WorldWideScience

Sample records for aerostatics

  1. Experimental investigation of gas aerostatic bearings

    Czech Academy of Sciences Publication Activity Database

    Steinbauer, P.; Šika, Z.; Kozánek, Jan; Šimek, J.

    2008-01-01

    Roč. 3, - (2008), s. 769-776. ISSN 1335-2393 R&D Projects: GA ČR GA101/06/1787 Institutional research plan: CEZ:AV0Z20760514 Keywords : aerostatic bearing * experimental identification * measurement Subject RIV: BI - Acoustics

  2. Spectral properties and identification of aerostatic bearings

    Institute of Scientific and Technical Information of China (English)

    Jan Kozánek; Ladislav P(u)st

    2011-01-01

    Modified rotor kit BentlyNevada was used for dynamic characteristics measurements of new developed aerostatic bearings. Mathematical model of these bearings is considered as linear. Model was identified with the help of harmonic force excitation independently from the speed of journal rotation. The stiffness and damping matrices were identified for different air inlet pressures. The calculated spectral properties allow to determine the stability boundary for suitable variation of model parameters.

  3. Determinattion of aerostatic journal bearing dynamic properties

    Czech Academy of Sciences Publication Activity Database

    Kozánek, Jan; Šimek, J.; Steinbauer, P.; Neusser, Z.

    Praha: Ústav termomechaniky AV ČR, v. v. i., 2008 - (Pešek, L.), s. 161-168 ISBN 978-80-87012-10-9. [Dynamika strojů 2008. Praha (CZ), 05.02.2008-06.02.2008] R&D Projects: GA ČR GA101/06/1787 Institutional research plan: CEZ:AV0Z20760514 Keywords : aerostatic bearing * stiffness and damping coefficients * identification Subject RIV: BI - Acoustics

  4. Advanced aerostatic analysis of long-span suspension bridges

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    As the span length of suspension bridges increases, the diameter of cables and thus the wind load acting on them, the nonlinear wind-structure interaction and the wind speed spatial non-uniformity all increase consequently, which may have unnegligible influence on the aerostatic behavior of long-span suspension bridges. In this work, a method of advanced aerostatic analysis is presented firstly by considering the geometric nonlinearity, the nonlinear wind-structures and wind speed spatial non-uniformity. By taking the Runyang Bridge over the Yangtze River as example, effects of the nonlinear wind-structure interaction, wind speed spatial non-uniformity, and the cable's wind load on the aerostatic behavior of the bridge are investigated analytically. The results showed that these factors all have important influence on the aerostatic behavior, and should be considered in the aerostatic analysis of long and particularly super long-span suspension bridges.

  5. Hydrostatic, aerostatic and hybrid bearing design

    CERN Document Server

    Rowe, W Brian

    2012-01-01

    Solve your bearing design problems with step-by-step procedures and hard-won performance data from a leading expert and consultant Compiled for ease of use in practical design scenarios, Hydrostatic, Aerostatic and Hybrid Bearing Design provides the basic principles, design procedures and data you need to create the right bearing solution for your requirements. In this valuable reference and design companion, author and expert W. Brian Rowe shares the hard-won lessons and figures from a lifetime's research and consultancy experience. Coverage includes: Clear e

  6. Spectral properties and identification of aerostatic bearings

    Czech Academy of Sciences Publication Activity Database

    Kozánek, Jan; Půst, Ladislav

    2011-01-01

    Roč. 27, č. 1 (2011), s. 63-67. ISSN 0567-7718. [International Conference on Dynamical Systems - Theory and Applications /10./. Lodz, 07.12.2009-10.12.2009] R&D Projects: GA ČR GA101/09/1522 Institutional research plan: CEZ:AV0Z20760514 Keywords : aerostatic bearing * identification * stiffness * damping coefficients Subject RIV: BI - Acoustics Impact factor: 0.860, year: 2011 http://www.springerlink.com/content/34l382r75g8wu716/

  7. Mechatronic stand for gas aerostatic bearing measurement

    Czech Academy of Sciences Publication Activity Database

    Steinbauer, P.; Kozánek, Jan; Neusser, Z.; Šika, Z.; Bauma, V.

    Berlin: Springer, 2008 - (Jablonski, R.; Turkowski, M.; Szewczyk, R.), s. 438-442 ISBN 978-3-540-73955-5. [International Symposium Mechatronics /7./. Waršava (PL), 19.09.2007-21.09.2007] R&D Projects: GA ČR GA101/06/1787 Institutional research plan: CEZ:AV0Z20760514 Keywords : gas aerostatic bearings * dynamical experiments * identification of stiffness and damping Subject RIV: BI - Acoustics http://www.springer.com/engineering/ robotics /book/978-3-540-73955-5

  8. Swot analysis of using aerostats for surveillance in counter terrorism

    Science.gov (United States)

    ćetin, Hüseyin

    2013-06-01

    In today's conjuncture, the terrorist activities are the most compelling issue for the defence forces in maintaining homeland security. Especially, the terrorist elements that penetrate the homeland may give harm. This harm can be minimized by preventing the terrorist penetrations from homeland borders. In counter terrorism, having Intelligence, Surveillance and Reconnaissance (ISR) capability and using this capability by twenty four hours is deterrence for the terrorist groups. Aerostats emerge as the ideal platform which can provide this capability. Aerostats are unmanned and aerodynamically shaped balloons that are stayed in the air, fixed to the ground by steel cable(s). The aerostat is made of a large fabric envelope that is filled with nonflammable helium gas, which provides the lifting force. The cables also serve to supply the electrical power to the aerostat systems, and for data relay between the aerostat and the ground station. Aerostats are different from the other manned and Unmanned Aerial Vehicles (UAVs) because of aerostats' capabilities such as cost effectiveness, long endurance and high resolution image transmission. Especially having uninterrupted image transmission and surveillance capabilities is important to be advantageous in counter terrorism. In this article, a short definition of terrorism has been given and then the importance of ensuring the homeland border security has been emphasized in counter terrorism. In addition, the questions of "what are the technical capabilities, the usage areas and the purposes of aerostats?" will be introduced as a result of literature review. Finally the strengths and weaknesses of aerostats, opportunities and threats for the near future will be introduced by using "SWOT" analysis method.

  9. Design, Testing, and Realisation of a Medium Size Aerostat Envelope

    Directory of Open Access Journals (Sweden)

    A. Kumar

    2016-03-01

    Full Text Available The design, testing and realisation aspects during the development of a medium size aerostat envelope in the present work. The payload capacity of this aerostat is 300 kg at 1 km above mean sea level. The aerostat envelope is the aerodynamically shaped fabric enclosure part of the aerostat which generally uses helium for lifting useful payloads to a specified height. The envelope volume estimation technique is discussed which provides the basis for sizing. The design, material selection, testing and realisation aspects of this aerostat envelope are also discussed. The empirical formulas and finite element analysis are used to estimate the aerodynamic, structural and other design related parameters of the aerostat. Equilibrium studies are then explained for balancing forces and moments in static conditions. The tether profile estimation technique is discussed to estimate blow by distance and tether length. A comparison of estimated and measured performance parameters during trials has also been discussed.Defence Science Journal, Vol. 66, No. 2, March 2016, pp.93-99, DOI: http://dx.doi.org/10.14429/dsj.66.9291

  10. Identification of stiffness and damping coefficients of aerostatic journal bearing

    Czech Academy of Sciences Publication Activity Database

    Kozánek, Jan; Šimek, J.; Steinbauer, P.; Bílkovský, A.

    2009-01-01

    Roč. 16, č. 3 (2009), s. 209-220. ISSN 1802-1484 R&D Projects: GA ČR GA101/06/1787 Institutional research plan: CEZ:AV0Z20760514 Keywords : aerostatic journal bearings * identification * spectral and modal properties Subject RIV: BI - Acoustics

  11. Using rotor kit Bently Nevada for experiments with aerostatic bearings

    Czech Academy of Sciences Publication Activity Database

    Šimek, J.; Kozánek, Jan; Steinbauer, P.; Neusser, Z.

    Liberec : Technical University of Liberec, 2008, s. 595-600. ISBN 978-80-7372-370-5. [International Conference on the Theory of Machines and Mechanism /10./. Liberec (CZ), 02.09.2008-04.09.2008] R&D Projects: GA ČR GA101/06/1787 Institutional research plan: CEZ:AV0Z20760514 Keywords : rotor systems * aerostatic bearings * stiffness and damping identification Subject RIV: BI - Acoustics

  12. Computation of dynamic properties of aerostatic journal bearings

    Czech Academy of Sciences Publication Activity Database

    Skarolek, A.; Kozánek, Jan

    Praha: Institute of Thermomechanics AS CR, v. v. i., 2007 - (Zolotarev, I.), s. 251-252 ISBN 978-80-87012-06-2. [Engineering Mechanics 2007: national conference with international participation. Svratka (CZ), 14.05.2007-17.05.2007] R&D Projects: GA ČR GA101/06/1787 Institutional research plan: CEZ:AV0Z20760514 Keywords : aerostatic journal bearings * mathematical model * stiffness and damping matrices Subject RIV: BI - Acoustics

  13. Studying fluid squeeze characteristics for aerostatic journal bearing

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Rahman, Gamal M. [Department of Mathematics, Faculty of Science, Benha University, Benha 13518 (Egypt)], E-mail: gamalm60@yahoo.com

    2008-07-01

    The Reynolds equation for studying fluid squeeze of aerostatic journal bearing is solved numerically by considering the quasi-steady behavior of the air film. The radial displacement can influence the air film thickness modifying the pressure distribution in the journal-bearing gap. Also, the variations in the seal characteristics with eccentricity, time, squeeze number, length-to-diameter and supply pressure are presented. The numerical results for the squeeze load-carrying capacity are given in a non-dimensional for000.

  14. Large eddy simulation of vortex shedding and pressure fluctuation in aerostatic bearings

    Science.gov (United States)

    Zhu, Jincheng; Chen, Han; Chen, Xuedong

    2013-07-01

    In aerostatic bearings, high speed air flow may induce small vibration, which has been harmful to the improvement of moving and positioning accuracy of aerostatically supported devices in ultra-precision applications. In this paper, the transient flow field in the aerostatic bearing is numerically investigated using the large eddy simulation method. Turbulent structures are studied and vortex shedding phenomenon is discovered in the bearing recess. Our computational results demonstrate that vortex shedding causes pressure fluctuation in the bearing clearance. Relationship between pressure fluctuation and bearing vibration is established based on our simulation results and experimentally measured vibration strength.

  15. Detection of impulsive sources from an aerostat-based acoustic array data collection system

    Science.gov (United States)

    Prather, Wayne E.; Clark, Robert C.; Strickland, Joshua; Frazier, Wm. Garth; Singleton, Jere

    2009-05-01

    An aerostat based acoustic array data collection system was deployed at the NATO TG-53 "Acoustic Detection of Weapon Firing" Joint Field Experiment conducted in Bourges, France during the final two weeks of June 2008. A variety of impulsive sources including mortar, artillery, gunfire, RPG, and explosive devices were fired during the test. Results from the aerostat acoustic array will be presented against the entire range of sources.

  16. Frictional Characteristics of a Small Aerostatic Linear Bearing

    Directory of Open Access Journals (Sweden)

    Ryosuke Araki

    2015-04-01

    Full Text Available Frictional characteristics of a small aerostatic linear bearing are accurately evaluated by means of a method, in which the force acting on the moving part of the bearing is measured as the inertial force. An optical interferometer is newly developed to measure the Doppler shift frequency of the laser light reflected on the small moving part. From the measured time-varying Doppler shift frequency, the velocity, the position, the acceleration and the inertial force of the moving part are numerically calculated. It is confirmed that the dynamic frictional force acting inside the bearing is almost proportional to the velocity of the moving part and is similar to the theoretical value calculated under the assumption that the flow inside the bearing is the Couette flow.

  17. AEROSTATIC AND AERODYNAMIC MODULES OF A HYBRID BUOYANT AIRCRAFT: AN ANALYTICAL APPROACH

    Directory of Open Access Journals (Sweden)

    Anwar Ul Haque

    2015-05-01

    Full Text Available An analytical approach is essential for the estimation of the requirements of aerodynamic and aerostatic lift for a hybrid buoyant aircraft. Such aircrafts have two different modules to balance the weight of aircraft; aerostatic module and aerodynamic module. Both these modules are to be treated separately for estimation of the mass budget of propulsion systems and required power. In the present work, existing relationships of aircraft and airship are reviewed for its further application for these modules. Limitations of such relationships are also disussed and it is precieved that it will provide a strating point for better understanding of design anatomy of such aircraft.

  18. Aerostat-Based Sampling of Emissions from Open Burning and Open Detonation of Military Ordnance

    Science.gov (United States)

    Emissions from open detonation (OD), open burning (OB), and static firing (SF) of obsolete military munitions were collected using an aerostat-lofted sampling instrument maneuvered into the plumes with remotely controlled tether winches. PM2.5, PM10, metals, volatile organic comp...

  19. Simulation of the fluid structure interaction for an aerostatic bearing and a flexible substrate

    NARCIS (Netherlands)

    Olieslagers, R.; Wild, M. de; Melick, S. van; Knaapen, R.

    2014-01-01

    The fluid structure interaction for an aerostatic bearing and a substrate is solved numerically by a semi-analytical model, programmed in the software package MATLAB. This semi-analytical model uses a fluidic network of resistances and capacities to solve the pressure field in the bearing channel. T

  20. A high-Q, ultrathin-walled microbubble resonator for aerostatic pressure sensing

    OpenAIRE

    Yang, Yong; Saurabh, Sunny; Ward, Jonathan M.; Chormaic, Síle Nic

    2015-01-01

    Sensors based on whispering gallery resonators have minute footprints and can push achievable sensitivities and resolutions to their limits. Here, we use a microbubble resonator, with a wall thickness of 500 nm and an intrinsic Q-factor of $10^7$ in the telecommunications C-band, to investigate aerostatic pressure sensing via stress and strain of the material. The microbubble is made using two counter-propagating CO$_2$ laser beams focused onto a microcapillary. The measured sensitivity is 19...

  1. Feasibility Study of Space Based Solar Power to Tethered Aerostat Systems

    Science.gov (United States)

    Blank, Stephen J.; Leete, Stephen J.; Jaffe, Paul

    2013-01-01

    The feasibility of two-stage Space-Based Solar Power to Tethered Aerostat to Earth (SSP-TA) system architectures that offer significant advantages over conventional single stage space-to-earth architectures is being studied. There have been many proposals for the transmission of solar power collected in space to the surface of the earth so that solar energy could provide a major part of the electric power requirements on earth. There are, however, serious difficulties in implementing the single stage space-based solar power systems that have been previously studied. These difficulties arise due to: i) the cost of transporting the components needed for the extremely large microwave transmit beaming aperture into space orbit, ii) the even larger collection apertures required on earth, iii) the potential radiation hazard to personnel and equipment on earth, and iv) a lack of flexibility in location of the collection station on the earth. Two candidate system architectures are described here to overcome these difficulties. In both cases a two-stage space to tethered aerostat to earth transmission system (SSP-TA) is proposed. The use of high altitude tethered aerostats (or powered airships) avoids the effects of attenuation of EM energy propagating through the earth s lower atmosphere. This allows the use of beaming frequencies to be chosen from the range of high millimeter (THz) to near-infra-red (NIR) to the visible. This has the potential for: i) greatly reduced transportation costs to space, ii) much smaller receiver collection apertures and ground stations, iii) elimination of the potential radiation hazard to personnel and equipment on earth, and iv) ease in transportation and flexibility in location of the collection station on the earth. A preliminary comparison of system performance and efficiencies is presented.

  2. High-Q, ultrathin-walled microbubble resonator for aerostatic pressure sensing.

    Science.gov (United States)

    Yang, Yong; Saurabh, Sunny; Ward, Jonathan M; Nic Chormaic, Síle

    2016-01-11

    Sensors based on whispering gallery resonators have minute footprints and can push achievable sensitivities and resolutions to their limits. Here, we use a microbubble resonator, with a wall thickness of 500 nm and an intrinsic Q-factor of 107 in the telecommunications C-band, to investigate aerostatic pressure sensing via stress and strain of the material. The microbubble is made using two counter-propagating CO2 laser beams focused onto a microcapillary. The measured sensitivity is 19 GHz/bar at 1.55 μm. We show that this can be further improved to 38 GHz/bar when tested at the 780 nm wavelength range. In this case, the resolution for pressure sensing can reach 0.17 mbar with a Q-factor higher than 5 × 107. PMID:26832260

  3. Acoustic detection and localization of weapons fire by unattended ground sensors and aerostat-borne sensors

    Science.gov (United States)

    Naz, P.; Marty, Ch.; Hengy, S.; Miller, L. S.

    2009-05-01

    The detection and localization of artillery guns on the battlefield is envisaged by means of acoustic and seismic waves. The main objective of this work is to examine the different frequency ranges usable for the detection of small arms, mortars, and artillery guns on the same hardware platform. The main stages of this study have consisted of: data acquisition of the acoustic signals of the different weapons used, signal processing and evaluation of the localization performance for various types of individual arrays, and modeling of the wave propagation in the atmosphere. The study of the propagation effects on the signatures of these weapons is done by comparing the acoustic signals measured during various days, at ground level and at the altitude of our aerostat (typically 200 m). Numerical modeling has also been performed to reinforce the interpretation of the experimental results.

  4. Vehicle tethered aerostat optoelectronic monitoring platform system for Shanghai World EXPO

    Science.gov (United States)

    Zhou, Weihu; Wang, Yawei; Han, Xiaoquan; Yuan, Jiang

    2010-08-01

    To monitor the whole Shanghai Expo Park, a vehicle tethered aerostat optoelectronic monitoring platform with the characteristic of time-sensitive and all-weather monitoring is described in detail in this paper, which is hung beneath the tethered balloon and equipped with a variety of payloads, including visible light monitoring system, infrared monitoring system, hyperspectral monitoring system, GPS/INS system, monitoring and control system and so on. These equipments can be used for real-time monitoring, environmental monitoring, and ground target location of Shanghai Expo Park. The output High Definition (HD) image of Shanghai Expo Park from visible light monitoring system is clear and stable, and the stabilization accuracy of visual axis is 0.07°(3δ). The optoelectronic monitoring platform system uses the target location technology based on Global Position System/Inertial Navigation System (GPS/INS) system to output real-time location data compatible with Geographic Information System (GIS). Test results show that the maximum errors between the location results (latitude and longitude) solved by the target location program and the reference target are 0.2 0/00(latitude) and 2 0/00(longitude). Now the whole system has been used for surveillance the Shanghai Expo Park since April 2010.

  5. Design and implementation of an active rectangular aerostatic thrust bearing stage with electromagnetic actuators

    Institute of Scientific and Technical Information of China (English)

    MAO JunHong; LI LiChuan

    2009-01-01

    The design and implementation of an active rectangular aerostaUc thrust bearing stage with electro-magnetic actuators are presented. The stage is fundamentally precise and simple since the out-of-plane degree-of-freedoms (DOF) of a thrust air bearing are closed-loop controlled by electromagnetic actua-tors. The design is one-moving-part with mechanical symmetry, and a commercially available air bear-ing is rigidly attached to the table. The actuators are four independent coils mounted to the guiding surface of the table with iron cores, which are directly machined on the table. A bench level prototype system is developed and out-of-plane axes decoupled models of the system are derived. A control al-gorithm synthesized by arbitrarily placing closed-loop poles according to the model with air bearing dynamics neglected is implemented by C programming language running on the DOS platform. The stage is capable of vertical direction precision micro-positioning and guiding 3-DOF plane motions without limiting the working range of plane motions. Positioning accuracy of the stage no longer de-pends upon design and manufacturing of an air bearing, while passive preload of the stage for a flat film aerostatic thrust bearing is eliminated.

  6. Acoustic data analysis and scenario over watch from an aerostat at the NATO SET-153 field experiment

    Science.gov (United States)

    Reiff, Christian; Scanlon, Michael

    2012-06-01

    The purpose of the NATO SET-153 field experiment was to provide an opportunity to demonstrate multiple sensor technologies in an urban environment and determine integration capabilities for future development. The Army Research Laboratory (ARL) experimental aerostat was used primarily as a persistent over watch capability as a substitute for a UAV. Continuous video was recorded on the aerostat and segments of video were captured of the scenarios on the ground that the camera was following manually. Some of the segments showing scenario activities will be presented. The captured pictures and video frames have telemetry in the headers that provides the UTM time and the Inertial Navigation System (INS) GPS location and the inertial roll, pitch, and yaw as well as the camera gimbal pan and tilt angles. The timing is useful to synchronize the images with the scenario events providing activity ground truth. The INS, GPS, and camera gimbal angle values can be used with the acoustic solution for the location of a sound source to determine the relative accuracy of the solution if the camera is pointed at the sound source. This method will be confirmed by the use of a propane cannon whose GPS location is logged. During the field experiment, other interesting acoustic events such as vehicle convoys, platoon level firefights with vehicles using blanks, and a UAV helicopter were recorded and will be presented in a quick analysis.

  7. The Design of The Journal Bearing of Dicing Saw's Aerostatic Motorized Spindle%划片机空气静压电主轴径向轴承的设计

    Institute of Scientific and Technical Information of China (English)

    李战伟; 刘婷婷

    2012-01-01

    径向轴承是划片机空气静压电主轴的关键零件,径向轴承的结构及尺寸直接影响转轴的高速旋转精度及工作性能。采用表压比法对划片机空气静压电主轴径向轴承进行设计计算,确定径向轴承的结构参数。%The journal bearing is the key part of the dicing saw's aerostatic motorized spindle. The journal bearing's structure and dimension infiuent indirectly on the spindle's rotating precision and working capacity at high speed. The journal beating of dicing saw's aerostatic motorized spindle are designed and calculated through gauge pressure ratio method, and the journal bearing's structural parameters are determined.

  8. 精密机床静压气体轴承静特性分析及基本参数的优化%Static Characteristics Analysis and Basic Parameters Optimization of Aerostatic Bearing for Precision Machine Tool

    Institute of Scientific and Technical Information of China (English)

    李树森; 郭永红; 朱赞彬; 曾剑锋

    2012-01-01

    对精密机床气体轴承静特性进行理论分析,运用有限元法将雷诺方程离散化,得到静压气体轴承的承载能力、刚度以及供气量的计算公式.对某精密机床小孔节流静压气体轴承的静态特性进行分析,得到供气压力、偏心率、节流孔直径和刚度以及承载能力之间的关系曲线;通过优化分析,得到精密机床主轴前后静压气体轴承优化的结构参数和操作参数.%The static characteristics of gas bearing for the precision machine tool were analyzed in theory, the Reynolds equation was discretized with the finite element method and the calculating formula of bearing capacity, stiffness and the amount of gas supply were got. The static characteristics of aerostatic bearing with orifice compensated for a precision ma chine tool were analyzed,the relation curves of gas supply pressure,eccentricity,orifice diameter stiffness and bearing ca pacity were got. By optimization analysis,the structure and operation parameters of aerostatic bearing for precision machine tool spindle were concluded.

  9. Experimental Study on Rub-impact Faults of High-speed Aerostatic Bearing-rotor Systems%高速气体轴承-转子系统碰磨故障的试验

    Institute of Scientific and Technical Information of China (English)

    付忠广; 边技超; 杨金福

    2015-01-01

    建立单跨、四圆盘结构的高速气体静压轴承-转子系统试验台,对系统的碰磨故障进行了试验研究。在试验过程中,呈现了轴向碰磨与径向碰磨,低频引起的碰磨与工频引起的碰磨等碰磨故障现象,通过分析系统振动信号的频谱特性、轴心运动轨迹、分岔图、伯德图及时间-频率-幅值三维谱图等给出了各种碰磨故障的典型特征,并分析了轴向碰磨与径向碰磨,低频引起的碰磨与工频引起的碰磨等碰磨故障之间的特征区别。为碰磨故障的识别与碰磨故障诊断系统的建立提供了一些试验依据。%The test bench for high-speed aerostatic bearing-rotor systems with single span and four disks structure was built, and the rub-impact faults of the systems were studied experimentally. The axial rub-impact and radial rub-impact at low frequency and working frequency were tested. Through the analyses of the frequency spectrum characteristics, shaft cen-ter kinetic trajectory, bifurcation diagram and time-frequency-amplitude waterfall diagrams, the typical features of all kinds of rub-impact faults were given. Meanwhile, the difference of the faults was analyzed. The work may provide a data base for rub-impact fault identification and the establishment of the diagnosis systems.

  10. 多箱渡槽槽身静风三分力系数风洞试验研究%A wind tunnel test study on aerostatic coefficients of large scale multi-box aqueduct bridge deck

    Institute of Scientific and Technical Information of China (English)

    李遇春; 邸庆霜; 张文杰; 张婷婷

    2012-01-01

    A wind tunnel test for the six scaled multi-box aqueduct decks (including 3 two-box and 3 three-box models) was conducted. The cases with full and without water, and with different wind attack an- gles are considered respectively. The drag, lift and pitching moment coefficients of multi-box aqueduct decks were obtained by the test result analyses. The surface pressure distributions and the aerostatic coeffi- cients of the test models were displayed and discussed. The results show that: (1) The wind flow field around multi-box aqueduct deck is similar to that of blunt body; (2) The drag force is the most important wind load among the three static loads; (3) The drag coefficient decreases with the increasing of width/ height ratio of aqueduct decks in the whole tendency.%对6个多箱式渡槽槽身刚性测压模型进行了风洞试验研究,分别模拟了满槽、空槽以及不同风攻角的试验工况。根据试验结果得到了槽身模型的静风三分力(阻力、升力和扭矩)系数,讨论了模型风压分布以及三分力系数的变化规律。试验结果表明:(1)多箱式渡槽槽身绕流更趋近于钝体绕流;(2)槽身风荷载主要表现为风阻力;(3)阻力系数在总体趋势上随着槽截面宽高比的增加而减小。试验结果可为多箱渡槽的抗风研究与设计提供初步的参考。

  11. Aerostat radio-electronic systems and complexes

    OpenAIRE

    V. A. Bychkovsky; Yu. Yu. Reutskaya

    2010-01-01

    The balloon systems and complexes possibilities intended for reception of the information on extended and local anomalies of a natural and technogenic origin in territories of limited access and supervision over surface territory are considered. Methods of construction of communication channels of ballon systems with high speed of the information transfer, based on technologies 3G and 4G are analysed.

  12. Aerostat radio-electronic systems and complexes

    Directory of Open Access Journals (Sweden)

    V. A. Bychkovsky

    2010-10-01

    Full Text Available The balloon systems and complexes possibilities intended for reception of the information on extended and local anomalies of a natural and technogenic origin in territories of limited access and supervision over surface territory are considered. Methods of construction of communication channels of ballon systems with high speed of the information transfer, based on technologies 3G and 4G are analysed.

  13. Dynamic Analysis of Aerostatic Guideway and FEA Model Development

    OpenAIRE

    Lim, Chee Wang

    2009-01-01

    A dynamically optimal design is essential for a motion system to perform high speed operation without compromising its accuracy, settling time and vibration specification. Good design practice which accounts for dynamic characteristics in the modelling of a motion system warrants higher performance precision machines and cuts down redevelopment effort to ‘patch’ inherent shortcoming of the machine dynamics. This research aimed to accurately describe the non-linear dynamics of a non-mechani...

  14. On The Modelling Of Hybrid Aerostatic - Gas Journal Bearings

    DEFF Research Database (Denmark)

    Morosi, Stefano; Santos, Ilmar

    2011-01-01

    modeling for hybrid lubrication of a compressible fluid film journal bearing. Additional forces are generated by injecting pressurized air into the bearing gap through orifices located on the bearing walls. A modified form of the compressible Reynolds equation for active lubrication is derived. By solving......Gas journal bearing have been increasingly adopted in modern turbo-machinery applications, as they meet the demands of operation at higher rotational speeds, in clean environment and great efficiency. Due to the fact that gaseous lubricants, typically air, have much lower viscosity than more...... and drawbacks of this special kind of hybrid fluid film bearing....

  15. On The Modeling Of Hybrid Aerostatic - Gas Journal Bearings

    DEFF Research Database (Denmark)

    Morosi, Stefano; Santos, Ilmar

    2010-01-01

    compressible fluid film journal bearing. Control forces are generated by injecting pressurized air into the bearing gap through orifices located on the bearing walls. A modified form of the compressible Reynolds equation for active lubrication is derived. By solving this equation, stiffness and damping......Gas journal bearing have been increasingly adopted in modern turbo-machinery applications, as they meet the demands of operation at higher rotational speeds, in clean environment and great efficiency. Due to the fact that gaseous lubricants, typically air, have much lower viscosity than more...... conventional oil bearings, carrying capacity and dynamic characteristics of passive systems are generally poorer. In order to enhance these characteristics, one solution is to employ active control strategies. The present contribution presents a detailed mathematical modeling for active lubrication of a...

  16. On the stability analysis of flexible rotors supported by Hybrid Aerostatic - Gas Journal Bearings

    DEFF Research Database (Denmark)

    Morosi, Stefano; Santos, Ilmar

    external pressurization. The present contribution presents a detailed mathematical modeling for hybrid lubrication of a compressible fluid film journal bearing. Piezo-actuated valves are used in order to inject pressurized air into the bearing gap through orifices located on the bearing walls. A modified...... form of the compressible Reynolds equation for active lubrication is derived. Particular attention is given to the injections terms and a comparison is carried on between fully nonlinear and linearized expressions. By solving this equation, stiffness and damping coefficients can be determined. A...... this special kind of hybrid fluid film bearing....

  17. 飞艇续航时间论证方法研究%Study of Airborne Endurance Analyzing Method of Tethered Aerostat

    Institute of Scientific and Technical Information of China (English)

    姜琬

    2013-01-01

    由于飞艇续航时间受飞行速度、重力浮力配平方式、载油量变化、风场条件等多种因素的影响,飞机续航时间计算方法并不适用于飞艇,因此提出了一种新的基于试验设计和统计分析方法的飞艇续航时间论证方法。分析了工作高度的风场速度分布规律,分别给出完全靠发动机推力矢量平衡和完全靠动升力平衡两种不同情况下飞艇续航时间计算方法,以某大型对流层飞艇为研究对象,计算了初始方案在不同平均巡航速度、配平重量和配平方式下的平均燃油消耗率和最大续航时间,对经过减阻、减重、减少耗油率等技术改进后优化方案能达到的续航时间和概率进行了分析和论证。研究表明,某飞艇初始方案在使用区域风场条件下基本能满足留空时间72 h的指标要求,经技术改进后,指标仍有较大的提升的空间。方法考虑了飞艇续航时间的多种影响因素、取值变化和交互影响,比较适宜在飞艇这类涉及重浮力配平和任务耗油率变化的浮空器上使用。%The cruise duration calculating method of aircraft is not suitable for airship because airship ′s endurance in flight is influenced by many factors , such as velocity , balance of weight and buoyancy , change of fuel load and wind condition ,and therefore a new endurance analyzing method according to air-ship on the basis of experiment design and statistic analysis means is presented .Firstly,the wind velocity distributing regulation at working altitude is analyzed .Then two kinds of airship endurance calculating methods under different conditions are given respectively ,including power plant thrust vector counterbal-ance and aerodynamic lift counterbalance .After that,taking a large troposphere airship as study object , the average fuel consumption and maximum endurance of its primary scheme at different average cruise velocity,trim weight and means are calculated .At last,the endurance capacity and probability of the opti-mized scheme after technique improvement with drag , weight and fuel consumption decreasing are ana-lyzed and demonstrated .The study indicated that the primary scheme of the airship can basically meet the requirement of 72 h airborne endurance index with the given wind condition in the application region ,and the index can be further prolonged after technique improvement .The method takes into account multifari-ous influencing factors of airship endurance ,change of partial factor values and interaction between fac-tors,and is propitious to be used in the counterpart like airships which referring balance of weight and buoyancy ,together with task fuel consumption change .

  18. Power Gyroscopes of Stabilizing System

    OpenAIRE

    Šimek, Jiří; Šklíba, Jan; Sivčák, Michal; Škoda, Jan

    2011-01-01

    The paper deals with problems concerning power gyroscopes for stabilization of vibro-izolation system. Two variants of gyro support with air drive were designed, namely with gas bearings and precision rolling bearings. Precession frame of the gyro is supported in aerostatic journal bearings to achieve minimum passive resistance. Some special phenomena, such as pneumatic instability, were found in some test regimes both at aerostatic thrust bearing of gyro support and aerostatic journal bearin...

  19. A review of lighter-than-air progress in the United States and its technological significance

    Science.gov (United States)

    Mayer, N. J.; Krida, R. H.

    1977-01-01

    Lighter-than-air craft for transportation and communications systems are discussed, with attention given to tethered balloons used to provide stable platforms for airborne surveillance equipment, freight-carrying balloons, manned scientific research balloons such as Atmosat, high-altitude superpressure aerostats employed in satellite communications systems, airport feeder airships, and naval surveillance airships. In addition, technical problems associated with the development of advanced aerostats, including the aerodynamics of hybrid combinations of large rotor systems and aerostat hulls, the application of composites to balloon shells, computer analyses of the complex geometrical structures of aerostats and propulsion systems for airships, are considered.

  20. Design and Implementation of Software for Mobile Tethered Aerostat Measure and Control System%机动式系留气球测控系统软件设计与实现

    Institute of Scientific and Technical Information of China (English)

    唐黎江

    2013-01-01

    This paper first introduces content of real-time operation system and tethered airship measure and control system. It explains and analyses the composition and characteristic of tethered airship. On the basis of the properties of function, this paper introduce detailedly the process of the design and the implement of software structure of tethered airship measure and control system, and software designed process is also given. The application of software in actual system proved the feasibility, reliability and character of real-time.%介绍了VxWorks实时操作系统、系留气球测控系统的相关内容,阐述并分析了系留气球的组成和特点.根据系留气球测控系统的功能,详细介绍了系留气球测控系统软件的设计和实现过程,给出了软件设计的流程图,并通过在实际系统中的应用,验证了软件的可行性、可靠性和实时性.

  1. Analysis of Orifice Compensated Mode Affecting Aerostatic Bearing's Working Stiffness%小孔节流方式对气体静压轴承工作刚度影响的分析

    Institute of Scientific and Technical Information of China (English)

    李树森; 刘暾; 张鹏顺

    2000-01-01

    本文对小孔节流方式中的简单孔节流和环形孔节流形式对气体静压轴承工作刚度的影响进行了理论分析,通过比较从而得出,采用简单孔节流方式的轴承比环形孔节流方式的轴承具有更高的工作刚度.

  2. Grassland and forest understory biomass emissions from prescribed fires in the southeastern United States – RxCADRE 2012

    Science.gov (United States)

    Smoke measurements were made during grass and forest understory prescribed fires as part of a comprehensive program to understand fire and smoke behaviour. Instruments deployed on the ground, airplane and tethered aerostat platforms characterized the smoke plumes through measure...

  3. СИНТЕЗ АЛГОРИТМУ ОПТИМАЛЬНОГО КЕРУВАННЯ РУХОМ АЕРОСТАТИЧНОГО ЛІТАЛЬНОГО АПАРАТА НА ЕТАПІ ПОСАДКИ

    OpenAIRE

    ГУСИНІН Андрій Вячеславович

    2013-01-01

    The automated control algorithm by aerostatic vehicle thrust vector tilting at landing stage was synthesized. The possibility and effectiveness of synthesized control algorithm by thrust vector tilting was presented by simulation of airship «Zeppelin NT» landing.

  4. Mechanics problems in undergraduate physics

    CERN Document Server

    Strelkov, S P

    2013-01-01

    Problems in Undergraduate Physics, Volume I: Mechanics focuses on solutions to problems in physics. The book first discusses the fundamental problems in physics. Topics include laws of conservation of momentum and energy; dynamics of a point particle in circular motion; dynamics of a rotating rigid body; hydrostatics and aerostatics; and acoustics. The text also offers information on solutions to problems in physics. Answers to problems in kinematics, statics, gravity, elastic deformations, vibrations, and hydrostatics and aerostatics are discussed. Solutions to problems related to the laws of

  5. СИНТЕЗ АЛГОРИТМУ ОПТИМАЛЬНОГО КЕРУВАННЯ РУХОМ АЕРОСТАТИЧНОГО ЛІТАЛЬНОГО АПАРАТА НА ЕТАПІ ПОСАДКИ

    Directory of Open Access Journals (Sweden)

    ГУСИНІН Андрій Вячеславович

    2013-06-01

    Full Text Available The automated control algorithm by aerostatic vehicle thrust vector tilting at landing stage was synthesized. The possibility and effectiveness of synthesized control algorithm by thrust vector tilting was presented by simulation of airship «Zeppelin NT» landing.

  6. Sound source localization using distributed elevated acoustic sensors

    Science.gov (United States)

    Di, Xiao; Wagstaff, Ronald A.; Anderson, John D.; Gilbert, Kenneth E.

    2009-05-01

    Detecting and localizing impulsive acoustic sources in the daytime using distributed elevated acoustic sensors with large baseline separations has distinct advantages over small ground-based arrays. There are generally two reasons for this: first, during the daytime, because of more direct and less encumbered propagation paths, signal levels are generally larger at altitude than near the ground. Second, larger baselines provide improved localization accuracy. Results are reported from a distributed array of acoustic sensors deployed during an experiment near Bourges, France during June of 2008. The distributed array consisted of microphones and GPS receivers attached to the tether lines of three widely separated aerostats. The sound sources were various impulsive devices. Results from the measurements are presented and discussed. Localization errors (GPS accuracy, propagation calculation, and aerostat motion, etc) are discussed. Possible ways to improve the localization accuracy are suggested.

  7. A Solar Power System for High Altitude Airships

    Science.gov (United States)

    Mei, Qiang

    This research is intended to produce a power system suitable for an aerostat operating at 67,500 ft and powered only by solar energy. A battery will be charged during daylight hours and will then power the system whenever adequate sunlight is not available. To obtain adequate solar energy, it is necessary to mount solar panels on several different surfaces such as the top, two sides, and the front of the aerostat. Although power can be provided by all of these panels, their output curves can vary widely because of various levels of solar intensity. These panels should not be connected in parallel because the higher power panels will be loaded by the lower power panels. Therefore a system that provides peak power tracking (PPT) for each of the panel surfaces is proposed in this research. Moreover, in order to guarantee the safety of the battery, a battery management system (BMS) is included. Embedded systems are applied to the solar power system to realize the PPT and BMS functions. Communication between PPTs and the BMS is implemented by a CAN (Controller Area Network) serial data link. A 1500W Laboratory Prototype will be developed to validate the feasibility of the proposed solar power system for the aerostat.

  8. Experimental verification of compressor performance for an ultra-microgasturbine

    OpenAIRE

    Peirs, Jan; Waumans, Tobias; Liu, Kun; Ferraris, Eleonora; Verstraete, Tom; Van den Braembussche, Rene; Reynaerts, Dominiek

    2009-01-01

    This paper presents the experimental verification of a 20 mm compressor prototype developed for a 1 kWe ultra-microgasturbine. The gasturbine has a nominal speed of 500 krpm, a nominal air flow of 20 g/s and a nominal pressure ratio of 3. The compressor is tested in a turbo-shaft setup containing compressor, turbine and aerostatic bearings. The test speed is currently limited to 261 krpm due to bearing instability. At this reduced speed, the generated relative static pressure reaches 0.41 bar...

  9. The balloon and the airship technological heritage

    Science.gov (United States)

    Mayer, N. J.

    1981-01-01

    The balloon and the airship are discussed with emphasis on the identification of commonalities and distinctions. The aerostat technology behind the shape and structure of the vehicles is reviewed, including a discussion of structural weight, internal pressure, buckling, and the development of a stable tethered balloon system. Proper materials for the envelope are considered, taking elongation and stress into account, and flight operation and future developments are reviewed. Airships and tethered balloons which are designed to carry high operating pressure with low gas loss characteristics are found to share similar problems in low speed flight operations, while possessing interchangeable technologies.

  10. Raman lasing in a hollow, bottle-like microresonator

    CERN Document Server

    Ooka, Yuta; Ward, Jonathan; Chromaic, Síle Nic

    2015-01-01

    We report on the fabrication of an ultrahigh quality factor, bottle-like microresonator from a hollow microcapillary, and the realisation of Raman lasing therein at pump wavelengths of $1.55~\\mathrm{\\mu m}$ and $780~\\mathrm{nm}$. Third-order cascaded Raman lasing was observed when pumped at $780~\\mathrm{nm}$. The aerostatic pressure tunability of the Raman laser was also investigated. Thence, we demonstrate that a high dynamic range, high resolution pressure sensor can be realised using the Raman spectrum of the hollow, bottle-like microresonator.

  11. Balloon concepts for scientific investigation of Mars and Jupiter

    Science.gov (United States)

    Ash, R. L.

    1979-01-01

    Opportunities for scientific investigation of the atmospheric planets using buoyant balloons have been explored. Mars and Jupiter were considered in this study because design requirements at those planets bracket nominally the requirements at Venus, and plans are already underway for a joint Russian-French balloon system at Venus. Viking data has provided quantitative information for definition of specific balloon systems at Mars. Free flying balloons appear capable of providing valuable scientific support for more sophisticated Martian surface probes, but tethered and powered aerostats are not attractive. The Jovian environment is so extreme, hot atmosphere balloons may be the only scientific platforms capable of extended operations there. However, the estimated system mass and thermal energy required are very large.

  12. Penetration depth testing the fuel element cladding and end element joint by eddy currents

    International Nuclear Information System (INIS)

    Advantage of the eddy method of testing the fuel cladding penetration depth as compared with ultrasonic and X-ray ones presupposes increase of sensitivity to low penetration and an opportunity of testing the penetration near the edge. Increase of the sensitivity is attained by means of an aerostatic bearing, on the working edge of which induction coils are dislocated, and increase of edge effect- by means of a superposed differential converter with sector windings, the adjacent linearly stretched sections of which are located at the right angle. At the diameter of the converter of 12 mm, nozzle chamber diameter of 5 mm, diffuser diameter of 7 mm the measuring range of the penetration depth makes up 0-1.1 mm

  13. Power Laser Ablation Symposia

    CERN Document Server

    Phipps, Claude

    2007-01-01

    Laser ablation describes the interaction of intense optical fields with matter, in which atoms are selectively driven off by thermal or nonthermal mechanisms. The field of laser ablation physics is advancing so rapidly that its principal results are seen only in specialized journals and conferences. This is the first book that combines the most recent results in this rapidly advancing field with authoritative treatment of laser ablation and its applications, including the physics of high-power laser-matter interaction. Many practical applications exist, ranging from inertial confinement fusion to propulsion of aerostats for pollution monitoring to laser ignition of hypersonic engines to laser cleaning nanoscale contaminants in high-volume computer hard drive manufacture to direct observation of the electronic or dissociative states in atoms and molecules, to studying the properties of materials during 200kbar shocks developed in 200fs. Selecting topics which are representative of such a broad field is difficu...

  14. Oil-free bearing development for high-speed turbomachinery in distributed energy systems - dynamic and environmental evaluation

    Science.gov (United States)

    Tkacz, Eliza; Kozanecka, Dorota; Kozanecki, Zbigniew; Łagodziński, Jakub

    2015-09-01

    Modern distributed energy systems, which are used to provide an alternative to or an enhancement of traditional electric power systems, require small size highspeed rotor turbomachinery to be developed. The existing conventional oil-lubricated bearings reveal performance limits at high revolutions as far as stability and power loss of the bearing are concerned. Non-conventional, oil-free bearings lubricated with the machine working medium could be a remedy to this issue. This approach includes a correct design of the machine flow structure and an accurate selection of the bearing type. Chosen aspects of the theoretical and experimental investigations of oil-free bearings and supports; including magnetic, tilting pad, pressurized aerostatic and hydrostatic bearings as well as some applications of oil-free bearing technology for highspeed turbomachinery; are described in the paper.

  15. Experimental investigations of active air bearings

    DEFF Research Database (Denmark)

    Santos, Ilmar; Morosi, Stefano

    2012-01-01

    greatest challenges in a high-speed gas bearing design. A great deal of research is devoted to attack such issues, where most propose passive designs such as compliant foil bearings, tilting pad and flexure pivot gas bearings. These solutions proved to be effective in improving static and dynamic......Along with traditional oil lubrication, increasing demand for high-speed applications has renewed attention to gas bearings technology. Traditional aerostatic and aerodynamic gas lubrication has been widely used in a variety of applications, ranging from high-speed spindles to micro and meso......-scale turbomachinery. The present paper deals with experimental rotordynamic testing of a flexible rotor supported by hybrid aerostaticaerodynamic gas journal bearing equipped with an electronic radial air injection system. From a rotordynamic point of view there are two phenomena that limit the widespread of...

  16. Oil-free bearing development for high-speed turbomachinery in distributed energy systems – dynamic and environmental evaluation

    Directory of Open Access Journals (Sweden)

    Tkacz Eliza

    2015-09-01

    Full Text Available Modern distributed energy systems, which are used to provide an alternative to or an enhancement of traditional electric power systems, require small size highspeed rotor turbomachinery to be developed. The existing conventional oil-lubricated bearings reveal performance limits at high revolutions as far as stability and power loss of the bearing are concerned. Non-conventional, oil-free bearings lubricated with the machine working medium could be a remedy to this issue. This approach includes a correct design of the machine flow structure and an accurate selection of the bearing type. Chosen aspects of the theoretical and experimental investigations of oil-free bearings and supports; including magnetic, tilting pad, pressurized aerostatic and hydrostatic bearings as well as some applications of oil-free bearing technology for highspeed turbomachinery; are described in the paper.

  17. Airships: A New Horizon for Science

    CERN Document Server

    Miller, Sarah H; Hillenbrand, Lynne; Rhodes, Jason; Baird, Gil; Blake, Geoffrey; Booth, Jeff; Carlile, David E; Duren, Riley; Edworthy, Frederick G; Freeze, Brent; Friedl, Randall R; Goldsmith, Paul F; Hall, Jeffery L; Hoffman, Scott E; Hovarter, Scott E; Jensen-Clem, Rebecca M; Jones, Ross M; Kauffmann, Jens; Kiessling, Alina; King, Oliver G; Konidaris, Nick; Lachenmeier, Timothy L; Lord, Steven D; Neu, Jessica; Quetin, Gregory R; Ram, Alan; Sander, Stanley; Simard, Marc; Smith, Mike; Smith, Steve; Smoot, Sara; Susca, Sara; Swann, Abigail; Young, Eliot F; Zambrano, Thomas

    2014-01-01

    The "Airships: A New Horizon for Science" study at the Keck Institute for Space Studies investigated the potential of a variety of airships currently operable or under development to serve as observatories and science instrumentation platforms for a range of space, atmospheric, and Earth science. The participants represent a diverse cross-section of the aerospace sector, NASA, and academia. Over the last two decades, there has been wide interest in developing a high altitude, stratospheric lighter-than-air (LTA) airship that could maneuver and remain in a desired geographic position (i.e., "station-keeping") for weeks, months or even years. Our study found considerable scientific value in both low altitude ( 60 kft) airships across a wide spectrum of space, atmospheric, and Earth science programs. Over the course of the study period, we identified stratospheric tethered aerostats as a viable alternative to airships where station-keeping was valued over maneuverability. By opening up the sky and Earth's strato...

  18. The Identification of Nonlinear Systems Using Ct-Kt Plane Coordinates

    Directory of Open Access Journals (Sweden)

    Ming-Fei Chen

    2014-01-01

    Full Text Available In order to instantaneously distinguish the Ct (coefficient of viscous damping and Kt (coefficient of stiffness, which are both functions of time in an M.C.K. nonlinear system, a new identification method is proposed in this paper. The graphs of the Ct-Kt are analyzed and the dynamic behavior of M.C.K. systems in a Ct-Kt coordinate plane is discussed. This method calculates two adjacent sampling data, the displacement, velocity, and acceleration (which are obtained from the responses of a pulse response experiment and then distinguishes Ct and Kt of an instantaneous system. Finally, this method is used to identify the aerostatic bearing dynamic parameters, C and K.

  19. Figurative lights: Images of Techno-Scientific slides and Secularization in Spain during the 18th Century

    Directory of Open Access Journals (Sweden)

    Germán LABRADOR MÉNDEZ

    2010-06-01

    Full Text Available This paper asembles and studies a set of iconological representations linked to technical and scientific transformations during the eighteenth Century in Spain, reading them in a dialectic between modern science, Enlightenment policies and popular culture. After analyzing the emergence of representations both of science and scientists according to the process of institutionalizing science as a socio-professional language, two specific eighteenth century technologies are studied: magic lanterns and aerostats. By interpreting their first images and their infiltration into popular and official speeches and the imagination of the moment, it is argued that in those images a tale of demo-Enlightenment is expressed, a tale about secularization and progress as a collective aesthetic experience.

  20. To sail the skies of Mars - Scientific ballooning on the red planet

    Science.gov (United States)

    Gaidos, Eric J.; Burke, James D.

    1988-01-01

    Balloons represent a novel approach to exploring the surface of Mars. One promising aerostat system incorporates a solar-powered balloon as a means of generating diurnally varying lift and so can 'hop' across the surface, obtaining detailed information at a large number of sites. Two important areas of research and testing are underway on solar balloon technology and balloon payload design. The solar balloon concept has been demonstrated on earth, but more work is needed on a 'flyable' version for Mars. Particular attention must be paid to radiation heat transfer and aerodynamic effects. A special 'snake' payload concept has been demonstrated that allows for balloon system traverses of the surface and provides a usable instrument platform. A balloon system of this type could obtain unique surface imaging and physical and chemical data. The flight of the balloon also provides in situ atmospheric boundary-layer and circulation measurements.

  1. Exploring Venus with high-altitude balloons: Science objectives and mission architectures

    Science.gov (United States)

    Baines, Kevin; Limaye, Sanjay; Zahnle, Kevin; Atreya, Sushil K.

    Following the trailblazing flights of the 1985 twin Soviet VEGA balloons, missions to fly in the high atmosphere of Venus near 55 km altitude have been proposed to both NASA's Discovery Program and ESA's Cosmic Vision. Such missions would address a variety of fundamental science issues highlighted in a variety of high-level NASA-authorized science documents in recent years, including the Decadal Study, various NASA roadmaps, and recommendations coming out of the Venus Exploration Analysis Group (VEXAG). Such missions would in particular address key questions of Venus's origin, evolution, and current state, including detailed measurements of (1) trace gases associated with Venus's active photoand thermo-chemistry and (2) measurements of vertical motions and local temperature which characterize convective and wave processes. As an example of what can be done with a small mission (less than 500M US dollars), the Venus Aerostatic-Lift Observatories for in-situ Research (VALOR) Discovery mission will be discussed. This mission would fly twin balloon-borne aerostats over temperate and polar latitudes, sampling rare gases, chemicals and dynamics in two distinct latitude regions for several days. A variety of scenarios for the origin, formation, and evolution of Venus would be tested by sampling all the noble gases and their isotopes, especially the heaviest elements never reliably measured previously: xenon and krypton. Riding the gravity and planetary waves of Venus, the VALOR balloons would sample the chemistry, meteorology and dynamics of Venus's sulfur-cloud region. Tracked by an array of Earth-based telescopes, zonal, meridional, and vertical winds would be measured with unprecedented precision. Such measurements would help to develop a fundamental understanding of (1) the circulation of Venus, especially its enigmatic super-rotation, (2) the nature of Venus's sulfur cycle, key to Venus's current climate, and (3) how Venus formed and evolved over the aeons.

  2. Bridging Informatics and Earth Science: a Look at Gregory Leptoukh's Contributions

    Science.gov (United States)

    Lynnes, C.

    2012-12-01

    With the tragic passing this year of Gregory Leptoukh, the Earth and Space Sciences community lost a tireless participant in--and advocate for--science informatics. Throughout his career at NASA, Dr. Leptoukh established a theme of bridging the gulf between the informatics and science communities. Nowhere is this more evident than his leadership in the development of Giovanni (GES DISC Interactive Online Visualization ANd aNalysis Infrastructure). Giovanni is an online tool that serves to hide the often-complex technical details of data format and structure, making science data easier to explore and use by Earth scientists. To date Giovanni has been acknowledged as a contributor in 500-odd scientific articles. In recent years, Leptoukh concentrated his efforts on multi-sensor data inter-comparison, merging and fusion. This work exposed several challenges at the intersection of data and science. One of these was the ease with which a naive user might generate spurious comparisons, a potential hazard that was the genesis of the Multi-sensor Data Synergy Advisor (MDSA). The MDSA uses semantic ontologies and inference rules to organize knowledge about dataset quality and other salient characteristics in order to advise users on potential caveats for comparing or merging two datasets. Recently, Leptoukh also led the development of AeroStat, an online Giovanni instance to investigate aerosols via statistics from station and satellite comparisons and merged maps of data from more than one instrument. Aerostat offers a neural net based bias adjustment to "harmonize" the data by removing systematic offsets between datasets before merging. These examples exhibit Leptoukh's talent for adopting advanced computer technologies in the service of making science data more accessible to researchers. In this, he set an example that is at once both vital and challenging for the ESSI community to emulate.

  3. Bridging Informatics and Earth Science: a Look at Gregory Leptoukh's Contributions

    Science.gov (United States)

    2012-01-01

    With the tragic passing this year of Gregory Leptoukh, the Earth and Space Sciences community lost a tireless participant in--and advocate for--science informatics. Throughout his career at NASA, Dr. Leptoukh established a theme of bridging the gulf between the informatics and science communities. Nowhere is this more evident than his leadership in the development of Giovanni (GES DISC Interactive Online Visualization ANd aNalysis Infrastructure). Giovanni is an online tool that serves to hide the often-complex technical details of data format and structure, making science data easier to explore and use by Earth scientists. To date Giovanni has been acknowledged as a contributor in 500-odd scientific articles. In recent years, Leptoukh concentrated his efforts on multi-sensor data inter-comparison, merging and fusion. This work exposed several challenges at the intersection of data and science. One of these was the ease with which a naive user might generate spurious comparisons, a potential hazard that was the genesis of the Multi-sensor Data Synergy Advisor (MDSA). The MDSA uses semantic ontologies and inference rules to organize knowledge about dataset quality and other salient characteristics in order to advise users on potential caveats for comparing or merging two datasets. Recently, Leptoukh also led the development of AeroStat, an online Giovanni instance to investigate aerosols via statistics from station and satellite comparisons and merged maps of data from more than one instrument. Aerostat offers a neural net based bias adjustment to harmonize the data by removing systematic offsets between datasets before merging. These examples exhibit Leptoukh's talent for adopting advanced computer technologies in the service of making science data more accessible to researchers. In this, he set an example that is at once both vital and challenging for the ESSI community to emulate.

  4. 径向变体飞艇总体参数估算方法%Parameters estimation method of radial transformable airship

    Institute of Scientific and Technical Information of China (English)

    肖治垣; 郦正能

    2012-01-01

    To break the crucial technical difficulties of controllable aerostat in near space,and make it possible of controlling aerostat going and returning between ground and near space,the conception of solar powered radial transformable airship was raised,and it’s parameters estimation method was given.The method was based on Archimedes theory and Li-style transformable airship theory.The self-adapting and controllable-transformation of sectional area was actualized by radial transformation of structure,net lift was changed by controlling the volume of airship.Controllable aerodynamic configuration was consistently kept through the change of volume,thereby the controls for ascending,descending and staying of airship were actualized.Size of inside ballonet and outside ballonet were accounted by designing transformation project,length of airship was accounted by analyzing dynamics balance and energy balance.Based on study out design parameter,an overall design project for solar powered radial transformable airship was given,feasibility and practicality of the method was validated by example.%为突破临近空间可操纵浮空器的关键技术难点,使可操纵浮空器往返地面至临近空间成为可能,提出了一种径向变体飞艇的总体参数估算方法,该方法基于阿基米德浮力定律和李式变体飞艇原理(Li-Style Transformable Airship Theory),通过艇体结构的径向变形来实现艇体截面积的自适与可控变化,控制飞艇容积变化以改变净升力大小,并使飞艇在容积变化中始终保持可操纵的气动外形,从而实现飞艇的升、降与驻空和飞行等控制.通过设计变形方案估算内气囊与外气囊尺寸,分析力学平衡与能源平衡估算飞艇长度.在拟定设计参数的基础上,给出了一种太阳能径向变体飞艇的总体设计方案,并通过设计实例验证了此方法的可行性与实用性.

  5. Final report on the development and operation of high pressure irradiation capsules for determination of nuclear fuel swelling in FR2

    International Nuclear Information System (INIS)

    The design of advanced fuel element concepts for FBR and the evaluation through models of fuel rod behavior during the planned service life call inter alia for knowledge of creep and swelling processes taking place in the selected fuels exposed to irradiation. In a recently developed irradiation capsule omnilateral loads of up to 45 N/mm2 were applied, at temperatures up to 17500C at the maximum, to thin ring pellet fuel specimens, using an aerostatic gas pressure of 450 bar (45 MPa) at the maximum. Extensive preliminary experiments and testing had been necessary because of the extremely high stress to which these high pressure capsules had been exposed under irradiation. In addition to the description of the test facility and a short outline of the many problems to be solved, this final report gives a survey of the assembly work done on the three capsule test rigs containing two sample packages each and of the operating experience gathered during irradiation. (orig./HP)

  6. Modeling and Simulation Tools for Heavy Lift Airships

    Science.gov (United States)

    Hochstetler, Ron; Chachad, Girish; Hardy, Gordon; Blanken, Matthew; Melton, John

    2016-01-01

    For conventional fixed wing and rotary wing aircraft a variety of modeling and simulation tools have been developed to provide designers the means to thoroughly investigate proposed designs and operational concepts. However, lighter-than-air (LTA) airships, hybrid air vehicles, and aerostats have some important aspects that are different from heavier-than-air (HTA) vehicles. In order to account for these differences, modifications are required to the standard design tools to fully characterize the LTA vehicle design and performance parameters.. To address these LTA design and operational factors, LTA development organizations have created unique proprietary modeling tools, often at their own expense. An expansion of this limited LTA tool set could be accomplished by leveraging existing modeling and simulation capabilities available in the National laboratories and public research centers. Development of an expanded set of publicly available LTA modeling and simulation tools for LTA developers would mitigate the reliance on proprietary LTA design tools in use today. A set of well researched, open source, high fidelity LTA design modeling and simulation tools would advance LTA vehicle development and also provide the analytical basis for accurate LTA operational cost assessments. This paper will present the modeling and analysis tool capabilities required for LTA vehicle design, analysis of operations, and full life-cycle support. A survey of the tools currently available will be assessed to identify the gaps between their capabilities and the LTA industry's needs. Options for development of new modeling and analysis capabilities to supplement contemporary tools will also be presented.

  7. External laser locking using a pressure-tunable microbubble resonator

    CERN Document Server

    Madugani, Ramgopal; Le, Vu H; Ward, Jonathan M; Chormaic, Síle Nic

    2015-01-01

    The tunability of an optical cavity is an essential requirement for many areas of research especially for the rapidly progressing field of photonics. In particular, low-cost laser tuning methods and miniaturization of the optical components are desirable. By applying aerostatic pressure to the interior surface of a microbubble resonator, optical mode shift rates of around $58$ GHz/MPa are achieved. The micobubble can measure pressure with a limit of detection of $2\\times 10^{-4}$ MPa. Here we use the Pound-Drever-Hall technique, whereby a laser is locked to a whispering gallery mode (WGM) of the microbubble resonator, to show that linear tuning of the WGM and the corresponding locked laser display almost zero hysteresis. The long-term frequency stability of this tuning method for different input pressures is measured. The frequency noise of the WGM, measured over 10 minutes, with a maximum input pressure of 0.5 MPa has a standard deviation of 36 MHz.

  8. Acoustic properties in the low and middle atmospheres of Mars and Venus.

    Science.gov (United States)

    Petculescu, Andi

    2016-08-01

    Generic predictions for acoustic dispersion and absorption in the atmospheres of Mars and Venus are presented. For Mars, Pathfinder and Mars Express ambient data and averaged thermophysical parameters are used as inputs to a preliminary model based on the continuum approximation for Mars' thin atmosphere-the need for Boltzmann-based treatment is discussed in the context of Knudsen numbers. Strong absorption constrains acoustic sensing within the Martian planetary boundary layer. For the dense atmosphere of Venus, the van der Waals equation of state is used. The thermophysical and transport parameters were interpolated at the ambient conditions. Acoustic sensing is discussed at 50 km above Venus' surface, a level where aerostats (e.g., European Space Agency's EVE) and manned airships (e.g., NASA's HAVOC) may be deployed in the future. The salient atmospheric characteristics are described in terms of temperature, pressure, and convective stability profiles, followed by wavenumber predictions, and discussions of low- and high-frequency sensing applications. At low frequencies, emphasis is placed on infrasound. A simple generation mechanism by Martian dust devils is presented, yielding fundamental frequencies between 0.1 and 10 Hz. High-frequency sensing is exemplified by ultrasonic anemometry. Of the two environments, Venus is notably more dispersive in the ultrasonic range. PMID:27586769

  9. A high-precision instrument for analyzing nonlinear dynamic behavior of bearing cage

    Science.gov (United States)

    Yang, Z.; Chen, H.; Yu, T.; Li, B.

    2016-08-01

    The high-precision ball bearing is fundamental to the performance of complex mechanical systems. As the speed increases, the cage behavior becomes a key factor in influencing the bearing performance, especially life and reliability. This paper develops a high-precision instrument for analyzing nonlinear dynamic behavior of the bearing cage. The trajectory of the rotational center and non-repetitive run-out (NRRO) of the cage are used to evaluate the instability of cage motion. This instrument applied an aerostatic spindle to support and spin test the bearing to decrease the influence of system error. Then, a high-speed camera is used to capture images when the bearing works at high speeds. A 3D trajectory tracking software tema Motion is used to track the spot which marked the cage surface. Finally, by developing the matlab program, a Lissajous' figure was used to evaluate the nonlinear dynamic behavior of the cage with different speeds. The trajectory of rotational center and NRRO of the cage with various speeds are analyzed. The results can be used to predict the initial failure and optimize cage structural parameters. In addition, the repeatability precision of instrument is also validated. In the future, the motorized spindle will be applied to increase testing speed and image processing algorithms will be developed to analyze the trajectory of the cage.

  10. The development of a mathematical model of a hybrid airship

    Science.gov (United States)

    Abdul Ghaffar, Alia Farhana

    The mathematical model of a winged hybrid airship is developed for the analysis of its dynamic stability characteristics. A full nonlinear equation of motion that describes the dynamics of the hybrid airship is determined and for completeness, some of the components in the equations are estimated using the appropriate methods that has been established and used in the past. Adequate assumptions are made in order to apply any relevant computation and estimation methods. While this hybrid airship design is unique, its modeling and stability analysis were done according to the typical procedure of conventional airships and aircrafts. All computations pertaining to the hybrid airship's equation of motion are carried out and any issues related to the integration of the wing to the conventional airship design are discussed in this thesis. The design of the hybrid airship is also slightly modified to suit the demanding requirement of a complete and feasible mathematical model. Then, linearization is performed under a chosen trim condition, and eigenvalue analysis is carried out to determine the general dynamic stability characteristics of the winged hybrid airship. The result shows that the winged hybrid airship possesses dynamic instability in longitudinal pitch motion and lateral-directional slow roll motion. This is due to the strong coupling between the aerostatic lift from the buoyant gas and aerodynamic lift from the wing.

  11. LISA: a java API for performing simulations of trajectories for all types of balloons

    Science.gov (United States)

    Conessa, Huguette

    2016-07-01

    LISA (LIbrarie de Simulation pour les Aerostats) is a java API for performing simulations of trajectories for all types of balloons (Zero Pressure Balloons, Pressurized Balloons, Infrared Montgolfier), and for all phases of flight (ascent, ceiling, descent). This library has for goals to establish a reliable repository of Balloons flight physics models, to capitalize developments and control models used in different tools. It is already used for flight physics study software in CNES, to understand and reproduce the behavior of balloons, observed during real flights. It will be used operationally for the ground segment of the STRATEOLE2 mission. It was developed with quality rules of "critical software." It is based on fundamental generic concepts, linking the simulation state variables to interchangeable calculation models. Each LISA model defines how to calculate a consistent set of state variables combining validity checks. To perform a simulation for a type of balloon and a phase of flight, it is necessary to select or create a macro-model that is to say, a consistent set of models to choose from among those offered by LISA, defining the behavior of the environment and the balloon. The purpose of this presentation is to introduce the main concepts of LISA, and the new perspectives offered by this library.

  12. Thematic outlook: the technical outlook for the fuel cell research network (PACO). December 22, 2003 update no. 19; Veille thematique. La veille technique pour le reseau PACO. Actualisation du 22 decembre 2003, no. 19

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    Summaries of several recent articles and patents are gathered here. They deal with fuel cells, the means of transport, the hydrogen production and with the different new other energies. Their different titles are given below : 1)gas turbine/fuel cell arrangement 2)design and fabrication of a SOFC by CERAMIC FUEL CELLS 3)a 'microbial' fuel cell able of converting glucose in electricity with high yields and velocity 4)a hybrid system: combined cycle gas turbine - multi-stage SOFC 5)a SOFC as auxiliary generator of electricity in an aircraft 6)recent development results of fuel in the Juelich research center 7)state of development of the SOFC at Haldor Topsoe/Risoe 8)a cost/advantage analysis of 'clean cars': methodology and applications to the electric cars 9)the generation of current and heat in a aerostat 10)hydrogen free from CO, produced from bio-ethanol steam reforming on cobalt catalysts supported on ZnO. Effect of the metallic precursor 11)device and method based on the cyclic auto-thermal reforming 12)the ammonia, source of hydrogen for a hybrid system: alkaline fuel/battery 13)effect of the Nafion on the activity of Pt-Ru electrocatalysts for the methanol electro-oxidation 14)'VISION 21': an integration of systems based on coal. The references of these articles and patents are detailed. (O.M.)

  13. Characterization of the particulate emissions from the BP Deepwater Horizon surface oil burns.

    Science.gov (United States)

    Gullett, Brian K; Hays, Michael D; Tabor, Dennis; Wal, Randy Vander

    2016-06-15

    Sampling of the smoke plumes from the BP Deepwater Horizon surface oil burns led to the unintentional collection of soot particles on the sail of an instrument-bearing, tethered aerostat. This first-ever plume sampling from oil burned at an actual spill provided an opportunistic sample from which to characterize the particles' chemical properties for polycyclic aromatic hydrocarbons (PAHs), organic carbon, elemental carbon, metals, and polychlorinated dibenzodioxins/dibenzofurans (PCDDs/PCDFs) and physical properties for size and nanostructure. Thermal-optical analyses indicated that the particulate matter was 93% carbon with 82% being refractory elemental carbon. PAHs accounted for roughly 68μg/g of the PM filter mass and 5mg/kg oil burned, much lower than earlier laboratory based studies. Microscopy indicated that the soot is distinct from more common soot by its aggregate size, primary particle size, and nanostructure. PM-bound metals were largely unremarkable but PCDD/PCDF formation was observed, contrary to other's findings. Levels of lighter PCDD/PCDF and PAH compounds were reduced compared to historical samples, possibly due to volatilization or photo-oxidation. PMID:27084200

  14. A method for establishing a long duration, stratospheric platform for astronomical research

    Science.gov (United States)

    Fesen, Robert; Brown, Yorke

    2015-10-01

    During certain times of the year at middle and low latitudes, winds in the upper stratosphere move in nearly the opposite direction than the wind in the lower stratosphere. Here we present a method for maintaining a high-altitude balloon platform in near station-keeping mode that utilizes this stratospheric wind shear. The proposed method places a balloon-borne science platform high in the stratosphere connected by a lightweight, high-strength tether to a tug vehicle located in the lower or middle stratosphere. Using aerodynamic control surfaces, wind-induced aerodynamic forces on the tug can be manipulated to counter the wind drag acting on the higher altitude science vehicle, thus controlling the upper vehicle's geographic location. We describe the general framework of this station-keeping method, some important properties required for the upper stratospheric science payload and lower tug platforms, and compare this station-keeping approach with the capabilities of a high altitude airship and conventional tethered aerostat approaches. We conclude by discussing the advantages of such a platform for a variety of missions with emphasis on astrophysical research.

  15. In-situ exploration of Venus on a global scale : direct measurements of origins and evolution, meterology, dynamics, and chemistry by a long-duration aerial science station

    Science.gov (United States)

    Baines, Kevin H.; Atreya, Sushi; Carlson, Robert W.; Chutjian, Ara; Crisp, David; Hall, Jeffrey L.; Jones, Dayton L.; Kerzhanovich, Victor V.; Limaye, Sanjay S.

    2005-01-01

    Drifting in the strong winds of Venus under benign Earth-like temperature and pressure conditions, an instrumented balloon-borne science station presents a viable means to explore, in-situ, the Venusian atmosphere on a global scale. Flying over the ground at speeds exceeding 240 km/hour while floating in the Venusian skies near 55 km altitude for several weeks, such an aerostat can conduct a 'world tour' of our neighboring planet, as it circumnavigates the globe multiple times during its flight from equatorial to polar latitudes. Onboard science sensors can repeatedly and directly sample gas compositions, atmospheric pressures and temperatures and cloud particle properties, giving unprecedented insight into the chemical processes occurring within the sulfuric clouds. Additionally, interferometric tracking via Earth-based radio observatories can yield positions and windspeeds to better than 10 cm/sec over one-hour periods, providing important information for understanding the planet's meridional circulation and enigmatic zonal super-rotation, as well as local dynamics associated with meteorological processes. As well, hundreds of GCMS spectra collected during the flight can provide measurements of noble gas compositions and their isotopes with unprecedented accuracy, thereby enabling fundamental new insights into Venus's origin and evolution.

  16. Two hundred years of flight in America: A bicentennial survey

    Science.gov (United States)

    Emme, E. M.

    1977-01-01

    The first recorded balloon ascension in America took place on June 19, 1784, when an unmanned balloon was raised in a public demonstration at Bladensburg, Maryland. On June 24, 1784, a thirteen-year-old boy ascended in the same balloon. The history of actual flight during the nineteenth century was entirely concerned with balloons except for several gliders and models leading to the coming of the airship and the aircraft. The history of practical flight in America begins in the twentieth century. The described developments related to aerostatics are concerned with balloons, rigid airships, and blimps. In a review of the evolution of aeronautics, attention is given to general aviation and its search for a market, trends in military aeronautics, and commercial aviation. It is pointed out that American air transport had its birth on New Year's Day, 1914, at Tampa Bay, Florida. The evolution of astronautics during the period from 1957 to 1976 is also examined, taking into account scientific satellites, the Apollo project, the exploration of the planets with the aid of unmanned spacecraft, strategic reconnaissance satellites, missile alarm satellites, instrumental satellites for detecting nuclear and thermonuclear explosions, weather satellites, communications satellites, and earth resource survey and geodetic satellites.

  17. Software for Correcting the Dynamic Error of Force Transducers

    Directory of Open Access Journals (Sweden)

    Naoki Miyashita

    2014-07-01

    Full Text Available Software which corrects the dynamic error of force transducers in impact force measurements using their own output signal has been developed. The software corrects the output waveform of the transducers using the output waveform itself, estimates its uncertainty and displays the results. In the experiment, the dynamic error of three transducers of the same model are evaluated using the Levitation Mass Method (LMM, in which the impact forces applied to the transducers are accurately determined as the inertial force of the moving part of the aerostatic linear bearing. The parameters for correcting the dynamic error are determined from the results of one set of impact measurements of one transducer. Then, the validity of the obtained parameters is evaluated using the results of the other sets of measurements of all the three transducers. The uncertainties in the uncorrected force and those in the corrected force are also estimated. If manufacturers determine the correction parameters for each model using the proposed method, and provide the software with the parameters corresponding to each model, then users can obtain the waveform corrected against dynamic error and its uncertainty. The present status and the future prospects of the developed software are discussed in this paper.

  18. Gondola development for CNES stratospheric balloons

    Science.gov (United States)

    Vargas, A.; Audoubert, J.; Cau, M.; Evrard, J.; Verdier, N.

    The CNES has been supporting scientific ballooning since its establishment in 1962. The two main parts of the balloon system or aerostat are the balloon itself and the flight train, comprising the house-keeping gondola, for the control of balloon flight (localization and operational telemetry & telecommand - TM/TC), and the scientific gondola with its dedicated telecommunication system. For zero pressure balloon, the development of new TM/TC system for the housekeeping and science data transmission are going on from 1999. The main concepts are : - for balloon house-keeping and low rate scientific telemetry, the ELITE system, which is based on single I2C bus standardizing communication between the different components of the system : trajectography, balloon control, power supply, scientific TM/TC, .... In this concept, Radio Frequency links are developed between the house keeping gondola and the components of the aerostat (balloon valve, ballast machine, balloon gas temperature measurements, ...). The main objectives are to simplify the flight train preparation in term of gondola testing before flight, and also by reducing the number of long electrical cables integrated in the balloon and the flight train; - for high rate scientific telemetry, the use of functional interconnection Internet Protocol (IP) in interface with the Radio Frequency link. The main idea is to use off-the-shelf IP hardware products (routers, industrial PC, ...) and IP software (Telnet, FTP, Web-HTTP, ...) to reduce the development costs; - for safety increase, the adding, in the flight train, of a totally independent house keeping gondola based on the satellite Inmarsat M and Iridium telecommunication systems, which permits to get real time communications between the on-board data mobile and the ground station, reduced to a PC computer with modem connected to the phone network. These GEO and LEO telecommunication systems give also the capability to operate balloon flights over longer distance

  19. Calibration of non-contact incremental linear encoders using a macro-micro dual-drive high-precision comparator

    Science.gov (United States)

    Yu, Haoyu; Liu, Hongzhong; Li, Xuan; Ye, Guoyong; Shi, Yongsheng; Yin, Lei; Jiang, Weitao; Chen, Bangdao; Liu, Xiaokang

    2015-09-01

    The accuracy of a linear encoder is determined by encoder-specific errors, which consist of both long-range and cyclic errors. Generally, it is difficult to measure the two errors of a non-contact incremental linear encoder with a large measuring range and small signal period in one measurement because of the contradiction between long travel range and high resolution. To resolve this issue, a prototype high-precision interferometric comparator with a macro-micro dual-drive system is presented. The measurement and motion resolution of the comparator are 1 nm and 3 nm, respectively. A measuring range of 320 mm is realized and the theoretical maximum range of the comparator is 2 m. The comparator mainly includes a high-accuracy aerostatic linear-motion stage, a constant displacement ratio piezoelectric-driven stage, two laser interferometers, a 6-DOF grating pair position adjustment devices and a PC-based data processor. The measurable linear movement is afforded, respectively, by the long-stroke stage and the piezoelectric-driven stage for the long-range error and cyclic error measurement. The movement can be measured by the encoder and then be calibrated by the corresponding laser interferometer. In the experiment, the accuracy of a non-contact incremental linear encoder with a 20 μm-long signal period and 320 mm measuring range proposed by our team was calibrated after proper mounting. The long-range error is measured to be 3.123 μm, and the cyclic error is within  ±0.159 μm, which matches well with the theoretical estimation given by  ±0.145 μm. The measurement uncertainties are estimated and the results confirm the effectiveness and feasibility of the proposed scheme and instruments.

  20. Calibration of non-contact incremental linear encoders using a macro–micro dual-drive high-precision comparator

    International Nuclear Information System (INIS)

    The accuracy of a linear encoder is determined by encoder-specific errors, which consist of both long-range and cyclic errors. Generally, it is difficult to measure the two errors of a non-contact incremental linear encoder with a large measuring range and small signal period in one measurement because of the contradiction between long travel range and high resolution. To resolve this issue, a prototype high-precision interferometric comparator with a macro–micro dual-drive system is presented. The measurement and motion resolution of the comparator are 1 nm and 3 nm, respectively. A measuring range of 320 mm is realized and the theoretical maximum range of the comparator is 2 m. The comparator mainly includes a high-accuracy aerostatic linear-motion stage, a constant displacement ratio piezoelectric-driven stage, two laser interferometers, a 6-DOF grating pair position adjustment devices and a PC-based data processor. The measurable linear movement is afforded, respectively, by the long-stroke stage and the piezoelectric-driven stage for the long-range error and cyclic error measurement. The movement can be measured by the encoder and then be calibrated by the corresponding laser interferometer. In the experiment, the accuracy of a non-contact incremental linear encoder with a 20 μm-long signal period and 320 mm measuring range proposed by our team was calibrated after proper mounting. The long-range error is measured to be 3.123 μm, and the cyclic error is within  ±0.159 μm, which matches well with the theoretical estimation given by  ±0.145 μm. The measurement uncertainties are estimated and the results confirm the effectiveness and feasibility of the proposed scheme and instruments. (paper)

  1. Nano-level instrumentation for analyzing the dynamic accuracy of a rolling element bearing

    International Nuclear Information System (INIS)

    The rotational performance of high-precision rolling bearings is fundamental to the overall accuracy of complex mechanical systems. A nano-level instrument to analyze rotational accuracy of high-precision bearings of machine tools under working conditions was developed. In this instrument, a high-precision (error motion < 0.15 μm) and high-stiffness (2600 N axial loading capacity) aerostatic spindle was applied to spin the test bearing. Operating conditions could be simulated effectively because of the large axial loading capacity. An air-cylinder, controlled by a proportional pressure regulator, was applied to drive an air-bearing subjected to non-contact and precise loaded axial forces. The measurement results on axial loading and rotation constraint with five remaining degrees of freedom were completely unconstrained and uninfluenced by the instrument's structure. Dual capacity displacement sensors with 10 nm resolution were applied to measure the error motion of the spindle using a double-probe error separation method. This enabled the separation of the spindle's error motion from the measurement results of the test bearing which were measured using two orthogonal laser displacement sensors with 5 nm resolution. Finally, a Lissajous figure was used to evaluate the non-repetitive run-out (NRRO) of the bearing at different axial forces and speeds. The measurement results at various axial loadings and speeds showed the standard deviations of the measurements’ repeatability and accuracy were less than 1% and 2%. Future studies will analyze the relationship between geometrical errors and NRRO, such as the ball diameter differences of and the geometrical errors in the grooves of rings

  2. Error analysis of motion correction method for laser scanning of moving objects

    Science.gov (United States)

    Goel, S.; Lohani, B.

    2014-05-01

    The limitation of conventional laser scanning methods is that the objects being scanned should be static. The need of scanning moving objects has resulted in the development of new methods capable of generating correct 3D geometry of moving objects. Limited literature is available showing development of very few methods capable of catering to the problem of object motion during scanning. All the existing methods utilize their own models or sensors. Any studies on error modelling or analysis of any of the motion correction methods are found to be lacking in literature. In this paper, we develop the error budget and present the analysis of one such `motion correction' method. This method assumes availability of position and orientation information of the moving object which in general can be obtained by installing a POS system on board or by use of some tracking devices. It then uses this information along with laser scanner data to apply correction to laser data, thus resulting in correct geometry despite the object being mobile during scanning. The major application of this method lie in the shipping industry to scan ships either moving or parked in the sea and to scan other objects like hot air balloons or aerostats. It is to be noted that the other methods of "motion correction" explained in literature can not be applied to scan the objects mentioned here making the chosen method quite unique. This paper presents some interesting insights in to the functioning of "motion correction" method as well as a detailed account of the behavior and variation of the error due to different sensor components alone and in combination with each other. The analysis can be used to obtain insights in to optimal utilization of available components for achieving the best results.

  3. The Measurement of Nine Inertial Parameters of Rigid Body Based on the Moment of Inertia%基于转动惯量的刚体9个惯性参数的测量

    Institute of Scientific and Technical Information of China (English)

    王瑾; 孙宁

    2012-01-01

    针对三维空间,提出了一种可以同时测量刚体9个惯性参数的新方法.利用气体静压轴承低速自由转动时其角速度是一个随时间衰减的单指数函数这一运动规律,测量物体绕任意的转动惯量,通过9次测量最终求出刚体的9个惯性参数.设计了一套物体惯性参数测量仪,该测量仪可以同时测量三维空间中物体的9个惯性参数.测量过程中无需重新装配,减少了中间测试量及人为干预误差,使测量时间缩短,测量精度提高.%For three-dimensional space, a new method which can measure the nine inertial parameters of a rigid body simultaneously is proposed. With the law of motion that when aerostatic bearing move slowly its angular velocity is a single exponential function decayed with time, the moment of inertia of the rigid body rotating a axis in an arbitrary direction is obtained, through nine measurements, the inertial parameters of a rigid body can be got finally. A set of instrument used for measuring the rigid body inertial parameters is designed. This instrument can measure the nine inertial parameters of a rigid body in three-dimensional space simultaneously. There' s no need to re-assembly in the process of measurement, so intermediate testing quantity, error made by human and measuring time are all reduced.

  4. Miniature robotic sample analysis lab for planetary in situ mineralogy and microbiology

    Science.gov (United States)

    Kruzelecky, Roman; Wong, Brian; Haddad, Emile; Jamroz, Wes; Cloutis, Edward; Strong, Kimberly; Ghafoor, Nadeem; Jessen, Sean

    the data synergy provided by infrared (IR) reflection between 900 and 4300 nm at about 4 nm resolution, visible micro-imaging, and complementary IR Raman spectroscopy from about 400 to 4000 cm-1 . IR spectroscopy provides direct information on the presence of H2 O or OH, either as free H2 O or bonded within hydrated minerals. The IR Raman provides for direct C-C biological detection and supplementary measurement of IR inactive modes. The boresight microimaging provides information on the sample grain structure to assist the spectral data analysis. The combined data synergy can, for the first time, directly and unambiguously detect H2 O and determine its state (ice/liquid/structural), distinguish key mineral species (including those associated with favourable habitats for microbial activity) and determine their hydration states, as well as detect and differentiate various C-H and C-C molecular structures for astrobiological investigations. The mission features a small He-inflatable Skycam aerostat tethered to the rover. It will provide stereographic 2-D VIS surface maps of the rover and its geolocation from a 10-15 m altitude to improve the rover autonomy and maneuverability around obstacles. The Skycam aerostat will also provide boundary layer investigations of Mars weather and residual atmospheric processes with high 0.015 nm spectral resolution for CO2 and CH4 using tunable fiber-optic sources to study the C isotopic ratios. Mission cost effectiveness is achieved through a synergistic instrument suite based on advanced but mature patented MPBC miniaturization technologies that enable high IR spectral measurement performance with minimal mass and power, and an innovative MDA tethered mole drill design. The estimated Inukshuk net payload mass including instrument suite, robotic tethered mole drill with insitu bore-hole probe and Skycam aerostat is under 12 kg. The core IR spectral processor is based on MPBC's patented IOSPEC technology for miniature guided

  5. Nuclear Polar VALOR: An ASRG-Enabled Venus Balloon Mission Concept

    Science.gov (United States)

    Balint, T. S.; Baines, K. H.

    2008-12-01

    In situ exploration of Venus is expected to answer high priority science questions about the planet's origin, evolution, chemistry, and dynamics as identified in the NRC Decadal Survey and in the VEXAG White Paper. Furthermore, exploration of the polar regions of Venus is key to understanding its climate and global circulation, as well as providing insight into the circulation, chemistry, and climatological processes on Earth. In this paper we discuss our proposed Nuclear Polar VALOR mission, which would target one of the polar regions of Venus, while building on design heritage from the Discovery class VALOR concept, proposed in 2004 and 2006. Riding the strong zonal winds at 55 km altitude and drifting poleward from mid-latitude this balloon-borne aerial science station (aerostat) would circumnavigate the planet multiple times over its one- month operation, extensively investigating polar dynamics, meteorology, and chemistry. Rising and descending over 1 km altitude in planetary waves - similar to the two VEGA balloons in 1985 - onboard instrumentation would accurately and constantly sample and measure other meteorological and chemical parameters, such as atmospheric temperature and pressure, cloud particle sizes and their local column abundances, the vertical wind component, and the chemical composition of cloud-forming trace gases. As well, when viewed with terrestrial radio telescopes on the Earth-facing side of Venus, both zonal and meridional winds would be measured to high accuracy (better than 10 cm/sec averaged over an hour). Due to three factors: the lack of sunlight near the poles; severe limitations on the floating mass-fraction available for a power source; and the science requirements for intensive and continuous measurements of the balloon's environment and movement, a long-duration polar balloon mission would require a long-lived internal power source in a relatively lightweight package. For our concept we assumed an Advanced Stirling Radioisotope

  6. Coherent Uncertainty Analysis of Aerosol Measurements from Multiple Satellite Sensors

    Science.gov (United States)

    Petrenko, M.; Ichoku, C.

    2013-01-01

    Aerosol retrievals from multiple spaceborne sensors, including MODIS (on Terra and Aqua), MISR, OMI, POLDER, CALIOP, and SeaWiFS altogether, a total of 11 different aerosol products were comparatively analyzed using data collocated with ground-based aerosol observations from the Aerosol Robotic Network (AERONET) stations within the Multi-sensor Aerosol Products Sampling System (MAPSS, http://giovanni.gsfc.nasa.gov/mapss/ and http://giovanni.gsfc.nasa.gov/aerostat/). The analysis was performed by comparing quality-screened satellite aerosol optical depth or thickness (AOD or AOT) retrievals during 2006-2010 to available collocated AERONET measurements globally, regionally, and seasonally, and deriving a number of statistical measures of accuracy. We used a robust statistical approach to detect and remove possible outliers in the collocated data that can bias the results of the analysis. Overall, the proportion of outliers in each of the quality-screened AOD products was within 12%. Squared correlation coefficient (R2) values of the satellite AOD retrievals relative to AERONET exceeded 0.6, with R2 for most of the products exceeding 0.7 over land and 0.8 over ocean. Root mean square error (RMSE) values for most of the AOD products were within 0.15 over land and 0.09 over ocean. We have been able to generate global maps showing regions where the different products present advantages over the others, as well as the relative performance of each product over different landcover types. It was observed that while MODIS, MISR, and SeaWiFS provide accurate retrievals over most of the landcover types, multi-angle capabilities make MISR the only sensor to retrieve reliable AOD over barren and snow / ice surfaces. Likewise, active sensing enables CALIOP to retrieve aerosol properties over bright-surface shrublands more accurately than the other sensors, while POLDER, which is the only one of the sensors capable of measuring polarized aerosols, outperforms other sensors in

  7. International Design Concepts for the SKA

    Science.gov (United States)

    Tarter, J.

    2001-12-01

    In August of 2000, representatives of eleven countries signed a Memorandum of Understanding to Establish the International Square Kilometre Array Steering Committee (ISSC). Arguably, the SKA could be built today, but without question it would be unaffordable. Increasing collecting area by a factor of 100 beyond today's largest array cannot be done cost effectively by simple extensions of what has been done before. New concepts, new designs, and new technologies will be required, as well as a paradigm shift. It will be necessary to heavily exploit emerging communications and consumer market technologies; to "hammer" them into shapes required to solve the SKA challenges, rather than inventing our own solutions from scratch. Or if we do invent ab initio solutions, we should look at creating consumer markets to embrace them, so that the full benefits of mass production and manufacturing can be realized. The strawman science goals of the SKA are extremely ambitious. Today there are six primary design concepts being studied that attempt to meet some or all of these goals; phased arrays of active elements embedded into flat tiles, "super Arecibo" antennas constructed in individual limestone karst sinkholes and arrayed together, large arrays of small, spherical (or hemispherical) Luneberg lenses, large deformable apertures with long focal ratios and aerostat-borne focal plane array receivers, arrays of large parabolic antennas constructed from steel "ropes," and large arrays of small parabolic dishes derived from the TVRO industry. This talk summarizes the strengths and weaknesses of these various designs in their current, incomplete state. In the US, the US SKA Consortium of 10 academic and research organizations has generated a roadmap to guide and assess the technology development that will be required to produce a successful SKA design, with well understood costs, performance, and minimal risk. The design and construction efforts for the ATA, LOFAR and the EVLA will

  8. 双斜塔钢箱梁斜拉桥抗风性能试验研究%Experimental investigation on wind-resistant behavior of double pylon cable stayed bridge with steel box beam

    Institute of Scientific and Technical Information of China (English)

    马存明; 陈勉; 王玉柱; 高伟

    2011-01-01

    In order to evaluate wind-resistant behavior of a double pylon cable stayed bridge with steel box beam, dynamic response characteristics of the bridge were analyzed. The aerostatic force coefficient, the critical wind velocity of vibration and vortex-induced vibration response were measured using the combined method of numerical analysis and wind tunnel test, to assess wind-resistant behavior of the bridge. The results showed that the aerodynamic and flutter stability characteristics were good, but there were two obvious vertical vortex-induced resonance regions, and the peak excursion was much larger than the allowable value. Therefore, the bridge needs an aerodynamic shape optimization to reduce or control vortex-induced vibration. By comparing a variety of optimization solutions given by vortex-induced vibration experiments, the most optimized measure for vortex-induced vibration control was to add a fair water fin of 1m wide and 30° incline to the bottom slab.%为了评价某拟建大跨度双斜塔钢箱梁斜拉桥的抗风安全性能,通过数值分析与风洞试验相结合的方法研究其结构动力特性,测定静力三分力系数、颤振临界风速和涡激振动响应,据此分析评估该桥的抗风性能.结果表明,该桥具有较好的气动和颤振稳定性,但存在两个明显的竖向涡激共振区,且最大振幅远超过规定容许值.因此,该桥需要通过气动外形优化,以减小或控制涡激振动.经多种主梁涡激振动性能优化方案对比试验得出其最优措施为轨道内侧增加一条宽1m、与底板夹角成30°的导流板.

  9. Sights from the air

    Science.gov (United States)

    Tartara, P.

    2009-04-01

    The first aerial shots were taken by aerostat balloon during the second half of the nineteen century for military purpose and subsequently utilized for civilian, archaeological and town planning uses (Roman Forum 1900, Pompei 1910, Venezia 1913, etc.). Sights from the air have given the most objective representation of the landscape and traces progressively left by human activities. After the First World War the use of airplanes for photogrammetric shots suitable to create cartography (territorial map making) has permitted to realize a good basic documentation; successively it has been increased by aerial reconnaissance during the Second World War. Aerial shots by RAF, USAF and Luftwaffe brought to the establishment of rich aerial photograph Archives, particularly in Europe, which have had a very low utilization for the historical restoration of landscape. From the fifties, aerial documentation becomes systematic for different scale analysis and territorial planning. The use of satellite imagery and multispectral bands integrates the historical and recent aerial photographs; the former is particularly helpful for cartography updating, for large scale environmental analysis, for study and research of territories with not available air photographs or lacking in aerial shots. The amount and density of archaeological buried evidences, unknown at the most, is very substantial in Italy and in the whole Mediterranean area; here air-photo interpretation is being applied at advanced levels, but not systematically, since several decades. Some archaeological research teams, working for the knowledge of territorial cultural heritage, utilize historical and recent aerial photographs intensively (aerial photographs previous the II WW, just before the intensive and extensive use of mechanical means to till the land, preserve a large amount of traces or cropmarks of buried evidences; recent shots taken on different conditions of climate and crops, allow to see and read important

  10. Hydroelastic Response of Surface-Effect Ship Bow Seals: Large-Scale Experiments and Post-Buckling Analysis

    Science.gov (United States)

    Wiggins, Andrew D.

    Bow seals are critical components on advanced marine vehicles that rely on aerostatic support to reduce drag. They consist of a series of open-ended fabric cylinders ("fingers") that contact the free surface and, when inflated, form a compliant pressure barrier. Bow seals are unique in that, unlike a majority of structures in civil and mechanical engineering, bow seals operate in a buckled state. The response characteristics of these structures are of practical interest due to unacceptable wear rates on seal components and difficulties in predicting seal performance. Despite this, the hydroelastic response of the seal system, particularly basic information on seal vibration modes and the mechanisms responsible for seal wear, remains largely unknown. Similarly, estimates of the hydrodynamic loads on the seal system are inaccurate and based on heuristic scaling of data from small-scale experiments, where similitude is challenging to maintain. Thus, a large-scale test system is necessary to obtain accurate estimates of bow seal response. The work is comprised of three parts. Part one presents detailed observations of bow seal response acquired using a large-scale test platform developed as part of the present study. These high-resolution observations, the first of their kind, show bow seal response to be characterized by complex post-buckling behavior. Part two proposes an analytical framework for interpreting the wide range of behavior observed at large scale. Using this framework, key parameters driving seal conformation and stability are identified. It is found that, due to their buckled state, bow seals are highly susceptible to a mode switching instability, which may be a potential mechanism responsible for the damaging vibrations. In part three, a benchtop experiment is used to demonstrate that the scalings identified in this study hold across a wide range of bending rigidities. This work has implications for improving drag and wear characteristics in future bow

  11. 旋转冲压发动机高速动静混合气体轴承性能分析%Performance analysis of high-speed hybrid gas bearings for rotating ramjet

    Institute of Scientific and Technical Information of China (English)

    张广辉; 刘占生

    2009-01-01

    The performance of high-speed hybrid gas bearings for rotating ramjet was studied theoretically and numerically to fulfill the requirement of bearing support for rotating ramjet.The gas supply pressure was determined firstly by the work condition of the rotating ramjet.By employing the Newton method and finite difference method,the Reynolds equations for the gas flow in the bearings were solved.The pressure distributions of the hybrid bearings with different eccentricities and rotating speed were obtained and the coupling mechanics of aerostatic and aerodynamic was analyzed.And also the number of orifices sets,which has effect on the pressure distribution and load capacity,was discussed.The maximum rotor weights for different rotating speeds and orifices set numbers,which the hybrid gas bearings could provide,were listed to establish the foundation for the design of rotating ramjet rotor system.%为了满足旋转冲压发动机对高速支撑的要求,本文对动静压混合高速气体轴承进行理论分析与数值研究.首先通过旋转冲压发动机的工作条件确定了气体轴承的供气压力,对描述轴承内气体流动的雷诺方程采用牛顿迭代与有限差分法进行求解,获得不同偏心、不同转速下轴承内气体压力分布并分析动静压耦合机理.同时分析了不同供气孔排数对压力分布与承载能力的影响,给出了不同转速、不同供气孔排数下轴承所能支撑的最大转子重量,为下一步旋转冲压发动机转子系统设计奠定基础.

  12. Biotic pump of atmospheric moisture as driver of the hydrological cycle on land

    Directory of Open Access Journals (Sweden)

    A. M. Makarieva

    2007-01-01

    Full Text Available In this paper the basic geophysical and ecological principles are jointly analyzed that allow the landmasses of Earth to remain moistened sufficiently for terrestrial life to be possible. 1. Under gravity, land inevitably loses water to the ocean. To keep land moistened, the gravitational water runoff must be continuously compensated by the atmospheric ocean-to-land moisture transport. Using data for five terrestrial transects of the International Geosphere Biosphere Program we show that the mean distance to which air fluxes can transport moisture over non-forested areas, does not exceed several hundred kilometers; precipitation decreases exponentially with distance from the ocean. 2. In contrast, precipitation over extensive natural forests does not depend on the distance from the ocean along several thousand kilometers, as illustrated for the Amazon and Yenisey river basins and Equatorial Africa. This points to the existence of an active biotic pump transporting atmospheric moisture inland from the ocean. 3. Physical principles of the biotic moisture pump are investigated based on the previously unstudied properties of atmospheric water vapor, which can be either in or out of aerostatic equilibrium depending on the lapse rate of air temperature. A novel physical principle is formulated according to which the low-level air moves from areas with weak evaporation to areas with more intensive evaporation. Due to the high leaf area index, natural forests maintain high evaporation fluxes, which support the ascending air motion over the forest and "suck in" moist air from the ocean, which is the essence of the biotic pump of atmospheric moisture. In the result, the gravitational runoff water losses from the optimally moistened forest soil can be fully compensated by the biotically enhanced precipitation at any distance from the ocean. 4. It is discussed how a continent-scale biotic water pump mechanism could be produced by natural selection acting on

  13. Design of measuring machine for complex geometry based on form-free measurement mode%基于免形状测量模式的复杂形状测量机设计

    Institute of Scientific and Technical Information of China (English)

    石照耀; 张斌; 林家春

    2012-01-01

    To measure complex geometries without nominal mathematics models, a "form-free measurement mode" is introduced, and its basic requirements for measuring machine are analyzed. A fixed column structure coordinate measuring machine with high accuracy and efficiency was designed based on the novel mode. The machine is driven by linear motors, and high accuracy gratings are used as measurement devices. To decrease the influence of work-piece weight, a closed aerostatic bearing with vacuum preload and an H style two dimensional co-planar structure are designed. A pneumatic cylinder balanced axis Z assembly with brake function is designed, and a vibration isolation assembly is also designed. The measurement span of the machine is 300 mm × 300 mm × 300 mm and the measurement uncertainty is 1.8 μm. It can be applied to measure complex geometries without nominal mathematics models.%为了高精度高效率地测量数学模型未知的复杂几何形状,介绍了“免形状测量模式”,分析了该测量模式对仪器的基本要求,基于该模式设计了一台移动工作台式测量机.测量机以直线电机为驱动元件,以高精度长光栅为测量元件.为减小被测件重量对测量机的影响,设计了封闭式真空负压的空气静压气浮导轨和共平面的H形二维结构.设计了具有制动功能的Z轴和气浮隔振等关键部件.仪器量程为300 mm × 300 mm×300 mm,测量不确定度为1.8μm,能测量数学模型未知的复杂几何形状.

  14. Unmanned Airborne Platforms for Validation of Volcanic Emission Composition and Transport Models

    Science.gov (United States)

    Pieri, D. C.; Diaz, J. A.; Bland, G.; Fladeland, M. M.

    2012-12-01

    satellite remote sensing data remain systematically unvalidated by in situ data. Of special concern with respect to aircraft operations are the validity syn-and-post eruption of estimates of the lateral and vertical extent, concentrations, and spatio-temporal variability of drifting volcanic ash clouds provided by aerosol transport models and remote sensing techniques. Within NASA there exist a variety of novel technological approaches for conducting in situ validation experiments, particularly the use of specially designed unmanned aircraft and miniaturized (e.g., mass spectrometers, optical particle detectors, impact samplers) instrumentation to range through ash and gas clouds, and the deployment of instrumented tethered aerostats up into such clouds, in coordination with multispectral satellite, airborne, and ground-based observations. For instance, new more powerful electric-powered UAVs may be most appropriate for these very hazardous regimes. A brief review of scientific issues and operational practices will be presented, along with a case study of our work at Turrialba Volcano in Costa Rica. This work was carried out in part at the Jet Propulsion Laboratory of the California Institute of Technology under contract to NASA.

  15. Device development for radioecology monitoring in Azerbaijan Republic

    International Nuclear Information System (INIS)

    Last time in the territory of Azerbaijan Republic that's in the land and especially in Azerbaijan sector of Caspian Sea have observed the irreversible processes as result of anthropogenic influences to the environment. In the main these inclinations envelope following from signed oil contracts the boring works for prospecting and production, building works on the oil pipelines and increase of quantity of the wastes created by these kinds of an activity. But at the land these inclinations envelope the revealing of radioactive materials at not controlled sectors of military bases leave in inheritance by former Soviet Union. At the same time have observed sharp increase of the transit load transporting power on the 'Silk way' route restored within the frames of TRACEKA. And that, in its turn, demand the organization of corresponding control of these loads. For organization of above-mentioned works have proposed next devices and equipment: The device DRG-01Az designed for an exposure dose power measurements of gamma radiations. Air gamma spectrometer. Managed from scientific-research craft the gamma spectrometer for gamma removals of seabed. Stationary radiation post for continuous control of the transit trucks. Proposed devices have worked out by the group of Special Space Device Development Bureau of Azerbaijan National Aerospace Agency. It should be noted that this group had important achievements at the sphere of space device development still since 70-th years. So in 1981 within the frames of the Soviet-French combined experiment was make a multi-channel gamma spectrometer mounted on the aerostat flied on the large heights (30-40 km). In 1983 was work out an orbital device 'RS-17' located at the satellite 'Cosmos-1638'. In 1987 was make a gamma telescope 'Pulsar X-1' established on the orbital station 'Mir'. A telescope is working successfully till now. Above-mentioned devices establish on the basis of obtained achievements. For example, the constructional demands

  16. after tomorrow

    Directory of Open Access Journals (Sweden)

    Elena Grigoryeva

    2011-05-01

    Full Text Available It is ridiculous to make plans in this world, especially when Bulgakov’s Annushka has already spilled the oil. The convulsion of nature in the neighbouring Japan confirms this once again. The destiny of Japan in general and of the UIA Tokyo Congress in particular is of great concern, as well as the courageous behaviour of the whole nation in the face of Mother Nature’s devastating anger. Actually, the subject of this issue – a long-term prognosis – was suggested by the themes of the UIA Congress “Design 2050” and of the next Winter University Session “Irkutsk 2036”.If you want to make God laugh, tell Him your plans. However, the essence of our profession is creation of environment for future life. So we cannot do without long-term prognoses. An architect works for the future, but there are many futures. There are a number of trajectories of further development starting from the point of today. Every scenario leads to its own future, and the architect is to choose the future with maximum realization chances, to reveal and to study several vectors of possible course of events and to choose the most harmonious among the realistic ones.Sometimes an architect’s imagination pictures a future that seems to other people absolutely impossible. There are times when this very scenario, quite unexpectedly for skeptics, becomes realized and makes others believe in it. Nobel laureates say that levitation is beyond doubt, and any time a human body can rise above the ground. Obviously, the cities will look quite different in this case, if they remain at all. But aerostatic architecture has already got adherents with concrete proposals (36The science of future development appeared more than one hundred years ago. Today its first experiments look childishly naïve. The day before yesterday’s fantasies of cities in the early 2000s evoke a gracious smile more often than admiration for their precise

  17. Evolution of temperature and humidity in an underground repository over the exploitation period

    International Nuclear Information System (INIS)

    vapor fluxes in the air are solved on a 1 dimensional network mesh with an upwind scheme as temperatures in the host rock are solved on a 2 dimensional axisymmetrical mesh. Air and rock temperatures are coupled through an iterative process. Both the solid and air meshes extend step by step every 2 years as the opening of new storage modules occurs. Furthermore, imposed air-flow rate is adapted to supply the new network according to the updated exploitation phase. Specified flow rates depend on the exploitation phase of each storage disposal: work stage (15 m3/s), storage stage (10-15 m3/s) and time pending closure (1-3 m3/s). In the supply air shaft, the high flow rate (100-380 m3/s range) induces efficient heat exchanges with walls but without sensible effect on air temperature, while the 60 mbar aero-static pressure gain between surface and bottom levels induces a 5 C temperature raise in the air flowing down the shaft, all things otherwise being equal, and reduces relative humidity from 78 % to 58 % in yearly average. In the repository, on the contrary, thermal exchanges with walls, combined with the walls thermal inertia, have great effects on air characteristics, especially on seasonal variations, due to lower flow rates and the long distance of the gallery network. Smaller time pending variations end up all being absorbed during the air transfer through galleries. For example, in the Central Zone the walls absorb up to 95% of the hourly air temperature fluctuations. In the ILLLW zone, daily temperature fluctuations are absorbed up to 86% by reaching the last module after crossing the side galleries, 3.5 km from the supply shaft. Seasonal variations are less affected by heat exchanges with walls. They are absorbed up to 92% when leaving the storage modules, 0.5 km further away from the entrance shaft. Indeed, air temperature downstream the MAVL zone remains around 20 C all year long. The summer usually results in an increase in moisture in the repository as the