory of Open Access Journals (Sweden)

    Ján Kamenický

    2000-01-01

    engine's both coaxial rotors, their supports (including their hydrodynamic dampers, and its casing as well. Besides the short description of the engine design peculiarities and of its calculating model, there is also a short description of the used method of calculations, with focus on its peculiarities as well. Finally, some results of calculations and conclusions that follow from them are presented.

  17. Development of the optimum rotor theories

    DEFF Research Database (Denmark)

    Okulov, Valery; Sørensen, Jens Nørkær; van Kuik, Gijs A.M.

    The purpose of this study is the examination of optimum rotor theories with ideal load distributions along the blades, to analyze some of the underlying ideas and concepts, as well as to illuminate them. The book gives the historical background of the issue and presents the analysis of the proble...

  18. Quantum beats of the rigid rotor

    OpenAIRE

    Kowalski, K.; Rembieliński, J.

    2013-01-01

    The dynamics is investigated of a free particle on a sphere (rigid rotor or rotator) that is initially in a coherent state. The instability of coherent states with respect to the free evolution leads to nontrivial time-development of averages of observables representing the position of a particle on a sphere that can be interpreted as quantum beats.

  19. rotor of the SC rotating condenser

    CERN Multimedia

    1974-01-01

    The rotor of the rotating condenser was installed instead of the tuning fork as the modulating element of the radiofrequency system, when the SC accelerator underwent extensive improvements between 1973 to 1975 (see object AC-025). The SC was the first accelerator built at CERN. It operated from August 1957 until it was closed down at the end of 1990.

  20. Rotor Vibration Reduction via Active Hybrid Bearings

    DEFF Research Database (Denmark)

    Nicoletti, Rodrigo; Santos, Ilmar

    2002-01-01

    The use of fluid power to reduce and control rotor vibration in rotating machines is investigated. An active hybrid bearing is studied, whose main objective is to reduce wear and vibration between rotating and stationary machinery parts. By injecting pressurised oil into the oil film, through...... with experiment, and simulations show the feasibility of controlling shaft vibration through this active device....

  1. MODIFIED SAVONIUS ROTOR FOR DOMESTIC POWER PRODUCTION

    Directory of Open Access Journals (Sweden)

    VINAY P V

    2012-07-01

    Full Text Available Conventional fuels which are fast depleting, have ever fluctuating price and polluting characteristic of theirs is pushing mankind towards energies which are renewable and green. Wind being one of the renewable energies among solar, geothermal, biomass, ocean and others is being more patronized in places where wind is copious by governmental and with private partnership to generate electricity. Vertical axis rotor was selected over the horizontal ones due to its simplicity and reliability. At a selected location a prototype was built and installed. The design and development process and the need of the new type of machine will be described in this paper. This paper produces an investigational exploration of a vertical axis rotor (Savonius rotor wind turbine adapted for household/domestic electricity generation. The model machine collects wind energy and generates a 12 volt output which is used to charge one heavy duty battery. As a result, the home is served simultaneously by the wind turbine and the utility. The wind turbine responds well to low wind velocities and also various materials for vanes, various transmission mechanisms were also tried to evaluate the performance of the rotor.

  2. Rotor Design for Diffuser Augmented Wind Turbines

    Directory of Open Access Journals (Sweden)

    Søren Hjort

    2015-09-01

    Full Text Available Diffuser augmented wind turbines (DAWTs can increase mass flow through the rotor substantially, but have often failed to fulfill expectations. We address high-performance diffusers, and investigate the design requirements for a DAWT rotor to efficiently convert the available energy to shaft energy. Several factors can induce wake stall scenarios causing significant energy loss. The causality between these stall mechanisms and earlier DAWT failures is discussed. First, a swirled actuator disk CFD code is validated through comparison with results from a far wake swirl corrected blade-element momentum (BEM model, and horizontal-axis wind turbine (HAWT reference results. Then, power efficiency versus thrust is computed with the swirled actuator disk (AD code for low and high values of tip-speed ratios (TSR, for different centerbodies, and for different spanwise rotor thrust loading distributions. Three different configurations are studied: The bare propeller HAWT, the classical DAWT, and the high-performance multi-element DAWT. In total nearly 400 high-resolution AD runs are generated. These results are presented and discussed. It is concluded that dedicated DAWT rotors can successfully convert the available energy to shaft energy, provided the identified design requirements for swirl and axial loading distributions are satisfied.

  3. A numerical study of automotive turbocharger mixed flow turbine inlet geometry for off design performance

    International Nuclear Information System (INIS)

    Mixed flow turbines represent a potential solution to the increasing requirement for high pressure, low velocity ratio operation in turbocharger applications. While literature exists for the use of these turbines at such operating conditions, there is a lack of detailed design guidance for defining the basic geometry of the turbine, in particular, the cone angle – the angle at which the inlet of the mixed flow turbine is inclined to the axis. This investigates the effect and interaction of such mixed flow turbine design parameters. Computational Fluids Dynamics was initially used to investigate the performance of a modern radial turbine to create a baseline for subsequent mixed flow designs. Existing experimental data was used to validate this model. Using the CFD model, a number of mixed flow turbine designs were investigated. These included studies varying the cone angle and the associated inlet blade angle. The results of this analysis provide insight into the performance of a mixed flow turbine with respect to cone and inlet blade angle

  4. Modelling of Outer and Inner Film Oil Pressure for Floating Ring Bearing Clearance in Turbochargers

    Science.gov (United States)

    Zhang, Hao; Shi, Zhanqun; Gu, Fengshou; Ball, Andrew

    2011-07-01

    Floating ring bearing is widely used in turbochargers to undertake the extreme condition of high rotating speed and high operating temperature. It is also the most concerned by the designers and users alike due to its high failure rate and high maintenance cost. Any little clearance change may result in oil leakage, which in turn cause blue smoke or black smoke according to leakage types. However, there is no condition monitoring of this bearing because it is almost impossible to measure the clearance especially the inner clearance, in which the inner oil film directly bears the high speed rotation. In stead of measuring clearance directly, this paper has proposed a method that uses film pressure as a measure to monitor the bearing clearance and its variation. A non-linear mathematical model is developed by using Reynolds equations with non-linear oil film pressure. A full description of the outer and inner film is provided along both axial and radial directions. A numerical simulation is immediately carried out. Variable clearance changes are investigated using the mathematical model. Results show the relationship between clearance and film pressure.

  5. A numerical study of automotive turbocharger mixed flow turbine inlet geometry for off design performance

    Science.gov (United States)

    Leonard, T.; Spence, S.; Early, J.; Filsinger, D.

    2013-12-01

    Mixed flow turbines represent a potential solution to the increasing requirement for high pressure, low velocity ratio operation in turbocharger applications. While literature exists for the use of these turbines at such operating conditions, there is a lack of detailed design guidance for defining the basic geometry of the turbine, in particular, the cone angle - the angle at which the inlet of the mixed flow turbine is inclined to the axis. This investigates the effect and interaction of such mixed flow turbine design parameters. Computational Fluids Dynamics was initially used to investigate the performance of a modern radial turbine to create a baseline for subsequent mixed flow designs. Existing experimental data was used to validate this model. Using the CFD model, a number of mixed flow turbine designs were investigated. These included studies varying the cone angle and the associated inlet blade angle. The results of this analysis provide insight into the performance of a mixed flow turbine with respect to cone and inlet blade angle.

  6. Research on Control-Oriented Modeling for Turbocharged SI and DI Gasoline Engines

    Directory of Open Access Journals (Sweden)

    Feitie Zhang

    2015-01-01

    Full Text Available In order to analyze system performance and develop model-based control algorithms for turbocharged spark ignition and direct injection (SIDI gasoline engines, a control oriented mean value model is developed and validated. The model is constructed based on theoretical analysis for the different components, including the compressor, turbine, air filter, intercooler, throttle, manifold, and combustion chamber. Compressor mass flow and efficiency are modeled as parameterized functions. A standard nozzle model is used to approximate the mass flow through the turbine, and the turbine efficiency is modeled as a function of blade speed ratio (BSR. The air filter is modeled as a tube for capturing its pressure drop feature. The effectiveness number of transfer units (NTU modeling method is utilized for the intercooler. The throttle model consists of the standard nozzle model with an effective area regressed to throttle position. Manifolds are modeled for their dynamically varying pressure state. For the cylinder, the air mass flow into cylinders, fuel mass, torque, and exhaust temperature are modeled. Compared to the conventional lookup table approach, transient dynamics error can be improved significantly through using the model from this work.

  7. Comparison of Propane and Methane Performance and Emissions in a Turbocharged Direct Injection Dual Fuel Engine

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, C. M.; Polk, A. C.; Shoemaker, N. T.; Srinivasan, K. K.; Krishnan, S. R.

    2011-01-01

    With increasingly restrictive NO x and particulate matter emissions standards, the recent discovery of new natural gas reserves, and the possibility of producing propane efficiently from biomass sources, dual fueling strategies have become more attractive. This paper presents experimental results from dual fuel operation of a four-cylinder turbocharged direct injection (DI) diesel engine with propane or methane (a natural gas surrogate) as the primary fuel and diesel as the ignition source. Experiments were performed with the stock engine control unit at a constant speed of 1800 rpm, and a wide range of brake mean effective pressures (BMEPs) (2.7-11.6 bars) and percent energy substitutions (PESs) of C 3 H 8 and CH 4. Brake thermal efficiencies (BTEs) and emissions (NO x, smoke, total hydrocarbons (THCs), CO, and CO 2) were measured. Maximum PES levels of about 80-95% with CH 4 and 40-92% with C 3 H 8 were achieved. Maximum PES was limited by poor combustion efficiencies and engine misfire at low loads for both C 3 H 8 and CH 4, and the onset of knock above 9 bar BMEP for C 3 H 8. While dual fuel BTEs were lower than straight diesel BTEs at low loads, they approached diesel BTE values at high loads. For dual fuel operation, NO x and smoke reductions (from diesel values) were as high as 66-68% and 97%, respectively, but CO and THC emissions were significantly higher with increasing PES at all engine loads

  8. Rotor Performance Enhancement Using Slats on the Inner Part of a 10MW Rotor

    DEFF Research Database (Denmark)

    Gaunaa, Mac; Zahle, Frederik; Sørensen, Niels N.;

    2013-01-01

    The present work continues the investigations of using slats on the inner parts of wind turbine rotors by using an updated version of the 2D CFD based airfoil/slat design tool earlier used by the authors in combination with the rotor design methods from [8] to design slats for 0:1 > r=R > 0:3 for...... the LightRotor baseline 10 MW reference rotor [10]. For the slatted case, a retwisting of the slatted inner part of the rotor was allowed for the slats to be able to work as intended. The new addition to the 2D CFD based design tool is that the representation of the airfoil and slats are done using...... splines, thus allowing for a much broader design space than in the previous works where only the position, size and additional camber of the slat airfoil could be adjusted. The aerodynamic performance of a slatted rotor is for the first time evaluated using 3D CFD in this work, and the results are...

  9. Rotor Performance Enhancement Using Slats on the Inner Part of a 10MW Rotor

    DEFF Research Database (Denmark)

    The present work continues the investigations of using slats on the inner parts of wind turbine rotors by using an updated version of the 2D CFD based airfoil/slat design tool earlier used by the authors in combination with the rotor design methods from [8] to design slats for 0:1 > r=R > 0:3 for...... the LightRotor baseline 10 MW reference rotor [10]. For the slatted case, a retwisting of the slatted inner part of the rotor was allowed for the slats to be able to work as intended. The new addition to the 2D CFD based design tool is that the representation of the airfoil and slats are done using...... splines, thus allowing for a much broader design space than in the previous works where only the position, size and additional camber of the slat airfoil could be adjusted. The aerodynamic performance of a slatted rotor is for the first time evaluated using 3D CFD in this work, and the results are...

  10. Utilization of rotor kinetic energy storage for hybrid vehicles

    Science.gov (United States)

    Hsu, John S.

    2011-05-03

    A power system for a motor vehicle having an internal combustion engine, the power system comprises an electric machine (12) further comprising a first excitation source (47), a permanent magnet rotor (28) and a magnetic coupling rotor (26) spaced from the permanent magnet rotor and at least one second excitation source (43), the magnetic coupling rotor (26) also including a flywheel having an inertial mass to store kinetic energy during an initial acceleration to an operating speed; and wherein the first excitation source is electrically connected to the second excitation source for power cycling such that the flywheel rotor (26) exerts torque on the permanent magnet rotor (28) to assist braking and acceleration of the permanent magnet rotor (28) and consequently, the vehicle. An axial gap machine and a radial gap machine are disclosed and methods of the invention are also disclosed.

  11. Reliable disk-type rotors for nuclear power plants

    International Nuclear Information System (INIS)

    Experience gained over the last 15 years has been outstanding with all low pressure (LP) turbine disk-type rotors of the authors' company employed in nuclear power plants. Not a single event of stress corrosion cracking has been found. A total of 40 rotors are in operation averaging close to seven years of service. Eleven of these rotors have been in operation for an average of 59,000 hours with a maximum of 83,000 hours before the first ultrasonic inspection was performed. No stress corrosion cracks were identified by these inspections which, in all cases, covered 100% volume of the entire disk hub bore and keyway area of all rotor disks. Reports of stress corrosion cracking of other disk-type LP rotors, however, initiated extensive research and development work to improve even further the disk-type rotor to a level where it becomes fully competitive with monoblock rotors in regard to equally reliable operating performance

  12. The inclusion of rotor dynamics in controller design for helicopters.

    Science.gov (United States)

    Hall, W. E., Jr.; Bryson, A. E., Jr.

    1972-01-01

    State-feedback-controllers and state-estimators (filters) are designed for the roll-pitch-horizontal motions of a helicopter near hover, using a new quadratic synthesis technique. One model (tenth order) uses a dynamic model of the rotor, whereas the other model (sixth order) assumes the rotor can be tilted instantaneously. It is shown that, for tight control, neglecting the rotor dynamics in designing the autopilot can produce unstable closed-loop response on the model that includes rotor dynamics. Two filters are designed to use only fuselage sensors and two are designed to use both fuselage and rotor sensors. It is shown that rotor states can be estimated with sufficient accuracy using only fuselage sensors so that it does not seem worthwhile to use rotor sensors. The mean square response of the vehicle to a gusty, random wind, using several different filter/state-feedback compensators, is shown to be satisfactory.

  13. The rotor theories by Professor Joukowsky: Vortex theories

    DEFF Research Database (Denmark)

    Okulov, Valery L.; Sørensen, Jens Nørkær; Wood, David H.

    2015-01-01

    This is the second of two articles with the main, and largely self-explanatory, title "Rotor theories by Professor Joukowsky". This article considers rotors with finite number of blades and is subtitled "Vortex theories". The first article with subtitle "Momentum theories", assessed the starring...... role of Joukowsky in aerodynamics in the historical context of rotor theory. The main focus in both articles is on wind turbine rotors, but much of the basic theory applies to propellers and helicopters as well. Thus this second article concentrates on the so-called blade element theory, the Kutta......-Joukowsky theorem, and the development of the rotor vortex theory of Joukowsky. This article is to a large extent based on our own work, which constitutes the first successful completion and further development of Joukowsky's work by deriving the first analytical solution of his rotor. This rotor has a finite...

  14. Boost Pressure Control Strategy to Account for Transient Behavior and Pumping Losses in a Two-Stage Turbocharged Air Path Concept

    Directory of Open Access Journals (Sweden)

    Thivaharan Albin

    2016-07-01

    Full Text Available Increasingly complex air path concepts are investigated to achieve a substantial reduction in fuel consumption while improving the vehicle dynamics. One promising technology is the two-stage turbocharging for gasoline engines, where a high pressure and a low pressure turbocharger are placed in series. For exploiting the high potential, a control concept has to be developed that allows for coordinated management of the two turbocharger stages. In this paper, the control strategy is investigated. Therefore, the effect of the actuated values on transient response and pumping losses is analyzed. Based on these findings, an optimization-based control algorithm is developed that allows taking both requirements into account. The developed new controller allows achieving a fast transient response, while at the same time reducing pumping losses in stationary operation.

  15. 基于PLC的柴油机大小涡轮相继增压控制系统设计%Design of Sequential Turbocharging Control System for Diesel Engine with Two Unequal Turbochargers Based on PLC

    Institute of Scientific and Technical Information of China (English)

    李先南; 王银燕; 杨传雷; 王贺春

    2012-01-01

    A three staged sequential turbocharging control system of the TBD234V12 diesel engine is designed. The PLC of SIMENS S7-300 series is used as the core to build hardware configuration of the control system. To satisfy the requirements of three staged sequential turbocharging control system, STEP 7 software development control procedures are applied, which mainly controls semesters to switch velocity and delay. The monitoring interface of the control system is designed by KingView software. The debugging and running of the control system proves that the three staged sequential turbocharging control system of diesel engine based on PLC is safe and reliable%设计了TBD234V12柴油机大小涡轮三区相继增压控制系统.以西门子S7-300系列PLC为核心构建控制系统的硬件配置,用STEP 7软件编写控制程序来满足柴油机大小涡轮相继增压系统的控制要求,其主要控制参数为切换转速和切换延迟.用组态王(KingView)软件设计控制系统的监控界面.经调试运行表明,基于PLC的柴油机大小涡轮相继增压控制系统安全可靠.

  16. Several Common Turbocharger Noises and Control%几种常见涡轮增压器噪声及其控制

    Institute of Scientific and Technical Information of China (English)

    王钦庆

    2012-01-01

    The paper introduces several common turbocharger noises and describes noise spectrum and frequency range, mechanisms and control methods, providing a reference for development of turbocharger systems.%本文简单阐述了涡轮增压器开发过程中几种常见的噪声,对其音谱特征,辨别方法,产生机理和控制方法进行了描述,为涡轮增压器降噪开发提供参考。

  17. 增压车型真空源设计分析研究%Design analysis research of vaccum source for turbocharged vechile

    Institute of Scientific and Technical Information of China (English)

    李光明; 施亮; 刘辉

    2011-01-01

    Design for vacuum source of some certain turbocharged vehile,and compare with theory and experiment of natual air inspiration,provide theory support and experiment verification method for vehicle design of turbocharged engine for later matching.%对某款增压车型的真空源进行了设计,并通过与自然吸气发动机的理论和试验进行比较,为后期匹配增压发动机的整车设计提供理论支持和试验验证方法。

  18. Artificial Neural Network Based Rotor Capacitive Reactance Control for Energy Efficient Wound Rotor Induction Motor

    Directory of Open Access Journals (Sweden)

    K. Siva Kumar

    2012-01-01

    Full Text Available Problem statement: The Rotor reactance control by inclusion of external capacitance in the rotor circuit has been in recent research for improving the performances of Wound Rotor Induction Motor (WRIM. The rotor capacitive reactance is adjusted such that for any desired load torque the efficiency of the WRIM is maximized. The rotor external capacitance can be controlled using a dynamic capacitor in which the duty ratio is varied for emulating the capacitance value. This study presents a novel technique for tracking maximum efficiency point in the entire operating range of WRIM using Artificial Neural Network (ANN. The data for ANN training were obtained on a three phase WRIM with dynamic capacitor control and rotor short circuit at different speed and load torque values. Approach: A novel neural network model based on the back-propagation algorithm has been developed and trained in determining the maximum efficiency of the motor with no prior knowledge of the machine parameters. The input variables to the ANN are stator current (Is, Speed (N and Torque (Tm and the output variable is the duty ratio (D. Results: The target is pre-set and the accuracy of the ANN model is measured using Mean Square Error (MSE and R2 parameters. The result of R2 value of the proposed ANN model is found to be 0.99980. Conclusion: The optimal duty ratio and corresponding optimal rotor capacitance for improving the performances of the motor are predicted for low, medium and full loads by using proposed ANN model.

  19. Determination of Number of Broken Rotor Bars in Squirrel-Cage Induction Motors Using Adaptive Neuro-Fuzzy Interface System

    Directory of Open Access Journals (Sweden)

    Mehran Amani Juneghani

    2012-09-01

    Full Text Available For determination the number of broken rotor bars in squirrel-cage induction motors when these motors are working, this study presents a new method based on an intelligent processing of the stator transient starting current. In light load condition, distinguishing between safe and faulty rotors is difficult, because the characteristic frequencies of rotor with broken bars are very close to the fundamental component and their amplitudes are small in comparison. In this study, an advanced technique based on the Wavelet Adaptive Neuro-Fuzzy Interface System is suggested for processing the starting current of induction motors. In order to increase the efficiency of the proposed method, the results of the wavelet analysis, before applying to the Adaptive Neuro-Fuzzy Interface System, are processed by Principal Component Analysis (PCA. Then the outcome results are supposed as Adaptive Neuro-Fuzzy Interface System's training and testing data set. The trained Adaptive Neuro-Fuzzy Interface Systems undertake of determining the number of broken rotor bars. The given statistical results, announce the proposed method’s high ability to determine the number of broken rotor bars. The proposed method is independent from loading conditions of machine and it is useable even when the motor is unloaded.

  20. Analysis of Two Stroke Marine Diesel Engine Operation Including Turbocharger Cut-Out by Using a Zero-Dimensional Model

    OpenAIRE

    Cong Guan; Gerasimos Theotokatos; Hui Chen

    2015-01-01

    In this article, the operation of a large two-stroke marine diesel engine including various cases with turbocharger cut-out was thoroughly investigated by using a modular zero-dimensional engine model built in MATLAB/Simulink environment. The model was developed by using as a basis an in-house modular mean value engine model, in which the existing cylinder block was replaced by a more detailed one that is capable of representing the scavenging ports-cylinder-exhaust valve processes. Simulatio...

  1. Noise Benefits of Rotor Trailing Edge Blowing for a Model Turbofan

    Science.gov (United States)

    Woodward, Richard P.; Fite, E. Brian; Podboy, Gary G.

    2007-01-01

    An advanced model turbofan was tested in the NASA Glenn 9- by 15-Foot Low Speed Wind Tunnel (9x15 LSWT) to explore far field acoustic effects associated with rotor Trailing-Edge-Blowing (TEB) for a modern, 1.294 stage pressure ratio turbofan model. The TEB rotor (Fan9) was designed to be aerodynamically similar to the previously tested Fan1, and used the same stator and nacelle hardware. Fan9 was designed with trailing edge blowing slots using an external air supply directed through the rotor hub. The TEB flow was heated to approximate the average fan exit temperature at each fan test speed. Rotor root blockage inserts were used to block TEB to all but the outer 40 and 20% span in addition to full-span blowing. A configuration with full-span TEB on alternate rotor blades was also tested. Far field acoustic data were taken at takeoff/approach conditions at 0.10 tunnel Mach. Far-field acoustic results showed that full-span blowing near 2.0% of the total flow could reduce the overall sound power level by about 2 dB. This noise reduction was observed in both the rotor-stator interaction tones and for the spectral broadband noise levels. Blowing only the outer span region was not very effective for lowering noise, and actually increased the far field noise level in some instances. Full-span blowing of alternate blades at 1.0% of the overall flow rate (equivalent to full-span blowing of all blades at 2.0% flow) showed a more modest noise decrease relative to full-span blowing of all blades. Detailed hot film measurements of the TEB rotor wake at 2.0% flow showed that TEB was not every effective for filling in the wake defect at approach fan speed toward the tip region, but did result in overfilling the wake toward the hub. Downstream turbulence measurements supported this finding, and support the observed reduction in spectral broadband noise.

  2. [Treatment of organic waste gas by adsorption rotor].

    Science.gov (United States)

    Zhu, Run-Ye; Zheng, Liang-Wei; Mao, Yu-Bo; Wang, Jia-De

    2013-12-01

    The adsorption rotor is applicable to treating organic waste gases with low concentration and high air volume. The performance of adsorption rotor for purifying organic waste gases was investigated in this paper. Toluene was selected as the simulative gaseous pollutant and the adsorption rotor was packed with honeycomb modified 13X molecular sieves (M-13X). Experimental results of the fixed adsorption and the rotor adsorption were analyzed and compared. The results indicated that some information on the fixed adsorption was useful for the rotor adsorption. Integrating the characteristics of the adsorbents, waste gases and the structures of the rotor adsorption, the formulas on optimal rotor speed and cycle removal efficiency of the adsorption rotor were deduced, based on the mass and heat balances of the adsorbing process. The numerical results were in good agreement with the experimental data, which meant that the formulas on optimal rotor speed and cycle removal efficiency could be effectively applied in design and operation of the adsorption rotor.

  3. Evaluation of Comparative Performance of Three Wind Turbine Rotors

    Directory of Open Access Journals (Sweden)

    Basharat Salim

    2013-01-01

    Full Text Available This study presents the performance evaluation of wind turbine implementing the mathematical model based on Blade Element Momentum (BEM theory. The investigation concentrates on the comparison of power producing characteristics of three types of rotors for a horizontal axis wind turbine. The rotors considered have rectangular plan form shape with sections fabricated from aerofoil sections of NACA families. The three families of NACA airfoils used in this investigation are NACA4424, NACA23024 and NACA62-206. The lift and drag characteristics, of the rotors were experimentally obtained using 250 mm span and 60 mm chord rotor blades in an Armfield 300×300 mm subsonic, suction type and closed jet wind tunnel. The wind speeds used in the investigation were in the range of 8 to 11 m/s, which is the range of wind speeds found near the coastal belt and the mountainous parts of Saudi Arabia. Three bladed rotor subscale models of the wind turbines rotors having 250 mm rotor diameter, 100 mm blade span and 30 mm chord were used for testing rotational behavior of the wind turbines in a Plinth 600×600 mm blow down wind tunnel facility. The parameters used for the comparison in this study include variations in setting angle, diameters, tip speed ratio, taper, wind speed and angle of attack. It is observed that rotors with NACA4424 aerofoil sectioned blades produce more power at lower wind speeds and lower angles of attack where as rotors with NACA23024 aerofoil sectioned blades generate better performance at higher wind speeds and higher angles of attack. Further the taper of the rotors produced more decrease in the mass of the rotors than the decrease power produced by these. The reduction in mass could drastically decrease the inertia of the rotors which could result in higher rotational motions. Results depict the dependence of power produced on the Cd/Cl characteristics of the rotors.

  4. Reduced In-Plane, Low Frequency Helicopter Noise of an Active Flap Rotor

    Science.gov (United States)

    Sim, Ben W.; Janakiram, Ram D.; Barbely, Natasha L.; Solis, Eduardo

    2009-01-01

    Results from a recent joint DARPA/Boeing/NASA/Army wind tunnel test demonstrated the ability to reduce in-plane, low frequency noise of the full-scale Boeing-SMART rotor using active flaps. Test data reported in this paper illustrated that acoustic energy in the first six blade-passing harmonics could be reduced by up to 6 decibels at a moderate airspeed, level flight condition corresponding to advance ratio of 0.30. Reduced noise levels were attributed to selective active flap schedules that modified in-plane blade airloads on the advancing side of the rotor, in a manner, which generated counteracting acoustic pulses that partially offset the negative pressure peaks associated with in-plane, steady thickness noise. These favorable reduced-noise operating states are a strong function of the active flap actuation amplitude, frequency and phase. The associated noise reductions resulted in reduced aural detection distance by up to 18%, but incurred significant vibratory load penalties due to increased hub shear forces. Small reductions in rotor lift-to-drag ratios, of no more than 3%, were also measured

  5. Effect of self recirculation casing treatment on the performance of a turbocharger centrifugal compressor

    Science.gov (United States)

    Gancedo, Matthieu

    Increase in emission regulations in the transport industry brings the need to have more efficient engines. A path followed by the automobile industry is to downsize the size of the internal combustion engine and increase the air density at the intake to keep the engine power when needed. Typically a centrifugal compressor is used to force the air into the engine, it can be powered from the engine shaft (superchargers) or extracting energy contained into the hot exhaust gases with a turbine (turbochargers). The flow range of the compressor needs to match the one of the engine. However compressors mass flow operating range is limited by choke on the high end and surge on the low end. In order to extend the operation at low mass flow rates, the use of passive devices for turbocharger centrifugal compressors was explored since the late 80's. Hence, casing treatments including flow recirculation from the inducer part of the compressor have been shown to move the surge limit to lower flows. Yet, the working mechanisms are still not well understood and thus, to optimize the design of this by-pass system, it is necessary to determine the nature of the changes induced by the device both on the dynamic stability of the pressure delivery and on the flow at the inlet. The compressor studied here features a self-recirculating casing treatment at the inlet. The recirculation passage could be blocked to carry a direct comparison between the cases with and without the flow feature. To grasp the effect on compressor stability, pressure measurements were taken in the different constituting elements of the compressor. The study of the mean pressure variations across the operating map showed that the tongue region is a limiting element. Dynamic pressure measurements revealed that the instabilities generated near the inducer when the recirculation is blocked increase the overall instability levels at the compressor outlet and propagating pressure waves starting at the tongue occurred

  6. Friction rotor gear shafts for hydraulic turbines

    Energy Technology Data Exchange (ETDEWEB)

    Staehle, M.; Schuch, M.; Theiler, U.

    1986-01-01

    In friction couplings of hydraulic turbines, the torque is transferred via highly pretensioned screw connections. This has several technical advantages over older forms of construction, such as a more homogeneous transfer of power, a reduction in shearing and a better exchangeability of the rotors. For this reason, friction coupling has been used by many manufacturers in the last few years. Some problems of detail which have recently been the cause of discussion will have to be subjected to more detailed investigation: The temperature stresses encountered upon sudden cooling down of the rotors after longer periods of phase converter operation, and the effect of increased centrifugal force in case of a burnthrough of the machine unit. To begin with, an examination is made of some of the difficulties encountered with friction couplings and the usual design practice for friction couplings.

  7. Estimation of cyclic durability for turbine rotors

    International Nuclear Information System (INIS)

    The paper deals with data on the effect of asymetry and cycle form on low-cycle fatigue and injurability of and 15kh1m1f rotor steels at high temperatures. It is shown that the sum of injuries from the effect of cyclic and static loads may vary within the limits of-1.2. The steels were analyzed for strength effect on their deformation kinetics and durability. It is noted that the low-cycle fatigue curves in the ''complete deformation scale-cycle number'' coordinates do not depend on the strength level, and therefore it is concluded possible to use these curves for estimating the turbine rotor material durability

  8. Simulation of flow around rotating Savonius rotors

    Science.gov (United States)

    Ishimatsu, Katsuya; Shinohara, Toshio

    1993-09-01

    Flow around Savonius rotors was simulated by solving 2-D (two-dimensional) Navier-Stokes equations. The equations were discretized by finite volume method for space and fractional step method for time. Convection terms were specially discretized by an upwinding scheme for unstructured grid. Only rotating rotors were simulated in this report. The values of parameters were as follows: Reynolds number, 10(exp 5); overlap ratio, zero and 0.16; and tip speed ratio, 0.25 to 1.75. Results showed good agreement with experimental data for the following points: optimum tip speed ratio is 0.75 to 1.0; overlapping is effective to increase power coefficient. Moreover, simulated flow fields showed that vortex shedding occur at not only tips of bucket but back of bucket and the shed vortex decrease torque.

  9. Vortex shedding by a Savonius rotor

    Science.gov (United States)

    Botrini, M.; Beguier, C.; Chauvin, A.; Brun, R.

    1984-05-01

    A series of flow visualizations was performed to characterize the wake vortices of a Savonius rotor. The trials were undertaken in an attempt to account for discrepancies between theoretical and experimentally-derived power coefficients. The Savonius examined was two-bladed with a center offset. All tests were made in a water tunnel. Dye injection provided the visualization, and average velocities and velocity fluctuations were measured using a laser Doppler anemometer. A system of three vortices was found to be periodically shed by the rotor. Flow velocity fluctuation intensity peaked as a vortex was shed. The vortex shedding alternated from blade to blade, so that one was shed from a blade moving upstream.

  10. The Dynamics of Rotor with Rubbing

    Directory of Open Access Journals (Sweden)

    Jerzy T. Sawicki

    1999-01-01

    characteristics of rub-induced rotor response, initial conditions, as well as appropriate ranges of system parameters. Of special interest are the changes in the apparent nonlinearity of the system dynamics as rubs are induced at different rotor speeds. In particular, starting with 2nd order sub/superharmonics, which are symptomatic of quadratic nonlinearity, progressively higher order polynomial behavior is excited, i.e., cubic, giving rise to 3rd order sub/superharmonics. As the speed is transitioned between such apparent nonlinearities, chaotic like behavior is induced because of the lack of whole or rational tone tuning between the apparent system frequency and the external source noise. The cause of such behavior will be discussed in detail along with the results of several parametric studies.

  11. Electrofriction method of manufacturing squirrel cage rotors

    Science.gov (United States)

    Hsu, John S.

    2005-04-12

    A method of making a squirrel cage rotor of copper material for use in AC or DC motors, includes forming a core with longitudinal slots, inserting bars of conductive material in the slots, with ends extending out of opposite ends of the core, and joining the end rings to the bars, wherein the conductive material of either the end rings or the bars is copper. Various methods of joining the end rings to the bars are disclosed including electrofriction welding, current pulse welding and brazing, transient liquid phase joining and casting. Pressure is also applied to the end rings to improve contact and reduce areas of small or uneven contact between the bar ends and the end rings. Rotors made with such methods are also disclosed.

  12. Rotor theories by Professor Joukowsky: Momentum theories

    DEFF Research Database (Denmark)

    van Kuik, G. A. M.; Sørensen, Jens Nørkær; Okulov, V. L.

    2015-01-01

    This paper is the first of two papers on the history of rotor aerodynamics with special emphasis on the role of Joukowsky. The present one focuses on the development of the momentum theory while the second one surveys the development of vortex theory for rotors. Joukowsky has played a major role......, and the contributions by individual researchers like Lanchester, Prandtl, Betz and Joukowslcy himself. After the one-dimensional momentum theory was well established, the introduction of torque and angular momentum was the next step. Joukowslcy has led the basis for this step, but Glauert's Blade Element Momentum still...... of inviscid flow. For very low tip speed ratios the general momentum theory gives unphysical results which disappear after applying a perturbation parameter representing phenomena not captured by the Euler equations. (C) 2014 Elsevier Ltd. All rights reserved....

  13. Prediction of aerodynamic performance for MEXICO rotor

    DEFF Research Database (Denmark)

    Hong, Zedong; Yang, Hua; Xu, Haoran;

    2013-01-01

    . The boundaries of fan-shaped both sides are defined as rotationally periodic connection, and the freeze rotor model is applied at the interface of the rotating and stationary domains, which means the relative position of rotating and stationary domains is fixed when calculating the flow field. Speed no......The aerodynamic performance of the MEXICO (Model EXperiments In Controlled cOnditions) rotor at five tunnel wind speeds is predicted by making use of BEM and CFD methods, respectively, using commercial MATLAB and CFD software. Due to the pressure differences on both sides of the blade, the tip-flow...... will produce secondary flow along the blade, consecutively resulting in decreases of torque. To overcome the above-mentioned issue, a variety of tip-correction models are developed, while most models overestimate the axial and tangential forces. To optimize accuracy, a new correction model summarized from CFD...

  14. Kicked rotor quantum resonances in position space

    OpenAIRE

    Lepers, Maxence; Zehnlé, Véronique; Garreau, Jean Claude

    2008-01-01

    We present an approach of the kicked rotor quantum resonances in position-space, based on its analogy with the optical Talbot effect. This approach leads to a very simple picture of the physical mechanism underlying the dynamics and to analytical expressions for relevant physical quantities, such as mean momentum or kinetic energy. The ballistic behavior, which is closely associated to quantum resonances, is analyzed and shown to emerge from a coherent adding of successive kicks applied to th...

  15. Dark rotors in the late universe.

    Science.gov (United States)

    Mayer, Frederick J

    2015-11-01

    The tresino phase-transition that took place about 300 years after the big-bang, converted most baryons into almost equal numbers of protons and tresinos. Many of these become oppositely-charged rotating pairs or "rotors". This paper examines the formation, evolution, disposition and observations of the protons and tresinos from the phase-transition to the present era. The solar corona is further examined within the same tresino phase-transition picture. PMID:27441225

  16. MODIFIED SAVONIUS ROTOR FOR DOMESTIC POWER PRODUCTION

    OpenAIRE

    VINAY P V

    2012-01-01

    Conventional fuels which are fast depleting, have ever fluctuating price and polluting characteristic of theirs is pushing mankind towards energies which are renewable and green. Wind being one of the renewable energies among solar, geothermal, biomass, ocean and others is being more patronized in places where wind is copious by governmental and with private partnership to generate electricity. Vertical axis rotor was selected over the horizontal ones due to its simplicity and reliability. At...

  17. Accelerator dynamics of a fractional kicked rotor

    OpenAIRE

    Iomin, A.

    2006-01-01

    It is shown that the Weyl fractional derivative can quantize an open system. A fractional kicked rotor is studied in the framework of the fractional Schrodinger equation. The system is described by the non-Hermitian Hamiltonian by virtue of the Weyl fractional derivative. Violation of space symmetry leads to acceleration of the orbital momentum. Quantum localization saturates this acceleration, such that the average value of the orbital momentum can be a direct current and the system behaves ...

  18. Dynamical Localization in Kicked Quantum Rotors

    CERN Document Server

    Kamalov, Andrei; Bucksbaum, Philip H

    2015-01-01

    The periodically $\\delta$-kicked quantum linear rotor is known to experience non-classical bounded energy growth due to quantum dynamical localization in angular momentum space. We study the effect of random deviations of the kick period in simulations and experiments. This breaks the energy and angular momentum localization and increases the rotational alignment, which is the analog of the onset of Anderson localization in 1-D chains.

  19. Ice Shapes on a Tail Rotor

    Science.gov (United States)

    Kreeger, Richard E.; Tsao, Jen-Ching

    2014-01-01

    Testing of a thermally-protected helicopter rotor in the Icing Research Tunnel (IRT) was completed. Data included inter-cycle and cold blade ice shapes. Accreted ice shapes were thoroughly documented, including tracing, scanning and photographing. This was the first time this scanning capability was used outside of NASA. This type of data has never been obtained for a rotorcraft before. This data will now be used to validate the latest generation of icing analysis tools.

  20. Dark rotors in the late universe.

    Science.gov (United States)

    Mayer, Frederick J

    2015-11-01

    The tresino phase-transition that took place about 300 years after the big-bang, converted most baryons into almost equal numbers of protons and tresinos. Many of these become oppositely-charged rotating pairs or "rotors". This paper examines the formation, evolution, disposition and observations of the protons and tresinos from the phase-transition to the present era. The solar corona is further examined within the same tresino phase-transition picture.

  1. Rotor/Stator Unsteady Pressure Interaction

    OpenAIRE

    Brennen, C. E.; Franz, R.; Arndt, N.

    1988-01-01

    This paper describes an investigation of rotor/stator interaction in centrifugal pumps with radial diffusers. Steady and unsteady diffuser vane pressure measurements were made for two impellers, one half of the double suction pump of the High Pressure Oxygen Turbopump (HPOTP) of the Space Shuttle Main Engine (SSME) and a two-dimensional impeller. Unsteady impeller blade pressure measurements were made for a second two-dimensional impeller with blade number and geometry identical to the two-di...

  2. LES of open rotor-stator flow

    International Nuclear Information System (INIS)

    Computer experiments (LES) of the axisymmetric and statistically steady turbulent flow between a rotating and a fixed disk have been performed. This flow is a representative of the flow in an unshrouded rotor-stator configuration. The flow is characterized only by a local Reynolds number and a local gap ratio, provided that the distance from the rotation axis is sufficiently large so that the flow is fully turbulent. Five different cases have been considered, two of which may be classified as 'wide-gap' simulations, whereas the others were 'narrow-gap' simulations. In the latter cases, the variation of the tangential mean flow between the disks closely resembled the S-shaped mean velocity profile in a turbulent Couette flow. In the wide-gap cases, however, a nearly homogeneous core region separated the three-dimensional boundary layers adjacent to the rotor and the stator. It was observed that the degree of three-dimensionality was gradually reduced with the distance from the axis of rotation. The Reynolds shear stress vector and the mean velocity gradient vector (both in planes perpendicular to the axis of rotation) became more aligned and the structural parameter increased towards the typical limit 0.15 found in two-dimensional boundary layers. The moment coefficient C θ deduced from the statistically averaged tangential wall-friction at the rotor compared excellently with empirical correlation formulae, whereas C θ at the stator side was substantially lower

  3. Stopped-Rotor Cyclocopter for Venus Exploration

    Science.gov (United States)

    Husseyin, Sema; Warmbrodt, William G.

    2016-01-01

    The cyclocopter system can use two or more rotating blades to create lift, propulsion and control. This system is explored for its use in a mission to Venus. Cyclocopters are not limited to speed and altitude and can provide 360 degrees of vector thrusting which is favorable for good maneuverability. The novel aspect of this study is that no other cyclocopter configuration has been previously proposed for Venus or any (terrestrial or otherwise) exploration application where the cyclocopters rotating blades are stopped, and act as fixed wings. The design considerations for this unique planetary aerial vehicle are discussed in terms of implementing the use of a cyclorotor blade system combined with a fixed wing and stopped rotor mechanism. This proposed concept avoids many of the disadvantages of conventional-rotor stopped-rotor concepts and accounts for the high temperature, pressure and atmospheric density present on Venus while carrying out the mission objectives. The fundamental goal is to find an ideal design that implements the combined use of cyclorotors and fixed wing surfaces. These design concepts will be analyzed with the computational fluid dynamics tool RotCFD for aerodynamic assessment. Aspects of the vehicle design is 3D printed and tested in a small water tunnel or wind tunnel.

  4. Turbine flowmeter for liquid helium with the rotor magnetically levitated

    Science.gov (United States)

    Rivetti, A.; Martini, G.; Goria, R.; Lorefice, S.

    A turbine flowmeter with no mechanical contact between rotor and body is described, to be used as a reference standard in our liquid helium flow rate calibration facility. The absence of contact, zeroing the bearings friction factor, ensures a good measurement repeatability, even at very low liquid helium flow rate values. The rotor is magnetically suspended by the Meissner effect: at liquid helium temperatures two magnetic fields generate sustaining forces against the surface of the two rotor ends, which are made of niobium. Due to the repulsive nature of the acting forces, the rotor equilibrium is intrinsically stable and no external electronics are required for its levitation. A particular configuration of the superconducting windings and of the rotor ends allow the rotor to levitate and hold good axial and radial stability. A detailed description of the solutions adopted for the realization of the prototype and the operation conditions are reported. The first results, made with the absolute liquid helium calibration facility, are shown.

  5. Two-Dimensional Computational Model for Wave Rotor Flow Dynamics

    Science.gov (United States)

    Welch, Gerard E.

    1996-01-01

    A two-dimensional (theta,z) Navier-Stokes solver for multi-port wave rotor flow simulation is described. The finite-volume form of the unsteady thin-layer Navier-Stokes equations are integrated in time on multi-block grids that represent the stationary inlet and outlet ports and the moving rotor passages of the wave rotor. Computed results are compared with three-port wave rotor experimental data. The model is applied to predict the performance of a planned four-port wave rotor experiment. Two-dimensional flow features that reduce machine performance and influence rotor blade and duct wall thermal loads are identified. The performance impact of rounding the inlet port wall, to inhibit separation during passage gradual opening, is assessed.

  6. Performance of Savonius Rotor for Environmentally Friendly Hydraulic Turbine

    Science.gov (United States)

    Nakajima, Miyoshi; Iio, Shouichiro; Ikeda, Toshihiko

    The aim of this investigation was to develop an environmentally friendly nano-hydraulic turbine. A model of a two-bucket Savonius type hydraulic turbine was constructed and tested in a water tunnel to arrive at an optimum installation condition. Effects of two installation parameters, namely a distance between a rotor and a bottom wall of the tunnel, a rotation direction of the rotor, on the power performance were studied. A flow field around the rotor was examined visually to clarify influences of installation conditions on the flow field. The flow visualization showed differences of flow pattern around the rotor by the change of these parameters. From this study it was found that the power performances of Savonius hydraulic turbine were changed with the distance between the rotor and the bottom wall of the tunnel and with a rotation direction of the rotor.

  7. Dynamics of a rigid rotor in the elastic bearings

    OpenAIRE

    Arkhipova Inga M.

    2004-01-01

    As a rule in the studies of a rigid rotor in the elastic bearings the authors consider the linear system corresponding to the plane-parallel motion and the effect of self-centring under unlimited growth of the rotation frequency. In the present paper rotor is considered as a mechanical system with four degrees of freedom. Different motions of a statically and dynamically unbalanced vertical rotor supported in the non-linear bearings are studied.

  8. Escape rates for rotor walk in Z^d

    OpenAIRE

    Florescu, Laura; Ganguly, Shirshendu; Levine, Lionel; Peres, Yuval

    2013-01-01

    Rotor walk is a deterministic analogue of random walk. We study its recurrence and transience properties on Z^d for the initial configuration of all rotors aligned. If n particles in turn perform rotor walks starting from the origin, we show that the number that escape (i.e., never return to the origin) is of order n in dimensions d>=3, and of order n/log(n) in dimension 2.

  9. Dynamics of a rigid rotor in the elastic bearings

    Directory of Open Access Journals (Sweden)

    Arkhipova Inga M.

    2004-01-01

    Full Text Available As a rule in the studies of a rigid rotor in the elastic bearings the authors consider the linear system corresponding to the plane-parallel motion and the effect of self-centring under unlimited growth of the rotation frequency. In the present paper rotor is considered as a mechanical system with four degrees of freedom. Different motions of a statically and dynamically unbalanced vertical rotor supported in the non-linear bearings are studied.

  10. Abrasion Resistance Comparison between Rotor and Ring Spun Yarn

    Institute of Scientific and Technical Information of China (English)

    YANG Jian-ping; YU Chong-wen

    2002-01-01

    On the base of literature review and the analysis of yarn properties, yarn structure and some other facts, the abrasion resistance of both rotor spun yarn and ring spun yarns are discussed. The results show that with the same raw material and twist, the rotor spun yarn has lower abrasion resistance than that of ring spun yarn, because of the higher twist employed, the abrasion resistance of rotor spun yarn is higher than that of ring spun yarn.

  11. Theoretical study on the flow about Savonius rotor

    Science.gov (United States)

    Ogawa, T.

    1984-03-01

    A method for the two-dimensional analysis of the separated flow about Savonius rotors is presented. Calculations are performed by combining the singularity method and the discrete vortex method. The method is applied to the simulation of flows about a stationary rotor and a rotating rotor. Moreover, torque and power coefficients are computed and compared with the experimental results presented by Sheldahl et al. Theoretical and experimental results agree well qualitatively.

  12. Performance of Savonius Rotor for Environmentally Friendly Hydraulic Turbine

    OpenAIRE

    M. Nakajima; Iio, S; Ikeda, T

    2008-01-01

    The aim of this investigation was to develop an environmentally friendly nano-hydraulic turbine. A model of a two-bucket Savonius type hydraulic turbine was constructed and tested in a water tunnel to arrive at an optimum installation condition. Effects of two installation parameters, namely a distance between a rotor and a bottom wall of the tunnel, a rotation direction of the rotor, on the power performance were studied. A flow field around the rotor was examined visually to clarify influen...

  13. A Brief Review on Dynamics of a Cracked Rotor

    OpenAIRE

    Chandan Kumar; Vikas Rastogi

    2009-01-01

    Fatigue crack is an important rotor fault, which can lead to catastrophic failure if undetected properly and in time. Study and Investigation of dynamics of cracked shafts are continuing since last four decades. Some review papers were also published during this period. The aim of this paper is to present a review on recent studies and investigations done on cracked rotor. It is not the intention of the authors to provide all literatures related with the cracked rotor. However, the main empha...

  14. Rotor-Stator Contact – Overview of Current Research

    OpenAIRE

    Alber Oliver; Markert Richard

    2014-01-01

    The aim of this paper is to provide a compact as well as comprehensive overview of Rotor-Stator Contact in rotor dynamics. A general model is described which accounts for most phenomena of Rotor-Stator Contact observed in literature. This model is compared to different modeling approaches used in the previous literature. A glance on the variety of motion patterns including analytical approaches to the synchronous motion and Backward Whirl motion is given. As an outlook a modal reduction techn...

  15. Dynamic behavior od rotor dynamics stystem vibrating in a liquid

    OpenAIRE

    Kučera, Martin

    2010-01-01

    This thesis deals with dynamic behavior of rotor dynamics system vibrating in a liquid. Work is factually oriented on influence of the liquid to natural frequences of rotor of vortex turbine. There is described the creation of geometric and computational model of the system and the results of natural frequences and damping in dependence on environment are presen-ted. There are compared variations in natural frequences of the rotor system, which are caused of the interaction of the various lev...

  16. Synchronization and Collective Dynamics in a Carpet of Microfluidic Rotors

    OpenAIRE

    Uchida, Nariya; Golestanian, Ramin

    2009-01-01

    We study synchronization of an array of rotors on a substrate that are coupled by hydrodynamic interaction. The rotors that are modeled by an effective rigid body, are driven by an internal torque and exerts an active force on the surrounding fluid. The long-ranged nature of the hydrodynamic interaction between the rotors causes a rich pattern of dynamical behaviors including phase ordering and turbulent spiral waves. The model provides a novel example of coupled oscillators with long-range i...

  17. Non-equilibrium steady states for chains of four rotors

    OpenAIRE

    Cuneo, Noé; Eckmann, Jean-Pierre

    2015-01-01

    We study a chain of four interacting rotors (rotators) connected at both ends to stochastic heat baths at different temperatures. We show that for non-degenerate interaction potentials the system relaxes, at a stretched exponential rate, to a non-equilibrium steady state (NESS). Rotors with high energy tend to decouple from their neighbors due to fast oscillation of the forces. Because of this, the energy of the central two rotors, which interact with the heat baths only through the external ...

  18. Study on Rotor IGBT Chopper Control for Induction Motor Drive

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Rotor chopper control is a simple and effective drive method for induction motor. This paper presents a novel IGBT chopper topology,which can both adjust rotor resistance and protect IGBT efficiently. Investigation on the quasi-transient state of the rotor rectifying circuit is made, and a nonlinear mapping between the equivalent resistance and the duty cycle is deduced. Furthermore, the method for determining the magnitude of the external resistor is introduced.

  19. Bursting calcium rotors in cultured cardiac myocyte monolayers

    OpenAIRE

    Bub, Gil; Glass, Leon; Publicover, Nelson G.; Shrier, Alvin

    1998-01-01

    Rotating waves (rotors) of cellular activity were observed in nonconfluent cultures of embryonic chick heart cells by using a macroscopic imaging system that detected fluorescence from intracellular Ca2+. Unlike previous observations of rotors or spiral waves in other systems, the rotors did not persist but exhibited a repetitive pattern of spontaneous onset and offset leading to a bursting rhythm. Similar dynamics were observed in a cellular automaton model of excitable media that incorporat...

  20. Analysis of thermal stress of the piston during non-stationary heat flow in a turbocharged Diesel engine

    Science.gov (United States)

    Gustof, P.; Hornik, A.

    2016-09-01

    In the paper, numeric calculations of thermal stresses of the piston in a turbocharged Diesel engine in the initial phase of its work were carried out based on experimental studies and the data resulting from them. The calculations were made using a geometrical model of the piston in a five-cylinder turbocharged Diesel engine with a capacity of about 2300 cm3, with a direct fuel injection to the combustion chamber and a power rating of 85 kW. In order to determine the thermal stress, application of own mathematical models of the heat flow in characteristic surfaces of the piston was required to show real processes occurring on the surface of the analysed component. The calculations were performed using a Geostar COSMOS/M program module. A three-dimensional geometric model of the piston was created in this program based on a real component, in order to enable the calculations and analysis of thermal stresses during non-stationary heat flow. Modelling of the thermal stresses of the piston for the engine speed n=4250 min-1 and engine load λ=1.69 was carried out.

  1. Mathematical model of secondary rotor of centrifuge based on magnetic or electromagnetic overhead and bottom viscous damper taking into account flexibility and viscosity of rotor, and program of calculating dynamics of rotor in centrifuge

    International Nuclear Information System (INIS)

    The attempts to development of the rotor-dampers universal model with ability of fast correction of the parameters of mock-up rotor and dampers, their construction were made. The model that takes into account viscous characteristics of the material of the centrifuge rotor and allows research numerically into the rotor behaviour during over-speeding is suggested. The examples of calculations as show good effect of electromagnetic damping on the dynamics of the centrifuge rotor are given

  2. 涡轮增压汽油机匹配计算及性能预测%Turbocharging Engine Matching and Performance Prediction

    Institute of Scientific and Technical Information of China (English)

    倪计民; 李钊; 张小矛; 陈明

    2012-01-01

    应用GT-power软件建立了某1.5 VCT发动机一维仿真模型,并通过试验数据对模型进行了标定.根据涡轮增压发动机的设计要求估算了涡轮增压器的性能参数值,从而选择了一款涡轮增压器.建立了加装涡轮增压器之后的发动机模型,增加了放气阀装置,并分别进行了平原、高原环境下的发动机的匹配计算和性能预测.结果表明,在平原、高原环境下发动机匹配情况均良好.%A 1-D model of a 1.5 VCT engine was with GT-power software was built and calibrated with the test data. Performance parameters of the turbocharger was estimated according to design requirement of turbocharged engine, thus a turbocharger is selected. An engine model added with turbocharger is established, in which a relief valve is added, and engine match calculation and performance predication are made under plain and plateau environment. The results show that the engine match is quite good both in plain and plateau environment.

  3. The Use and Maintenance of Turbocharged Gasoline Engine%废气涡轮增压汽油机的使用与维护

    Institute of Scientific and Technical Information of China (English)

    许冀阳; 郭炎伟; 吴晨

    2016-01-01

    涡轮增压技术的不断成熟,越来越多的合资汽车品牌将涡轮增压发动机引入国内。涡轮增压发动机具有良好的动力性、经济性和排放性,因此,装配涡轮增压发动机的轿车受到更多人的青睐。文章介绍了废气涡轮增压器的工作原理和结构,分析了涡轮增压的优点,并研究了如何正确保养和维护。%The turbo technology continues to mature, more and more joint venture automobile brand bring turbocharged engine into my country. Turbocharged engine has good power, economy and emissions, and therefore, The car fitted with a turbocharged engine is favored by more people.This article described the working principle and structure of the exhaust gas turbine, analyzed the advantages of the turbocharger, and studied how to properly care and maintenance.

  4. 废气涡轮增压汽油机的使用与维护%The Use and Maintenance of Turbocharged Gasoline Engine

    Institute of Scientific and Technical Information of China (English)

    许冀阳; 郭炎伟; 吴晨

    2016-01-01

    涡轮增压技术的不断成熟,越来越多的合资汽车品牌将涡轮增压发动机引入国内。涡轮增压发动机具有良好的动力性、经济性和排放性,因此,装配涡轮增压发动机的轿车受到更多人的青睐。文章介绍了废气涡轮增压器的工作原理和结构,分析了涡轮增压的优点,并研究了如何正确保养和维护。%The turbo technology continues to mature, more and more joint venture automobile brand bring turbocharged engine into my country. Turbocharged engine has good power, economy and emissions, and therefore, The car fitted with a turbocharged engine is favored by more people.This article described the working principle and structure of the exhaust gas turbine, analyzed the advantages of the turbocharger, and studied how to properly care and maintenance.

  5. Rotor-Stator Contact – Overview of Current Research

    Directory of Open Access Journals (Sweden)

    Alber Oliver

    2014-01-01

    Full Text Available The aim of this paper is to provide a compact as well as comprehensive overview of Rotor-Stator Contact in rotor dynamics. A general model is described which accounts for most phenomena of Rotor-Stator Contact observed in literature. This model is compared to different modeling approaches used in the previous literature. A glance on the variety of motion patterns including analytical approaches to the synchronous motion and Backward Whirl motion is given. As an outlook a modal reduction technique is pointed out, which is capable of reducing systems with many degrees of freedom for rotor as well as stator to the described model.

  6. Rotor dynamic considerations for large wind power generator systems

    Science.gov (United States)

    Ormiston, R. A.

    1973-01-01

    Successful large, reliable, low maintenance wind turbines must be designed with full consideration for minimizing dynamic response to aerodynamic, inertial, and gravitational forces. Much of existing helicopter rotor technology is applicable to this problem. Compared with helicopter rotors, large wind turbines are likely to be relatively less flexible with higher dimensionless natural frequencies. For very large wind turbines, low power output per unit weight and stresses due to gravitational forces are limiting factors. The need to reduce rotor complexity to a minimum favors the use of cantilevered (hingeless) rotor configurations where stresses are relieved by elastic deformations.

  7. Interface structure for hub and mass attachment in flywheel rotors

    Science.gov (United States)

    Deteresa, Steven J.; Groves, Scott E.

    1998-06-02

    An interface structure for hub and mass attachment in flywheel rotors. The interface structure efficiently transmits high radial compression forces and withstands both large circumferential elongation and local stresses generated by mass-loading and hub attachments. The interface structure is comprised of high-strength fiber, such as glass and carbon, woven into an angle pattern which is about 45.degree. with respect to the rotor axis. The woven fiber is bonded by a ductile matrix material which is compatible with and adheres to the rotor material. This woven fiber is able to elongate in the circumferential direction to match the rotor growth during spinning.

  8. STABILITY AND BIFURCATION OF UNBALANCE ROTOR/LABYRINTH SEAL SYSTEM

    Institute of Scientific and Technical Information of China (English)

    李松涛; 许庆余; 万方义; 张小龙

    2003-01-01

    The influence of labyrinth seal on the stability of unbalanced rotor system was presented. Under the periodic excitation of rotor unbalance, the whirling vibration of rotor is synchronous if the rotation speed is below stability threshold, whereas the vibration becomes severe and asynchronous which is defined as unstable if the rotation speed exceeds threshold. The Muszynska model of seal force and shooting method were used to investigate synchronous solution of the dynamic equation of rotor system. Then, based on Floquet theory the stability of synchronous solution and unstable dynamic characteristic of system were analyzed.

  9. Position Sensing for Rotor in Hybrid Stepper Motor

    Science.gov (United States)

    Howard, David E. (Inventor); Alhorn, Dean C. (Inventor); Smith, Dennis A. (Inventor)

    2011-01-01

    A method and system are provided for sensing the position of a rotor in a hybrid stepper motor. First and second Hall sensors are positioned in a spaced-apart relationship with the first and second armatures of the rotor such that the first and second Hall sensors generate electrical outputs that are 90.degree. out of phase with one another as the rotor rotates. The electrical outputs are adjusted relative to a reference, and the amplitude of the electrical outputs is further adjusted to account for spacing differences between the rotor and each of the first and second Hall sensors.

  10. Coupled Thermal Field of the Rotor of Liquid Floated Gyroscope

    Directory of Open Access Journals (Sweden)

    Wang Zhengjun

    2015-01-01

    Full Text Available Inertial navigation devices include star sensor, GPS, and gyroscope. Optical fiber and laser gyroscopes provide high accuracy, and their manufacturing costs are also high. Magnetic suspension rotor gyroscope improves the accuracy and reduces the production cost of the device because of the influence of thermodynamic coupling. Therefore, the precision of the gyroscope is reduced and drift rate is increased. In this study, the rotor of liquid floated gyroscope, particularly the dished rotor gyroscope, was placed under a thermal field, which improved the measurement accuracy of the gyroscope. A dynamic theory of the rotor of liquid floated gyroscope was proposed, and the thermal field of the rotor was simulated. The maximum stress was in x, 1.4; y, 8.43; min 97.23; and max 154.34. This stress occurred at the border of the dished rotor at a high-speed rotation. The secondary flow reached 5549 r/min, and the generated heat increased. Meanwhile, the high-speed rotation of the rotor was volatile, and the dished rotor movement was unstable. Thus, nanomaterials must be added to reduce the thermal coupling fluctuations in the dished rotor and improve the accuracy of the measurement error and drift rate.

  11. NONLINEAR DYNAMICS OF A CRACKED ROTOR IN A MANEUVERING AIRCRAFT

    Institute of Scientific and Technical Information of China (English)

    LIN Fu-sheng 林富生; MENG Guang 孟光; Eric Hahn

    2004-01-01

    The nonlinear dynamics of a cracked rotor system in an aircraft maneuvering with constant velocity or acceleration was investigated. The influence of the aircraft climbing angle on the cracked rotor system response is of particular interest and the results show that the climbing angle can markedly affect the parameter range for bifurcation, for quasi-periodic response and for chaotic response as well as for system stability. Aircraft acceleration is also shown to significantly affect the nonlinear behavior of the cracked rotor system, illustrating the possibility for on-line rotor crack fault diagnosis.

  12. Optimum design configuration of Savonius rotor through wind tunnel experiments

    Energy Technology Data Exchange (ETDEWEB)

    Saha, U.K.; Thotla, S. [Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati 781 039 (India); Maity, D. [Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati 781 039 (India)

    2008-08-15

    Wind tunnel tests were conducted to assess the aerodynamic performance of single-, two- and three-stage Savonius rotor systems. Both semicircular and twisted blades have been used in either case. A family of rotor systems has been manufactured with identical stage aspect ratio keeping the identical projected area of each rotor. Experiments were carried out to optimize the different parameters like number of stages, number of blades (two and three) and geometry of the blade (semicircular and twisted). A further attempt was made to investigate the performance of two-stage rotor system by inserting valves on the concave side of blade. (author)

  13. Performance testing of a Savonius windmill rotor in shear flows

    Science.gov (United States)

    Mojola, O. O.; Onasanya, O. E.

    The effects of flow shear and/or unsteady behavior on the power generation capability of a Savonius wind turbine rotor are assessed in view of measurements conducted, both in two statistically steady shear flows and in the wind, of rotor tip speed and torque at a number of streamwise stations for each of four values of the rotor bucket overlap ratio. It is found that, even in the absence of shear, the power coefficient of a Savonius wind turbine rotor is most strongly dependent on tip speed ratio.

  14. Influence of rubbing on rotor dynamics, part 2

    Science.gov (United States)

    Muszynska, Agnes; Bently, Donald E.; Franklin, Wesley D.; Hayashida, Robert D.; Kingsley, Lori M.; Curry, Arthur E.

    1989-01-01

    Rotor dynamic behavior depends considerably on how much the specific physical phenomena accompanying rotor rubbing against the stator is involved. The experimental results of rotor-to-stator rubbing contact are analyzed. The computer code is described for obtaining numerical calculations of rotor-to-stator rubbing system dynamic responses. Computer generated results are provided. The reduced dynamic data from High Pressure Fuel Turbo Pump (HPFTP) hot fire test are given. The results provide some significant conclusions. Information is provided on the electronic instrumentation used in the experimental testing.

  15. Helicopter rotor dynamics and aeroelasticity - Some key ideas and insights

    Science.gov (United States)

    Friedmann, Peretz P.

    1990-01-01

    Four important current topics in helicopter rotor dynamics and aeroelasticity are discussed: (1) the role of geometric nonlinearities in rotary-wing aeroelasticity; (2) structural modeling, free vibration, and aeroelastic analysis of composite rotor blades; (3) modeling of coupled rotor/fuselage areomechanical problems and their active control; and (4) use of higher-harmonic control for vibration reduction in helicopter rotors in forward flight. The discussion attempts to provide an improved fundamental understanding of the current state of the art. In this way, future research can be focused on problems which remain to be solved instead of producing marginal improvements on problems which are already understood.

  16. Airframe structural dynamic considerations in rotor design optimization

    Science.gov (United States)

    Kvaternik, Raymond G.; Murthy, T. Sreekanta

    1989-01-01

    An an overview and discussion of those aspects of airframe structural dynamics that have a strong influence on rotor design optimization is provided. Primary emphasis is on vibration requirements. The vibration problem is described, the key vibratory forces are identified, the role of airframe response in rotor design is summarized, and the types of constraints which need to be imposed on rotor design due to airframe dynamics are discussed. Some considerations of ground and air resonance as they might affect rotor design are included.

  17. Transient dynamics of a flexible rotor with squeeze film dampers

    Science.gov (United States)

    Buono, D. F.; Schlitzer, L. D.; Hall, R. G., III; Hibner, D. H.

    1978-01-01

    A series of simulated blade loss tests are reported on a test rotor designed to operate above its second bending critical speed. A series of analyses were performed which predicted the transient behavior of the test rig for each of the blade loss tests. The scope of the program included the investigation of transient rotor dynamics of a flexible rotor system, similar to modern flexible jet engine rotors, both with and without squeeze film dampers. The results substantiate the effectiveness of squeeze film dampers and document the ability of available analytical methods to predict their effectiveness and behavior.

  18. Control of Rotor Function in Light-Driven Molecular Motors

    OpenAIRE

    Lubbe, Anouk S.; Ruangsupapichat, Nopporn; Caroli, Giuseppe; Feringa, Ben L.

    2011-01-01

    A study is presented on the control of rotary motion of an appending rotor unit in a light-driven molecular motor. Two new light driven molecular motors were synthesized that contain aryl groups connected to the stereogenic centers. The aryl groups behave as bidirectional free rotors in three of the four isomers of the 360 degrees rotation cycle, but rotation of the rotors is hindered in the fourth isomer. Kinetic studies of both motor and rotor functions of the two new compounds are given, u...

  19. Numerical Analysis of Nonlinear Rotor-bearing-seal System

    Institute of Scientific and Technical Information of China (English)

    CHENG Mei; MENG Guang; JING Jian-ping

    2008-01-01

    The system state trajectory, Poincaré maps, largest Lyapunov exponents, frequency spectra and bifurcation diagrams were used to investigate the non-linear dynamic behaviors of a rotor-bearing-seal coupled system and to analyze the influence of the seal and bearing on the nonlinear characteristics of the rotor system. Various nonlinear phenomena in the rotor-bearing-seal system, such as periodic motion, double-periodicmotion, multi-periodic motion and quasi-periodic motion were investigated. The results may contribute to a further understanding of the non-linear dynamics of the rotor-bearing-seal coupled system.

  20. Mechanical coupling for a rotor shaft assembly of dissimilar materials

    Science.gov (United States)

    Shi, Jun; Bombara, David; Green, Kevin E.; Bird, Connic; Holowczak, John

    2009-05-05

    A mechanical coupling for coupling a ceramic disc member to a metallic shaft includes a first wedge clamp and a second wedge clamp. A fastener engages a threaded end of a tie-bolt to sandwich the ceramic disc between the wedge clamps. An axial spring is positioned between the fastener and the second wedge clamp to apply an axial preload along the longitudinal axis. Another coupling utilizes a rotor shaft end of a metallic rotor shaft as one wedge clamp. Still another coupling includes a solid ceramic rotor disc with a multiple of tie-bolts radially displaced from the longitudinal axis to exert the preload on the solid ceramic rotor disc.