Garcia-Ruiz, Eva; HamediRad, Mohammad; Zhao, Huimin
The microbial metabolic versatility found in nature has inspired scientists to create microorganisms capable of producing value-added compounds. Many endeavors have been made to transfer and/or combine pathways, existing or even engineered enzymes with new function to tractable microorganisms to generate new metabolic routes for drug, biofuel, and specialty chemical production. However, the success of these pathways can be impeded by different complications from an inherent failure of the pathway to cell perturbations. Pursuing ways to overcome these shortcomings, a wide variety of strategies have been developed. This chapter will review the computational algorithms and experimental tools used to design efficient metabolic routes, and construct and optimize biochemical pathways to produce chemicals of high interest.
SCURTU Iacob Liviu
Full Text Available This paper presents an optimization study in mechanical engineering. First part of the research describe the structural optimization method used, followed by the presentation of several optimization studies conducted in recent years. The second part of the paper presents the CAD modelling of an agricultural plough component. The beam of the plough is analysed using finite element method. The plough component is meshed in solid elements, and the load case which mimics the working conditions of agricultural equipment of this are created. The model is prepared to find the optimal structural design, after the FEA study of the model is done. The mass reduction of part is the criterion applied for this optimization study. The end of this research presents the final results and the model optimized shape.
Tajs-Zielińska, Katarzyna; Bochenek, Bogdan
The idea of the topology optimization is to find within a considered design domain the distribution of material that is optimal in some sense. Material, during optimization process, is redistributed and parts that are not necessary from objective point of view are removed. The result is a solid/void structure, for which an objective function is minimized. This paper presents an application of topology optimization to multi-material structures. The design domain defined by shape of a structure is divided into sub-regions, for which different materials are assigned. During design process material is relocated, but only within selected region. The proposed idea has been inspired by architectural designs like multi-material facades of buildings. The effectiveness of topology optimization is determined by proper choice of numerical optimization algorithm. This paper utilises very efficient heuristic method called Cellular Automata. Cellular Automata are mathematical, discrete idealization of a physical systems. Engineering implementation of Cellular Automata requires decomposition of the design domain into a uniform lattice of cells. It is assumed, that the interaction between cells takes place only within the neighbouring cells. The interaction is governed by simple, local update rules, which are based on heuristics or physical laws. The numerical studies show, that this method can be attractive alternative to traditional gradient-based algorithms. The proposed approach is evaluated by selected numerical examples of multi-material bridge structures, for which various material configurations are examined. The numerical studies demonstrated a significant influence the material sub-regions location on the final topologies. The influence of assumed volume fraction on final topologies for multi-material structures is also observed and discussed. The results of numerical calculations show, that this approach produces different results as compared with classical one
Keane, A J; Scanlan, J P
In this paper, we take a design-led perspective on the use of computational tools in the aerospace sector. We briefly review the current state-of-the-art in design search and optimization (DSO) as applied to problems from aerospace engineering, focusing on those problems that make heavy use of computational fluid dynamics (CFD). This ranges over issues of representation, optimization problem formulation and computational modelling. We then follow this with a multi-objective, multi-disciplinary example of DSO applied to civil aircraft wing design, an area where this kind of approach is becoming essential for companies to maintain their competitive edge. Our example considers the structure and weight of a transonic civil transport wing, its aerodynamic performance at cruise speed and its manufacturing costs. The goals are low drag and cost while holding weight and structural performance at acceptable levels. The constraints and performance metrics are modelled by a linked series of analysis codes, the most expensive of which is a CFD analysis of the aerodynamics using an Euler code with coupled boundary layer model. Structural strength and weight are assessed using semi-empirical schemes based on typical airframe company practice. Costing is carried out using a newly developed generative approach based on a hierarchical decomposition of the key structural elements of a typical machined and bolted wing-box assembly. To carry out the DSO process in the face of multiple competing goals, a recently developed multi-objective probability of improvement formulation is invoked along with stochastic process response surface models (Krigs). This approach both mitigates the significant run times involved in CFD computation and also provides an elegant way of balancing competing goals while still allowing the deployment of the whole range of single objective optimizers commonly available to design teams.
Coppola, Matthew Perkins; Merz, Alice H.
Today, elementary school teachers continue to revisit old lessons and seek out new ones, especially in engineering. Optimization is the process by which an existing product or procedure is revised and refined. Drawn from the authors' experiences working directly with students in grades K-5 and their teachers and preservice teachers, the…
Arora, Jasbir S.
The problem is to find a global minimum for the Problem P. Necessary and sufficient conditions are available for local optimality. However, global solution can be assured only under the assumption of convexity of the problem. If the constraint set S is compact and the cost function is continuous on it, existence of a global minimum is guaranteed. However, in view of the fact that no global optimality conditions are available, a global solution can be found only by an exhaustive search to satisfy Inequality. The exhaustive search can be organized in such a way that the entire design space need not be searched for the solution. This way the computational burden is reduced somewhat. It is concluded that zooming algorithm for global optimizations appears to be a good alternative to stochastic methods. More testing is needed; a general, robust, and efficient local minimizer is required. IDESIGN was used in all numerical calculations which is based on a sequential quadratic programming algorithm, and since feasible set keeps on shrinking, a good algorithm to find an initial feasible point is required. Such algorithms need to be developed and evaluated.
Gjirja, S [Chalmers Univ. of Technology, Gothenburg (Sweden). Dept. of Thermo- and Fluid Dynamics
The aim of this project was to optimize the Volvo AH10A245 engine design parameters for ethanol fuel with Beraid (Trade mark of the ignition improver manufactured by the Akzo Nobel Surface Chemistry AB). The method used was engine testing with variation of design, performance, and other functional parameters, which affect the engine thermodynamics, and exhaust gas composition. The first design parameter, which was tested and optimized was the compression ratio, which was optimized at the ratio of 23:1. In order to prevail the fuel spray impingement, which might affect the unburned or partially burned emissions (CO), the combustion chamber was redesigned to a straight-side wall bowl in piston. Furthermore, the injector position was optimized by means of lifting or descending it few millimeters. The best emission levels was achieved with the injector lift of 1.00 mm. The inlet air temperature was optimized for lower emissions by removing the intercooler thermostat. Injector nozzles with different cross section areas of holes were tested, and the 6 holes injector nozzles with smaller cross sectional area, compared with base nozzles, were selected. The engine performance was maintained for lower engine rated speed 2000 (instead of 2200 rpm for conventional engine) and lower intermediate speed 1250 (instead of 1320 rpm for conventional engine). Such engine performance optimization was followed by the improved specific fuel consumption, and lower emissions compared with conventional speeds. The backpressure governor, desperately needed during the first phase of engine design optimization was, finally avoided. It can only be used as in the conventional diesel engine. 7 refs, 26 figs, 18 tabs, 7 appendices
scientific and engineer- Q.- ’ method In the mid-19SOs along with modern digital com- ing applications. The paper highlights the difference puters, have made...is continuously tion software can call standard subroutines from the DBMS redefined in an application program, DDL must have j libary to define...operations. .. " type data usually encountered in engineering applications. GFDGT: Computes the number of digits needed to display " "’ A user
Koziel, Slawomir; Bandler, John W.; Madsen, Kaj
A simple, efficient optimization algorithm based on space mapping (SM) is presented. It utilizes input SM to reduce the misalignment between the coarse and fine models of the optimized object over a region of interest, and output space mapping (OSM) to ensure matching of response and first...... to a benchmark problem. In comparison with SMIS, the models presented are simple and have a small number of parameters that need to be extracted. The new algorithm is applied to the optimization of coupled-line band-pass filter....
Tarnowski, Wojciech [Koszalin University of Technology, Department of Control and Driving Systems, Institute of Mechatronics, Nanotechnology and Vacuum Technique, Koszalin (Poland); Krzyzynski, Tomasz; Maciejewski, Igor; Oleskiewicz, Robert [Koszalin University of Technology, Department of Mechatronics and Applied Mechanics, Institute of Mechatronics, Nanotechnology and Vacuum Technique, Koszalin (Poland)
The paper deals with the Engineering Design that is a general methodology of a design process. It is assumed that a designer has to solve a design task as an inverse problem in an iterative way. After each iteration, a decision should be taken on the information that is called a centre of integration in a systematic design system. For this purpose, poly-optimal solutions may be used. The poly-optimization is presented and contrasted against the Multi Attribute Decision Making, and a set of the poly-optimal solutions is defined. Then Mechatronics is defined and its characteristics given, to prove that mechatronic design process vitally needs CAD tools. Three examples are quoted to demonstrate a key role of the poly-optimization in the mechatronic design. (orig.)
Rao, S. S.; Pan, T. S.; Dhingra, A. K.; Venkayya, V. B.; Kumar, V.
This paper presents the applicability of a biological model, based on genetic evolution, for engineering design optimization. Algorithms embodying the ideas of reproduction, crossover, and mutation are developed and applied to solve different types of structural optimization problems. Both continuous and discrete variable optimization problems are solved. A two-bay truss for maximum fundamental frequency is considered to demonstrate the continuous variable case. The selection of locations of actuators in an actively controlled structure, for minimum energy dissipation, is considered to illustrate the discrete variable case.
Herskovits, J.; Asquier, J.
We present a quasi-Newton interior points algorithm for nonlinear constrained optimization. It is based on a general approach consisting of the iterative solution in the primal and dual spaces of the equalities in Karush-Kuhn-Tucker optimality conditions. This is done in such a way to have primal and dual feasibility at each iteration, which ensures satisfaction of those optimality conditions at the limit points. This approach is very strong and efficient, since at each iteration it only requires the solution of two linear systems with the same matrix, instead of quadratic programming subproblems. It is also particularly appropriate for engineering design optimization inasmuch at each iteration a feasible design is obtained. The present algorithm uses a quasi-Newton approximation of the second derivative of the Lagrangian function in order to have superlinear asymptotic convergence. We discuss theoretical aspects of the algorithm and its computer implementation.
Sobieszczanski-Sobieski, J.; Barthelemy, J. F. M.; Giles, G. L.
A method for systematic analysis and optimization of large engineering systems, by decomposition of a large task into a set of smaller subtasks that is solved concurrently is described. The subtasks may be arranged in hierarchical levels. Analyses are carried out in each subtask using inputs received from other subtasks, and are followed by optimizations carried out from the bottom up. Each optimization at the lower levels is augmented by analysis of its sensitivity to the inputs received from other subtasks to account for the couplings among the subtasks in a formal manner. The analysis and optimization operations alternate iteratively until they converge to a system design whose performance is maximized with all constraints satisfied. The method, which is still under development, is tentatively validated by test cases in structural applications and an aircraft configuration optimization.
Smith, J. R.; Aceves, S.
We have done system studies of series hydrogen hybrid automobiles that approach the PNGV design goal of 34 km/liter (80 mpg), for 384 km (240 mi) and 608 km (380 mi) ranges. Our results indicate that such a vehicle appears feasible using an optimized hydrogen engine. We have evaluated the impact of various on-board storage options on fuel economy. Experiments in an available engine at the Sandia CRF demonstrated NO(x) emissions of 10 to 20 ppM at an equivalence ratio of 0.4, rising to about 500 ppm at 0.5 equivalence ratio using neat hydrogen. Hybrid simulation studies indicate that exhaust NO(x) concentrations must be less than 180 ppM to meet the 0.2 g/mile ULEV or Federal Tier II emissions regulations. LLNL has designed and fabricated a first generation optimized hydrogen engine head for use on an existing Onan engine. This head features 15:1 compression ratio, dual ignition, water cooling, two valves and open quiescent combustion chamber to minimize heat transfer losses. Initial testing shows promise of achieving an indicated efficiency of nearly 50% and emissions of less than 100 ppM NO(x). Hydrocarbons and CO are to be measured, but are expected to be very low since their only source is engine lubricating oil. A successful friction reduction program on the Onan engine should result in a brake thermal efficiency of about 42% compared to today's gasoline engines of 32%. Based on system studies requirements, the next generation engine will be about 2 liter displacement and is projected to achieve 46% brake thermal efficiency with outputs of 15 kW for cruise and 40 kW for hill climb.
Full Text Available As one of the key part of automotive brake,the performance of brake block has a direct impact on the safety and comfort of cars. Modeling the brake block of disc brake in reverse parameterization by reverse engineering software, analyzing and optimizing the reconstructed model by CAE software. Processing the scanned point cloud by Geomagic Studio and reconstructing the CAD model of the brake block with the parametric surface function of the software, then analyzing and optimizing it by Wrokbench. The example shows that it is quick to reconstruct the CAD model of parts by using reverse parameterization method and reduce part re-design development cycle significantly.
Martini, W. R.
A calculation method is presented for a rhombic drive Stirling engine with a tubular heater and cooler and a screen type regenerator. Generally the equations presented describe power generation and consumption and heat losses. It is the simplest type of analysis that takes into account the conflicting requirements inherent in Stirling engine design. The method itemizes the power and heat losses for intelligent engine optimization. The results of engine analysis of the GPU-3 Stirling engine are compared with more complicated engine analysis and with engine measurements.
Full Text Available The lunar landing stage is usually divided into two parts: deorbit burn and powered descent phases. The optimal lunar landing problem is likely to be transformed to the trajectory design problem on the powered descent phase by using continuous thrusters. The optimal lunar landing trajectories in general have variety in shape, and the lunar lander frequently increases its altitude at the initial time to obtain enough time to reduce the horizontal velocity. Due to the increment in the altitude, the lunar lander requires more fuel for lunar landing missions. In this work, a hybrid engine for the lunar landing mission is introduced, and an optimal lunar landing strategy for the hybrid engine is suggested. For this approach, it is assumed that the lunar lander retrofired the impulsive thruster to reduce the horizontal velocity rapidly at the initiated time on the powered descent phase. Then, the lunar lander reduced the total velocity and altitude for the lunar landing by using the continuous thruster. In contradistinction to other formal optimal lunar landing problems, the initial horizontal velocity and mass are not fixed at the start time. The initial free optimal control theory is applied, and the optimal initial value and lunar landing trajectory are obtained by simulation studies.
Cho, Dong-Hyun; Kim, Donghoon; Leeghim, Henzeh
The lunar landing stage is usually divided into two parts: deorbit burn and powered descent phases. The optimal lunar landing problem is likely to be transformed to the trajectory design problem on the powered descent phase by using continuous thrusters. The optimal lunar landing trajectories in general have variety in shape, and the lunar lander frequently increases its altitude at the initial time to obtain enough time to reduce the horizontal velocity. Due to the increment in the altitude,...
Dulikravich, George S. (Editor)
Papers from the Third International Conference on Inverse Design Concepts and Optimization in Engineering Sciences (ICIDES) are presented. The papers discuss current research in the general field of inverse, semi-inverse, and direct design and optimization in engineering sciences. The rapid growth of this relatively new field is due to the availability of faster and larger computing machines.
You, Zhanping; Yang, Bo; Pan, Lisheng; Hao, Changsheng
Under given operation conditions, a stirling engine of 2 kW is designed which takes hydrogen as working medium. Through establishment of adiabatic model, the ways are achieved about performance improving. The ways are raising the temperature of hot terminal, lowering the temperature of cold end, increasing the average cycle pressure, speeding up the speed, phase angle being 90°, stroke volume ratio approximating to 1 and increasing the performance of regenerator.
R V Rao
The comparisons of the proposed algorithm are made with those obtained by using the decision-making methods like linear ... cooling water and had improved the thermal efficiency of ... integrated system of a free-piston Stirling engine and an.
Duan, Chen; Wang, Xinggang; Shu, Shuiming; Jing, Changwei; Chang, Huawei
Highlights: • An improved thermodynamic model taking into account irreversibility parameter was developed. • A multi-objective optimization method for designing Stirling engine was investigated. • Multi-objective particle swarm optimization algorithm was adopted in the area of Stirling engine for the first time. - Abstract: In the recent years, the interest in Stirling engine has remarkably increased due to its ability to use any heat source from outside including solar energy, fossil fuels and biomass. A large number of studies have been done on Stirling cycle analysis. In the present study, a mathematical model based on thermodynamic analysis of Stirling engine considering regenerative losses and internal irreversibilities has been developed. Power output, thermal efficiency and the cycle irreversibility parameter of Stirling engine are optimized simultaneously using Particle Swarm Optimization (PSO) algorithm, which is more effective than traditional genetic algorithms. In this optimization problem, some important parameters of Stirling engine are considered as decision variables, such as temperatures of the working fluid both in the high temperature isothermal process and in the low temperature isothermal process, dead volume ratios of each heat exchanger, volumes of each working spaces, effectiveness of the regenerator, and the system charge pressure. The Pareto optimal frontier is obtained and the final design solution has been selected by Linear Programming Technique for Multidimensional Analysis of Preference (LINMAP). Results show that the proposed multi-objective optimization approach can significantly outperform traditional single objective approaches
Vanderplaats, G. N.; Yang, Y. J.; Kim, D. S.
An efficient multilevel deisgn optimization technique is presented. The proposed method is based on the concept of providing linearized information between the system level and subsystem level optimization tasks. The advantages of the method are that it does not require optimum sensitivities, nonlinear equality constraints are not needed, and the method is relatively easy to use. The disadvantage is that the coupling between subsystems is not dealt with in a precise mathematical manner.
Xia, Yi; Liu, Xiaojie; Du, Gang
Stackelberg game-theoretic approaches are applied extensively in engineering design to handle distributed collaboration decisions. Bi-level genetic algorithms (BLGAs) and response surfaces have been used to solve the corresponding bi-level programming models. However, the computational costs for BLGAs often increase rapidly with the complexity of lower-level programs, and optimal solution functions sometimes cannot be approximated by response surfaces. This article proposes a new method, namely the optimal solution function approximation by kriging model (OSFAKM), in which kriging models are used to approximate the optimal solution functions. A detailed example demonstrates that OSFAKM can obtain better solutions than BLGAs and response surface-based methods, and at the same time reduce the workload of computation remarkably. Five benchmark problems and a case study of the optimal design of a thin-walled pressure vessel are also presented to illustrate the feasibility and potential of the proposed method for bi-level optimization in engineering design.
Son, Min; Ko, Sangho; Koo, Jaye
A genetic algorithm was used to develop optimal design methods for the regenerative cooled combustor and fuel-rich gas generator of a liquid rocket engine. For the combustor design, a chemical equilibrium analysis was applied, and the profile was calculated using Rao's method. One-dimensional heat transfer was assumed along the profile, and cooling channels were designed. For the gas-generator design, non-equilibrium properties were derived from a counterflow analysis, and a vaporization model for the fuel droplet was adopted to calculate residence time. Finally, a genetic algorithm was adopted to optimize the designs. The combustor and gas generator were optimally designed for 30-tonf, 75-tonf, and 150-tonf engines. The optimized combustors demonstrated superior design characteristics when compared with previous non-optimized results. Wall temperatures at the nozzle throat were optimized to satisfy the requirement of 800 K, and specific impulses were maximized. In addition, the target turbine power and a burned-gas temperature of 1000 K were obtained from the optimized gas-generator design.
Liu, Pei; Pistikopoulos, Efstratios N. [Centre for Process Systems Engineering (CPSE), Department of Chemical Engineering, Imperial College London, London SW7 2AZ (United Kingdom); Li, Zheng [Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China)
Energy consumption in commercial buildings accounts for a significant proportion of worldwide energy consumption. Any increase in the energy efficiency of the energy systems for commercial buildings would lead to significant energy savings and emissions reductions. In this work, we introduce an energy systems engineering framework towards the optimal design of such energy systems with improved energy efficiency and environmental performance. The framework features a superstructure representation of the various energy technology alternatives, a mixed-integer optimization formulation of the energy systems design problem, and a multi-objective design optimization solution strategy, where economic and environmental criteria are simultaneously considered and properly traded off. A case study of a supermarket energy systems design is presented to illustrate the key steps and potential of the proposed energy systems engineering approach. (author)
Liu Pei; Pistikopoulos, Efstratios N.; Li Zheng
Energy consumption in commercial buildings accounts for a significant proportion of worldwide energy consumption. Any increase in the energy efficiency of the energy systems for commercial buildings would lead to significant energy savings and emissions reductions. In this work, we introduce an energy systems engineering framework towards the optimal design of such energy systems with improved energy efficiency and environmental performance. The framework features a superstructure representation of the various energy technology alternatives, a mixed-integer optimization formulation of the energy systems design problem, and a multi-objective design optimization solution strategy, where economic and environmental criteria are simultaneously considered and properly traded off. A case study of a supermarket energy systems design is presented to illustrate the key steps and potential of the proposed energy systems engineering approach.
Liu Pei [Centre for Process Systems Engineering (CPSE), Department of Chemical Engineering, Imperial College London, London SW7 2AZ (United Kingdom); Pistikopoulos, Efstratios N., E-mail: email@example.com [Centre for Process Systems Engineering (CPSE), Department of Chemical Engineering, Imperial College London, London SW7 2AZ (United Kingdom); Li Zheng [Department of Thermal Engineering, Tsinghua University, Beijing 100084 (China)
Energy consumption in commercial buildings accounts for a significant proportion of worldwide energy consumption. Any increase in the energy efficiency of the energy systems for commercial buildings would lead to significant energy savings and emissions reductions. In this work, we introduce an energy systems engineering framework towards the optimal design of such energy systems with improved energy efficiency and environmental performance. The framework features a superstructure representation of the various energy technology alternatives, a mixed-integer optimization formulation of the energy systems design problem, and a multi-objective design optimization solution strategy, where economic and environmental criteria are simultaneously considered and properly traded off. A case study of a supermarket energy systems design is presented to illustrate the key steps and potential of the proposed energy systems engineering approach.
Liu, Yang; Liu, Ye; Wang, Meng
The development of synthetic biology and metabolic engineering has painted a great future for the bio-based economy, including fuels, chemicals, and drugs produced from renewable feedstocks. With the rapid advance of genome-scale modeling, pathway assembling and genome engineering/editing, our ability to design and generate microbial cell factories with various phenotype becomes almost limitless. However, our lack of ability to measure and exert precise control over metabolite concentration related phenotypes becomes a bottleneck in metabolic engineering. Genetically encoded small molecule biosensors, which provide the means to couple metabolite concentration to measurable or actionable outputs, are highly promising solutions to the bottleneck. Here we review recent advances in the design, optimization and application of small molecule biosensor in metabolic engineering, with particular focus on optimization strategies for transcription factor (TF) based biosensors.
Uth, Nicholas; Mueller, Jens; Smucker, Byran; Yousefi, Azizeh-Mitra
This study reports the development of biological/synthetic scaffolds for bone tissue engineering (TE) via 3D bioplotting. These scaffolds were composed of poly(L-lactic-co-glycolic acid) (PLGA), type I collagen, and nano-hydroxyapatite (nHA) in an attempt to mimic the extracellular matrix of bone. The solvent used for processing the scaffolds was 1,1,1,3,3,3-hexafluoro-2-propanol. The produced scaffolds were characterized by scanning electron microscopy, microcomputed tomography, thermogravimetric analysis, and unconfined compression test. This study also sought to validate the use of finite-element optimization in COMSOL Multiphysics for scaffold design. Scaffold topology was simplified to three factors: nHA content, strand diameter, and strand spacing. These factors affect the ability of the scaffold to bear mechanical loads and how porous the structure can be. Twenty four scaffolds were constructed according to an I-optimal, split-plot designed experiment (DE) in order to generate experimental models of the factor-response relationships. Within the design region, the DE and COMSOL models agreed in their recommended optimal nHA (30%) and strand diameter (460 μm). However, the two methods disagreed by more than 30% in strand spacing (908 μm for DE; 601 μm for COMSOL). Seven scaffolds were 3D-bioplotted to validate the predictions of DE and COMSOL models (4.5-9.9 MPa measured moduli). The predictions for these scaffolds showed relative agreement for scaffold porosity (mean absolute percentage error of 4% for DE and 13% for COMSOL), but were substantially poorer for scaffold modulus (51% for DE; 21% for COMSOL), partly due to some simplifying assumptions made by the models. Expanding the design region in future experiments (e.g., higher nHA content and strand diameter), developing an efficient solvent evaporation method, and exerting a greater control over layer overlap could allow developing PLGA-nHA-collagen scaffolds to meet the mechanical requirements for
Full Text Available In this paper the mathematical models of the main types of turning hydraulic engines, which at the present time widely used in the construction of handling systems of domestic and foreign mobile transport-technological machines wide functionality. They allow to take into consideration the most significant from the viewpoint of ensuring high technical-economic indicators of hydraulic efficiency criteria – minimum mass (weight, their volume and losses of power. On the basis of these mathematical models the problem of multicriterial constrained optimization of the constructive sizes of turning hydraulic engines are subject to complex constructive, strength and deformation limits. It allows you to de-velop the hydraulic engines in an optimized design which is required for the purpose of designing a comprehensive measure takes into account efficiency criteria. The multicriterial optimization problem is universal in nature, so when designing a turning hydraulic engines allows for one-, two - and three-criteria optimization without making any changes in the solution algorithm. This is a significant advantage for the development of universal software for the automation of design of mobile transport-technological machines.
Kirkegaard, Poul Henning
Optimal Systems of experiments for parametric identification of civil engineering structures is investigated. Design of experiments for parametric identification of dynamic systems is usually done by minimizing a scalar measure, e.g the determinant, the trace ect., of an estimated parameter...
Full Text Available The use of aluminum, particularly for engine blocks, has grown considerably in the past ten years, and continues to rise in the automotive industry. In order to enhance the quality and engineering functionality of die cast engine blocks, die design and processes have to be optimized. In this study, a computer simulation software, MAGMAsoft, as an advanced tool for optimizing die design and casting process, was emplooyed to virtually visualize cavity filling and patterns of a V6 engine block. The original die design and process was simulated first to establish a baseline. A reality check was used to verify the predicted results. Then, the die modification with a different unner system was made by using a CAD software, Unigraphics (UG. The simulation on combinations of the modified die design and revised process was performed to examine the effect of die modification and process change on flow filling of V6 engine blocks. The simulated prediction indicateds that the enhancement of cavity filling due to the die and process modification minimizeds the occurrence of defects during casting, and consequently improves the quality of blocks. The results of mechanical testing show a significant increase in fatigue strengths, and a moderately improvement on tensile properties for the blocks die cast with the new die design and prpocess in comparison with those produced by the original ones.
Search engine optimization techniques, often shortened to “SEO,” should lead to first positions in organic search results. Some optimization techniques do not change over time, yet still form the basis for SEO. However, as the Internet and web design evolves dynamically, new optimization techniques flourish and flop. Thus, we looked at the most important factors that can help to improve positioning in search results. It is important to emphasize that none of the techniques can guarantee high ...
Dias, Marta R; Guedes, José M; Flanagan, Colleen L; Hollister, Scott J; Fernandes, Paulo R
In bone tissue engineering, the scaffold has not only to allow the diffusion of cells, nutrients and oxygen but also provide adequate mechanical support. One way to ensure the scaffold has the right properties is to use computational tools to design such a scaffold coupled with additive manufacturing to build the scaffolds to the resulting optimized design specifications. In this study a topology optimization algorithm is proposed as a technique to design scaffolds that meet specific requirements for mass transport and mechanical load bearing. Several micro-structures obtained computationally are presented. Designed scaffolds were then built using selective laser sintering and the actual features of the fabricated scaffolds were measured and compared to the designed values. It was possible to obtain scaffolds with an internal geometry that reasonably matched the computational design (within 14% of porosity target, 40% for strut size and 55% for throat size in the building direction and 15% for strut size and 17% for throat size perpendicular to the building direction). These results support the use of these kind of computational algorithms to design optimized scaffolds with specific target properties and confirm the value of these techniques for bone tissue engineering. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.
Kim, Kyungmee O.; Roh, Taeseong; Lee, Jae-Woo; Zuo, Ming J.
Derating is the operation of an item at a stress that is lower than its rated design value. Previous research has indicated that reliability can be increased from operational derating. In order to derate an item in field operation, however, an engineer must rate the design of the item at a stress level higher than the operational stress level, which increases the item's nominal failure rate and development costs. At present, there is no model available to quantify the cost and reliability that considers the design uprating as well as the operational derating. In this paper, we establish the reliability expression in terms of the derating level assuming that the nominal failure rate is constant with time for a fixed rated design value. The total development cost is expressed in terms of the rated design value and the number of tests necessary to demonstrate the reliability requirement. The properties of the optimal derating level are explained for maximizing the reliability or for minimizing the cost. As an example, the proposed model is applied to the design of liquid rocket engines. - Highlights: • Modeled the effect of derating design on the reliability and the development cost. • Discovered that derating design may reduce the cost of reliability demonstration test. • Optimized the derating design parameter for reliability maximization or cost minimization.
Kirkegaard, Poul Henning
Optimal Systems of experiments for parametric identification of civil engineering structures is investigated. Design of experiments for parametric identification of dynamic systems is usually done by minimizing a scalar measure, e.g the determinant, the trace ect., of an estimated parameter covariance matrix, based on prior knowledge. The experimental conditions available for adjustment, considering in this thesis, are input signal, sampling rate, the location of sensors and number of sensors.
Monica, Z.; Sękala, A.; Gwiazda, A.; Banaś, W.
Nowadays a key issue is to reduce the energy consumption of road vehicles. In particular solution one could find different strategies of energy optimization. The most popular but not sophisticated is so called eco-driving. In this strategy emphasized is particular behavior of drivers. In more sophisticated solution behavior of drivers is supported by control system measuring driving parameters and suggesting proper operation of the driver. The other strategy is concerned with application of different engineering solutions that aid optimization the process of energy consumption. Such systems take into consideration different parameters measured in real time and next take proper action according to procedures loaded to the control computer of a vehicle. The third strategy bases on optimization of the designed vehicle taking into account especially main sub-systems of a technical mean. In this approach the optimal level of energy consumption by a vehicle is obtained by synergetic results of individual optimization of particular constructional sub-systems of a vehicle. It is possible to distinguish three main sub-systems: the structural one the drive one and the control one. In the case of the structural sub-system optimization of the energy consumption level is related with the optimization or the weight parameter and optimization the aerodynamic parameter. The result is optimized body of a vehicle. Regarding the drive sub-system the optimization of the energy consumption level is related with the fuel or power consumption using the previously elaborated physical models. Finally the optimization of the control sub-system consists in determining optimal control parameters.
Thompson, Mary Kathryn; Espensen, Christina; Clemmensen, Line Katrine Harder
This work characterizes and optimizes an outlier detection algorithm to identify potentially invalid scores produced by jury members while grading engineering design projects. The paper describes the original algorithm and the associated adjudication process in detail. The impact of the various...... (the base rule and the three additional conditions) play a role in the algorithm's performance and should be included in the algorithm. Because there is significant interaction between the base rule and the additional conditions, many acceptable combinations that balance the FPR and FNR can be found......, but no true optimum seems to exist. The performance of the best optimizations and the original algorithm are similar. Therefore, it should be possible to choose new coefficient values for jury populations in other cultures and contexts logically and empirically without a full optimization as long...
Full Text Available Using the downhole annular flow measurement system to get real-time information of downhole annular flow is the core and foundation of downhole microflux control drilling technology. The research work of electromagnetic flowmeter in recent years creates a challenge to the design of downhole annular flow measurement. This paper proposes a design and optimization of annular flow electromagnetic measurement system for drilling engineering based on the finite element method. Firstly, the annular flow measuring and optimization principle are described. Secondly, a simulation model of an annular flow electromagnetic measurement system with two pairs of coil is built based on the fundamental equation of electromagnetic flowmeter by COMSOL. Thirdly, simulations of the structure of excitation system of the measurement system are carried out, and simulations of the size of the electrode’s radius are also carried out based on the optimized structure, and then all the simulation results are analyzed to evaluate the optimization effect based on the evaluation indexes. The simulation results show that optimized shapes of the excitation system and electrode size can yield a better performance in the annular flow measurement.
Bower, Stanley [Ford Motor Company, Dearborn, MI (United States)
A 5.0L V8 twin-turbocharged direct injection engine was designed, built, and tested for the purpose of assessing the fuel economy and performance in the F-Series pickup of the Dual Fuel engine concept and of an E85 optimized FFV engine. Additionally, production 3.5L gasoline turbocharged direct injection (GTDI) EcoBoost engines were converted to Dual Fuel capability and used to evaluate the cold start emissions and fuel system robustness of the Dual Fuel engine concept. Project objectives were: to develop a roadmap to demonstrate a minimized fuel economy penalty for an F-Series FFV truck with a highly boosted, high compression ratio spark ignition engine optimized to run with ethanol fuel blends up to E85; to reduce FTP 75 energy consumption by 15% - 20% compared to an equally powered vehicle with a current production gasoline engine; and to meet ULEV emissions, with a stretch target of ULEV II / Tier II Bin 4. All project objectives were met or exceeded.
Hidalgo-Bastida, L Araida; Thirunavukkarasu, Sundaramoorthy; Griffiths, Sarah; Cartmell, Sarah H; Naire, Shailesh
Perfusion bioreactors have been used in different tissue engineering applications because of their consistent distribution of nutrients and flow-induced shear stress within the tissue-engineering scaffold. A widely used configuration uses a scaffold with a circular cross-section enclosed within a cylindrical chamber and inlet and outlet pipes which are connected to the chamber on either side through which media is continuously circulated. However, fluid-flow experiments and simulations have shown that the majority of the flow perfuses through the center. This pattern creates stagnant zones in the peripheral regions as well as in those of high flow rate near the inlet and outlet. This non-uniformity of flow and shear stress, owing to a circular design, results in limited cell proliferation and differentiation in these areas. The focus of this communication is to design an optimized perfusion system using computational fluid dynamics as a mathematical tool to overcome the time-consuming trial and error experimental method. We compared the flow within a circular and a rectangular bioreactor system. Flow simulations within the rectangular bioreactor are shown to overcome the limitations in the circular design. This communication challenges the circular cross-section bioreactor configuration paradigm and provides proof of the advantages of the new design over the existing one. Copyright © 2011 Wiley Periodicals, Inc.
Mou, Jian; Hong, Guotong
In this paper, the dimensionless power is used to optimize the free piston Stirling engines (FPSE). The dimensionless power is defined as a ratio of the heat power loss and the output work. The heat power losses include the losses of expansion space, heater, regenerator, cooler and the compression space and every kind of the heat loss calculated by empirical formula. The output work is calculated by the adiabatic model. The results show that 82.66% of the losses come from the expansion space and 54.59% heat losses of expansion space come from the shuttle loss. At different pressure the optimum bore-stroke ratio, heat source temperature, phase angle and the frequency have different values, the optimum phase angles increase with the increase of pressure, but optimum frequencies drop with the increase of pressure. However, no matter what the heat source temperature, initial pressure and frequency are, the optimum ratios of piston stroke and displacer stroke all about 0.8. The three-dimensional diagram is used to analyse Stirling engine. From the three-dimensional diagram the optimum phase angle, frequency and heat source temperature can be acquired at the same time. This study offers some guides for the design and optimization of FPSEs.
This book is the first major work covering applications in thermal engineering and offering a comprehensive introduction to optimal control theory, which has applications in mechanical engineering, particularly aircraft and missile trajectory optimization. The book is organized in three parts: The first part includes a brief presentation of function optimization and variational calculus, while the second part presents a summary of the optimal control theory. Lastly, the third part describes several applications of optimal control theory in solving various thermal engineering problems. These applications are grouped in four sections: heat transfer and thermal energy storage, solar thermal engineering, heat engines and lubrication.Clearly presented and easy-to-use, it is a valuable resource for thermal engineers and thermal-system designers as well as postgraduate students.
Niu, Zhiqiang; Diao, Hai; Yu, Shuhai; Jiao, Kui; Du, Qing; Shu, Gequn
Highlights: • A 3-D model for exhaust-based thermoelectric waste heat recovery is developed. • Various heat, mass and electric transfer characteristics are elucidated. • Channel size needs to be moderate to balance heat transfer and pressure drop. • Bafflers need to be placed at all locations near all TEG modules. • Baffler angle needs to be sufficiently large, especially for downstream locations. - Abstract: Thermoelectric generator (TEG) has attracted considerable attention for the waste heat recovery of internal combustion engine. In this study, a 3-D numerical model for engine exhaust-based thermoelectric generator (ETEG) system is developed. By considering the detailed geometry of thermoelectric generator (TEG) and exhaust channel, the various transport phenomena are investigated, and design optimization suggestions are given. It is found that the exhaust channel size needs to be moderate to balance the heat transfer to TEG modules and pressure drop along channel. Increasing the number of exhaust channels may improve the performance, however, since more space and TEG modules are needed, the system size and cost need to be considered as well. Although only placing bafflers at the channel inlet could increase the heat transfer coefficient for the whole channel, the near wall temperature downstream might decrease significantly, leading to performance degradation of the TEG modules downstream. To ensure effective utilization of hot exhaust gas, the baffler angle needs to be sufficiently large, especially for the downstream locations. Since larger baffler angles increase the pressure drop significantly, it is suggested that variable baffler angles, with the angle increasing along the flow direction, might be a middle course for balancing the heat transfer and pressure drop. A single ETEG design may not be suitable to all the engine operating conditions, and making the number of exhaust channels and baffler angle adjustable according to different engine
Shimko, Daniel Andrew
In 2000, 3.1 million surgical procedures on the musculoskeletal system were reported in the United States. For many of these cases, bone grafting was essential for successful fracture stabilization. Current techniques use intact bone obtained either from the patient (autograft) or a cadaver (allograft) to repair large defects, however, neither source is optimal. Allografts suffer integration problems, and for autografts, the tissue supply is limited. Because of these shortcomings, and the high demand for graft tissues, alternatives are being explored. To successfully engineer a bone graft replacement, one must employ a three pronged research approach, addressing (1) the cells that will inhabit the new tissue, (2) the culture environment that these cells will be exposed to, and (3) the scaffold in which these cells will reside. The work herein examines each of these three aspects in great detail. Both adult and embryonic stem cells (ESCs) were considered for the tissue-engineered bone graft. Both exhibited desirable qualities, however, neither were optimal in all categories examined. In the end, the possibility of teratoma formation and ethical issues surrounding ESCs, made the use of adult marrow-derived stem cells in the remaining experiments obligatory. In subsequent experiments, the adult stem cells' ability to form bone was optimized. Basic fibroblast growth factor, fetal bovine serum, and extracellular calcium supplementation studies were all performed. Ultimately, adult stem cells cultured in alpha-MEM supplemented with 10% fetal bovine serum, 10mM beta-glycerophosphate, 10nM dexamethasone, 50mug/ml ascorbic acid, 1%(v/v) antibiotic/antimycotic, and 10.4mM CaCl2 performed the best, producing nearly four times more mineral than any other medium formulation. Several scaffolds were then investigated including those fabricated from poly(alpha-hydroxy esters), tantalum, and poly-methylmethacrylate. In the final study, the most appealing cell type, medium
Van Dijk, R.E.C.; dIppolito, R.; Tosi, G.; La Rocca, G.
In order to remain competitive with respect to low-cost overseas markets, domestic moldmakers will have to increase the productivity of their engineers and maintain high quality standard, while dealing with the problem of an aging workforce. To increase the competitiveness of the European automotive
Awad, Ziad K.; Aravinthan, Thiru; Zhuge, Yan; Gonzalez, Felipe
Highlights: → We reviewed existing optimization techniques of fibre composite structures. → Proposed an improved methodology for design optimization. → Comparison showed the MRDO is most suitable. -- Abstract: Fibre composite structures have become the most attractive candidate for civil engineering applications. Fibre reinforced plastic polymer (FRP) composite materials have been used in the rehabilitation and replacement of the old degrading traditional structures or build new structures. However, the lack of design standards for civil infrastructure limits their structural applications. The majority of the existing applications have been designed based on the research and guidelines provided by the fibre composite manufacturers or based on the designer's experience. It has been a tendency that the final structure is generally over-designed. This paper provides a review on the available studies related to the design optimization of fibre composite structures used in civil engineering such as; plate, beam, box beam, sandwich panel, bridge girder, and bridge deck. Various optimization methods are presented and compared. In addition, the importance of using the appropriate optimization technique is discussed. An improved methodology, which considering experimental testing, numerical modelling, and design constrains, is proposed in the paper for design optimization of composite structures.
Zheng, Ling; Duan, Xuwei; Deng, Zhaoxue; Li, Yinong
A novel flow-mode magneto-rheological (MR) engine mount integrated a diaphragm de-coupler and the spoiler plate is designed and developed to isolate engine and the transmission from the chassis in a wide frequency range and overcome the stiffness in high frequency. A lumped parameter model of the MR engine mount in single degree of freedom system is further developed based on bond graph method to predict the performance of the MR engine mount accurately. The optimization mathematical model is established to minimize the total of force transmissibility over several frequency ranges addressed. In this mathematical model, the lumped parameters are considered as design variables. The maximum of force transmissibility and the corresponding frequency in low frequency range as well as individual lumped parameter are limited as constraints. The multiple interval sensitivity analysis method is developed to select the optimized variables and improve the efficiency of optimization process. An improved non-dominated sorting genetic algorithm (NSGA-II) is used to solve the multi-objective optimization problem. The synthesized distance between the individual in Pareto set and the individual in possible set in engineering is defined and calculated. A set of real design parameters is thus obtained by the internal relationship between the optimal lumped parameters and practical design parameters for the MR engine mount. The program flowchart for the improved non-dominated sorting genetic algorithm (NSGA-II) is given. The obtained results demonstrate the effectiveness of the proposed optimization approach in minimizing the total of force transmissibility over several frequency ranges addressed.
Kudo, Fumiya; Yoshikawa, Tomohiro; Furuhashi, Takeshi
Recentry, Multi-objective Genetic Algorithm, which is the application of Genetic Algorithm to Multi-objective Optimization Problems is focused on in the engineering design field. In this field, the analysis of design variables in the acquired Pareto solutions, which gives the designers useful knowledge in the applied problem, is important as well as the acquisition of advanced solutions. This paper proposes a new visualization method using Isomap which visualizes the geometric distances of solutions in the design variable space considering their distances in the objective space. The proposed method enables a user to analyze the design variables of the acquired solutions considering their relationship in the objective space. This paper applies the proposed method to the conceptual design optimization problem of hybrid rocket engine and studies the effectiveness of the proposed method.
Roe, K.A.; Roe, K.K.
The design objectives of low capital and operating costs and high reliability are best attained by carefully defining criteria early in the development stage. Throughout the design development, unusual attention to constructibility, reliability and availability requirements, and the early resolution of licensing issues by designated engineering specialists are some of the approaches used to minimize design restraints. Effective management of these design objectives and restraints can assure that, on balance, LMFBR costs can be improved, reliability increased, and maintenance can be effective. (author)
Rowell, Lawrence F.; Korte, John J.
NASA's Advanced Engineering Environment (AEE) is a research and development program that will improve collaboration among design engineers for launch vehicle conceptual design and provide the infrastructure (methods and framework) necessary to enable that environment. In this paper, three major technical challenges facing the AEE program are identified, and three specific design problems are selected to demonstrate how advanced methods can improve current design activities. References are made to studies that demonstrate these design problems and methods, and these studies will provide the detailed information and check cases to support incorporation of these methods into the AEE. This paper provides background and terminology for discussing the launch vehicle conceptual design problem so that the diverse AEE user community can participate in prioritizing the AEE development effort.
Nguyen, Q H; Choi, S B; Lee, Y S; Han, M S
This paper focuses on the optimal design of a compact and high damping force engine mount featuring magnetorheological fluid (MRF). In the mount, a MR valve structure with both annular and radial flows is employed to generate a high damping force. First, the configuration and working principle of the proposed MR mount is introduced. The MRF flows in the mount are then analyzed and the governing equations of the MR mount are derived based on the Bingham plastic behavior of the MRF. An optimal design of the MR mount is then performed to find the optimal structure of the MR valve to generate a maximum damping force with certain design constraints. In addition, the gap size of MRF ducts is empirically chosen considering the ‘lockup’ problem of the mount at high frequency. Performance of the optimized MR mount is then evaluated based on finite element analysis and discussions on performance results of the optimized MR mount are given. The effectiveness of the proposed MR engine mount is demonstrated via computer simulation by presenting damping force and power consumption. (paper)
Nguyen, Q. H.; Choi, S. B.; Lee, Y. S.; Han, M. S.
This paper focuses on the optimal design of a compact and high damping force engine mount featuring magnetorheological fluid (MRF). In the mount, a MR valve structure with both annular and radial flows is employed to generate a high damping force. First, the configuration and working principle of the proposed MR mount is introduced. The MRF flows in the mount are then analyzed and the governing equations of the MR mount are derived based on the Bingham plastic behavior of the MRF. An optimal design of the MR mount is then performed to find the optimal structure of the MR valve to generate a maximum damping force with certain design constraints. In addition, the gap size of MRF ducts is empirically chosen considering the ‘lockup’ problem of the mount at high frequency. Performance of the optimized MR mount is then evaluated based on finite element analysis and discussions on performance results of the optimized MR mount are given. The effectiveness of the proposed MR engine mount is demonstrated via computer simulation by presenting damping force and power consumption.
Behrendt, V.; Krehbiehl, T.; Hartfiel, H.D.; Mannhaupt, H.R.
The study contains two parts. In the first part an analytical procedure is developed to logically and reproducibly subdivide the control room personnel tasks resulting in a list of the elements (operations) and the structure (operations scheme) of a task. The second part lists together all knowledge of and influences on human engineering which are known at this time and which should be taken into account in designing control rooms. The content of this catalogue can best be used and presented by using a personal computer. Two fundamental different ways are possible to use the catalogue. Designing new control rooms or new parts of control rooms the results of the task analysis which should be done first, should guide the search in the catalogue to find the right human engineering factors. For assessing existing control room panels the performance shaping factors which are establishing the table of content, permit a quick access to the catalogue. Both the specific procedure of the task analysis and the different ways of access to the catalogue of human engineering knowledge for designing nuclear power plant control rooms have been proven by experienced system engineers and safety experts. The results are presented. They have been considered in this version of the study. (orig.) [de
Coelho, Pedro G; Hollister, Scott J; Flanagan, Colleen L; Fernandes, Paulo R
Bone scaffolds for tissue regeneration require an optimal trade-off between biological and mechanical criteria. Optimal designs may be obtained using topology optimization (homogenization approach) and prototypes produced using additive manufacturing techniques. However, the process from design to manufacture remains a research challenge and will be a requirement of FDA design controls to engineering scaffolds. This work investigates how the design to manufacture chain affects the reproducibility of complex optimized design characteristics in the manufactured product. The design and prototypes are analyzed taking into account the computational assumptions and the final mechanical properties determined through mechanical tests. The scaffold is an assembly of unit-cells, and thus scale size effects on the mechanical response considering finite periodicity are investigated and compared with the predictions from the homogenization method which assumes in the limit infinitely repeated unit cells. Results show that a limited number of unit-cells (3-5 repeated on a side) introduce some scale-effects but the discrepancies are below 10%. Higher discrepancies are found when comparing the experimental data to numerical simulations due to differences between the manufactured and designed scaffold feature shapes and sizes as well as micro-porosities introduced by the manufacturing process. However good regression correlations (R(2) > 0.85) were found between numerical and experimental values, with slopes close to 1 for 2 out of 3 designs. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.
Carreau, Michel; Morgenroth, Michael; Belashov, Oleg; Mdimagh, Asma; Hertz, Alain; Marcotte, Odile
Innovative numerical computer tools have been developed to streamline the estimation, the design process and to optimize the Wind Farm Design with respect to the overall return on investment. The optimization engine can find the collector system layout automatically which provide a powerful tool to quickly study various alternative taking into account more precisely various constraints or factors that previously would have been too costly to analyze in details with precision. Our Wind Farm Tools have evolved through numerous projects and created value for our clients yielding Wind Farm projects with projected higher returns.
Full Text Available Functionally Graded Scaffolds (FGSs are porous biomaterials where porosity changes in space with a specific gradient. In spite of their wide use in bone tissue engineering, possible models that relate the scaffold gradient to the mechanical and biological requirements for the regeneration of the bony tissue are currently missing. In this study we attempt to bridge the gap by developing a mechanobiology-based optimization algorithm aimed to determine the optimal graded porosity distribution in FGSs. The algorithm combines the parametric finite element model of a FGS, a computational mechano-regulation model and a numerical optimization routine. For assigned boundary and loading conditions, the algorithm builds iteratively different scaffold geometry configurations with different porosity distributions until the best microstructure geometry is reached, i.e. the geometry that allows the amount of bone formation to be maximized. We tested different porosity distribution laws, loading conditions and scaffold Young's modulus values. For each combination of these variables, the explicit equation of the porosity distribution law-i.e the law that describes the pore dimensions in function of the spatial coordinates-was determined that allows the highest amounts of bone to be generated. The results show that the loading conditions affect significantly the optimal porosity distribution. For a pure compression loading, it was found that the pore dimensions are almost constant throughout the entire scaffold and using a FGS allows the formation of amounts of bone slightly larger than those obtainable with a homogeneous porosity scaffold. For a pure shear loading, instead, FGSs allow to significantly increase the bone formation compared to a homogeneous porosity scaffolds. Although experimental data is still necessary to properly relate the mechanical/biological environment to the scaffold microstructure, this model represents an important step towards
Martini, W. R.
This manual is intended to serve both as an introduction to Stirling engine analysis methods and as a key to the open literature on Stirling engines. Over 800 references are listed and these are cross referenced by date of publication, author and subject. Engine analysis is treated starting from elementary principles and working through cycles analysis. Analysis methodologies are classified as first, second or third order depending upon degree of complexity and probable application; first order for preliminary engine studies, second order for performance prediction and engine optimization, and third order for detailed hardware evaluation and engine research. A few comparisons between theory and experiment are made. A second order design procedure is documented step by step with calculation sheets and a worked out example to follow. Current high power engines are briefly described and a directory of companies and individuals who are active in Stirling engine development is included. Much remains to be done. Some of the more complicated and potentially very useful design procedures are now only referred to. Future support will enable a more thorough job of comparing all available design procedures against experimental data which should soon be available.
Amanda K. Fisher
Full Text Available Microbial cell factories (MCFs are of considerable interest to convert low value renewable substrates to biofuels and high value chemicals. This review highlights the progress of computational models for the rational design of an MCF to produce a target bio-commodity. In particular, the rational design of an MCF involves: (i product selection, (ii de novo biosynthetic pathway identification (i.e., rational, heterologous, or artificial, (iii MCF chassis selection, (iv enzyme engineering of promiscuity to enable the formation of new products, and (v metabolic engineering to ensure optimal use of the pathway by the MCF host. Computational tools such as (i de novo biosynthetic pathway builders, (ii docking, (iii molecular dynamics (MD and steered MD (SMD, and (iv genome-scale metabolic flux modeling all play critical roles in the rational design of an MCF. Genome-scale metabolic flux models are of considerable use to the design process since they can reveal metabolic capabilities of MCF hosts. These can be used for host selection as well as optimizing precursors and cofactors of artificial de novo biosynthetic pathways. In addition, recent advances in genome-scale modeling have enabled the derivation of metabolic engineering strategies, which can be implemented using the genomic tools reviewed here as well.
Enevoldsen, I.; Sørensen, John Dalsgaard
In this paper reliability-based optimization problems in structural engineering are formulated on the basis of the classical decision theory. Several formulations are presented: Reliability-based optimal design of structural systems with component or systems reliability constraints, reliability...
Zhu, Dongming; Miller, Robert A.; Kuczmarski, Maria A.
Thermal barrier coatings will be more aggressively designed to protect gas turbine engine hot-section components in order to meet future rotorcraft engine higher fuel efficiency and lower emission goals. For thermal barrier coatings designed for rotorcraft turbine airfoil applications, further improved erosion and impact resistance are crucial for engine performance and durability, because the rotorcraft are often operated in the most severe sand erosive environments. Advanced low thermal conductivity and erosion-resistant thermal barrier coatings are being developed, with the current emphasis being placed on thermal barrier coating toughness improvements using multicomponent alloying and processing optimization approaches. The performance of the advanced thermal barrier coatings has been evaluated in a high temperature erosion burner rig and a laser heat-flux rig to simulate engine erosion and thermal gradient environments. The results have shown that the coating composition and architecture optimizations can effectively improve the erosion and impact resistance of the coating systems, while maintaining low thermal conductivity and cyclic oxidation durability
Menolascina, Filippo; Bellomo, Domenico; Maiwald, Thomas; Bevilacqua, Vitoantonio; Ciminelli, Caterina; Paradiso, Angelo; Tommasi, Stefania
Mechanistic models are becoming more and more popular in Systems Biology; identification and control of models underlying biochemical pathways of interest in oncology is a primary goal in this field. Unfortunately the scarce availability of data still limits our understanding of the intrinsic characteristics of complex pathologies like cancer: acquiring information for a system understanding of complex reaction networks is time consuming and expensive. Stimulus response experiments (SRE) have been used to gain a deeper insight into the details of biochemical mechanisms underlying cell life and functioning. Optimisation of the input time-profile, however, still remains a major area of research due to the complexity of the problem and its relevance for the task of information retrieval in systems biology-related experiments. We have addressed the problem of quantifying the information associated to an experiment using the Fisher Information Matrix and we have proposed an optimal experimental design strategy based on evolutionary algorithm to cope with the problem of information gathering in Systems Biology. On the basis of the theoretical results obtained in the field of control systems theory, we have studied the dynamical properties of the signals to be used in cell stimulation. The results of this study have been used to develop a microfluidic device for the automation of the process of cell stimulation for system identification. We have applied the proposed approach to the Epidermal Growth Factor Receptor pathway and we observed that it minimises the amount of parametric uncertainty associated to the identified model. A statistical framework based on Monte-Carlo estimations of the uncertainty ellipsoid confirmed the superiority of optimally designed experiments over canonical inputs. The proposed approach can be easily extended to multiobjective formulations that can also take advantage of identifiability analysis. Moreover, the availability of fully automated
SEO--short for Search Engine Optimization--is the art, craft, and science of driving web traffic to web sites. Web traffic is food, drink, and oxygen--in short, life itself--to any web-based business. Whether your web site depends on broad, general traffic, or high-quality, targeted traffic, this PDF has the tools and information you need to draw more traffic to your site. You'll learn how to effectively use PageRank (and Google itself); how to get listed, get links, and get syndicated; and much more. The field of SEO is expanding into all the possible ways of promoting web traffic. This
Full Text Available Experimental test methods for the evaluation of the resistance of heels of ladies' shoes in the case of impact loads are fully defined by International Organization for Standardization (ISO procedures that indicate all the conditions of experiment. A first Standard (ISO 19553 specifies the test method for determining the strength of the heels in the case of single impact. The result offers a valuation of the liability to fail under the sporadic heavy blows. A second Standard (ISO 19556 details a method for testing the capability of heels of women' shoes to survive to the repetition of small impacts provoked by normal walking. These Standards strictly define the features for two different testing devices (with specific materials, geometries, weights, etc. and all the experimental procedures to be followed during tests. On the contrary, this paper describes the technical solutions adopted to design one single experimental device able to perform impact testing of heels in both conditions. Joining the accuracy of mechanic movements with the speed of an electronic control system, a new and flexible equipment for the complete characterization of heels respect to (single or fatigue impacts was developed. Moreover a new level of performances in experimental validation of heel resistance was introduced by the versatility of the user-defined software control programs, able to encode every complex time-depending cycle of impact loads. Dynamic simulations permitted to investigate the impacts on heel in different conditions of testing, optimizing the machine design. The complexity of real stresses on shoes during an ordinary walk and in other common situations (as going up and downstairs was considered for a proper dimensioning.
Candon, M. J.; Ogawa, H.
Scramjets are a class of hypersonic airbreathing engine that offer promise for economical, reliable and high-speed access-to-space and atmospheric transport. The expanding flow in the scramjet nozzle comprises of unburned hydrogen. An after-burning scheme can be used to effectively utilize the remaining hydrogen by supplying additional oxygen into the nozzle, aiming to augment the thrust. This paper presents the results of a single-objective design optimization for a strut fuel injection scheme considering four design variables with the objective of maximizing thrust augmentation. Thrust is found to be augmented significantly owing to a combination of contributions from aerodynamic and combustion effects. Further understanding and physical insights have been gained by performing variance-based global sensitivity analysis, scrutinizing the nozzle flowfields, analyzing the distributions and contributions of the forces acting on the nozzle wall, and examining the combustion efficiency.
This book describes the principles of solving various problems in power engineering via the application of selected metaheuristic optimization methods including genetic algorithms, particle swarm optimization, and the gravitational search algorithm.
Oriekov, K. M.; Ushkin, M. P.
This article examines the processes intrachamber in hybrid rocket engine (HRE) and the comparative assessment of the use of solid rocket motors (SRM) and HRE for meteorological rockets with a mass of payload of the 364 kg. Results of the research showed the possibility of a significant increase in the ballistic effectiveness of meteorological rocket.
A. V. Krasniuk
Full Text Available AutoCAD possibilities of 3D solid modeling are described in the article. The optimum methods of designing for construction and machine drawing applying are analyzed. The choice of methods for 3D solids drawing is proved by samples.
Upreti, Simant Ranjan
Optimal Control for Chemical Engineers gives a detailed treatment of optimal control theory that enables readers to formulate and solve optimal control problems. With a strong emphasis on problem solving, the book provides all the necessary mathematical analyses and derivations of important results, including multiplier theorems and Pontryagin's principle.The text begins by introducing various examples of optimal control, such as batch distillation and chemotherapy, and the basic concepts of optimal control, including functionals and differentials. It then analyzes the notion of optimality, de
Blessing, Lucienne; Andreasen, Mogens Myrup
The importance og engineering design as an industrial activity, and the increasingly complex and dynamic context in which it takes place, has led to the wish to improve the effectiveness and efficiency of engineering design in practice as well as in education. Although attempts have been made...... to improve design for centuries, it was not until well in the second half of the 20th century that engineering design became a research topic (see pahl and Beitz (1996), Heymann (2004) for historical overviews). Engineering research, such as research into thermodynamics, mechanics and materials, has a much...... by PhD students. This has created the demand for a clear, efficient way of learning the crafmanship of doing design research, a demand which is in strong contrast to the state of design research in general. This article reflects the authors' efforts in running a summer school om engineering design...
Andersen, Stig Kildegård; Carlsen, Henrik; Thomsen, Per Grove
A new regenerator matrix design that improves the efficiency of a Stirling engine has been developed in a numerical study of the existing SM5 Stirling engine. A new, detailed, one-dimensional Stirling engine model that delivers results in good agreement with experimental data was used for mapping...... the per- formance of the engine, for mapping the effects of regenerator matrix temperature oscillations, and for optimising the regenerator design. The regenerator matrix temperatures were found to oscillate in two modes. The first mode was oscillation of a nearly linear axial matrix temperature profile...... while the second mode bended the ends of the axial matrix temperature profile when gas flowed into the regenerator with a temperature significantly different from the matrix temperature. The first mode of oscillation improved the efficiency of the engine but the second mode reduced both the work output...
Andersen, Stig Kildegard; Carlsen, Henrik; Thomsen, Per Grove
A new regenerator matrix design that improves the efficiency of a Stirling engine has been developed in a numerical study of the existing SM5 Stirling engine. A new, detailed, one-dimensional Stirling engine model that delivers results in good agreement with experimental data was used for mapping the performance of the engine, for mapping the effects of regenerator matrix temperature oscillations, and for optimising the regenerator design. The regenerator matrix temperatures were found to oscillate in two modes. The first mode was oscillation of a nearly linear axial matrix temperature profile while the second mode bended the ends of the axial matrix temperature profile when gas flowed into the regenerator with a temperature significantly different from the matrix temperature. The first mode of oscillation improved the efficiency of the engine but the second mode reduced both the work output and efficiency of the engine. A new regenerator with three differently designed matrix sections that amplified the first mode of oscillation and reduced the second improved the efficiency of the engine from the current 32.9 to 33.2% with a 3% decrease in power output. An efficiency of 33.0% was achievable with uniform regenerator matrix properties
Describes group design techniques used within the engineering design graphics sequence at Western Washington University. Engineering and design philosophies such as concurrent engineering place an emphasis on group collaboration for the solving of design problems. (Author/DDR)
Eriksen, Dawn T; Lian, Jiazhang; Zhao, Huimin
Design and construction of biochemical pathways has increased the complexity of biosynthetically-produced compounds when compared to single enzyme biocatalysis. However, the coordination of multiple enzymes can introduce a complicated set of obstacles to overcome in order to achieve a high titer and yield of the desired compound. Metabolic engineering has made great strides in developing tools to optimize the flux through a target pathway, but the inherent characteristics of a particular enzyme within the pathway can still limit the productivity. Thus, judicious protein design is critical for metabolic and pathway engineering. This review will describe various strategies and examples of applying protein design to pathway engineering to optimize the flux through the pathway. The proteins can be engineered for altered substrate specificity/selectivity, increased catalytic activity, reduced mass transfer limitations through specific protein localization, and reduced substrate/product inhibition. Protein engineering can also be expanded to design biosensors to enable high through-put screening and to customize cell signaling networks. These strategies have successfully engineered pathways for significantly increased productivity of the desired product or in the production of novel compounds. Copyright © 2013 Elsevier Inc. All rights reserved.
Full Text Available Recently, the high-pressure fuel injection performance of common-rail direct injection (CRDi engines has become more important, due to the need to improve the multi-injection strategy. A multiple injection strategy provides better emission and fuel economy characteristics than a normal single injection scheme. The CRDi engine performance changes with the type of high-pressure electro-mechanical injector that is used and its injection response in a multi-injection scheme. In this study, a direct needle-driven piezo injector (DPI was investigated, to optimize its actuation components, including the plate length, number of springs, and the elasticity of the spring between the injector needle and the piezo stack. Three prototype DPIs were proposed by this research. They were classified as Type 1, 2, and 3, depending on whether the injector needle was hydraulic or mechanical. Then, the optimal prototype was determined by conducting four evaluation experiments analyzing the maximum injection pressure, injection rate, spray visualization, and real engine combustion application. As a result, it was found that the Type 3 DPI prototype, with several pan-springs and plates, had the highest injection pressure, a steady injection rate, and the fastest spray speed. It also demonstrated the most effective emission reduction for a two-stage rapid spray injection in a single-cylinder CRDi engine. The Type 3 DPI displays an increased elasticity from its hydraulic needle that provides a synergy effect for improving DPI actuation.
Schrøder, Anne Lise
In various branches of society there is focus on the need for design skills and innovation potential as a means of communicating and handling constant change. In this context, the traditional idea of the engineer as a poly-technician inventing solutions by understanding the laws of nature...... concept of diagrammatic reasoning to some extent incarnates the very method of engineering and design. On this background, it is argued how the work field and techniques of the engineer and the engineering scientist could be characterized in a broader creative context of learning and communication....... This leads to considering the fundamental skills of the engineering practice as basic abilities to see the structures and dynamics of the world, to model it, and to create new solutions concerning practical as well as theoretical matters. Finally, it is assumed that the essence of engineering “bildung...
Aguilo Valentin, Miguel Alejandro [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Computational Solid Mechanics and Structural Dynamics
The Design Optimization Toolkit (DOTk) is a stand-alone C++ software package intended to solve complex design optimization problems. DOTk software package provides a range of solution methods that are suited for gradient/nongradient-based optimization, large scale constrained optimization, and topology optimization. DOTk was design to have a flexible user interface to allow easy access to DOTk solution methods from external engineering software packages. This inherent flexibility makes DOTk barely intrusive to other engineering software packages. As part of this inherent flexibility, DOTk software package provides an easy-to-use MATLAB interface that enables users to call DOTk solution methods directly from the MATLAB command window.
Tobias B. Alter
Full Text Available To date, several independent methods and algorithms exist for exploiting constraint-based stoichiometric models to find metabolic engineering strategies that optimize microbial production performance. Optimization procedures based on metaheuristics facilitate a straightforward adaption and expansion of engineering objectives, as well as fitness functions, while being particularly suited for solving problems of high complexity. With the increasing interest in multi-scale models and a need for solving advanced engineering problems, we strive to advance genetic algorithms, which stand out due to their intuitive optimization principles and the proven usefulness in this field of research. A drawback of genetic algorithms is that premature convergence to sub-optimal solutions easily occurs if the optimization parameters are not adapted to the specific problem. Here, we conducted comprehensive parameter sensitivity analyses to study their impact on finding optimal strain designs. We further demonstrate the capability of genetic algorithms to simultaneously handle (i multiple, non-linear engineering objectives; (ii the identification of gene target-sets according to logical gene-protein-reaction associations; (iii minimization of the number of network perturbations; and (iv the insertion of non-native reactions, while employing genome-scale metabolic models. This framework adds a level of sophistication in terms of strain design robustness, which is exemplarily tested on succinate overproduction in Escherichia coli.
Holst, Malene Kirstine
foundation. The basis of the present study lies in solving the architectural design problem in order to respond to functionalities and performances. The emphasis is the practical applicability for architects, engineers and hospital planners for assuring usability and a holistic approach of functionalities...... a correlation matrix. The correlation factor defines the framework for conceptual design, whereby the design considers functionalities and their requirements and preferences. It facilitates implementation of evidence-based design as it is prepared for ongoing update and it is based on actual data. Hence......, this contribution is a model for hospital design, where design derives as a response to the defined variables, requirements and preferences....
Rolf D. Reitz
The goal of this project was to develop methods to optimize and control Homogeneous-Charge Compression Ignition (HCCI) engines, with emphasis on diesel-fueled engines. HCCI offers the potential of nearly eliminating IC engine NOx and particulate emissions at reduced cost over Compression Ignition Direct Injection engines (CIDI) by controlling pollutant emissions in-cylinder. The project was initiated in January, 2002, and the present report is the final report for work conducted on the project through December 31, 2004. Periodic progress has also been reported at bi-annual working group meetings held at USCAR, Detroit, MI, and at the Sandia National Laboratories. Copies of these presentation materials are available on CD-ROM, as distributed by the Sandia National Labs. In addition, progress has been documented in DOE Advanced Combustion Engine R&D Annual Progress Reports for FY 2002, 2003 and 2004. These reports are included as the Appendices in this Final report.
Full coverage of electronics, MEMS, and instrumentation andcontrol in mechanical engineering This second volume of Mechanical Engineers' Handbookcovers electronics, MEMS, and instrumentation and control, givingyou accessible and in-depth access to the topics you'll encounterin the discipline: computer-aided design, product design formanufacturing and assembly, design optimization, total qualitymanagement in mechanical system design, reliability in themechanical design process for sustainability, life-cycle design,design for remanufacturing processes, signal processing, dataacquisition and dis
Klapproth, J. F.; Neitzel, R. E.; Seeley, C. T.
The results are presented of a preliminary flight engine design study based on the Quiet Engine Program high-bypass, low-noise turbofan engines. Engine configurations, weight, noise characteristics, and performance over a range of flight conditions typical of a subsonic transport aircraft were considered. High and low tip speed engines in various acoustically treated nacelle configurations were included.
This book provides an introduction to the design and mechanical development of reciprocating piston engines for vehicular applications. Beginning from the determination of required displacement and performance, coverage moves into engine configuration and architecture. Critical layout dimensions and design trade-offs are then presented for pistons, crankshafts, engine blocks, camshafts, valves, and manifolds. Coverage continues with material strength and casting process selection for the cylinder block and cylinder heads. Each major engine component and sub-system is then taken up in turn, from lubrication system, to cooling system, to intake and exhaust systems, to NVH. For this second edition latest findings and design practices are included, with the addition of over sixty new pictures and many new equations.
Boone, J.; Goeree, J.K.
This paper introduces three methodological advances to study the optimal design of static and dynamic markets. First, we apply a mechanism design approach to characterize all incentive-compatible market equilibria. Second, we conduct a normative analysis, i.e. we evaluate alternative competition and
Ferreira, Desiree Della Monica; Christensen, Finn Erland; Jakobsen, Anders Clemen
The optimization of coating design for the ATHENA mission si described and the possibility of increasing the telescope effective area in the range between 0.1 and 10 keV is investigated. An independent computation of the on-axis effective area based on the mirror design of ATHENA is performed...... in order to review the current coating baseline. The performance of several material combinations, considering a simple bi-layer, simple multilayer and linear graded multilayer coatings are tested and simulation of the mirror performance considering both the optimized coating design and the coating...
The essential aspects of the design and engineering of fuel assemblies for LWR reactors are outlined, and the major criteria to be met by the materials used are given. The fuel rods must be mechanically designed to withstand many stresses which are shortly dealt with here. (RB) [de
Lammi, Matthew; Becker, Kurt
Engineering design thinking is "a complex cognitive process" including divergence-convergence, a systems perspective, ambiguity, and collaboration (Dym, Agogino, Eris, Frey, & Leifer, 2005, p. 104). Design is often complex, involving multiple levels of interacting components within a system that may be nested within or connected to other systems.…
Childs, Peter R N
Mechanical Design Engineering Handbook is a straight-talking and forward-thinking reference covering the design, specification, selection, use and integration of machine elements fundamental to a wide range of engineering applications. Develop or refresh your mechanical design skills in the areas of bearings, shafts, gears, seals, belts and chains, clutches and brakes, springs, fasteners, pneumatics and hydraulics, amongst other core mechanical elements, and dip in for principles, data and calculations as needed to inform and evaluate your on-the-job decisions. Covering the full spectrum
This book offers an introduction to numerical optimization methods in structural design. Employing a readily accessible and compact format, the book presents an overview of optimization methods, and equips readers to properly set up optimization problems and interpret the results. A ‘how-to-do-it’ approach is followed throughout, with less emphasis at this stage on mathematical derivations. The book features spreadsheet programs provided in Microsoft Excel, which allow readers to experience optimization ‘hands-on.’ Examples covered include truss structures, columns, beams, reinforced shell structures, stiffened panels and composite laminates. For the last three, a review of relevant analysis methods is included. Exercises, with solutions where appropriate, are also included with each chapter. The book offers a valuable resource for engineering students at the upper undergraduate and postgraduate level, as well as others in the industry and elsewhere who are new to these highly practical techniques.Whi...
of different evolutionary approaches to multiobjective optimal design are given by Van Veldhuizen ,7 Van Veldhuizen and Lamont,8 and Zitzler and Thiele...and Machine Learning, Addison-Wesley, Boston, 1989. 7. D. A. Van Veldhuizen , "Multiobjective Evolutionary Algorithms: Classifications, Analyses, and...New Innovations," Ph.D. Dissertation, Air Force Institute of Technology, 1999. 39 8. D. A. Van Veldhuizen and G. B. Lamont, "Multiobjective
Lutz, T. [Stuttgart Univ. (Germany). Inst. fuer Aerodynamik und Gasdynamik
The aerodynamic efficiency of mildly swept wings is mainly influenced by the characteristics of the airfoil sections. The specific design of airfoils is therefore one of the classical tasks of aerodynamics. Since the airfoil characteristics are directly dependent on the inviscid pressure distribution the application of inverse calculation methods is obvious. The direct numerical airfoil optimization offers an alternative to the manual design and attracts increasing interest. (orig.)
Buden, D.; Hunt, R.N.M.
Improved design techniques are needed to achieve high reliability at minimum cost. This is especially true of space systems where lifetimes of many years without maintenance are needed and severe mass limitations exist. Reliability must be designed into these systems from the start. Techniques are now being explored to structure a formal design process that will be more complete and less expensive. The intent is to integrate the best features of design, reliability analysis, and expert systems to design highly reliable systems to meet stressing needs. Taken into account are the large uncertainties that exist in materials, design models, and fabrication techniques. Expert systems are a convenient method to integrate into the design process a complete definition of all elements that should be considered and an opportunity to integrate the design process with reliability, safety, test engineering, maintenance and operator training. 1 fig
Crowder, James A
This book examines the paradigm of the engineering design process. The authors discuss agile systems and engineering design. The book captures the entire design process (functionbases), context, and requirements to affect real reuse. It provides a methodology for an engineering design process foundation for modern and future systems design. This book captures design patterns with context for actual Systems Engineering Design Reuse and contains a new paradigm in Design Knowledge Management.
This report documents the Ground Vehicle System Integration (GVSI) and Design Optimization Model GVSI is a top-level analysis tool designed to support engineering tradeoff studies and vehicle design optimization efforts...
Saito, Ryusei; Kobayashi, Takeshi; Yamada, Masao
Major engineering design philosophies are described, which are essential bases for an engineering design and may have significant impacts on a reactor design concept. Those design philosophies are classified into two groups, engineering design drivers and engineering design constraints. The design drivers are featured by the fact that a designer is free to choose and the choice may be guided by his opinion, such as coil system, a mechanical configuration, a tritium breeding scenario, etc.. The design constraints may follow a natural law or engineering limit, such as material strength, coil current density, and so on. (author)
The idea of this monograph is to present the latest results related to design and computation of engineering materials and structures. The contributions cover the classical fields of mechanical, civil and materials engineering up to biomechanics and advanced materials processing and optimization. The materials and structures covered can be categorized into modern steels and titanium alloys, composite materials, biological and natural materials, material hybrids and modern joining technologies. Analytical modelling, numerical simulation, the application of state-of-the-art design tools and sophisticated experimental techniques are applied to characterize the performance of materials and to design and optimize structures in different fields of engineering applications.
Rao, R Venkata
Mechanical design includes an optimization process in which designers always consider objectives such as strength, deflection, weight, wear, corrosion, etc. depending on the requirements. However, design optimization for a complete mechanical assembly leads to a complicated objective function with a large number of design variables. It is a good practice to apply optimization techniques for individual components or intermediate assemblies than a complete assembly. Analytical or numerical methods for calculating the extreme values of a function may perform well in many practical cases, but may fail in more complex design situations. In real design problems, the number of design parameters can be very large and their influence on the value to be optimized (the goal function) can be very complicated, having nonlinear character. In these complex cases, advanced optimization algorithms offer solutions to the problems, because they find a solution near to the global optimum within reasonable time and computational ...
Rao, R Venkata
Describing a new optimization algorithm, the “Teaching-Learning-Based Optimization (TLBO),” in a clear and lucid style, this book maximizes reader insights into how the TLBO algorithm can be used to solve continuous and discrete optimization problems involving single or multiple objectives. As the algorithm operates on the principle of teaching and learning, where teachers influence the quality of learners’ results, the elitist version of TLBO algorithm (ETLBO) is described along with applications of the TLBO algorithm in the fields of electrical engineering, mechanical design, thermal engineering, manufacturing engineering, civil engineering, structural engineering, computer engineering, electronics engineering, physics and biotechnology. The book offers a valuable resource for scientists, engineers and practitioners involved in the development and usage of advanced optimization algorithms.
This thesis presents a coordination method for the distributed design optimization of engineering systems. The design of advanced engineering systems such as aircrafts, automated distribution centers, and microelectromechanical systems (MEMS) involves multiple components that together realize the
Keywords: reinforced concrete slabs, flexure, m. 1. Introduction ntroduction ntroduction. An evaluation of the flexural resistance of reinforced concrete solid slabs with the optimu weight required for structural safety a economy and as stated in design codes. 5] is presented. It is a well-known fact by many design enginee.
Chizek, Lisa; VanMeeteren, Beth; McDermott, Mark; Uhlenberg, Jill
Engineering is an intriguing way for students to connect the design process with their knowledge of science (NRC 2012). This article describes the "Engineering a Pancake Recipe" design process which was created to make the structure and properties of matter more meaningful for fifth grade students. The whole pancake recipe engineering…
The Co-Optimization of Fuels and Engines (Co-Optima) initiative is a new DOE initiative focused on accelerating the introduction of affordable, scalable, and sustainable biofuels and high-efficiency, low-emission vehicle engines. The simultaneous fuels and vehicles research and development (R&D) are designed to deliver maximum energy savings, emissions reduction, and on-road vehicle performance. The initiative's integrated approach combines the previously independent areas of biofuels and combustion R&D, bringing together two DOE Office of Energy Efficiency & Renewable Energy research offices, ten national laboratories, and numerous industry and academic partners to simultaneously tackle fuel and engine research and development (R&D) to maximize energy savings and on-road vehicle performance while dramatically reducing transportation-related petroleum consumption and greenhouse gas (GHG) emissions. This multi-year project will provide industry with the scientific underpinnings required to move new biofuels and advanced engine systems to market faster while identifying and addressing barriers to their commercialization. This project's ambitious, first-of-its-kind approach simultaneously tackles fuel and engine innovation to co-optimize performance of both elements and provide dramatic and rapid cuts in fuel use and emissions. This presentation provides an overview of the project.
The Co-Optimization of Fuels and Engines (Co-Optima) initiative is a new DOE initiative focused on accelerating the introduction of affordable, scalable, and sustainable biofuels and high-efficiency, low-emission vehicle engines. The simultaneous fuels and vehicles research and development (R&D) are designed to deliver maximum energy savings, emissions reduction, and on-road vehicle performance. The initiative's integrated approach combines the previously independent areas of biofuels and combustion R&D, bringing together two DOE Office of Energy Efficiency & Renewable Energy research offices, ten national laboratories, and numerous industry and academic partners to simultaneously tackle fuel and engine research and development (R&D) to maximize energy savings and on-road vehicle performance while dramatically reducing transportation-related petroleum consumption and greenhouse gas (GHG) emissions. This multi-year project will provide industry with the scientific underpinnings required to move new biofuels and advanced engine systems to market faster while identifying and addressing barriers to their commercialization. This project's ambitious, first-of-its-kind approach simultaneously tackles fuel and engine innovation to co-optimize performance of both elements and provide dramatic and rapid cuts in fuel use and emissions. This presentation provides an overview of the initiative and reviews recent progress focused on both advanced spark-ignition and compression-ignition approaches.
Halper, Sean M; Cetnar, Daniel P; Salis, Howard M
Engineering many-enzyme metabolic pathways suffers from the design curse of dimensionality. There are an astronomical number of synonymous DNA sequence choices, though relatively few will express an evolutionary robust, maximally productive pathway without metabolic bottlenecks. To solve this challenge, we have developed an integrated, automated computational-experimental pipeline that identifies a pathway's optimal DNA sequence without high-throughput screening or many cycles of design-build-test. The first step applies our Operon Calculator algorithm to design a host-specific evolutionary robust bacterial operon sequence with maximally tunable enzyme expression levels. The second step applies our RBS Library Calculator algorithm to systematically vary enzyme expression levels with the smallest-sized library. After characterizing a small number of constructed pathway variants, measurements are supplied to our Pathway Map Calculator algorithm, which then parameterizes a kinetic metabolic model that ultimately predicts the pathway's optimal enzyme expression levels and DNA sequences. Altogether, our algorithms provide the ability to efficiently map the pathway's sequence-expression-activity space and predict DNA sequences with desired metabolic fluxes. Here, we provide a step-by-step guide to applying the Pathway Optimization Pipeline on a desired multi-enzyme pathway in a bacterial host.
Increasingly engineering design research involves the use of empirical studies that are conducted within an industrial environment [Ahmed, 2001; Court 1995; Hales 1987]. Research into the use of information by designers or understanding how engineers build up experience are examples of research...... of research issues. This paper describes case studies of empirical research carried out within industry in engineering design focusing upon information, knowledge and experience in engineering design. The paper describes the research methods employed, their suitability for the particular research aims...
Yuen, J. H.
This program was developed as part of a research study on the topology design and performance analysis for the Space Station Information System (SSIS) network. It uses an efficient algorithm to generate candidate network designs (consisting of subsets of the set of all network components) in increasing order of their total costs, and checks each design to see if it forms an acceptable network. This technique gives the true cost-optimal network, and is particularly useful when the network has many constraints and not too many components. It is intended that this new design technique consider all important performance measures explicitly and take into account the constraints due to various technical feasibilities. In the current program, technical constraints are taken care of by the user properly forming the starting set of candidate components (e.g. nonfeasible links are not included). As subsets are generated, they are tested to see if they form an acceptable network by checking that all requirements are satisfied. Thus the first acceptable subset encountered gives the cost-optimal topology satisfying all given constraints. The user must sort the set of "feasible" link elements in increasing order of their costs. The program prompts the user for the following information for each link: 1) cost, 2) connectivity (number of stations connected by the link), and 3) the stations connected by that link. Unless instructed to stop, the program generates all possible acceptable networks in increasing order of their total costs. The program is written only to generate topologies that are simply connected. Tests on reliability, delay, and other performance measures are discussed in the documentation, but have not been incorporated into the program. This program is written in PASCAL for interactive execution and has been implemented on an IBM PC series computer operating under PC DOS. The disk contains source code only. This program was developed in 1985.
Capobianco, Brenda M.; Nyquist, Chell; Tyrie, Nancy
This article describes the steps incorporated to teach an engineering design process in a fifth-grade science classroom. The engineering design-based activity was an existing scientific inquiry activity using UV light--detecting beads and purposefully creating a series of engineering design-based challenges around the investigation. The…
Flanagan, C.A.; Steiner, D.; Smith, G.E.
The US Magnetic Fusion Engineering Act of 1980 calls for the operation of a Fusion Engineering Device (FED) by 1990. It is the intent of the Act that the FED, in combination with other testing facilities, will establish the engineering feasibility of magnetic fusion energy. During 1981, the Fusion Engineering Design Center (FEDC), under the guidance of a Technical Management Board (TMB), developed a baseline design for the FED. This design is summarized herein.
Flanagan, C.A.; Steiner, D.; Smith, G.E.
The US Magnetic Fusion Engineering Act of 1980 calls for the operation of a Fusion Engineering Device (FED) by 1990. It is the intent of the Act that the FED, in combination with other testing facilities, will establish the engineering feasibility of magnetic fusion energy. During 1981, the Fusion Engineering Design Center (FEDC), under the guidance of a Technical Management Board (TMB), developed a baseline design for the FED. This design is summarized herein
Flanagan, C.A.; Steiner, D.; Smith, G.E.
The US Magnetic Fusion Engineering Act of 1980 calls for the operation of a Fusion Engineering Device (FED) by 1990. It is the intent of the Act that the FED, in combination with other testing facilities, will establish the engineering feasibility of magnetic fusion energy. During 1981, the Fusion Engineering Design Center (FEDC), under the guidance of a Technical Management Board (TMB), developed a baseline design for the FED. This design is summarized herein
Jiang, Li; Lee, Donghoon; Yilmaz, Hakan; Stefanopoulou, Anna
Methods and systems for optimizing a performance of a vehicle engine are provided. The method includes determining an initial value for a first engine control parameter based on one or more detected operating conditions of the vehicle engine, determining a value of an engine performance variable, and artificially perturbing the determined value of the engine performance variable. The initial value for the first engine control parameter is then adjusted based on the perturbed engine performance variable causing the engine performance variable to approach a target engine performance variable. Operation of the vehicle engine is controlled based on the adjusted initial value for the first engine control parameter. These acts are repeated until the engine performance variable approaches the target engine performance variable.
This book presents a selection of advanced case studies that cover a substantial range of issues and real-world challenges and applications in space engineering. Vital mathematical modeling, optimization methodologies and numerical solution aspects of each application case study are presented in detail, with discussions of a range of advanced model development and solution techniques and tools. Space engineering challenges are discussed in the following contexts: •Advanced Space Vehicle Design •Computation of Optimal Low Thrust Transfers •Indirect Optimization of Spacecraft Trajectories •Resource-Constrained Scheduling, •Packing Problems in Space •Design of Complex Interplanetary Trajectories •Satellite Constellation Image Acquisition •Re-entry Test Vehicle Configuration Selection •Collision Risk Assessment on Perturbed Orbits •Optimal Robust Design of Hybrid Rocket Engines •Nonlinear Regression Analysis in Space Engineering< •Regression-Based Sensitivity Analysis and Robust Design ...
Stevens, Susan A. R.; Wilkins, Linda C.
Engineering is the science, art, and business of designing and getting things done; engineers are required to make things happen through interpersonal relationships. At Monash University (Australia), a new course, Management for Engineers, was set up in 1990 to encourage a more holistic approach to the process of engineering. The course included…
Documentation of ideas and the engineering design process is a critical, daily component of a professional engineer's job. While patent protection is often cited as the primary rationale for documentation, it can also benefit the engineer, the team, company, and stakeholders through creating a more rigorously designed and purposeful solution.…
Crismond, David; Gellert, Laura; Cain, Ryan; Wright, Shequana
The "Next Generation Science Standards" (NGSS) (Achieve Inc. 2013) asks teachers to give engineering design equal standing with scientific inquiry in their science lessons. This article asks the following questions: What do engineering design practices look like, and how do you assess them? How similar and different is engineering design…
Chen, Wei; Wassenaar, Henk Jan
Building upon the fundamental principles of decision theory, Decision-Based Design: Integrating Consumer Preferences into Engineering Design presents an analytical approach to enterprise-driven Decision-Based Design (DBD) as a rigorous framework for decision making in engineering design. Once the related fundamentals of decision theory, economic analysis, and econometrics modelling are established, the remaining chapters describe the entire process, the associated analytical techniques, and the design case studies for integrating consumer preference modeling into the enterprise-driven DBD framework. Methods for identifying key attributes, optimal design of human appraisal experiments, data collection, data analysis, and demand model estimation are presented and illustrated using engineering design case studies. The scope of the chapters also provides: •A rigorous framework of integrating the interests from both producer and consumers in engineering design, •Analytical techniques of consumer choice model...
This textbook covers the fundamentals of optimization, including linear, mixed-integer linear, nonlinear, and dynamic optimization techniques, with a clear engineering focus. It carefully describes classical optimization models and algorithms using an engineering problem-solving perspective, and emphasizes modeling issues using many real-world examples related to a variety of application areas. Providing an appropriate blend of practical applications and optimization theory makes the text useful to both practitioners and students, and gives the reader a good sense of the power of optimization and the potential difficulties in applying optimization to modeling real-world systems. The book is intended for undergraduate and graduate-level teaching in industrial engineering and other engineering specialties. It is also of use to industry practitioners, due to the inclusion of real-world applications, opening the door to advanced courses on both modeling and algorithm development within the industrial engineering ...
Sandal, Kasper; Verbart, Alexander; Stolpe, Mathias
Structural optimization can explore a large design space (400 jackets) in a short time (2 hours), and thus lead to better conceptual jacket designs.......Structural optimization can explore a large design space (400 jackets) in a short time (2 hours), and thus lead to better conceptual jacket designs....
This book gives design of molded plastics, design of press product, design of die casting products, the application of communication terminal design, application and design of machine elements(screw, spring, bearing, gear, retaining ridge, drawing standards, KS and JIS material marks list), 3D CAD, concurrent engineering of product design, creative concept design.
Zhu, Guoming [Michigan State Univ., East Lansing, MI (United States). Mechanical Engineering; Schock, Harold [Michigan State Univ., East Lansing, MI (United States). Mechanical Engineering; Yang, Xiaojian [Michigan State Univ., East Lansing, MI (United States). Mechanical Engineering; Huisjen, Andrew [Michigan State Univ., East Lansing, MI (United States). Mechanical Engineering; Stuecken, Tom [Michigan State Univ., East Lansing, MI (United States). Mechanical Engineering; Moran, Kevin [Michigan State Univ., East Lansing, MI (United States). Mechanical Engineering; Zhen, Ren [Michigan State Univ., East Lansing, MI (United States). Mechanical Engineering; Zhang, Shupeng [Michigan State Univ., East Lansing, MI (United States). Mechanical Engineering; Opra, John [Chrysler Corporation, Auburn Hill, MI (United States); Reese, Ron [Chrysler Corporation, Auburn Hill, MI (United States)
The central objective of the proposed work is to demonstrate an HCCI (homogeneous charge compression ignition) capable SI (spark ignited) engine that is capable of fast and smooth mode transition between SI and HCCI combustion modes. The model-based control technique was used to develop and validate the proposed control strategy for the fast and smooth combustion mode transition based upon the developed control-oriented engine; and an HCCI capable SI engine was designed and constructed using production ready two-step valve-train with electrical variable valve timing actuating system. Finally, smooth combustion mode transition was demonstrated on a metal engine within eight engine cycles. The Chrysler turbocharged 2.0L I4 direct injection engine was selected as the base engine for the project and the engine was modified to fit the two-step valve with electrical variable valve timing actuating system. To develop the model-based control strategy for stable HCCI combustion and smooth combustion mode transition between SI and HCCI combustion, a control-oriented real-time engine model was developed and implemented into the MSU HIL (hardware-in-the-loop) simulation environment. The developed model was used to study the engine actuating system requirement for the smooth and fast combustion mode transition and to develop the proposed mode transition control strategy. Finally, a single cylinder optical engine was designed and fabricated for studying the HCCI combustion characteristics. Optical engine combustion tests were conducted in both SI and HCCI combustion modes and the test results were used to calibrate the developed control-oriented engine model. Intensive GT-Power simulations were conducted to determine the optimal valve lift (high and low) and the cam phasing range. Delphi was selected to be the supplier for the two-step valve-train and Denso to be the electrical variable valve timing system supplier. A test bench was constructed to develop control strategies for
van de Poel, I.R.; van der Poel, Ibo; Verbeek, Peter P.C.C.
Engineering ethics and science and technology studies (STS) have until now developed as separate enterprises. The authors argue that they can learn a lot from each other. STS insights can help make engineering ethics open the black box of technology and help discern ethical issues in engineering
Wieringa, Roelf J.; Heerkens, Johannes M.G.
Engineering sciences study different topics than natural sciences, and utility is an essential factor in choosing engineering research problems. But despite these differences, research methods for the engineering sciences are no different than research methods for any other kind of science. At most
Full Text Available We exploit slow light (high ng modes in planar photonic crystals in order to design a compact cavity, which provides an attractive path towards the miniaturization of near-infrared integrated fast pulsed lasers. By applying dispersion engineering techniques, we can design structures with a low dispersion, as needed by mode-locking operation. Our basic InP SiO2 heterostructure is robust and well suited to integrated laser applications. We show that an optimized 30 μm long cavity design yields 9 frequency-equidistant modes with a FSR of 178 GHz within a 11.5 nm bandwidth, which could potentially sustain the generation of optical pulses shorter than 700 fs. In addition, the numerically calculated quality factors of these modes are all above 10,000, making them suitable for reaching laser operation. Thanks to the use of a high group index (28, this cavity design is almost one order of magnitude shorter than standard rib-waveguide based mode-locked lasers. The use of slow light modes in planar photonic crystal based cavities thus relaxes the usual constraints that tightly link the device size and the quality (peak power, repetition rate of the pulsed laser signal.
Kemiche, Malik; Lhuillier, Jérémy; Callard, Ségolène; Monat, Christelle
We exploit slow light (high ng) modes in planar photonic crystals in order to design a compact cavity, which provides an attractive path towards the miniaturization of near-infrared integrated fast pulsed lasers. By applying dispersion engineering techniques, we can design structures with a low dispersion, as needed by mode-locking operation. Our basic InP SiO2 heterostructure is robust and well suited to integrated laser applications. We show that an optimized 30 μm long cavity design yields 9 frequency-equidistant modes with a FSR of 178 GHz within a 11.5 nm bandwidth, which could potentially sustain the generation of optical pulses shorter than 700 fs. In addition, the numerically calculated quality factors of these modes are all above 10,000, making them suitable for reaching laser operation. Thanks to the use of a high group index (28), this cavity design is almost one order of magnitude shorter than standard rib-waveguide based mode-locked lasers. The use of slow light modes in planar photonic crystal based cavities thus relaxes the usual constraints that tightly link the device size and the quality (peak power, repetition rate) of the pulsed laser signal.
Full Text Available Euro 6 norms emphasize on reduction of emissions from the engines. New injection methods are being adopted for homogenous mixture formation in diesel engines. During steady state conditions homogenous combustion gave noise levels in lower frequencies. In this work noise produced in a 440 cc diesel engine has been investigated. The engine was run under various operating conditions varying various injection parameters.
Donoghue, J. F.; Burghart, J. H.
The use of optimization methods as an effective design tool in the design of hybrid vehicle propulsion systems is demonstrated. Optimization techniques were used to select values for three design parameters (battery weight, heat engine power rating and power split between the two on-board energy sources) such that various measures of vehicle performance (acquisition cost, life cycle cost and petroleum consumption) were optimized. The apporach produced designs which were often significant improvements over hybrid designs already reported on in the literature. The principal conclusions are as follows. First, it was found that the strategy used to split the required power between the two on-board energy sources can have a significant effect on life cycle cost and petroleum consumption. Second, the optimization program should be constructed so that performance measures and design variables can be easily changed. Third, the vehicle simulation program has a significant effect on the computer run time of the overall optimization program; run time can be significantly reduced by proper design of the types of trips the vehicle takes in a one year period. Fourth, care must be taken in designing the cost and constraint expressions which are used in the optimization so that they are relatively smooth functions of the design variables. Fifth, proper handling of constraints on battery weight and heat engine rating, variables which must be large enough to meet power demands, is particularly important for the success of an optimization study. Finally, the principal conclusion is that optimization methods provide a practical tool for carrying out the design of a hybrid vehicle propulsion system.
Full Text Available This paper describes an investigation of the external search engine optimization (SEO action planning tool, dedicated to automatically extract a small set of most important keywords for each month during whole year period. The keywords in the set are extracted accordingly to external measured parameters, such as average number of searches during the year and for every month individually. Additionally the position of the optimized web site for each keyword is taken into account. The generated optimization plan is similar to the optimization plans prepared manually by the SEO professionals and can be successfully used as a support tool for web site search engine optimization.
Connolly, Joseph W.; Csank, Jeffrey T.; Chicatelli, Amy
This paper covers the application of a model-based engine control (MBEC) methodology featuring a self tuning on-board model for an aircraft turbofan engine simulation. The nonlinear engine model is capable of modeling realistic engine performance, allowing for a verification of the advanced control methodology over a wide range of operating points and life cycle conditions. The on-board model is a piece-wise linear model derived from the nonlinear engine model and updated using an optimal tuner Kalman Filter estimation routine, which enables the on-board model to self-tune to account for engine performance variations. MBEC is used here to show how advanced control architectures can improve efficiency during the design phase of a turbofan engine by reducing conservative operability margins. The operability margins that can be reduced, such as stall margin, can expand the engine design space and offer potential for efficiency improvements. Application of MBEC architecture to a nonlinear engine simulation is shown to reduce the thrust specific fuel consumption by approximately 1% over the baseline design, while maintaining safe operation of the engine across the flight envelope.
Killingsworth, Nicholas J.
Homogeneous charge compression ignition (HCCI) engines have the benefit of high efficiency with low emissions of nitrogen oxides and particulates. These benefits are due to the autoignition process of the dilute mixture of fuel and air during compression. However, because there is no direct ignition trigger, control of ignition is inherently more difficult than in standard internal combustion engines. This difficulty necessitates that a feedback controller be used to keep the engine at a desi...
The vehicle by which the fusion program would move into the engineering testing phase of fusion power development is designated the Engineering Test Facility (ETF). The ETF would provide a test bed for reactor components in the fusion environment. In order to initiate preliminary planning for the ETF decision, the Office of Fusion Energy established the ETF Design Center activity to prepare the design of the ETF. This section describes the status of this design
Dunne, Suzanne; Cummins, Niamh Maria; Hannigan, Ailish; Shannon, Bill; Dunne, Colum; Cullen, Walter
The Internet is a widely used source of information for patients searching for medical/health care information. While many studies have assessed existing medical/health care information on the Internet, relatively few have examined methods for design and delivery of such websites, particularly those aimed at the general public. This study describes a method of evaluating material for new medical/health care websites, or for assessing those already in existence, which is correlated with higher rankings on Google's Search Engine Results Pages (SERPs). A website quality assessment (WQA) tool was developed using criteria related to the quality of the information to be contained in the website in addition to an assessment of the readability of the text. This was retrospectively applied to assess existing websites that provide information about generic medicines. The reproducibility of the WQA tool and its predictive validity were assessed in this study. The WQA tool demonstrated very high reproducibility (intraclass correlation coefficient=0.95) between 2 independent users. A moderate to strong correlation was found between WQA scores and rankings on Google SERPs. Analogous correlations were seen between rankings and readability of websites as determined by Flesch Reading Ease and Flesch-Kincaid Grade Level scores. The use of the WQA tool developed in this study is recommended as part of the design phase of a medical or health care information provision website, along with assessment of readability of the material to be used. This may ensure that the website performs better on Google searches. The tool can also be used retrospectively to make improvements to existing websites, thus, potentially enabling better Google search result positions without incurring the costs associated with Search Engine Optimization (SEO) professionals or paid promotion.
Full Text Available A special type of the gas engine with external combustion is called Stirling engine. The mechanism has two pistons with two volumes inside. The pistons are connected together through cooler, regenerator and warmer. The engine effectivity depends on the piston movement behaviour. The usual sinusoidal time curve leads to low effectiveness. The quick movement from lower to upper position with a certain delay in both top and bottom dead centres is more effective. The paper deals with three types of mechanisms, analyzing the piston movement, and their behavior. Special emphasize is taken to the piston movement regime.
Holst, Malene Kirstine; Kirkegaard, Poul Henning; Christoffersen, L.D.
Present paper presents a parametric performancebased design model for optimizing hospital design. The design model operates with geometric input parameters defining the functional requirements of the hospital and input parameters in terms of performance objectives defining the design requirements...... and preferences of the hospital with respect to performances. The design model takes point of departure in the hospital functionalities as a set of defined parameters and rules describing the design requirements and preferences....
Visser, H.J.; Keyrouz, S.; Smolders, A.B.
Design steps are outlined for maximizing the RF-to-dc power conversion efficiency (PCE) of a rectenna. It turns out that at a frequency of 868 MHz, a high-ohmic loaded rectifier will lead to a highly sensitive and power conversion efficient rectenna. It is demonstrated that a rectenna thus designed,
T. Velsker; M. Eerme; J. Majak; M. Pohlak; K. Karjust
Purpose: Purpose of this paper is investigation of optimization strategies eligible for solving complex engineering design problems. An aim is to develop numerical algorithms for solving optimal design problems which may contain real and integer variables, a number of local extremes, linear- and non-linear constraints and multiple optimality criteria.Design/methodology/approach: The methodology proposed for solving optimal design problems is based on integrated use of meta-modeling techniques...
Fernández-Castané, Alfred; Fehér, Tamás; Carbonell, Pablo; Pauthenier, Cyrille; Faulon, Jean-Loup
The development and application of biotechnology-based strategies has had a great socio-economical impact and is likely to play a crucial role in the foundation of more sustainable and efficient industrial processes. Within biotechnology, metabolic engineering aims at the directed improvement of cellular properties, often with the goal of synthesizing a target chemical compound. The use of computer-aided design (CAD) tools, along with the continuously emerging advanced genetic engineering techniques have allowed metabolic engineering to broaden and streamline the process of heterologous compound-production. In this work, we review the CAD tools available for metabolic engineering with an emphasis, on retrosynthesis methodologies. Recent advances in genetic engineering strategies for pathway implementation and optimization are also reviewed as well as a range of bionalytical tools to validate in silico predictions. A case study applying retrosynthesis is presented as an experimental verification of the output from Retropath, the first complete automated computational pipeline applicable to metabolic engineering. Applying this CAD pipeline, together with genetic reassembly and optimization of culture conditions led to improved production of the plant flavonoid pinocembrin. Coupling CAD tools with advanced genetic engineering strategies and bioprocess optimization is crucial for enhanced product yields and will be of great value for the development of non-natural products through sustainable biotechnological processes. Copyright © 2014 Elsevier B.V. All rights reserved.
Puffelen, van E.A.M.
Universities have to deal with larger differences of engagement between students and more need for outcomes-based teaching and learning that allows for differences in learning styles. In addition for engineers, the rapidly changing world brings the need to engage students in diverse learning.
Wheeler, Lindsay B.; Whitworth, Brooke A.; Gonczi, Amanda L.
The number of students majoring in science, technology, engineering, and math (STEM) is declining due in part to a lack of student interest (Fairweather 2008; NRC 2012; PCAST 2010). One reason may be the difference between how science is done in school and how it is done in the field (Osborne, Simon, and Collins 2003). An interdisciplinary…
ENGINEERING TOOLS USING MODERN GROUND ARCHITECTURES by Ryan P. McArdle December 2017 Thesis Advisor: Marc Peters Co-Advisor: I.M. Ross...Master’s thesis 4. TITLE AND SUBTITLE OPTIMIZING ENGINEERING TOOLS USING MODERN GROUND ARCHITECTURES 5. FUNDING NUMBERS 6. AUTHOR(S) Ryan P. McArdle 7... engineering tools. First, the effectiveness of MathWorks’ Parallel Computing Toolkit is assessed when performing somewhat basic computations in
This report is an evaluation of engineering frameworks that could be used to augment, supplement, or replace the existing FIDO 3.5 (Framework for Interdisciplinary Design and Optimization Version 3.5) framework. The report begins with the motivation for this effort, followed by a description of an "ideal" multidisciplinary design and optimization (MDO) framework. The discussion then turns to how each candidate framework stacks up against this ideal. This report ends with recommendations as to the "best" frameworks that should be down-selected for detailed review.
Li, Victor O. K.; Yuen, Joseph H.; Hou, Ting-Chao; Lam, Yuen Fung
Candidate network designs tested for acceptability and cost. Optimal Network Topology Design computer program developed as part of study on topology design and analysis of performance of Space Station Information System (SSIS) network. Uses efficient algorithm to generate candidate network designs consisting of subsets of set of all network components, in increasing order of total costs and checks each design to see whether it forms acceptable network. Technique gives true cost-optimal network and particularly useful when network has many constraints and not too many components. Program written in PASCAL.
Barthelemy, Jean-Francois M.
Some engineering applications of heuristic multilevel optimization methods are presented and the discussion focuses on the dependency matrix that indicates the relationship between problem functions and variables. Coordination of the subproblem optimizations is shown to be typically achieved through the use of exact or approximate sensitivity analysis. Areas for further development are identified.
Harding, D.C.; Witkowski, W.R.
The design of structures and engineering systems has always been an iterative process whose complexity was dependent upon the boundary conditions, constraints and available analytical tools. Transportation packaging design is no exception with structural, thermal and radiation shielding constraints based on regulatory hypothetical accident conditions. Transportation packaging design is often accomplished by a group of specialists, each designing a single component based on one or more simple criteria, pooling results with the group, evaluating the open-quotes pooledclose quotes design, and then reiterating the entire process until a satisfactory design is reached. The manual iterative methods used by the designer/analyst can be summarized in the following steps: design the part, analyze the part, interpret the analysis results, modify the part, and re-analyze the part. The inefficiency of this design practice and the frequently conservative result suggests the need for a more structured design methodology, which can simultaneously consider all of the design constraints. Numerical optimization is a structured design methodology whose maturity in development has allowed it to become a primary design tool in many industries. The purpose of this overview is twofold: first, to outline the theory and basic elements of numerical optimization; and second, to show how numerical optimization can be applied to the transportation packaging industry and used to increase efficiency and safety of radioactive and hazardous material transportation packages. A more extensive review of numerical optimization and its applications to radioactive material transportation package design was performed previously by the authors (Witkowski and Harding 1992). A proof-of-concept Type B package design is also presented as a simplified example of potential improvements achievable using numerical optimization in the design process
Yan Changqi; Li Guijing; Wang Jianjun
Complex algorithm (CA) has got popular application to the region of nuclear engineering. In connection with the specific features of the application of traditional complex algorithm (TCA) to the optimization design in engineering structures, an improved method, colony complex algorithm (CCA), was developed based on the optimal combination of many complexes, in which the disadvantages of TCA were overcame. The optimized results of benchmark function show that CCA has better optimizing performance than TCA. CCA was applied to the high-pressure heater optimization design, and the optimization effect is obvious. (authors)
This slide presentation reviews NASA's use of systems engineering for the complete life cycle of a project. Systems engineering is a methodical, disciplined approach for the design, realization, technical management, operations, and retirement of a system. Each phase of a NASA project is terminated with a Key decision point (KDP), which is supported by major reviews.
Gilmour, J. L.
The optimization of an electric vehicle layout requires a weight distribution in the range of 53/47 to 62/38 in order to assure dynamic handling characteristics comparable to current production internal combustion engine vehicles. It is possible to achieve this goal and also provide passenger and cargo space comparable to a selected current production sub-compact car either in a unique new design or by utilizing the production vehicle as a base. Necessary modification of the base vehicle can be accomplished without major modification of the structure or running gear. As long as batteries are as heavy and require as much space as they currently do, they must be divided into two packages - one at front under the hood and a second at the rear under the cargo area - in order to achieve the desired weight distribution. The weight distribution criteria requires the placement of batteries at the front of the vehicle even when the central tunnel is used for the location of some batteries. The optimum layout has a front motor and front wheel drive. This configuration provides the optimum vehicle dynamic handling characteristics and the maximum passsenger and cargo space for a given size vehicle.
Babaei, Hadi; Siddiqui, Kamran
Thermoacoustics deals with the conversion of heat energy into sound energy and vice versa. It is a new and emerging technology which has a strong potential towards the development of sustainable and renewable energy systems by utilizing waste heat or solar energy. Although simple to fabricate, the designing of thermoacoustic devices is very challenging. In the present study, a comprehensive design and optimization algorithm is developed for designing thermoacoustic devices. The unique feature of the present algorithm is its ability to design thermoacoustically-driven thermoacoustic refrigerators that can serve as sustainable refrigeration systems. In addition, new features based on the energy balance are also included to design individual thermoacoustic engines and acoustically-driven thermoacoustic refrigerators. As a case study, a thermoacoustically-driven thermoacoustic refrigerator has been designed and optimized based on the developed algorithm. The results from the algorithm are in good agreement with that obtained from the computer code DeltaE
LDRD research activities have focused on increasing the robustness and efficiency of optimization studies for computationally complex engineering problems. Engineering applications can be characterized by extreme computational expense, lack of gradient information, discrete parameters, non-converging simulations, and nonsmooth, multimodal, and discontinuous response variations. Guided by these challenges, the LDRD research activities have developed application-specific techniques, fundamental optimization algorithms, multilevel hybrid and sequential approximate optimization strategies, parallel processing approaches, and automatic differentiation and adjoint augmentation methods. This report surveys these activities and summarizes the key findings and recommendations.
Vidal, Rene Victor Valqui; Ravn, Hans V.
Many problems of design and operation of engineering systems can be formulated as optimal control problems where time has been discretisized. This is also true even if 'time' is not involved in the formulation of the problem, but rather another one-dimensional parameter. This paper gives a review...... of some well-known and new results in discrete time optimal control methods applicable to practical problem solving within engineering. Emphasis is placed on dynamic programming, the classical maximum principle and generalized versions of the maximum principle for optimal control of discrete time systems...
Dekeyser, W.; Baelmans, M.; Reiter, D.
Due to the conflicting requirements, complex physical processes and large number of design variables, divertor design for next step fusion reactors is a challenging problem, often relying on large numbers of computationally expensive numerical simulations. In this paper, we attempt to partially automate the design process by solving an appropriate shape optimization problem. Design requirements are incorporated in a cost functional which measures the performance of a certain design. By means of changes in the divertor shape, which in turn lead to changes in the plasma state, this cost functional can be minimized. Using advanced adjoint methods, optimal solutions are computed very efficiently. The approach is illustrated by designing divertor targets for optimal power load spreading, using a simplified edge plasma model (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
Maria Dragan, Johanna; Zubov, Alexandr; Sin, Gürkan
Design of Wastewater Treatment Plants (WWTPs) is a complex engineering task which requires integration of knowledge and experience from environmental biotechnology, process engineering, process synthesis and design as well as mathematical programming. A methodology has been formulated and applied...... for the systematic analysis and development of plantwide design of WWTPs using mathematical optimization and statistical methods such as sensitivity and uncertainty analyses....
Search Engines are an indispensible platform for users all over the globe to search for relevant information online. Search Engine Optimization (SEO) is the exercise of improving the position of a website in search engine rankings, for a chosen set of keywords. SEO is divided into two parts: On-Page and Off-Page SEO. In order to be successful, both the areas require equal attention. This paper aims to explain the functioning of the search engines along with the role and importance of search e...
The focus of this thesis is topology optimization of material microstructures. That is, creating new materials, with attractive properties, by combining classic materials in periodic patterns. First, large-scale topology optimization is used to design complicated three-dimensional materials......, throughout the thesis extra attention is given to obtain structures that can be manufactured. That is also the case in the final part, where a simple multiscale method for the optimization of structural damping is presented. The method can be used to obtain an optimized component with structural details...
Rasch, Dieter; Verdooren, L R; Gebhardt, Albrecht
Experimental design is often overlooked in the literature of applied and mathematical statistics: statistics is taught and understood as merely a collection of methods for analyzing data. Consequently, experimenters seldom think about optimal design, including prerequisites such as the necessary sample size needed for a precise answer for an experimental question. Providing a concise introduction to experimental design theory, Optimal Experimental Design with R: Introduces the philosophy of experimental design Provides an easy process for constructing experimental designs and calculating necessary sample size using R programs Teaches by example using a custom made R program package: OPDOE Consisting of detailed, data-rich examples, this book introduces experimenters to the philosophy of experimentation, experimental design, and data collection. It gives researchers and statisticians guidance in the construction of optimum experimental designs using R programs, including sample size calculations, hypothesis te...
HU Jie; PENG Yinghong; XIONG Guangleng
A new parameter coordination and robust optimization approach for multidisciplinary design is presented. Firstly, the constraints network model is established to support engineering change, coordination and optimization. In this model, interval boxes are adopted to describe the uncertainty of design parameters quantitatively to enhance the design robustness. Secondly, the parameter coordination method is presented to solve the constraints network model, monitor the potential conflicts due to engineering changes, and obtain the consistency solution space corresponding to the given product specifications. Finally, the robust parameter optimization model is established, and genetic arithmetic is used to obtain the robust optimization parameter. An example of bogie design is analyzed to show the scheme to be effective.
Brinkop, Axel; Laudwein, Norbert; Maasen, Rudiger
COMIX (configuration of mixing machines) is a system that assists members of the EKATO Sales Department in designing a mixing machine that fulfills the requirements of a customer. It is used to help the engineer design the requested machine and prepare an offer that's to be submitted to the customer. comix integrates more traditional software techniques with explicit knowledge representation and constraint propagation. During the process of routine design, some design decisions have to be mad...
Yin, Yong; Chen, Lingen; Wu, Feng
A quantum Stirling heat engine model is established in this paper in which imperfect regeneration and heat leakage are considered. A single particle which contained in a one-dimensional infinite potential well is studied, and the system consists of countless replicas. Each particle is confined in its own potential well, whose occupation probabilities can be expressed by the thermal equilibrium Gibbs distributions. Based on the Schrödinger equation, the expressions of power output and efficiency for the engine are obtained. Effects of imperfect regeneration and heat leakage on the optimal performance are discussed. The optimal performance region and the optimal values of important parameters of the engine cycle are obtained. The results obtained can provide some guidelines for the design of a quantum Stirling heat engine.
Pehlivanoglu, Yasin Volkan
The purpose of optimization is to obtain the best solution under certain conditions. There are numerous optimization methods because different problems need different solution methodologies; therefore, it is difficult to construct patterns. Also mathematical modeling of a natural phenomenon is almost based on differentials. Differential equations are constructed with relative increments among the factors related to yield. Therefore, the gradients of these increments are essential to search the yield space. However, the landscape of yield is not a simple one and mostly multi-modal. Another issue is differentiability. Engineering design problems are usually nonlinear and they sometimes exhibit discontinuous derivatives for the objective and constraint functions. Due to these difficulties, non-gradient-based algorithms have become more popular in recent decades. Genetic algorithms (GA) and particle swarm optimization (PSO) algorithms are popular, non-gradient based algorithms. Both are population-based search algorithms and have multiple points for initiation. A significant difference from a gradient-based method is the nature of the search methodologies. For example, randomness is essential for the search in GA or PSO. Hence, they are also called stochastic optimization methods. These algorithms are simple, robust, and have high fidelity. However, they suffer from similar defects, such as, premature convergence, less accuracy, or large computational time. The premature convergence is sometimes inevitable due to the lack of diversity. As the generations of particles or individuals in the population evolve, they may lose their diversity and become similar to each other. To overcome this issue, we studied the diversity concept in GA and PSO algorithms. Diversity is essential for a healthy search, and mutations are the basic operators to provide the necessary variety within a population. After having a close scrutiny of the diversity concept based on qualification and
Diem, H. G.
The design characteristics of the baseline engine configuration of the advanced expander cycle engine are described. Several aspects of engine optimization are considered which directly impact the design of the baseline thrust chamber. Four major areas of the power cycle optimization are emphasized: main turbine arrangement; cycle engine source; high pressure pump design; and boost pump drive.
This doctoral thesis is concerned with the experimental part of combustion optimization of a large bore gas engine. Nevertheless there was a very close co-operation with the simultaneous numeric simulation. The terms of reference were a systematic investigation of the optimization potential of the current combustion mode with the objective target to get a higher brake efficiency and lower NO x emissions. In a second part a new combustion mode for fuels containing H 2 , for fuels with very low heating value and for special fuels should be developed. The optimization contained all relevant components of the engine to achieve a stable and well suited combustion with short duration even with very lean mixture. After the optimization the engine was running stable with substantial lower NO x emissions. It was world-wide the first time when a gas medium-sized engine could reach a total electrical efficiency of more than 40 percent. Finally a combustion mode for gaseous fuels containing H 2 was developed. The engine is running now with direct ignition and with prechamber ignition. Both modes reach approximately the same efficiency and thermodynamic stability. (author)
GOOS, Peter; JONES, Bradley; SYAFITRI, Utami
In mixture experiments, the factors under study are proportions of the ingredients of a mixture. The special nature of the factors in a mixture experiment necessitates specific types of regression models, and specific types of experimental designs. Although mixture experiments usually are intended to predict the response(s) for all possible formulations of the mixture and to identify optimal proportions for each of the ingredients, little research has been done concerning their I-optimal desi...
Ahmadi, Mohammad H.; Ahmadi, Mohammad Ali; Pourfayaz, Fathollah; Bidi, Mokhtar; Hosseinzade, Hadi; Feidt, Michel
Highlights: • Based on finite speed method and direct method, the optimal performance is investigated. • The effects of major parameters on the optimal performance are investigated. • The accuracy of the results was compared with previous works. - Abstract: Popular thermodynamic analyses including finite time thermodynamic analysis was lately developed based upon external irreversibilities while internal irreversibilities such as friction, pressure drop and entropy generation were not considered. The aforementioned disadvantage reduces the reliability of the finite time thermodynamic analysis in the design of an accurate Stirling engine model. Consequently, the finite time thermodynamic analysis could not sufficiently satisfy researchers for implementing in design and optimization issues. In this study, finite speed thermodynamic analysis was employed instead of finite time thermodynamic analysis for studying Stirling heat engine. The finite speed thermodynamic analysis approach is based on the first law of thermodynamics for a closed system with finite speed and the direct method. The effects of heat source temperature, regenerating effectiveness, volumetric ratio, piston stroke as well as rotational speed are included in the analysis. Moreover, maximum output power in optimal rotational speed was calculated while pressure losses in the Stirling engine were systematically considered. The result reveals the accuracy and the reliability of the finite speed thermodynamic method in thermodynamic analysis of Stirling heat engine. The outcomes can help researchers in the design of an appropriate and efficient Stirling engine.
Civil Discipline Engineering department in Foster Wheeler Energia Oy takes care of the construction of foundation, steel frame, platforms, cladding/roofing, HVAC, elevator, hoist and central vacuum system of the boiler building. The goal of the thesis was to compile a design manual for the department to ease up the startup of the design of a new project and standardize the design. Main objective was to gather together all the existing guidelines, standards and directives regarding the des...
Kirkegaard, Poul Henning
A structural system identification experiment design method is formulated in the light of decision theory, structural reliability theory and optimization theory. The experiment design is based on a preposterior analysis, well-known from the classical decision theory. I.e. the decisions concerning...... reflecting the cost of the experiment and the value of obtained additional information. An example concerning design of an experiment for parametric identification of a single degree of freedom structural system shows the applicability of the experiment design method....... the experiment design are not based on obtained experimental data. Instead the decisions are based on the expected experimental data assumed to be obtained from the measurements, estimated based on prior information and engineering judgement. The design method provides a system identification experiment design...
Dühring, Maria Bayard; Jensen, Jakob Søndergaard; Sigmund, Ole
To bring down noise levels in human surroundings is an important issue and a method to reduce noise by means of topology optimization is presented here. The acoustic field is modeled by Helmholtz equation and the topology optimization method is based on continuous material interpolation functions...... in the density and bulk modulus. The objective function is the squared sound pressure amplitude. First, room acoustic problems are considered and it is shown that the sound level can be reduced in a certain part of the room by an optimized distribution of reflecting material in a design domain along the ceiling...
The book presents recently developed efficient metaheuristic optimization algorithms and their applications for solving various optimization problems in civil engineering. The concepts can also be used for optimizing problems in mechanical and electrical engineering.
Laursen, Esben Skov; Møller, Louise
The aim of the paper is to understand the challenges sharing the product frame between industrial designers with the engineering designers. The study is based on six case studies. The analysis showed correspondence between industrial designers and engineering designers in their understanding...... of the key elements of the context and concept. However the analysis also showed a lack of correspondence between the industrial designers and engineering designers in regards to the product framing and thereby how the different elements of the product frame is connected and interrelated....
Designing reliable, low cost, and operable space systems has become the key to future space operations. Designing high quality space systems at low cost is an economic and technological challenge to the designer. A systematic and efficient way to meet this challenge is a new method of design optimization for performance, quality, and cost, called Robust Design. Robust Design is an approach for design optimization. It consists of: making system performance insensitive to material and subsystem variation, thus allowing the use of less costly materials and components; making designs less sensitive to the variations in the operating environment, thus improving reliability and reducing operating costs; and using a new structured development process so that engineering time is used most productively. The objective in Robust Design is to select the best combination of controllable design parameters so that the system is most robust to uncontrollable noise factors. The robust design methodology uses a mathematical tool called an orthogonal array, from design of experiments theory, to study a large number of decision variables with a significantly small number of experiments. Robust design also uses a statistical measure of performance, called a signal-to-noise ratio, from electrical control theory, to evaluate the level of performance and the effect of noise factors. The purpose is to investigate the Robust Design methodology for improving quality and cost, demonstrate its application by the use of an example, and suggest its use as an integral part of space system design process.
This book presents the latest findings on mechanical and materials engineering as applied to the design of modern engineering materials and components. The contributions cover the classical fields of mechanical, civil and materials engineering, as well as bioengineering and advanced materials processing and optimization. The materials and structures discussed can be categorized into modern steels, aluminium and titanium alloys, polymers/composite materials, biological and natural materials, material hybrids and modern nano-based materials. Analytical modelling, numerical simulation, state-of-the-art design tools and advanced experimental techniques are applied to characterize the materials’ performance and to design and optimize structures in different fields of engineering applications.
Olhoff, Niels; Bendsøe, M.P.; Rasmussen, John
Concepts underlying an interactive CAD-based engineering design optimization system are developed, and methods of optimizing the topology, shape and sizing of mechanical components are presented. These methods are integrated in the system, and the method for determining the optimal topology is used...
Andreasen, Mogens Myrup; Howard, Thomas J.
Most systems and products need to be engineered during their design, based upon scientific insight into principles, mechanisms, materials and production pos-sibilities, leading to reliability, durability and value for the user. Despite the central importance and design’s crucial dependency...
Goodarzi, Ehsan; Hosseinipour, Edward Zia
This book presents the basics of linear and nonlinear optimization analysis for both single and multi-objective problems in hydrosystem engineering. The book includes several examples with various levels of complexity in different fields of water resources engineering. All examples are solved step by step to assist the reader and to make it easier to understand the concepts. In addition, the latest tools and methods are presented to help students, researchers, engineers and water managers to properly conceptualize and formulate resource allocation problems, and to deal with the complexity of constraints in water demand and available supplies in an appropriate way.
Song, Zheng; Howard, Thomas J.; Achiche, Sofiane
a methodology based on Kansei Engineering, which has done significant work in product and industrial design but not quite been adopted in the IT field, in order to discover implicit emotional needs of users toward web site and transform them into design details. Survey and interview techniques and statistical...... methods were performed in this paper. A prototype web site was produced based on the Kansei results integrated with technical expertise and practical considerations. The results showed that the Kansei Engineering methodology in this paper played a significant role in web site design in terms of satisfying......Capturing users’ needs is critical in web site design. However, a lot of attention has been paid to enhance the functionality and usability, whereas much less consideration has been given to satisfy the emotional needs of users, which is also important to a successful design. This paper explores...
90 standards is developed for the design optimization of framed structures - continuous beams, plane and space trusses and rigid frames, grids and composite truss-rigid frames. The package will enable the structural engineer to effectively and ...
Zheng Jing; Yan Changqi; Wang Jianjun
The condenser is an important component in nuclear power plants, which dimension and weight will effect the economical performance and the arrangement of the nuclear power plants. In this paper, the calculation model is established according to the design experience. The corresponding codes are also developed, and the sensitivity of design parameters which influence the condenser weight is analyzed. The present design optimization of the condenser, taking the weight minimization as the objective, is carried out with the self-developed complex-genetic algorithm. The results show that the reference condenser design is far from the best scheme, and also verify the feasibility of the complex-genetic algorithm. (authors)
Design optimization relies heavily on time-consuming simulations, especially when using gradient-free optimization methods. These methods require a large number of simulations in order to get a remarkable improvement over reference designs, which are nowadays based on the accumulated engineering
Patel, Vivek; Savsani, Vimal; Mudgal, Anurag
This paper presents a rigorous investigation of many-objective (four-objective) thermodynamic optimization of a Stirling heat engine. Many-objective optimization problem is formed by considering maximization of thermal efficiency, power output, ecological function and exergy efficiency. Multi-objective heat transfer search (MOHTS) algorithm is proposed and applied to obtain a set of Pareto-optimal points. Many objective optimization results form a solution in a four dimensional hyper objective space and for visualization it is represented on a two dimension objective space. Thus, results of four-objective optimization are represented by six Pareto fronts in two dimension objective space. These six Pareto fronts are compared with their corresponding two-objective Pareto fronts. Quantitative assessment of the obtained Pareto solutions is reported in terms of spread and the spacing measures. Different decision making approaches such as LINMAP, TOPSIS and fuzzy are used to select a final optimal solution from Pareto optimal set of many-objective optimization. Finally, to reveal the level of conflict between these objectives, distribution of each decision variable in their allowable range is also shown in two dimensional objective spaces. - Highlights: • Many-objective (i.e. four objective) optimization of Stirling engine is investigated. • MOHTS algorithm is introduced and applied to obtain a set of Pareto points. • Comparative results of many-objective and multi-objectives are presented. • Relationship of design variables in many-objective optimization are obtained. • Optimum solution is selected by using decision making approaches.
Cote, Jean; Pelletier, Michel
For many years, industrial robots have been used to execute specific repetitive tasks. In those cases, the optimal configuration and location of the manipulator only has to be found once. The optimal configuration or position where often found empirically according to the tasks to be performed. In telemanipulation, the nature of the tasks to be executed is much wider and can be very demanding in terms of dexterity and workspace. The position/orientation of the robot's base could be required to move during the execution of a task. At present, the choice of the initial position of the teleoperator is usually found empirically which can be sufficient in the case of an easy or repetitive task. In the converse situation, the amount of time wasted to move the teleoperator support platform has to be taken into account during the execution of the task. Automatic optimization of the position/orientation of the platform or a better designed robot configuration could minimize these movements and save time. This paper will present two algorithms. The first algorithm is used to optimize the position and orientation of a given manipulator (or manipulators) with respect to the environment on which a task has to be executed. The second algorithm is used to optimize the position or the kinematic configuration of a robot. For this purpose, the tasks to be executed are digitized using a position/orientation measurement system and a compact representation based on special octrees. Given a digitized task, the optimal position or Denavit-Hartenberg configuration of the manipulator can be obtained numerically. Constraints on the robot design can also be taken into account. A graphical interface has been designed to facilitate the use of the two optimization algorithms.
McCormick, Robert L.
The development of advanced engines has significant potential advantages in reduced aftertreatment costs for air pollutant emission control, and just as importantly for efficiency improvements and associated greenhouse gas emission reductions. There are significant opportunities to leverage fuel properties to create more optimal engine designs for both advanced spark-ignition and compression-ignition combustion strategies. The fact that biofuel blendstocks offer a potentially low-carbon approach to fuel production, leads to the idea of optimizing the entire fuel production-utilization value chain as a system from the standpoint of life cycle greenhouse gas emissions. This is a difficult challenge that has yet to be realized. This presentation will discuss the relationship between chemical structure and critical fuel properties for more efficient combustion, survey the properties of a range of biofuels that may be produced in the future, and describe the ongoing challenges of fuel-engine co-optimization.
Sheng, Hanlin; Zhang, Tianhong
In view of the necessity of highly precise and reliable thrust estimator to achieve direct thrust control of aircraft engine, based on support vector regression (SVR), as well as least square support vector machine (LSSVM) and a new optimization algorithm - gravitational search algorithm (GSA), by performing integrated modelling and parameter optimization, a GSA-LSSVM-based thrust estimator design solution is proposed. The results show that compared to particle swarm optimization (PSO) algorithm, GSA can find unknown optimization parameter better and enables the model developed with better prediction and generalization ability. The model can better predict aircraft engine thrust and thus fulfills the need of direct thrust control of aircraft engine.
Full Text Available Underground reinforced concrete bifurcation pipe is an important part of conveyance structure. During construction, the workload of excavation and concrete pouring can be significantly decreased according to optimized pipe structure, and the engineering quality can be improved. This paper presents an optimization mathematical model of underground reinforced concrete bifurcation pipe structure according to real working status of several common pipe structures from real cases. Then, an optimization design system was developed based on Particle Swarm Optimization algorithm. Furthermore, take the bifurcation pipe of one hydropower station as an example: optimization analysis was conducted, and accuracy and stability of the optimization design system were verified successfully.
Jiang, Li; Lee, Donghoon; Yilmaz, Hakan; Stefanopoulou, Anna
Methods and systems for engine control optimization are provided. One or more operating conditions of a vehicle engine are detected. A value for each of a plurality of engine control parameters is determined based on the detected one or more operating conditions of the vehicle engine. A range of the most commonly detected operating conditions of the vehicle engine is identified and a region of optimization is defined based on the range of the most commonly detected operating conditions of the vehicle engine. The engine control optimization routine is initiated when the one or more operating conditions of the vehicle engine are within the defined region of optimization.
Peña, Francisco J; Ferré, Michel; Orellana, P A; Rojas, René G; Vargas, P
We present an optimal analysis for a quantum mechanical engine working between two energy baths within the framework of relativistic quantum mechanics, adopting a first-order correction. This quantum mechanical engine, with the direct energy leakage between the energy baths, consists of two adiabatic and two isoenergetic processes and uses a three-level system of two noninteracting fermions as its working substance. Assuming that the potential wall moves at a finite speed, we derive the expression of power output and, in particular, reproduce the expression for the efficiency at maximum power.
Parallel Kinematics- Type, Kinematics, and Optimal Design presents the results of 15 year's research on parallel mechanisms and parallel kinematics machines. This book covers the systematic classification of parallel mechanisms (PMs) as well as providing a large number of mechanical architectures of PMs available for use in practical applications. It focuses on the kinematic design of parallel robots. One successful application of parallel mechanisms in the field of machine tools, which is also called parallel kinematics machines, has been the emerging trend in advanced machine tools. The book describes not only the main aspects and important topics in parallel kinematics, but also references novel concepts and approaches, i.e. type synthesis based on evolution, performance evaluation and optimization based on screw theory, singularity model taking into account motion and force transmissibility, and others. This book is intended for researchers, scientists, engineers and postgraduates or above with interes...
Song, Ting; Becker, Kurt; Gero, John; DeBerard, Scott; DeBerard, Oenardi; Reeve, Edward
The authors investigated the differences in using problem decomposition and problem recomposition between dyads of engineering experts, engineering seniors, and engineering freshmen. Participants worked in dyads to complete an engineering design challenge within 1 hour. The entire design process was video and audio recorded. After the design…
Full Text Available In the framework of the European research project LEMCOTEC, a section was devoted to the further optimization of the recuperation system of the Intercooled Recuperated Aero engine (IRA engine concept, of MTU Aero Engines AG. This concept is based on an advanced thermodynamic cycle combining both intercooling and recuperation. The present work is focused only on the recuperation process. This is carried out through a system of heat exchangers mounted inside the hot-gas exhaust nozzle, providing fuel economy and reduced pollutant emissions. The optimization of the recuperation system was performed using computational fluid dynamics (CFD computations, experimental measurements and thermodynamic cycle analysis for a wide range of engine operating conditions. A customized numerical tool was developed based on an advanced porosity model approach. The heat exchangers were modeled as porous media of predefined heat transfer and pressure loss behaviour and could also incorporate major and critical heat exchanger design decisions in the CFD computations. The optimization resulted in two completely new innovative heat exchanger concepts, named as CORN (COnical Recuperative Nozzle and STARTREC (STraight AnnulaR Thermal RECuperator, which provided significant benefits in terms of fuel consumption, pollutants emission and weight reduction compared to more conventional heat exchanger designs, thus proving that further optimization potential for this technology exists.
The current preliminary design tools lack the product performance, quality and cost prediction fidelity required to design Six Sigma products. They are also frequently incompatible with the tools used in detailed design, leading to a great deal of rework and lost or discarded data in the transition from preliminary to detailed design. Thus, enhanced preliminary design tools are needed in order to produce adequate financial returns to the business. To achieve this goal, GEAE has focused on building the preliminary design system around the same geometric 3D solid model that will be used in detailed design. With this approach, the preliminary designer will no longer convert a flowpath sketch into an engine cross section but rather, automatically create 3D solid geometry for structural integrity, life, weight, cost, complexity, producibility, and maintainability assessments. Likewise, both the preliminary design and the detailed design can benefit from the use of the same preliminary part sizing routines. The design analysis tools will also be integrated with the 3D solid model to eliminate manual transfer of data between programs. GEAE has aggressively pursued the computerized control of engineering knowledge for many years. Through its study and validation of 3D CAD programs and processes, GEAE concluded that total system control was not feasible at that time. Prior CAD tools focused exclusively on detail part geometry and Knowledge Based Engineering systems concentrated on rules input and data output. A system was needed to bridge the gap between the two to capture the total system. With the introduction of WAVE Engineering from UGS, the possibilities of an engineering system control device began to formulate. GEAE decided to investigate the new WAVE functionality to accomplish this task. NASA joined GEAE in funding this validation project through Task Order No. 1. With the validation project complete, the second phase under Task Order No. 2 was established to
Ingvarsson, Pall Thor; Yang, Mingshi; Mulvad, Helle; Nielsen, Hanne Mørck; Rantanen, Jukka; Foged, Camilla
The purpose of this study was to identify and optimize spray drying parameters of importance for the design of an inhalable powder formulation of a cationic liposomal adjuvant composed of dimethyldioctadecylammonium (DDA) bromide and trehalose-6,6'-dibehenate (TDB). A quality by design (QbD) approach was applied to identify and link critical process parameters (CPPs) of the spray drying process to critical quality attributes (CQAs) using risk assessment and design of experiments (DoE), followed by identification of an optimal operating space (OOS). A central composite face-centered design was carried out followed by multiple linear regression analysis. Four CQAs were identified; the mass median aerodynamic diameter (MMAD), the liposome stability (size) during processing, the moisture content and the yield. Five CPPs (drying airflow, feed flow rate, feedstock concentration, atomizing airflow and outlet temperature) were identified and tested in a systematic way. The MMAD and the yield were successfully modeled. For the liposome size stability, the ratio between the size after and before spray drying was modeled successfully. The model for the residual moisture content was poor, although, the moisture content was below 3% in the entire design space. Finally, the OOS was drafted from the constructed models for the spray drying of trehalose stabilized DDA/TDB liposomes. The QbD approach for the spray drying process should include a careful consideration of the quality target product profile. This approach implementing risk assessment and DoE was successfully applied to optimize the spray drying of an inhalable DDA/TDB liposomal adjuvant designed for pulmonary vaccination.
Aerodynamic design, like many other engineering applications, is increasingly relying on computational power. The growing need for multi-disciplinarity and high fidelity in design optimization for industrial applications requires a huge number of repeated simulations in order to find an optimal design candidate. The main drawback is that each simulation can be computationally expensive – this becomes an even bigger issue when used within parametric studies, automated search or optimization loops, which typically may require thousands of analysis evaluations. The core issue of a design-optimization problem is the search process involved. However, when facing complex problems, the high-dimensionality of the design space and the high-multi-modality of the target functions cannot be tackled with standard techniques. In recent years, global optimization using meta-models has been widely applied to design exploration in order to rapidly investigate the design space and find sub-optimal solutions. Indeed, surrogat...
Shen, Stewart N. T.; Chew, Meng-Sang; Issa, Ghassan F.
Artificial intelligence is becoming an increasingly important subject of study for computer scientists, engineering designers, as well as professionals in other fields. Even though AI technology is a relatively new discipline, many of its concepts have already found practical applications. Expert systems, in particular, have made significant contributions to technologies in such fields as business, medicine, engineering design, chemistry, and particle physics. This paper describes an expert system developed to aid the mechanical designer with the preliminary design of variable-stroke internal-combustion engines. The expert system accomplished its task by generating and evaluating a large number of design alternatives represented in the form of graphs. Through the application of structural and design rules directly to the graphs, optimal and near optimal preliminary design configurations of engines are deduced.
Bekdaş, Gebrail; Nigdeli, Sinan
This timely book deals with a current topic, i.e. the applications of metaheuristic algorithms, with a primary focus on optimization problems in civil engineering. The first chapter offers a concise overview of different kinds of metaheuristic algorithms, explaining their advantages in solving complex engineering problems that cannot be effectively tackled by traditional methods, and citing the most important works for further reading. The remaining chapters report on advanced studies on the applications of certain metaheuristic algorithms to specific engineering problems. Genetic algorithm, bat algorithm, cuckoo search, harmony search and simulated annealing are just some of the methods presented and discussed step by step in real-application contexts, in which they are often used in combination with each other. Thanks to its synthetic yet meticulous and practice-oriented approach, the book is a perfect guide for graduate students, researchers and professionals willing to applying metaheuristic algorithms in...
In designing large civil engineering structures, an important consideration is prospective dynamic loadings which may include earthquake ground motion, wind gusts, severe sea states and moving vehicles, rotating and reciprocating machinery and others. successful design of such structures requires...... providing for the safety and integrity of the structure, and in some cases also providing for a measure of comfort for the occupants during such loading which the structure and its occupants must endure. Due to these uncertainties, the civil engineering community has traditionally adopted a very...
Full Text Available engineering screening methodology that could be used to screen potential systems engineers. According to their design, this can be achieved by defining a system engineering profile according to specific psychological attributes, and using this profile...
Many important applications can be formalized as constrained optimization tasks. For example, we are studying the engineering domain of two-dimensional (2-D) structural design. In this task, the goal is to design a structure of minimum weight that bears a set of loads. A solution to a design problem in which there is a single load (L) and two stationary support points (S1 and S2) consists of four members, E1, E2, E3, and E4 that connect the load to the support points is discussed. In principle, optimal solutions to problems of this kind can be found by numerical optimization techniques. However, in practice [Vanderplaats, 1984] these methods are slow and they can produce different local solutions whose quality (ratio to the global optimum) varies with the choice of starting points. Hence, their applicability to real-world problems is severely restricted. To overcome these limitations, we propose to augment numerical optimization by first performing a symbolic compilation stage to produce: (a) objective functions that are faster to evaluate and that depend less on the choice of the starting point and (b) selection rules that associate problem instances to a set of recommended solutions. These goals are accomplished by successive specializations of the problem class and of the associated objective functions. In the end, this process reduces the problem to a collection of independent functions that are fast to evaluate, that can be differentiated symbolically, and that represent smaller regions of the overall search space. However, the specialization process can produce a large number of sub-problems. This is overcome by deriving inductively selection rules which associate problems to small sets of specialized independent sub-problems. Each set of candidate solutions is chosen to minimize a cost function which expresses the tradeoff between the quality of the solution that can be obtained from the sub-problem and the time it takes to produce it. The overall solution
Engineering has gained considerable traction in many K-12 schools. However, there are several obstacles or challenges to an effective approach that leads to student learning. Questions such as where engineering best fits in the curriculum; how to include it authentically and appropriately; toward what educational end; and how best to prepare…
Full Text Available Electrical machines are the hearts of many appliances, industrial equipment and systems. In the context of global sustainability, they must fulfill various requirements, not only physically and technologically but also environmentally. Therefore, their design optimization process becomes more and more complex as more engineering disciplines/domains and constraints are involved, such as electromagnetics, structural mechanics and heat transfer. This paper aims to present a review of the design optimization methods for electrical machines, including design analysis methods and models, optimization models, algorithms and methods/strategies. Several efficient optimization methods/strategies are highlighted with comments, including surrogate-model based and multi-level optimization methods. In addition, two promising and challenging topics in both academic and industrial communities are discussed, and two novel optimization methods are introduced for advanced design optimization of electrical machines. First, a system-level design optimization method is introduced for the development of advanced electric drive systems. Second, a robust design optimization method based on the design for six-sigma technique is introduced for high-quality manufacturing of electrical machines in production. Meanwhile, a proposal is presented for the development of a robust design optimization service based on industrial big data and cloud computing services. Finally, five future directions are proposed, including smart design optimization method for future intelligent design and production of electrical machines.
Hofman, T.; Naaborg, M.; Sciberras, E.
Designing a new vessel is a complex multi-objective design process. It involves knowledge from different fields, like naval architecture and mechanical engineering. Assessment of an optimal design for more complex topologies than a conventional Diesel powertrain becomes more difficult due to the
Journal of Modeling, Design and Management of Engineering Systems ... DESIGN PARAMETERS FOR CONSECUTIVE REACTIONS IN SERIALLY CONNECTED ... for the process equipments such as chemical reactors used in industries.
Noriyasu, Hirokawa; Fujita, Kikuo
This paper discusses the potential role of cache mechanism for complicated design optimization While design optimization is an application of mathematical programming techniques to engineering design problems over numerical computation, its progress has been coevolutionary. The trend in such progress indicates that more complicated applications become the next target of design optimization beyond growth of computational resources. As the progress in the past two decades had required response surface techniques, decomposition techniques, etc., any new framework must be introduced for the future of design optimization methods. This paper proposes a possibility of what we call cache mechanism for mediating the coming challenge and briefly demonstrates some promises in the idea of Voronoi diagram based cumulative approximation as an example of its implementation, development of strict robust design, extension of design optimization for product variety
Hald, Frederik; Kirkegaard, Poul Henning; Andersen, Lars Vabbersgaard
This paper shows the use of topology optimization for finding an optimized form for civil engineering structures. Today topology optimization and shape optimization have been integrated in several commercial finite element codes. Here, the topology of two complex civil engineering structures...
Im, K.H.; Cho, S.; Her, N.I.
The main components of the KSTAR (Korea Superconducting Tokamak Advanced Research) tokamak including vacuum vessel, plasma facing components, cryostat, thermal shield and magnet supporting structure are in the final stage of engineering design. Hundai Heavy Industries (HHI) has been involved in the engineering design of these components. The current configuration and the final engineering design results for the KSTAR main structure are presented. (author)
Akcay-Perdahcioglu, Didem; de Boer, Andries; van der Hoogt, Peter; Tiskarna, T
This paper introduces the design optimization strategies, especially for structures which have dynamic constraints. Design optimization involves first the modeling and then the optimization of the problem. Utilizing the Finite Element (FE) model of a structure directly in an optimization process
Okkels, Fridolin; Bruus, Henrik
We address the design of optimal reactors for supporting biological cultures using the method of topology optimization. For some years this method have been used to design various optimal microfluidic devices.1-4 We apply this method to distribute optimally biologic cultures within a flow...
Bremicker, M.; Chirehdast, M.; Kikuchi, N.; Papalambros, P. Y.
Structural optimization procedures usually start from a given design topology and vary its proportions or boundary shapes to achieve optimality under various constraints. Two different categories of structural optimization are distinguished in the literature, namely sizing and shape optimization. A major restriction in both cases is that the design topology is considered fixed and given. Questions concerning the general layout of a design (such as whether a truss or a solid structure should be used) as well as more detailed topology features (e.g., the number and connectivities of bars in a truss or the number of holes in a solid) have to be resolved by design experience before formulating the structural optimization model. Design quality of an optimized structure still depends strongly on engineering intuition. This article presents a novel approach for initiating formal structural optimization at an earlier stage, where the design topology is rigorously generated in addition to selecting shape and size dimensions. A three-phase design process is discussed: an optimal initial topology is created by a homogenization method as a gray level image, which is then transformed to a realizable design using computer vision techniques; this design is then parameterized and treated in detail by sizing and shape optimization. A fully automated process is described for trusses. Optimization of two dimensional solid structures is also discussed. Several application-oriented examples illustrate the usefulness of the proposed methodology.
Bercaw, R. W.; Seikel, G. R.
The Engineering Test Facility (ETF) is the major focus of the Department of Energy (DOE) Magnetohydrodynamics (MHD) Program to facilitate commercialization and to demonstrate the commercial operability of MHD/steam electric power. The ETF will be a fully integrated commercial prototype MHD power plant with a nominal output of 200 MW sub e. Performance of this plant is expected to meet or surpass existing utility standards for fuel, maintenance, and operating costs; plant availability; load following; safety; and durability. It is expected to meet all applicable environmental regulations. The current design concept conforming to the general definition, the basis for its selection, and the process which will be followed in further defining and updating the conceptual design.
Gilmour, J. L.
The optimum vehicle configuration and component locations are determined for an electric drive vehicle based on using the basic structure of a current production subcompact vehicle. The optimization of an electric vehicle layout requires a weight distribution in the range of 53/47 to 62/38 in order to assure dynamic handling characteristics comparable to current internal combustion engine vehicles. Necessary modification of the base vehicle can be accomplished without major modification of the structure or running gear. As long as batteries are as heavy and require as much space as they currently do, they must be divided into two packages, one at front under the hood and a second at the rear under the cargo area, in order to achieve the desired weight distribution. The weight distribution criteria requires the placement of batteries at the front of the vehicle even when the central tunnel is used for the location of some batteries. The optimum layout has a front motor and front wheel drive. This configuration provides the optimum vehicle dynamic handling characteristics and the maximum passenger and cargo space for a given size vehicle.
Eder, Wolfgang Ernst
"Design" can be a noun, or a verb. Six paths for research into engineering design (as verb) are identified, they must be coordinated for internal consistency and plausibility. Design research tries to clarify design processes and their underlying theories--for designing in general, and for particular forms, e.g., design engineering. Theories are a…
Sigmund, Ole; Jensen, Jakob Søndergaard
The goal of this study is to design and optimize structures and devices that are subjected to acoustic waves. Examples are acoustic lenses, sound walls, waveguides and loud speakers. We formulate the design problem as a topology optimization problem, i.e. distribute material in a design domain...... such that the acoustic response is optimized....
Chaitou, Hussein; Nika, Philippe
Highlights: ► Optimization of a thermoacoustic engine using the particle swarm optimization method. ► Exergetic efficiency, acoustic power and their product are the optimized functions. ► PSO method is used successfully for the first time in the TA research. ► The powerful PSO tool is advised to be more involved in the TA research and design. ► EE times AP optimized function is highly recommended to design any new TA devices. - Abstract: Thermoacoustic engines convert heat energy into acoustic energy. Then, the acoustic energy can be used to pump heat or to generate electricity. It is well-known that the acoustic energy and therefore the exergetic efficiency depend on parameters such as the stack’s hydraulic radius, the stack’s position in the resonator and the traveling–standing-wave ratio. In this paper, these three parameters are investigated in order to study and analyze the best value of the produced acoustic energy, the exergetic efficiency and the product of the acoustic energy by the exergetic efficiency of a thermoacoustic engine with a parallel-plate stack. The dimensionless expressions of the thermoacoustic equations are derived and calculated. Then, the Particle Swarm Optimization method (PSO) is introduced and used for the first time in the thermoacoustic research. The use of the PSO method and the optimization of the acoustic energy multiplied by the exergetic efficiency are novel contributions to this domain of research. This paper discusses some significant conclusions which are useful for the design of new thermoacoustic engines.
Heinsch, Stephen C; Das, Siba R; Smanski, Michael J
Increasing the final titer of a multi-gene metabolic pathway can be viewed as a multivariate optimization problem. While numerous multivariate optimization algorithms exist, few are specifically designed to accommodate the constraints posed by genetic engineering workflows. We present a strategy for optimizing expression levels across an arbitrary number of genes that requires few design-build-test iterations. We compare the performance of several optimization algorithms on a series of simulated expression landscapes. We show that optimal experimental design parameters depend on the degree of landscape ruggedness. This work provides a theoretical framework for designing and executing numerical optimization on multi-gene systems.
Householder, Daniel L.; Hailey, Christine E.
Successful strategies for incorporating engineering design challenges into science, technology, engineering, and mathematics (STEM) courses in American high schools are presented in this paper. The developers have taken the position that engineering design experiences should be an important component of the high school education of all American youth. In most instances, these experiences in engineering design are infused into instruction programs in standards-based courses in science, technol...
labor cost requirements are broken into tasks of work. Each task is usually performd by a labor crew. Crews may vary in size and mix of skills. The...requested in advance of the expected purchase date. Suppliers are reluctant to guarantee future pricw and ofien will only quote current prices. It may be...unit cost is the overhead cost for the item. g. Sources for Pricing. The Cost Engineer must rely on judgement, historical data, and current labor market
Full Text Available This paper investigates the optimization of the performance of a solar powered Stirling engine based on finite-time thermodynamics. Heat transference in the heat exchangers between a concentrating solar collector and the Stirling engine is studied. The irreversibility of a Stirling engine is considered with the heat transfer following Newton's law. The power generated by a Stirling engine is used as an objective function for maximum power output design with the concentrating solar collector temperature and the engine thermal efficiency as the optimization parameters. The maximum output power of engine and its corresponding system parameters are determined using a genetic algorithm.
Ahmed-Kristensen, Saeema; Babar, Muhammad Ali
Observational studies of engineering design activities can inform the research community on the problem solving models that are employed by professional engineers. Design is defined as an ill-defined problem which includes both engineering design and software design, hence understanding problem...... solving models from other design domains is of interest to the engineering design community. For this paper an observational study of two software design sessions performed for the workshop on “Studying professional Software Design” is compared to analysis from engineering design. These findings provide...... useful insights of how software designers move from a problem domain to a solution domain and the commonalities between software designers’ and engineering designers’ design activities. The software designers were found to move quickly to a detailed design phase, employ co-.evolution and adopt...
Ahmed-Kristensen, Saeema; Babar, Muhammad Ali
solving models from other design domains is of interest to the engineering design community. For this paper an observational study of two software design sessions performed for the workshop on “Studying professional Software Design” is compared to analysis from engineering design. These findings provide......Observational studies of engineering design activities can inform the research community on the problem solving models that are employed by professional engineers. Design is defined as an ill-defined problem which includes both engineering design and software design, hence understanding problem...... useful insights of how software designers move from a problem domain to a solution domain and the commonalities between software designers’ and engineering designers’ design activities. The software designers were found to move quickly to a detailed design phase, employ co-.evolution and adopt...
Tjalve, E; Frackmann Schmidt, F
Engineering Graphic Modelling: A Practical Guide to Drawing and Design covers how engineering drawing relates to the design activity. The book describes modeled properties, such as the function, structure, form, material, dimension, and surface, as well as the coordinates, symbols, and types of projection of the drawing code. The text provides drawing techniques, such as freehand sketching, bold freehand drawing, drawing with a straightedge, a draughting machine or a plotter, and use of templates, and then describes the types of drawing. Graphic designers, design engineers, mechanical engine
Van Dijk, R.E.C.; Zhao, X.; Wang, H.; Van Dalen, F.
Competitive aircraft box structures are a perfect compromise between weight and price. The conceptual design process of these structures is a typical Multidisciplinary Design and Optimization effort, normally conducted by human engineers. The iterative nature of MDO turns development into a long and
A holistic view is essential in the engineering of technical systems. This thesis presents an integrative approach for designing solar thermal power plants. The methodology is based on a techno-economic plant model and a powerful optimization algorithm. Typically, contemporary design methods treat technical and economic parameters and sub-systems separately, making it difficult or even impossible to realize the full optimization potential of power plant systems. The approach presented here ov...
Gaol, Ford Lumban; Webb, Jeff; Ding, Jun
The 2nd International Conference on Manufacturing, Optimization, Industrial and Material Engineering 2014 (MOIME 2014), was held at the Grand Mercure Harmoni, Opal Room 3rd Floor, Jakarta, Indonesia, during 29–30 March 2014. The MOIME 2014 conference is designed to bring together researchers, engineers and scientists in the domain of interest from around the world. MOIME 2014 is placed on promoting interaction between the theoretical, experimental, and applied communities, so that a high level exchange is achieved in new and emerging areas within Material Engineering, Industrial Engineering and all areas that relate to Optimization. We would like to express our sincere gratitude to all in the Technical Program Committee who have reviewed the papers and developed a very interesting Conference Program as well as the invited and plenary speakers. This year, we received 97 papers and after rigorous review, 24 papers were accepted. The participants come from 7 countries. There are 4 (four) parallel session and 2 Invited Speakers and one workshop. It is an honour to present this volume of IOP Conference Series: Materials Science and Engineering (MSE) and we deeply thank the authors for their enthusiastic and high-grade contributions. Finally, we would like to thank the conference chairmen, the members of the steering committee, the organizing committee, the organizing secretariat and the financial support from the conference sponsors that allowed the success of MOIME 2014. The Editors of the MOIME 2014 Proceedings Editors Dr Ford Lumban Gaol Jeff Webb, PhD Professor Jun Ding, PhD
McCormick, Mary E.; Hammer, David
Novel Engineering activities are premised on the integration of engineering and literacy: students identify and engineer solutions to problems that arise for fictional characters in stories they read for class. There are advantages to this integration, for both engineering and literacy goals of instruction: the stories provide ''clients'' to…
McFarland Kendall, Amber Leigh
K-12 standards and curricula are beginning to include engineering design as a key practice within Science Technology Engineering and Mathematics (STEM) education. However, there is little research on how the youngest students engage in engineering design within the elementary classroom. This dissertation focuses on iteration as an essential aspect of engineering design, and because research at the college and professional level suggests iteration improves the designer's understanding of problems and the quality of design solutions. My research presents qualitative case studies of students in kindergarten and third-grade as they engage in classroom engineering design challenges which integrate with traditional curricula standards in mathematics, science, and literature. I discuss my results through the lens of activity theory, emphasizing practices, goals, and mediating resources. Through three chapters, I provide insight into how early-elementary students iterate upon their designs by characterizing the ways in which lesson design impacts testing and revision, by analyzing the plan-driven and experimentation-driven approaches that student groups use when solving engineering design challenges, and by investigating how students attend to constraints within the challenge. I connect these findings to teacher practices and curriculum design in order to suggest methods of promoting iteration within open-ended, classroom-based engineering design challenges. This dissertation contributes to the field of engineering education by providing evidence of productive engineering practices in young students and support for the value of engineering design challenges in developing students' participation and agency in these practices.
Engau, A; Wiecek, M. M
The high dimensionality encountered in engineering design optimization due to large numbers of performance criteria and specifications leads to cumbersome and sometimes unachievable tradeoff analyses...
Householder, Daniel L., Ed.; Hailey, Christine E., Ed.
Successful strategies for incorporating engineering design challenges into science, technology, engineering, and mathematics (STEM) courses in American high schools are presented in this paper. The developers have taken the position that engineering design experiences should be an important component of the high school education of all American…
Dankenbring, Chelsey; Capobianco, Brenda M.; Eichinger, David
In this article, the authors provide an overview of engineering and the engineering design process, and describe the steps they took to develop a fifth grade-level, standards-based engineering design task titled "Getting the Dirt on Decomposition." Their main goal was to focus more on modeling the discrete steps they took to create and…
McFarland Kendall, Amber Leigh
K-12 standards and curricula are beginning to include engineering design as a key practice within Science Technology Engineering and Mathematics (STEM) education. However, there is little research on how the youngest students engage in engineering design within the elementary classroom. This dissertation focuses on iteration as an essential aspect…
Silva, N.; Alves, N.; Pascoal-Faria, P.
The generative modeling paradigm is a shift from static models to flexible models. It describes a modeling process using functions, methods and operators. The result is an algorithmic description of the construction process. Each evaluation of such an algorithm creates a model instance, which depends on its input parameters (width, height, volume, roof angle, orientation, location). These values are normally chosen according to aesthetic aspects and style. In this study, the model's parameters are automatically generated according to an objective function. A generative model can be optimized according to its parameters, in this way, the best solution for a constrained problem is determined. Besides the establishment of an overall framework design, this work consists on the identification of different building shapes and their main parameters, the creation of an algorithmic description for these main shapes and the formulation of the objective function, respecting a building's energy consumption (solar energy, heating and insulation). Additionally, the conception of an optimization pipeline, combining an energy calculation tool with a geometric scripting engine is presented. The methods developed leads to an automated and optimized 3D shape generation for the projected building (based on the desired conditions and according to specific constrains). The approach proposed will help in the construction of real buildings that account for less energy consumption and for a more sustainable world.
Yang, Long; Yu, Suyuan
Helium gas turbine is the key component of the power conversion system for direct cycle High Temperature Gas-cooled Reactors (HTGR), of which an optimal design is essential for high efficiency. Gas turbine design currently is a multidisciplinary process in which the relationships between constraints, objective functions and variables are very noisy. Due to the ever-increasing complexity of the process, it has becomes very hard for the engineering designer to foresee the consequences of changing certain parts. With classic design procedures which depend on adaptation to baseline design, this problem is usually averted by choosing a large number of design variables based on the engineer's judgment or experience in advance, then reaching a solution through iterative computation and modification. This, in fact, leads to a reduction of the degree of freedom of the design problem, and therefore to a suboptimal design. Furthermore, helium is very different in thermal properties from normal gases; it is uncertain whether the operation experiences of a normal gas turbine could be used in the conceptual design of a helium gas turbine. Therefore, it is difficult to produce an optimal design with the general method of adaptation to baseline. Since their appearance in the 1970s, Genetic algorithms (GAs) have been broadly used in many research fields due to their robustness. GAs have also been used recently in the design and optimization of turbo-machines. Researchers at the General Electronic Company (GE) developed an optimization software called Engineous, and used GAs in the basic design and optimization of turbines. The ITOP study group from Xi'an Transportation University also did some work on optimization of transonic turbine blades. However, since GAs do not have a rigorous theory base, many problems in utilities have arisen, such as premature convergence and uncertainty; the GA doesn't know how to locate the optimal design, and doesn't even know if the optimal solution
Courtney, William Tucker; Stolpe, Mathias; Buhl, Thomas
Tosca Structure coupled with the finite element software Abaqus. The solutions to these optimization problems are then manually interpreted as a new design concept. Results show that shape optimization of the initial design can reduce stress concentrations by 38%. Additionally, topology optimization has...
Full Text Available The aim of this paper is to employ the Particle Swarm Optimization (PSO technique to a mechanical engineering design problem which is minimizing the volume of a cantilevered beam subject to bending strength constraints. Mechanical engineering design problems are complex activities which are computing capability are more and more required. The most of these problems are solved by conventional mathematical programming techniques that require gradient information. These techniques have several drawbacks from which the main one is becoming trapped in local optima. As an alternative to gradient-based techniques, the PSO does not require the evaluation of gradients of the objective function. The PSO algorithm employs the generation of guided random positions when they search for the global optimum point. The PSO which is a nature inspired heuristics search technique imitates the social behavior of bird flocking. The results obtained by the PSO are compared with Mathematical Programming (MP. It is demonstrated that the PSO performed and obtained better convergence reliability on the global optimum point than the MP. Using the MP, the volume of 2961000 mm3 was obtained while the beam volume of 2945345 mm3 was obtained by the PSO.
Lee, Dong HO; Decker, D. Richard
Designing engineering objects requires many engineers' knowledge from different domains. There needs to be cooperative work among engineering designers to complete a design. Revisions of a design are time consuming, especially if designers work at a distance and with different design description formats. In order to reduce the design cycle, there needs to be a sharable design describing the engineering community, which can be electronically transportable. Design is a process of integrating that is not easy to define definitively. This paper presents Design Script which is a generic engineering design knowledge representation scheme that can be applied in any engineering domain. The Design Script is developed through encapsulation of common design activities and basic design components based on problem decomposition. It is implemented using CLIPS with a Windows NT graphical user interface. The physical relationships between engineering objects and their subparts can be constructed in a hierarchical manner. The same design process is repeatedly applied at each given level of hierarchy and recursively into lower levels of the hierarchy. Each class of the structure can be represented using the Design Script.
Jiang, Li; Lee, Donghoon; Yilmaz, Hakan; Stefanopoulou, Anna
Methods and systems for real-time engine control optimization are provided. A value of an engine performance variable is determined, a value of a first operating condition and a value of a second operating condition of a vehicle engine are detected, and initial values for a first engine control parameter and a second engine control parameter are determined based on the detected first operating condition and the detected second operating condition. The initial values for the first engine control parameter and the second engine control parameter are adjusted based on the determined value of the engine performance variable to cause the engine performance variable to approach a target engine performance variable. In order to cause the engine performance variable to approach the target engine performance variable, adjusting the initial value for the first engine control parameter necessitates a corresponding adjustment of the initial value for the second engine control parameter.
Farrell, John T [National Renewable Energy Laboratory (NREL), Golden, CO (United States)
This is the keynote presentation on the Co-Optimization of Fuels and Engines (Co-Optima) Initiative delivered at SAE International's ICE 2017 - 13th International Conference on Engines & Vehicles held in Capri, Italy.
Stigter Johannes D
Full Text Available Abstract Background Current research in network reverse engineering for genetic or metabolic networks very often does not include a proper experimental and/or input design. In this paper we address this issue in more detail and suggest a method that includes an iterative design of experiments based, on the most recent data that become available. The presented approach allows a reliable reconstruction of the network and addresses an important issue, i.e., the analysis and the propagation of uncertainties as they exist in both the data and in our own knowledge. These two types of uncertainties have their immediate ramifications for the uncertainties in the parameter estimates and, hence, are taken into account from the very beginning of our experimental design. Findings The method is demonstrated for two small networks that include a genetic network for mRNA synthesis and degradation and an oscillatory network describing a molecular network underlying adenosine 3’-5’ cyclic monophosphate (cAMP as observed in populations of Dyctyostelium cells. In both cases a substantial reduction in parameter uncertainty was observed. Extension to larger scale networks is possible but needs a more rigorous parameter estimation algorithm that includes sparsity as a constraint in the optimization procedure. Conclusion We conclude that a careful experiment design very often (but not always pays off in terms of reliability in the inferred network topology. For large scale networks a better parameter estimation algorithm is required that includes sparsity as an additional constraint. These algorithms are available in the literature and can also be used in an adaptive optimal design setting as demonstrated in this paper.
Full Text Available The aim of this study is to describe and analyze learning taking place in a collaborative design exercise involving engineering students. The students perform a time-constrained, open-ended, complex interaction design task, an “interactionary”. A multimodal learning perspective is used. We have performed detailed analyses of video recordings of the engineering students, including classifying aspects of interaction. Our results show that the engineering students carry out and articulate their design work using a technology-centred approach and focus more on the function of their designs than on aspects of interaction. The engineering students mainly make use of ephemeral communication strategies (gestures and speech rather than sketching in physical materials. We conclude that the interactionary may be an educational format that can help engineering students learn the messiness of design work. We further identify several constraints to the engineering students’ design learning and propose useful interventions that a teacher could make during an interactionary. We especially emphasize interventions that help engineering students-retain aspects of human-centered design throughout the design process. This study partially replicates a previous study which involved interaction design students.
Andre, G.R.; Jansen, R.L.
The Westinghouse Technical Specification Program (TOP) was designed to evaluate on a quantitative basis revisions to Nuclear Power Plant Technical Specifications. The revisions are directed at simplifying plant operation, and reducing unnecessary transients, shutdowns, and manpower requirements. In conjunction with the Westinghouse Owners Group, Westinghouse initiated a program to develop a methodology to justify Technical Specification revisions; particularly revisions related to testing and maintenance requirements on plant operation for instrumentation systems. The methodology was originally developed and applied to the reactor trip features of the reactor protection system (RPS). The current study further refined the methodology and applied it to the engineered safety features of the RPS
Heidinger, R.; Knaster, J.; Matsumoto, H.; Sugimoto, M.; Mosnier, A.; Arbeiter, F.; Baluc, N.; Cara, P.; Chel, S.; Facco, A.; Favuzza, P.; Heinzel, V.; Ibarra, A.; Massaut, V.; Micciche, G.; Nitti, F.S.; Theile, J.
Highlights: ► The IFMIF/EVEDA project has entered into the crucial phase of concluding the Interim IFMIF Engineering Design Report. ► The IFMIF plant configuration has been established with the definition of five IFMIF facilities and of their interfaces. ► Three major prototypes of the IFMIF main systems have been designed and are being manufactured, commissioned and operated. -- Abstract: The International Fusion Materials Irradiation Facility (IFMIF) Engineering Design and Engineering Validation Activities (EVEDA) are being developed in a joint project in the framework of the Broader Approach (BA) Agreement between EU and Japan. This project has now entered into a crucial phase as the engineering design of IFMIF is now being formulated in a series of 3 subsequent phases for delivering an Interim IFMIF Engineering Design Report (IIEDR) by mid of 2013. Content of these phases is explained, including the plant configuration detailing the 5 IFMIF facilities and their systems. Together with the Engineering Design Activities, prototyping sub-projects are pursued in the Engineering Validation Activities which consist of the design, manufacturing and testing of the following prototypical systems: Linear IFMIF Prototype Accelerator (LIPAc), EVEDA Lithium Test Loop (ELTL), and High Flux Test Module (HFTM) with the prototypical helium cooling loop (HELOKA). Highlights are described from recent experiments in the Engineering Validation Activities
Dhawan, Atam P.
This project was awarded for understanding the problem and developing a plan for Data Mining tools for use in designing and implementing an Engine Condition Monitoring System. Tricia Erhardt and I studied the problem domain for developing an Engine Condition Monitoring system using the sparse and non-standardized datasets to be available through a consortium at NASA Lewis Research Center. We visited NASA three times to discuss additional issues related to dataset which was not made available to us. We discussed and developed a general framework of data mining and optimization tools to extract useful information from sparse and non-standard datasets. These discussions lead to the training of Tricia Erhardt to develop Genetic Algorithm based search programs which were written in C++ and used to demonstrate the capability of GA algorithm in searching an optimal solution in noisy, datasets. From the study and discussion with NASA LeRC personnel, we then prepared a proposal, which is being submitted to NASA for future work for the development of data mining algorithms for engine conditional monitoring. The proposed set of algorithm uses wavelet processing for creating multi-resolution pyramid of tile data for GA based multi-resolution optimal search.
engineering design education. Educating engineering designers today significantly differs from traditional engineering education (McAloone, et.al., 2007). However, a broader view of design activities gains little attention. The project course Product/Service-Systems, which is coupled to the lecture based...... course Product life and Environmental issues at the Technical University of Denmark (DTU) and the master programme Product Development Processes at the Luleå University of Technology (LTU), Sweden, are both curriculums with a broader view than traditional (mechanical) engineering design. Based...... on these two representatives of a Scandinavian approach, the purpose in this presentation is to describe two ways of educating engineering designers to enable them to develop these broader competencies of socio-technical aspects of engineering design. Product Development Processes at LTU A process, called...
Hall-Andersen, Lene Bjerg
Integrating ergonomic knowledge into engineering design processes has been shown to contribute to healthy and effective designs of workplaces. However, it is also well-recognized that, in practice, ergonomists often have difficulties gaining access to and impacting engineering design processes...... employed in the same company, constituted a supporting factor for the possibilities to integrate ergonomic knowledge into the engineering design processes. However, the integration activities remained discrete and only happened in some of the design projects. A major barrier was related to the business...... to the ergonomic ambitions of the clients. The ergonomists’ ability to navigate, act strategically, and compromise on ergonomic inputs is also important in relation to having an impact in the engineering design processes. Familiarity with the engineering design terminology and the setup of design projects seems...
Brook, N; Metlica, F; Muir, A; Phillips, A; Buckley, A; Gibson, V; Harrison, K; Jones, C R; Katvars, S G; Lazzeroni, C; Storey, J; Ward, CP; Wotton, S; Alemi, M; Arnabaldi, C; Bellunato, T F; Calvi, M; Matteuzzi, C; Musy, M; Negri, P; Perego, D L; Pessina, G; Chamonal, R; Eisenhardt, S; Lawrence, J; McCarron, J; Muheim, F; Playfer, S; Walker, A; Cuneo, S; Fontanelli, F; Gracco, Valerio; Mini, G; Musico, P; Petrolini, A; Sannino, M; Bates, A; MacGregor, A; O'Shea, V; Parkes, C; Paterson, S; Petrie, D; Pickford, A; Rahman, M; Soler, F; Allebone, L; Barber, J H; Cameron, W; Clark, D; Dornan, Peter John; Duane, A; Egede, U; Hallam, R; Howard, A; Plackett, R; Price, D; Savidge, T; Vidal-Sitjes, G; Websdale, D M; Adinolfi, M; Bibby, J H; Cioffi, C; Gligorov, Vladimir V; Harnew, N; Harris, F; McArthur, I A; Newby, C; Ottewell, B; Rademacker, J; Senanayake, R; Somerville, L P; Soroko, A; Smale, N J; Topp-Jørgensen, S; Wilkinson, G; Yang, S; Benayoun, M; Khmelnikov, V A; Obraztsov, V F; Densham, C J; Easo, S; Franek, B; Kuznetsov, G; Loveridge, P W; Morrow, D; Morris, JV; Papanestis, A; Patrick, G N; Woodward, M L; Aglieri-Rinella, G; Albrecht, A; Braem, André; Campbell, M; D'Ambrosio, C; Forty, R W; Frei, C; Gys, Thierry; Jamet, O; Kanaya, N; Losasso, M; Moritz, M; Patel, M; Piedigrossi, D; Snoeys, W; Ullaland, O; Van Lysebetten, A; Wyllie, K
This document describes the concepts of the engineering design to be adopted for the upstream Ring Imaging Cherenkov detector (RICH1) of the reoptimized LHCb detector. Our aim is to ensure that coherent solutions for the engineering design and integration for all components of RICH1 are available, before proceeding with the detailed design of these components.
Madsen, Jens Ingemann
The power of computational fluid dynamics is boosted through the use of automated design optimization methodologies. The thesis considers both derivative-based search optimization and the use of response surface methodologies.......The power of computational fluid dynamics is boosted through the use of automated design optimization methodologies. The thesis considers both derivative-based search optimization and the use of response surface methodologies....
Wang, Fengwen; Jensen, Jakob Søndergaard; Mørk, Jesper
This paper employs topology optimization to systematically design free-topology loss-engineered slow-light waveguides with enlarged group index bandwidth product (GBP). The propagation losses of guided modes are evaluated by the imaginary part of eigenvalues in complex band structure calculations......, where the scattering losses due to manufacturing imperfections are represented by an edge-related effective dissipation. The loss engineering of slow-light waveguides is realized by minimizing the propagation losses of design modes. Numerical examples illustrate that the propagation losses of free......-topology dispersion-engineered waveguides can be significantly suppressed by loss engineering. Comparisons between fixed- and free-topology loss-engineered waveguides demonstrate that the GBP can be enhanced significantly by the free-topology loss-engineered waveguides with a small increase of the propagation losses....
Ross, R. G., Jr.
An analysis is presented which integrates the results of specific studies in the areas of photovoltaic structural design optimization, optimization of array series/parallel circuit design, thermal design optimization, and optimization of environmental protection features. The analysis is based on minimizing the total photovoltaic system life-cycle energy cost including repair and replacement of failed cells and modules. This approach is shown to be a useful technique for array optimization, particularly when time-dependent parameters such as array degradation and maintenance are involved.
Westinghouse Idaho Nuclear Company, Inc. (WINCO) purchased a Design Management software package called SHERPA for use on the $1 billion Special Isotope Separation Project Sherpa is a customizable software shell that provides for the administrative management of the design function including production, approval, distribution and configuration control of project information. This project information can be either electronic or the traditional paper hardcopy. The use of this computerized system resulted in enhanced productivity and quality performance for the management, engineering, and administrative personnel on the project. The software currently runs on an HP9000 model 835 using the HP-UX operating system. The software had been completely customized to meet specific project needs. Existing databases were converted or left in tact to be accessed through the Sherpa software. Access to the system is available through IBM PCs. Dec terminals, Sun work stations, HP terminals, and X-windows terminals, in short most existing WINCO workstations. The software and hardware were delivered in February of 1990, and the system was on-line with all necessary data converted by the end of ApriL Through the use of the electronic approval function and the highly sophisticated query capabilities of the software, a cost savings of over 1500 personnel hours were realized during the closeout of the Project. The software has since been modified for use in the management of WINCO Environmental Compliance Information including Permits, NEPA, and RECRA documentation and records. Use of this software and hardware has resulted in an increase in quality and a large cost savings to WINCO
Chen, Zhen; Zeng, An-Ping
Accelerating the process of industrial bacterial host strain development, aimed at increasing productivity, generating new bio-products or utilizing alternative feedstocks, requires the integration of complementary approaches to manipulate cellular metabolism and regulatory networks. Systems metabolic engineering extends the concept of classical metabolic engineering to the systems level by incorporating the techniques used in systems biology and synthetic biology, and offers a framework for the development of the next generation of industrial strains. As one of the most useful tools of systems metabolic engineering, protein design allows us to design and optimize cellular metabolism at a molecular level. Here, we review the current strategies of protein design for engineering cellular synthetic pathways, metabolic control systems and signaling pathways, and highlight the challenges of this subfield within the context of systems metabolic engineering. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Crowder, James A; Demijohn, Russell
This book presents Systems Engineering from a modern, multidisciplinary engineering approach, providing the understanding that all aspects of systems design, systems, software, test, security, maintenance and the full life-cycle must be factored in to any large-scale system design; up front, not factored in later. It lays out a step-by-step approach to systems-of-systems architectural design, describing in detail the documentation flow throughout the systems engineering design process. It provides a straightforward look and the entire systems engineering process, providing realistic case studies, examples, and design problems that will enable students to gain a firm grasp on the fundamentals of modern systems engineering. Included is a comprehensive design problem that weaves throughout the entire text book, concluding with a complete top-level systems architecture for a real-world design problem.
This edited volume, dedicated to Henry P. Wynn, reflects his broad range of research interests, focusing in particular on the applications of optimal design theory in optimization and statistics. It covers algorithms for constructing optimal experimental designs, general gradient-type algorithms for convex optimization, majorization and stochastic ordering, algebraic statistics, Bayesian networks and nonlinear regression. Written by leading specialists in the field, each chapter contains a survey of the existing literature along with substantial new material. This work will appeal to both the
Nawaz, Muhammad; Zondervan, Edwin; Woodley, John
In this paper we propose a biorefinery optimization model that can be used to find the optimal processing route for the production of ethanol, butanol, succinic acid and blends of these chemicals with fossil fuel based gasoline. The approach unites transshipment models with a superstructure...
Product development processes are continuously challenged by demands for increased efficiency. As engineering products become more and more complex, efficient tools and methods for integrated and automated design are needed throughout the development process. Multidisciplinary Design Optimization (MDO) is one promising technique that has the potential to drastically improve concurrent design. MDO frameworks combine several disciplinary models with the aim of gaining a holistic perspective of ...
Hartvig, Susanne C
This short paper discusses typical engineering tasks and problem solving methods, based on a field study of engineering tasks at a Danish engineering firm. The field study has identified ten classes of design tasks and in this paper these classes are related to problem solving methods. The descri...
Hopfe, C.J.; Struck, C.; Hensen, J.L.M.
The A/E/C (Architecture, Engineering, Construction) industry is very traditional. In contrast to other industries (e.g. car or ship industry) no prototypes are trialled and tested before manufacturing. Each building is unique, thereby excluding large scale production. Over the past thirty years,
Kumar, V.; German, Marjorie D.; Lee, S.-J.
An overview is given of a design optimization project that is in progress at the GE Research and Development Center for the past few years. The objective of this project is to develop a methodology and a software system for design automation and optimization of structural/mechanical components and systems. The effort focuses on research and development issues and also on optimization applications that can be related to real-life industrial design problems. The overall technical approach is based on integration of numerical optimization techniques, finite element methods, CAE and software engineering, and artificial intelligence/expert systems (AI/ES) concepts. The role of each of these engineering technologies in the development of a unified design methodology is illustrated. A software system DESIGN-OPT has been developed for both size and shape optimization of structural components subjected to static as well as dynamic loadings. By integrating this software with an automatic mesh generator, a geometric modeler and an attribute specification computer code, a software module SHAPE-OPT has been developed for shape optimization. Details of these software packages together with their applications to some 2- and 3-dimensional design problems are described.
Dumas, L.; Druez, B.; Lecerf, N.
A new fully adaptive hybrid optimization method (AHM) has been developed and applied to an industrial problem in the field of the aircraft engine industry. The adaptivity of the coupling between a global search by a population-based method (Genetic Algorithms or Evolution Strategies) and the local search by a descent method has been particularly emphasized. On various analytical test cases, the AHM method overperforms the original global search method in terms of computational time and accuracy. The results obtained on the industrial case have also confirmed the interest of AHM for the design of new and original solutions in an affordable time.
Wang, Xiaoping; Zheng, Zhenrong; Wang, Kaiwei; Zheng, Xiaodong; Ye, Song; Zhu, Yuhui
The optimized curriculum of College of Optical Science and Engineering is accomplished at Zhejiang University, based on new trends from both research and industry. The curriculum includes general courses, foundation courses such as mathematics and physics, major core courses, laboratory courses and several module courses. Module courses include optical system designing, optical telecommunication, imaging and vision, electronics and computer science, optoelectronic sensing and metrology, optical mechanics and materials, basics and extension. These curricula reflect the direction of latest researches and relates closely with optoelectronics. Therefore, students may combine flexibly compulsory courses with elective courses, and establish the personalized curriculum of "optoelectronics + X", according to their individual strengths and preferences.
This book presents recent advances in optimization and control methods with applications to industrial engineering and construction management. It consists of 15 chapters authored by recognized experts in a variety of fields including control and operation research, industrial engineering, and project management. Topics include numerical methods in unconstrained optimization, robust optimal control problems, set splitting problems, optimum confidence interval analysis, a monitoring networks optimization survey, distributed fault detection, nonferrous industrial optimization approaches, neural networks in traffic flows, economic scheduling of CCHP systems, a project scheduling optimization survey, lean and agile construction project management, practical construction projects in Hong Kong, dynamic project management, production control in PC4P, and target contracts optimization. The book offers a valuable reference work for scientists, engineers, researchers and practitioners in industrial engineering and c...
Rafique, Amer Farhan
As system design is becoming more and more multifaceted, integrated, and complex, the traditional single objective optimization trends of optimal design are becoming less and less efficient and effective. Single objective optimization methods present a unique optimal solution whereas multiobjective methods present pareto front. The foremost intent is to predict a reasonable distributed pareto-optimal solution set independent of the problem instance through multiobjective scheme. Other objective of application of intended approach is to improve the worthiness of outputs of the complex engineering system design process at the conceptual design phase. The process is automated in order to provide the system designer with the leverage of the possibility of studying and analyzing a large multiple of possible solutions in a short time. This article presents Multiobjective Hyper Heuristic Optimization Scheme based on low level meta-heuristics developed for the application in engineering system design. Herein, we present a stochastic function to manage meta-heuristics (low-level) to augment surety of global optimum solution. Generic Algorithm, Simulated Annealing and Swarm Intelligence are used as low-level meta-heuristics in this study. Performance of the proposed scheme is investigated through a comprehensive empirical analysis yielding acceptable results. One of the primary motives for performing multiobjective optimization is that the current engineering systems require simultaneous optimization of conflicting and multiple. Random decision making makes the implementation of this scheme attractive and easy. Injecting feasible solutions significantly alters the search direction and also adds diversity of population resulting in accomplishment of pre-defined goals set in the proposed scheme.
Mcruer, Duane T.; Boehm, Barry W.; Debra, Daniel B.; Green, C. Cordell; Henry, Richard C.; Maycock, Paul D.; Mcelroy, John H.; Pierce, Chester M.; Stafford, Thomas P.; Young, Laurence R.
Space Station Freedom topics addressed include: general design issues; issues related to utilization and operations; issues related to systems requirements and design; and management issues relevant to design.
Pereira, C.M.N.A.; Schirru, R.; Martinez, A.S.
A genetic algorithm is a powerful search technique that simulates natural evolution in order to fit a population of computational structures to the solution of an optimization problem. This technique presents several advantages over classical ones such as linear programming based techniques, often used in nuclear engineering optimization problems. However, genetic algorithms demand some extra computational cost. Nowadays, due to the fast computers available, the use of genetic algorithms has increased and its practical application has become a reality. In nuclear engineering there are many difficult optimization problems related to nuclear reactor design. Genetic algorithm is a suitable technique to face such kind of problems. This chapter presents applications of genetic algorithms for nuclear reactor core design optimization. A genetic algorithm has been designed to optimize the nuclear reactor cell parameters, such as array pitch, isotopic enrichment, dimensions and cells materials. Some advantages of this genetic algorithm implementation over a classical method based on linear programming are revealed through the application of both techniques to a simple optimization problem. In order to emphasize the suitability of genetic algorithms for design optimization, the technique was successfully applied to a more complex problem, where the classical method is not suitable. Results and comments about the applications are also presented. (orig.)
Martini, W. R.
This manual is intended to serve as an introduction to Stirling cycle heat engines, as a key to the available literature on Stirling engines and to identify nonproprietary Stirling engine design methodologies. Two different fully described Stirling engines are discussed. Engine design methods are categorized as first order, second order, and third order with increased order number indicating increased complexity. FORTRAN programs are listed for both an isothermal second order design program and an adiabatic second order design program. Third order methods are explained and enumerated. In this second edition of the manual the references are updated. A revised personal and corporate author index is given and an expanded directory lists over 80 individuals and companies active in Stirling engines.
G-optimality is a popular design criterion for optimal prediction, it tries to minimize the kriging variance over the whole design region. A G-optimal design minimizes the maximum variance of all predicted values. If we use kriging methods for prediction it is self-evident to use the kriging variance as a measure of uncertainty for the estimates. Though the computation of the kriging variance and even more the computation of the empirical kriging variance is computationally very costly and finding the maximum kriging variance in high-dimensional regions can be time demanding such that we cannot really find the G-optimal design with nowadays available computer equipment in practice. We cannot always avoid this problem by using space-filling designs because small designs that minimize the empirical kriging variance are often non-space-filling. D-optimality is the design criterion related to parameter estimation. A D-optimal design maximizes the determinant of the information matrix of the estimates. D-optimality in terms of trend parameter estimation and D-optimality in terms of covariance parameter estimation yield basically different designs. The Pareto frontier of these two competing determinant criteria corresponds with designs that perform well under both criteria. Under certain conditions searching the G-optimal design on the above Pareto frontier yields almost as good results as searching the G-optimal design in the whole design region. In doing so the maximum of the empirical kriging variance has to be computed only a few times though. The method is demonstrated by means of a computer simulation experiment based on data provided by the Belgian institute Management Unit of the North Sea Mathematical Models (MUMM) that describe the evolution of inorganic and organic carbon and nutrients, phytoplankton, bacteria and zooplankton in the Southern Bight of the North Sea.
ARL-TR-8034 ● JUN 2017 US Army Research Laboratory Optimization of In-Cylinder Pressure Filter for Engine Research by Kenneth...Laboratory Optimization of In-Cylinder Pressure Filter for Engine Research by Kenneth S Kim, Michael T Szedlmayer, Kurt M Kruger, and Chol-Bum M...
Rispoli, Fred; Shah, Vishal
Screening ingredients for the optimization of media is an important first step to reduce the many potential ingredients down to the vital few components. In this study, we propose a new method of screening for mixture experiments called the centroid screening design. Comparison of the proposed design with Plackett-Burman, fractional factorial, simplex lattice design, and modified mixture design shows that the centroid screening design is the most efficient of all the designs in terms of the small number of experimental runs needed and for detecting high-order interaction among ingredients. (c) 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009.
Kelley, Todd R.
As technology education continues to consider a move toward an engineering design focus as proposed by various leaders in technology education, it will be necessary to employ new pedagogical approaches. Hill (2006) provided some new perspectives regarding pedagogical approaches for technology education with an engineering design focus. One…
Walz, Kenneth A.; Christian, Jon R.
Capstone engineering design courses have been a feature at research universities and four-year schools for many years. Although such classes are less common at two-year colleges, the experience is equally beneficial for this population of students. With this in mind, Madison College introduced a project-based Engineering Design course in 2007.…
This book covers design of experiments (DoE) applied in production engineering as a combination of manufacturing technology with applied management science. It presents recent research advances and applications of design experiments in production engineering and the chapters cover metal cutting tools, soft computing for modelling and optmization of machining, waterjet machining of high performance ceramics, among others.
Vallgårda, Anna; Grönvall, Erik; Fritsch, Jonas
In this paper we propose Experimental Engineering as a way to articulate open- ended technological experiments as a legitimate design research practice. Experimental Engineering introduces a move away from an outcome or result driven design process towards an interest in existing technologies and...
Zhuang, Xiaotian; Pan, Rong; Du, Xiaoping
Different types of uncertainties need to be addressed in a product design optimization process. In this paper, the uncertainties in both product design variables and environmental noise variables are considered. The reliability-based design optimization (RBDO) is integrated with robust product design (RPD) to concurrently reduce the production cost and the long-term operation cost, including quality loss, in the process of product design. This problem leads to a multi-objective optimization with probabilistic constraints. In addition, the model uncertainties associated with a surrogate model that is derived from numerical computation methods, such as finite element analysis, is addressed. A hierarchical experimental design approach, augmented by a sequential sampling strategy, is proposed to construct the response surface of product performance function for finding optimal design solutions. The proposed method is demonstrated through an engineering example. - Highlights: • A unifying framework for integrating RBDO and RPD is proposed. • Implicit product performance function is considered. • The design problem is solved by sequential optimization and reliability assessment. • A sequential sampling technique is developed for improving design optimization. • The comparison with traditional RBDO is provided
Shiva Prakasha, Prajwal; Ciampa, Pier Davide; Nagel, Björn
A Collaborative, Inside-Out Aircraft Design approach is presented in this paper. An approach using physics based analysis to evaluate the correlations between the airframe design, as well as sub-systems integration from the early design process, and to exploit the synergies within a simultaneous optimization process. Further, the disciplinary analysis modules involved in the optimization task are located in different organization. Hence, the Airframe and Subsystem design tools are integrated ...
Harding, D.C.; Witkowski, W.R.
The purpose of this overview is twofold: first, to outline the theory and basic elements of numerical optimization; and second, to show how numerical optimization can be applied to the transportation packaging industry and used to increase efficiency and safety of radioactive and hazardous material transportation packages. A more extensive review of numerical optimization and its applications to radioactive material transportation package design was performed previously by the authors (Witkowski and Harding 1992). A proof-of-concept Type B package design is also presented as a simplified example of potential improvements achievable using numerical optimization in the design process
Jensen, Jakob Søndergaard
The method of topology optimization is used to design structures for wave propagation with one lossy material component. Optimized designs for scalar elastic waves are presented for mininimum wave transmission as well as for maximum wave energy dissipation. The structures that are obtained...... are of the 1D or 2D bandgap type depending on the objective and the material parameters....
Frandsen, Lars Hagedorn; Sigmund, Ole
Utilizing the inverse design engineering method of topology optimization, we have realized high-performing all-silicon ultra-compact polarization beam splitters. We show that the device footprint of the polarization beam splitter can be as compact as similar to 2 µm2 while performing experimentally...
This volume summarizes the design of the FED. It includes a description of the major systems and subsystems, the supporting plasma design analysis, a projected device cost and associated construction schedule, and a description of the facilities to house and support the device. This effort represents the culmination of the FY81 studies conducted at the Fusion Engineering Design Center (FEDC). Unique in these design activities has been the collaborative involvement of the Design Center personnel and numerous resource physicists from the fusion community who have made significant contributions in the physics design analysis as well as the physics support of the engineering design of the major FED systems and components
Simpson, Timothy W.; Peplinski, Jesse; Koch, Patrick N.; Allen, Janet K.
The use of statistical techniques to build approximations of expensive computer analysis codes pervades much of todays engineering design. These statistical approximations, or metamodels, are used to replace the actual expensive computer analyses, facilitating multidisciplinary, multiobjective optimization and concept exploration. In this paper we review several of these techniques including design of experiments, response surface methodology, Taguchi methods, neural networks, inductive learning, and kriging. We survey their existing application in engineering design and then address the dangers of applying traditional statistical techniques to approximate deterministic computer analysis codes. We conclude with recommendations for the appropriate use of statistical approximation techniques in given situations and how common pitfalls can be avoided.
Januszkiewicz, Krystyna; Banachowicz, Marta
The paper explores the possibilities of using Structural Optimization Tools (ESO) digital tools in an integrated structural and architectural design in response to the current needs geared towards sustainability, combining ecological and economic efficiency. The first part of the paper defines the Evolutionary Structural Optimization tools, which were developed specifically for engineering purposes using finite element analysis as a framework. The development of ESO has led to several incarnations, which are all briefly discussed (Additive ESO, Bi-directional ESO, Extended ESO). The second part presents result of using these tools in structural and architectural design. Actual building projects which involve optimization as a part of the original design process will be presented (Crematorium in Kakamigahara Gifu, Japan, 2006 SANAA“s Learning Centre, EPFL in Lausanne, Switzerland 2008 among others). The conclusion emphasizes that the structural engineering and architectural design mean directing attention to the solutions which are used by Nature, designing works optimally shaped and forming their own environments. Architectural forms never constitute the optimum shape derived through a form-finding process driven only by structural optimization, but rather embody and integrate a multitude of parameters. It might be assumed that there is a similarity between these processes in nature and the presented design methods. Contemporary digital methods make the simulation of such processes possible, and thus enable us to refer back to the empirical methods of previous generations.
Nightingale, Noel P.
The design of an automotive Stirling engine that achieves the superior fuel economy potential of the Stirling cycle is described. As the culmination of a 9-yr development program, this engine, designated the Mod 2, also nullifies arguments that Stirling engines are heavy, expensive, unreliable, demonstrating poor performance. Installed in a General Motors Chevrolet Celebrity car, this engine has a predicted combined fuel economy on unleaded gasoline of 17.5 km/l (41 mpg)- a value 50% above the current vehicle fleet average. The Mod 2 Stirling engine is a four-cylinder V-drive design with a single crankshaft. The engine is also equipped with all the controls and auxiliaries necessary for automotive operation.
Haertel, Jan Hendrik Klaas
printeddry-cooled power plant condensers using a simpliffed thermouid topology optimizationmodel is presented in another study. A benchmarking of the optimized geometriesagainst a conventional heat exchanger design is conducted and the topologyoptimized designs show a superior performance. A thermouid......The goalof this thesis is to apply topology optimization to the design of differentthermal systems such as heat sinks and heat exchangers in order to improve thethermal performance of these systems compared to conventional designs. Thedesign of thermal systems is a complex task that has...... of optimized designs are presentedwithin this thesis. The maincontribution of the thesis is the development of several numerical optimizationmodels that are applied to different design challenges within thermalengineering. Topology optimization isapplied in an industrial project to design the heat rejection...
The objective of the study was to generate the system design of a performance-optimized, advanced LOX/hydrogen expander cycle space engine. The engine requirements are summarized, and the development and operational experience with the expander cycle RL10 engine were reviewed. The engine development program is outlined.
Topcu, Okan; Taşcıoğlu, Yiğit; Konukseven, Erhan İlhan
Particle swarm optimization (PSO) is a popular method to solve the optimization problems. However, calculations for each particle will be excessive when the number of particles and complexity of the problem increases. As a result, the execution speed will be too slow to achieve the optimized solution. Thus, this paper proposes an automated design and optimization method for rotary MRF brakes and similar multi-physics problems. A modified PSO algorithm is developed for solving multi-physics engineering optimization problems. The difference between the proposed method and the conventional PSO is to split up the original single population into several subpopulations according to the division of labor. The distribution of tasks and the transfer of information to the next party have been inspired by behaviors of a hunting party. Simulation results show that the proposed modified PSO algorithm can overcome the problem of heavy computational burden of multi-physics problems while improving the accuracy. Wire type, MR fluid type, magnetic core material, and ideal current inputs have been determined by the optimization process. To the best of the authors' knowledge, this multi-physics approach is novel for optimizing rotary MRF brakes and the developed PSO algorithm is capable of solving other multi-physics engineering optimization problems. The proposed method has showed both better performance compared to the conventional PSO and also has provided small, lightweight, high impedance rotary MRF brake designs.
Aoki, Takayuki; Mimaki, Hidehito; Oda, Mitsuyuki
In order to deal with the optimization of preservation activities and 'preservation engineering' which makes it possible, the viewpoint and the approach of the optimization of the ex post facto preservation and the content to be possessed in 'preservation engineering' are described. The optimization of the ex post facto preservation is shown respectively in the four stages of planning, implementation, result evaluation and countermeasure. (K. Kato)
Schuman, Todd; DeWeck, Oliver L.; Sobieski, Jaroslaw
The introduction of concurrent design practices to the aerospace industry has greatly increased the productivity of engineers and teams during design sessions as demonstrated by JPL's Team X. Simultaneously, advances in computing power have given rise to a host of potent numerical optimization methods capable of solving complex multidisciplinary optimization problems containing hundreds of variables, constraints, and governing equations. Unfortunately, such methods are tedious to set up and require significant amounts of time and processor power to execute, thus making them unsuitable for rapid concurrent engineering use. This paper proposes a framework for Integration of System-Level Optimization with Concurrent Engineering (ISLOCE). It uses parametric neural-network approximations of the subsystem models. These approximations are then linked to a system-level optimizer that is capable of reaching a solution quickly due to the reduced complexity of the approximations. The integration structure is described in detail and applied to the multiobjective design of a simplified Space Shuttle external fuel tank model. Further, a comparison is made between the new framework and traditional concurrent engineering (without system optimization) through an experimental trial with two groups of engineers. Each method is evaluated in terms of optimizer accuracy, time to solution, and ease of use. The results suggest that system-level optimization, running as a background process during integrated concurrent engineering sessions, is potentially advantageous as long as it is judiciously implemented.
Ganji, Prabhakara Rao; Mahmood, Al-Qarttani Abdulrahman Shakir; Kandula, Aasrith; Raju, Vysyaraju Rajesh Khana; Rao, Surapaneni Srinivasa
In the present study, the Variable Compression Ratio (VCR) engine was analyzed numerically using CONVERGE™ Computational Fluid Dynamics code in order to optimize the design/operating parameters such as Compression Ratio (CR), Start of Injection (SOI) and Exhaust Gas Recirculation (EGR). VCR engine was run for 100 % load to test its performance and it was validated for standard configuration. Simulations were performed by varying the design/operating parameters such as CR (18-14), SOI (17°-26° bTDC) and EGR (0-15 %) at constant fuel injection pressure of 230 bar and speed of 1500 rpm. The effect of each of these parameters on pressure, oxides of nitrogen (NOx) and soot are presented. Finally, regression equations were developed for pressure, NOx and soot by using the simulation results. The regression equations were solved for multi objective criteria in order to reduce the NOx and soot while maintaining the baseline performance. The optimized configuration was tested for validation and found satisfactory.
Feringa, Jelle; Søndergaard, Asbjørn
Integral structural optimization and fabrication seeks the synthesis of two original approaches; that of topological optimization (TO) and robotic hotwire cutting (HWC) (Mcgee 2011). TO allows for the reduction of up to 70% of the volume of concrete to support a given structure (Sondergaard...... & Dombernowsky 2011). A strength of the method is that it allows to come up with structural designs that lie beyond the grasp of traditional means of design. A design space is a discretized volume, delimiting where the optimization will take place. The number of cells used to discretize the design space thus...
the cost of prime interest being life-cycle cost, climate that is hot or cold, in atmosphere that is humid Chapter 3 discusses helicopter performance...required to satisfy 8-3.2 ENGINE INSTALLATION LOSSES varying climatic and environmental factors. For in- stance, maintenance of the helicopter should be...thammable h aulic , asytem l at mhtproidtem a considering the overall flight mission in segments, dur- source of flammable fluids, as well as electrical
Karthik, K.; Janardhan Reddy, K., Dr
Changes are fundamental to product development. Engineering changes are unavoidable and can arise at any phase of the product life cycle. The consideration of market requirements, customer/user feedbacks, manufacturing constraints, design innovations etc., turning them into viable products can be accomplished when product change is managed properly. In the early design cycle, informal changes are accepted. However, changes become formal when its complexity and cost increases, and as product matures. To maximize the market shares, manufacturers have to effectively and efficiently manage engineering changes by means of Configuration Control. The paper gives a broad overview about ‘Engineering Change Management’ (ECM) through configuration management and its implications in product design. The aim is to give an idea and understanding about the engineering changes in product design scenario to the new researchers. This paper elaborates the significant aspect of managing the engineering changes and the importance of ECM in a product life cycle.
Jordan, Shawn; Pereira, Nielsen
Hands-on learning experiences and interactive learning environments can be effective in teaching K-12 students. Design, in essence, is an interactive, hands-on experience. Engineering design can be taught in the classroom using innovative hands-on projects, such as designing and building serve to teach design, promote creativity, and provide opportunities for hands-on problem solving, in addition to giving students experience working in cooperative teams. In turn, these experiences could enco...
Transformer Engineering: Design, Technology, and Diagnostics, Second Edition helps you design better transformers, apply advanced numerical field computations more effectively, and tackle operational and maintenance issues. Building on the bestselling Transformer Engineering: Design and Practice, this greatly expanded second edition also emphasizes diagnostic aspects and transformer-system interactions. What's New in This Edition Three new chapters on electromagnetic fields in transformers, transformer-system interactions and modeling, and monitoring and diagnostics An extensively revised chap
Manral, Jai; Hossain, Mohammed Alamgir
This paper presents an approach to identify efficient techniques used in Web Search Engine Optimization (SEO). Understanding SEO factors which can influence page ranking in search engine is significant for webmasters who wish to attract large number of users to their website. Different from previous relevant research, in this study we developed an intelligent Meta search engine which aggregates results from various search engines and ranks them based on several important SEO parameters. The r...
Sørensen, John Dalsgaard
The theoretical basis for reliability-based structural optimization within the framework of Bayesian statistical decision theory is briefly described. Reliability-based cost benefit problems are formulated and exemplitied with structural optimization. The basic reliability-based optimization...... problems are generalized to the following extensions: interactive optimization, inspection and repair costs, systematic reconstruction, re-assessment of existing structures. Illustrative examples are presented including a simple introductory example, a decision problem related to bridge re...
Jiang Huawei; Li Yuan; Yan Shuailing
For cable-in-conduit conductor (CICC) structure design, a numeric simulation is proposed for conductor configuration based on optimization of ratio of copper to superconductor. The simulation outcome is in agreement with engineering design one. (authors)
Ulrikkeholm, Jeppe Bjerrum
, the engineering companies need to have efficient engineering design processes in place, so they can design customised product variants faster and more efficiently. It is however not an easy task to model and develop such processes. To conduct engineering design is often a highly iterative, illdefined and complex...... the process can be fully understood and eventually improved. Taking its starting point in this proposition, the outcome of the research is an operational 5-phased procedure for assessing and developing engineering design processes through integrated modelling of product and process, designated IPPM......, and eventually the results are discussed, overall conclusions are made and future research is proposed. The results produced throughout the research project are developed in close collaboration with the Marine Low Speed business unit within the company MAN Diesel & Turbo. The business unit is the world market...
Full Text Available The article presents a pneumatic engine constructed by Angelo Di Pietro. 3D solid models of pneumatic engine components were presented therein. A directional valve is a key element of the control system. The valve functions as a camshaft distributing air to particular engine chambers. The construction designed by Angelo Di Pietro is modern and innovative. A pneumatic engine requires low pressure to start rotary movement. With the use of CFD software, the fields of velocity vectors’ distribution were determined. Moreover, the author determined the distribution of pressure values in engine inlet and outlet channels. CFD model studies on engine operation were conducted for chosen stages of operating cycles. On the basis of simulation tests that were conducted, the values of flow rates for the engine were determined. The distribution of pressure values made it possible to evaluate the torque value on the rotating shaft.
The article presents a pneumatic engine constructed by Angelo Di Pietro. 3D solid models of pneumatic engine components were presented therein. A directional valve is a key element of the control system. The valve functions as a camshaft distributing air to particular engine chambers. The construction designed by Angelo Di Pietro is modern and innovative. A pneumatic engine requires low pressure to start rotary movement. With the use of CFD software, the fields of velocity vectors' distribution were determined. Moreover, the author determined the distribution of pressure values in engine inlet and outlet channels. CFD model studies on engine operation were conducted for chosen stages of operating cycles. On the basis of simulation tests that were conducted, the values of flow rates for the engine were determined. The distribution of pressure values made it possible to evaluate the torque value on the rotating shaft.
The objective of this research was to explore design thinking among teams of high school students. This objective was encompassed in the research question driving the inquiry: How do teams of high school students allocate time across stages of design? Design thinking on the professional level typically occurs in a team environment. Many…
Petersen, Rikke Premer; Buch, Anders
This article aims to explore the challenges that occur from a practice perspective when a new approach to engineering design enters an existing ecology of professional practices in a workplace. Using four empirical episodes, the article illustrates a concrete effort to challenge what counts...... as ‘real engineering’ or what is recognized as part of the engineering expertise. Using an ethnographic, case-studybased research design the article documentshowholistically minded professionals do engineering design ‘by other means’, in ways that strive to promote user experience approaches. The article...... aims to show how engineering practices do not exist in isolation within an organization and how ambitions to transform professional engineering work practices require a change in the very ecologies of practices that exist across an organization...
Full Text Available The design of harbours, as with any other system design, must be an optimization process. In this study, a global examination of the different constraints in coastal engineering was performed and an optimization problem was defined. The problem has multiple objectives, and the criteria to be minimized are the structure cost and wave height disturbance inside a harbour. As concluded in this survey, the constraints are predefined parameters, mandatory constraints or optional constraints. All of these constraints are categorized into four categories: environmental, fluid mechanical, structural and manoeuvring.
Rudbeck, Claus Christian; Esbensen, Peter Kjær; Svendsen, Sv Aa Højgaard
concern which can be seen during the construction of new buildings. People want energy-friendly solutions, but they should be economical optimized. An exonomical optimized building design with respect to energy consumption is the design with the lowest total cost (investment plus operational cost over its...... to evaluate different separate solutions when they interact in the building.When trying to optimize several parameters there is a need for a method, which will show the correct price-performance of each part of a building under design. The problem with not having such a method will first be showed...
Aleong, Richard James Chung Mun
There is a societal need for design education to prepare holistic engineers with the knowledge, skills, and attitudes to innovate and compete globally. Design skills are paramount to the espoused values of higher education, as institutions of higher learning strive to develop in students the cognitive abilities of critical thinking, problem solving, and creativity. To meet these interests from industry and academia, it is important to advance the teaching and learning of engineering design. This research aims to understand how engineering students learn and think about design, as a way for engineering educators to optimize instructional practice and curriculum development. Qualitative research methodology was used to investigate the meaning that engineering students' ascribe to engineering design. The recruitment of participants and corresponding collection of data occurred in two phases using two different data collection techniques. The first phase involved the distribution of a one-time online questionnaire to all first year, third year, and fourth year undergraduate engineering students at three Canadian Universities. After the questionnaire, students were asked if they would be willing to participate in the second phase of data collection consisting of a personal interview. A total of ten students participated in interviews. Qualitative data analysis procedures were conducted on students' responses from the questionnaire and interviews. The data analysis process consisted of two phases: a descriptive phase to code and categorize the data, followed by an interpretative phase to generate further meaning and relationships. The research findings present a conceptual understanding of students' descriptions about engineering design, structured within two educational orientations: a learning studies orientation and a curriculum studies orientation. The learning studies orientation captured three themes of students' understanding of engineering design: awareness
Strimel, Greg Joseph
The intent of this dissertation was to identify the cognitive processes used by advanced pre-engineering students to solve complex engineering design problems. Students in technology and engineering education classrooms are often taught to use an ideal engineering design process that has been generated mostly by educators and curriculum developers. However, the review of literature showed that it is unclear as to how advanced pre-engineering students cognitively navigate solving a complex and multifaceted problem from beginning to end. Additionally, it was unclear how a student thinks and acts throughout their design process and how this affects the viability of their solution. Therefore, Research Objective 1 was to identify the fundamental cognitive processes students use to design, construct, and evaluate operational solutions to engineering design problems. Research Objective 2 was to determine identifiers within student cognitive processes for monitoring aptitude to successfully design, construct, and evaluate technological solutions. Lastly, Research Objective 3 was to create a conceptual technological and engineering problem-solving model integrating student cognitive processes for the improved development of problem-solving abilities. The methodology of this study included multiple forms of data collection. The participants were first given a survey to determine their prior experience with engineering and to provide a description of the subjects being studied. The participants were then presented an engineering design challenge to solve individually. While they completed the challenge, the participants verbalized their thoughts using an established "think aloud" method. These verbalizations were captured along with participant observational recordings using point-of-view camera technology. Additionally, the participant design journals, design artifacts, solution effectiveness data, and teacher evaluations were collected for analysis to help achieve the
Parraguez, Pedro; Maier, Anja
Complex engineering design projects need to manage simultaneously multiple information flows across design activities associated with different areas of the design process. Previous research on this area has mostly focused on either analysing the “required information flows” through activity...... networks at the project level or in studying the social networks that deliver the “actual information flow”. In this paper we propose and empirically test a model and method that integrates both social and activity networks into one compact representation, allowing to compare actual and required...... information flows between design spaces, and to assess the influence that these misalignments could have on the performance of engineering design projects....
Hill-Cunningham, P. Renee; Mott, Michael S.; Hunt, Anna-Blair
STEM education in elementary school is guided by the understanding that engineering represents the application of science and math concepts to make life better for people. The Engineering Design Process (EDP) guides the application of creative solutions to problems. Helping teachers understand how to apply the EDP to create lessons develops a…
Logan, Nikolas; Zhu, Caoxiang
Recent progress in 3D tokamak modeling is now leveraged to create a conceptual design of new external 3D field coils for the DIII-D tokamak. Using the IPEC dominant mode as a target spectrum, the Finding Optimized Coils Using Space-curves (FOCUS) code optimizes the currents and 3D geometry of multiple coils to maximize the total set's resonant coupling. The optimized coils are individually distorted in space, creating toroidal ``arrays'' containing a variety of shapes that often wrap around a significant poloidal extent of the machine. The generalized perturbed equilibrium code (GPEC) is used to determine optimally efficient spectra for driving total, core, and edge neoclassical toroidal viscosity (NTV) torque and these too provide targets for the optimization of 3D coil designs. These conceptual designs represent a fundamentally new approach to 3D coil design for tokamaks targeting desired plasma physics phenomena. Optimized coil sets based on plasma response theory will be relevant to designs for future reactors or on any active machine. External coils, in particular, must be optimized for reliable and efficient fusion reactor designs. Work supported by the US Department of Energy under DE-AC02-09CH11466.
Das, Premadhis; Mandal, Nripes Kumar; Sinha, Bikas Kumar
This book primarily addresses the optimality aspects of covariate designs. A covariate model is a combination of ANOVA and regression models. Optimal estimation of the parameters of the model using a suitable choice of designs is of great importance; as such choices allow experimenters to extract maximum information for the unknown model parameters. The main emphasis of this monograph is to start with an assumed covariate model in combination with some standard ANOVA set-ups such as CRD, RBD, BIBD, GDD, BTIBD, BPEBD, cross-over, multi-factor, split-plot and strip-plot designs, treatment control designs, etc. and discuss the nature and availability of optimal covariate designs. In some situations, optimal estimations of both ANOVA and the regression parameters are provided. Global optimality and D-optimality criteria are mainly used in selecting the design. The standard optimality results of both discrete and continuous set-ups have been adapted, and several novel combinatorial techniques have been applied for...
Crismond, David; Soobyiah, Mark; Cain, Ryan
This article highlights what inquiry and design have in common, and what makes engineering design uniquely different from inquiry. A case study is presented that gives students practice in conducting fair-test experiments, in troubleshooting to learn how to make designs better, and in building science-based explanations for how things work. The…
The INTOR engineering design has been strongly influenced by considerations for assembly and maintenance. A maintenance philosophy was established at the outset of the conceptual design to insure that the tokamak configuration would be developed to accommodate maintenance requirements. The main features of the INTOR design are summarized in this paper with primary emphasis on the impact of maintenance considerations
Khalaf, Kinda; Balawi, Shadi; Hitt, George Wesley; Radaideh, Ahmad
This paper presents an innovative, interdisciplinary, design-and-build course created to improve placement, content, and pedagogy for introductory engineering design education. Infused at the freshman level, the course aims to promote expert design thinking by using problem-based learning (PBL) as the mode of delivery. The course is structured to…
The INTOR engineering design has been strongly influenced by considerations for assembly and maintenance. A maintenance philosophy was established at the outset of the conceptual design to insure that the tokamak configuration would be developed to accommodate maintenance requirements. The main features of the INTOR design are summarized in this paper with primary emphasis on the impact of maintenance considerations
Li, Jie; Fan, Ding; Sreeram, Victor
In order to drastically exploit the potential of the aero engine and improve acceleration performance in the combat state, an on-line optimized controller based on genetic algorithms is designed for an aero engine. For testing the validity of the presented control method, detailed joint simulation tests of the designed controller and the aero engine model are performed in the whole flight envelope. Simulation test results show that the presented control algorithm has characteristics of rapid convergence speed, high efficiency and can fully exploit the acceleration performance potential of the aero engine. Compared with the former controller, the designed on-line optimized controller (DOOC) can improve the security of the acceleration process and greatly enhance the aero engine thrust in the whole range of the flight envelope, the thrust increases an average of 8.1% in the randomly selected working states. The plane which adopts DOOC can acquire better fighting advantage in the combat state.
Restrepo-Giraldo, John Dairo
Studying information usage by design engineers involves considering technical, social, cognitive and volitional factors. This makes it challenging, especially for researchers without a cognitive psychology background. This paper presents a summary of key findings in researching information use...
This report reviews the STSC's recommendations for the selection and usage of software engineering products aimed at the requirements analysis and high-level design portions of the software lifecycle...
Ooteghem, van R.J.C.
Abstract: An optimal climate control has been designed for a solar greenhouse to achieve optimal crop production with sustainable instead of fossil energy. The solar greenhouse extends a conventional greenhouse with an improved roof cover, ventilation with heat recovery, a heat pump, a heat
Enevoldsen, I.; Sørensen, John Dalsgaard
Reliability-based design of structural systems is considered. Especially systems where the reliability model is a series system of parallel systems are analysed. A sensitivity analysis for this class of problems is presented. Direct and sequential optimization procedures to solve the optimization...
Tong, S.S.; Powell, D.; Goel, S.
A new software system called Engineous combines artificial intelligence and numerical methods for the design and optimization of complex aerospace systems. Engineous combines the advanced computational techniques of genetic algorithms, expert systems, and object-oriented programming with the conventional methods of numerical optimization and simulated annealing to create a design optimization environment that can be applied to computational models in various disciplines. Engineous has produced designs with higher predicted performance gains that current manual design processes - on average a 10-to-1 reduction of turnaround time - and has yielded new insights into product design. It has been applied to the aerodynamic preliminary design of an aircraft engine turbine, concurrent aerodynamic and mechanical preliminary design of an aircraft engine turbine blade and disk, a space superconductor generator, a satellite power converter, and a nuclear-powered satellite reactor and shield. 23 refs
The Internet is a widely used source of information for patients searching for medical\\/health care information. While many studies have assessed existing medical\\/health care information on the Internet, relatively few have examined methods for design and delivery of such websites, particularly those aimed at the general public.
This document provides general engineering design guidelines specific to nuclear criticality safety for a facility where the potential for a criticality accident exists. The guide is applicable to the design of new SRP/SRL facilities and to major modifications Of existing facilities. The document is intended an: A guide for persons actively engaged in the design process. A resource document for persons charged with design review for adequacy relative to criticality safety. A resource document for facility operating personnel. The guide defines six basic criticality safety design objectives and provides information to assist in accomplishing each objective. The guide in intended to supplement the design requirements relating to criticality safety contained in applicable Department of Energy (DOE) documents. The scope of the guide is limited to engineering design guidelines associated with criticality safety and does not include other areas of the design process, such as: criticality safety analytical methods and modeling, nor requirements for control of the design process
Mangun, Firdause; Idres, Moumen; Abdullah, Kassim
This paper presents an optimization work on hybrid electric vehicle (HEV) powertrain using Genetic Algorithm (GA) method. It focused on optimization of the parameters of powertrain components including supercapacitors to obtain maximum fuel economy. Vehicle modelling is based on Quasi-Static-Simulation (QSS) backward-facing approach. A combined city (FTP-75)-highway (HWFET) drive cycle is utilized for the design process. Seeking global optimum solution, GA was executed with different initial settings to obtain sets of optimal parameters. Starting from a benchmark HEV, optimization results in a smaller engine (2 l instead of 3 l) and a larger battery (15.66 kWh instead of 2.01 kWh). This leads to a reduction of 38.3% in fuel consumption and 30.5% in equivalent fuel consumption. Optimized parameters are also compared with actual values for HEV in the market.
Zhang, Bo; Sarathy, Mani
This study presents a lifecycle (well-to-wheel) analysis to determine the CO2 emissions associated with ethanol blended gasoline in optimized turbocharged engines. This study provides a more accurate assessment on the best-achievable CO2 emission
The topology optimization method can be used to determine the material distribution in a design domain such that an objective function is maximized and constraints are fulfilled. The method which is based on Finite Element Analysis may be applied to all kinds of material distribution problems like...... extremal material design, sensor and actuator design and MEMS synthesis. The state-of-the-art in topology optimization will be reviewed and older as well as new applications in phononic and photonic crystals design will be presented....
Liu Chengyang; Yan Changqi; Wang Jianjun
The marine steam turbine is one of the key equipment in marine power plant, and it tends to using high power steam turbine, which makes the steam turbine to be heavier and larger, it causes difficulties to the design and arrangement of the steam turbine, and the marine maneuverability is seriously influenced. Therefore, it is necessary to apply optimization techniques to the design of the steam turbine in order to achieve the minimum weight or volume by means of finding the optimum combination of design parameters. The math model of the marine steam turbine design calculation was established. The sensitivities of condenser pressure, power ratio of HP turbine with LP turbine, and the ratio of diameter with height at the end stage of LP turbine, which influence the weight of the marine steam turbine, were analyzed. The optimal design of the marine steam turbine, aiming at the weight minimization while satisfying the structure and performance constraints, was carried out with the hybrid particle swarm optimization algorithm. The results show that, steam turbine weight is reduced by 3.13% with the optimization scheme. Finally, the optimization results were analyzed, and the steam turbine optimization design direction was indicated. (authors)
Sørensen, John Dalsgaard; Thoft-Christensen, Palle; Siemaszko, A.
Interactive design/optimization of large, complex structural systems is considered. The objective function is assumed to model the expected costs. The constraints are reliability-based and/or related to deterministic code requirements. Solution of this optimization problem is divided in four main...... tasks, namely finite element analyses, sensitivity analyses, reliability analyses and application of an optimization algorithm. In the paper it is shown how these four tasks can be linked effectively and how existing information on design variables, Lagrange multipliers and the Hessian matrix can...
Brailov, Aleksandr Yurievich
This professional treatise on engineering graphics emphasizes engineering geometry as the theoretical foundation for communication of design ideas with real world structures and products. It considers each theoretical notion of engineering geometry as a complex solution of direct- and inverse-problems of descriptive geometry and each solution of basic engineering problems presented is accompanied by construction of biunique two- and three-dimension models of geometrical images. The book explains the universal structure of formal algorithms of the solutions of positional, metric, and axonometric problems, as well as the solutions of problems of construction in developing a curvilinear surface. The book further characterizes and explains the added laws of projective connections to facilitate construction of geometrical images in any of eight octants. Laws of projective connections allow constructing the complex drawing of a geometrical image in the American system of measurement and the European system of measu...
Lienau, P.J.; Lunis, B.C.
The Geothermal Direct Use Engineering and Design Guidebook is designed to be a comprehensive, thoroughly practical reference guide for engineers and designers of direct heat projects. These projects could include the conversion of geothermal energy into space heating and cooling of buildings, district heating, greenhouse heating, aquaculture and industrial processing. The Guidebook is directed at understanding the nature of geothermal resources and the exploration of the resources, fluid sampling techniques, drilling, and completion of geothermal wells through well testing, and reservoir evaluation. It presents information useful to engineers on the specification of equipment including well pumps, piping, heat exchangers, space heating equipment, heat pumps and absorption refrigeration. A compilation of current information about greenhouse aquaculture and industrial applications is included together with a discussion of engineering cost analysis, regulation requirements, and environmental consideration. The purpose of the Guidebook is to provide an integrated view for the development of direct use projects for which there is a very large potential in the United States
Lienau, P.J.; Lunis, B.C. (eds.)
The Geothermal Direct Use Engineering and Design Guidebook is designed to be a comprehensive, thoroughly practical reference guide for engineers and designers of direct heat projects. These projects could include the conversion of geothermal energy into space heating and cooling of buildings, district heating, greenhouse heating, aquaculture and industrial processing. The Guidebook is directed at understanding the nature of geothermal resources and the exploration of the resources, fluid sampling techniques, drilling, and completion of geothermal wells through well testing, and reservoir evaluation. It presents information useful to engineers on the specification of equipment including well pumps, piping, heat exchangers, space heating equipment, heat pumps and absorption refrigeration. A compilation of current information about greenhouse aquaculture and industrial applications is included together with a discussion of engineering cost analysis, regulation requirements, and environmental consideration. The purpose of the Guidebook is to provide an integrated view for the development of direct use projects for which there is a very large potential in the United States.
Bloomquist, R.G.; Culver, G.; Ellis, P.F.; Higbee, C.; Kindle, C.; Lienau, P.J.; Lunis, B.C.; Rafferty, K.; Stiger, S.; Wright, P.M.
The Geothermal Direct Use Engineering and Design Guidebook is designed to be a comprehensive, thoroughly practical reference guide for engineers and designers of direct heat projects. These projects could include the conversion of geothermal energy into space heating cooling of buildings, district heating, greenhouse heating, aquaculture and industrial processing. The Guidebook is directed at understanding the nature of geothermal resources and the exploration of these resources, fluid sampling techniques, drilling, and completion of geothermal wells through well testing, and reservoir evaluation. It presents information useful to engineers on the specification of equipment including well pumps, piping, heat exchangers, space heating equipment, heat pumps and absorption refrigeration. A compilation of current information about greenhouse, aquaculture and industrial applications is included together with a discussion of engineering cost analysis, regulation requirements, and environmental considerations. The purpose of the Guidebook is to provide an integrated view for the development of direct use projects for which there is a very potential in the United States.
Full Text Available This paper proposes a novel and robust strategy for the optimal design of the drive system integrated in a wind generators test bench. The PI regulator coefficients used in control systems are usually computed based on simplified hypotheses and then tuned manually so as the system response meet certain specifications in terms of stability, accuracy and speed. The proposed methodology permits the automatic identification of PI regulator coefficients using intelligent optimization algorithms, the initial guess for the search procedure being determined based on particular simplified hypotheses. The proposed procedure can help the design engineers to drastically reduce the effort for finding the best PI regulator coefficients offering a range of feasible solutions depending on the imposed optimum criteria. The characteristics and performances of the optimization strategy are highlighted by using it for the design of a DC motor drive system used to simulate the wind prime mover integrated in a wind generators test bench.
Full Text Available This article discusses a collaborative research and teaching project between the University of Cincinnati, Perkins+Will’s Tech Lab, and the University of North Carolina Greensboro. The primary investigation focuses on the simulation, optimization, and generation of architectural designs using performance-based computational design approaches. The projects examine various design methods, including relationships between building form, performance and the use of proprietary software tools for parametric design.
Bhunia, Uttam, E-mail: firstname.lastname@example.org; Saha, Subimal; Chakrabarti, Alok
Highlights: • The optimization approach minimizes both the magnet size and necessary cable length of a sectored toroidal SMES unit. • Design approach is suitable for low temperature superconducting cable suitable for medium size SMES unit. • It investigates coil parameters with respect to practical engineering aspects. - Abstract: A novel multi-objective optimization design approach for sectored toroidal superconducting magnetic energy storage coil has been developed considering the practical engineering constraints. The objectives include the minimization of necessary superconductor length and torus overall size or volume, which determines a significant part of cost towards realization of SMES. The best trade-off between the necessary conductor length for winding and magnet overall size is achieved in the Pareto-optimal solutions, the compact magnet size leads to increase in required superconducting cable length or vice versa The final choice among Pareto optimal configurations can be done in relation to other issues such as AC loss during transient operation, stray magnetic field at outside the coil assembly, and available discharge period, which is not considered in the optimization process. The proposed design approach is adapted for a 4.5 MJ/1 MW SMES system using low temperature niobium–titanium based Rutherford type cable. Furthermore, the validity of the representative Pareto solutions is confirmed by finite-element analysis (FEA) with a reasonably acceptable accuracy.
Bhunia, Uttam; Saha, Subimal; Chakrabarti, Alok
Highlights: • The optimization approach minimizes both the magnet size and necessary cable length of a sectored toroidal SMES unit. • Design approach is suitable for low temperature superconducting cable suitable for medium size SMES unit. • It investigates coil parameters with respect to practical engineering aspects. - Abstract: A novel multi-objective optimization design approach for sectored toroidal superconducting magnetic energy storage coil has been developed considering the practical engineering constraints. The objectives include the minimization of necessary superconductor length and torus overall size or volume, which determines a significant part of cost towards realization of SMES. The best trade-off between the necessary conductor length for winding and magnet overall size is achieved in the Pareto-optimal solutions, the compact magnet size leads to increase in required superconducting cable length or vice versa The final choice among Pareto optimal configurations can be done in relation to other issues such as AC loss during transient operation, stray magnetic field at outside the coil assembly, and available discharge period, which is not considered in the optimization process. The proposed design approach is adapted for a 4.5 MJ/1 MW SMES system using low temperature niobium–titanium based Rutherford type cable. Furthermore, the validity of the representative Pareto solutions is confirmed by finite-element analysis (FEA) with a reasonably acceptable accuracy
Ayşegül Akdogan Eker
Full Text Available There is a close relationship between material chose and quality in mechanical engineering application like there is in all the other engineering applications. If this relation is balanced then engineering success increases. Material chose comes to fore in the design process most of the time. The two most important responsibilities of the design engineer in here is to chose suitable material and to know the production processes about design. The chose of material of a design that will fulfill the needs all through its life has great importance. It is needed to limit the material applicants by choosing the most suitable ones among variable material. Choosing materials that were examined before and whose behavior is well known provides the designer to feel confident. However since using highly successful materials would increase the competitive power of the designs; designers should follow the developments in materials and know the features of new materials. The description of these features can be interpreted within quality. Quality from the point of engineer is the total fulfillment of expectations.Engineer today are faced with very important problems such as fast technological innovations, a dynamic socio-economical environment, global rivalry. One of the life buoys they stick while trying to solve these problems is total method of quality control. Total Quality model which can provide higher competitive power compared to classical management model brings success only when applied with its whole components. "Approach toward prevention" and "measurement and statistics" have an important place among these elements. The first step of the approach toward prevention composes of design quality and Quality Function Deployment (QFD, or in other words The House of Quality method that will provide this. In this paper; considering the quality function deployment, how the chose of material are done in mechanical engineering applications will be explained.
The Tokamak Physics Experiment (TPX) is designed to develop the scientific basis for a compact and continuously operating tokamak fusion reactor. TPX has a long pulse (1000s) capability, can accommodate high divertor heat loads, has a flexible PF system, and auxiliary heating and current drive systems that make it an ideal test bed for development of attractive reactor concepts. The design incorporates superconducting magnets in both the toroidal and poloidal field magnets. Long pulse deuterium operation will produce 6 x 10 21 neutrons per year requiring remote maintenance of the in-vessel hardware. This paper provides an overview of the TPX Project and describes the design approach with emphasis on salient features of the tokamak
Full Text Available The North Dakota State University, USA, capstone course was developed as a unique model in response to the effort of the Accreditation Board of Engineering and Technology, USA, to streamline and improve design instruction in the curriculum and has steadily evolved to keep pace with the ever-changing technology and the expectations of the profession and the society we serve. A capstone design course by definition should be a design experience for students in the final year before graduation integrating all major design concepts they have learned up until then in the program. Carefully chosen real world projects with design content in all sub-disciplines of civil engineering are assigned in this team-taught course. Faculty and practicing professionals make presentations on design process; project management; leadership in an engineering environment; and public policy; global perspectives in engineering; and professional career and licensure. Practicing professionals also critique the final student presentations. Students work in teams with number of faculty serving as technical consultants, and a faculty mentor for each team to provide non-technical guidance and direction. The course requires students to demonstrate mastery of the curriculum and to work with others in a team environment. Course assessment includes evaluation of the final design, presentations, written technical reports, project design schedule, a project design journal, and reaction papers.
Mok, Ji Won
This dissertation introduces the process of optimizing active twist rotor blades in the presence of embedded anisotropic piezo-composite actuators. Optimum design of active twist blades is a complex task, since it involves a rich design space with tightly coupled design variables. The study presents the development of an optimization framework for active helicopter rotor blade cross-sectional design. This optimization framework allows for exploring a rich and highly nonlinear design space in order to optimize the active twist rotor blades. Different analytical components are combined in the framework: cross-sectional analysis (UM/VABS), an automated mesh generator, a beam solver (DYMORE), a three-dimensional local strain recovery module, and a gradient based optimizer within MATLAB. Through the mathematical optimization problem, the static twist actuation performance of a blade is maximized while satisfying a series of blade constraints. These constraints are associated with locations of the center of gravity and elastic axis, blade mass per unit span, fundamental rotating blade frequencies, and the blade strength based on local three-dimensional strain fields under worst loading conditions. Through pre-processing, limitations of the proposed process have been studied. When limitations were detected, resolution strategies were proposed. These include mesh overlapping, element distortion, trailing edge tab modeling, electrode modeling and foam implementation of the mesh generator, and the initial point sensibility of the current optimization scheme. Examples demonstrate the effectiveness of this process. Optimization studies were performed on the NASA/Army/MIT ATR blade case. Even though that design was built and shown significant impact in vibration reduction, the proposed optimization process showed that the design could be improved significantly. The second example, based on a model scale of the AH-64D Apache blade, emphasized the capability of this framework to
This paper presents the works realized, in course and to realize of Lagoa Real Design, including the works for implantation of Mineral-Industrial complex with the production capacity of 1.000 ton of U sub(3) O sub(8) per year from 1988. (author)
Ahmed, Saeema; Aurisicchio, Marco
This research describes an understanding of design activity through design questions. From a number of previous studies two types of questions have been identified: 1) reasoning questions; and 2) strategic questions. Strategic questions are part of an experienced designers approach to solving a d...... solving model. An example of aerospace engineering design is used to illustrate the argument. The research contributes to an understanding of design activity....
Lobato, Fran Sérgio
This book is aimed at undergraduate and graduate students in applied mathematics or computer science, as a tool for solving real-world design problems. The present work covers fundamentals in multi-objective optimization and applications in mathematical and engineering system design using a new optimization strategy, namely the Self-Adaptive Multi-objective Optimization Differential Evolution (SA-MODE) algorithm. This strategy is proposed in order to reduce the number of evaluations of the objective function through dynamic update of canonical Differential Evolution parameters (population size, crossover probability and perturbation rate). The methodology is applied to solve mathematical functions considering test cases from the literature and various engineering systems design, such as cantilevered beam design, biochemical reactor, crystallization process, machine tool spindle design, rotary dryer design, among others.
In fusion reactors, the blanket design and its characteristics have a major impact on the reactor performance, size, and economics. The selection and arrangement of the blanket materials, dimensions of the different blanket zones, and different requirements of the selected materials for a satisfactory performance are the main parameters, which define the blanket performance. These parameters translate to a large number of variables and design constraints, which need to be simultaneously considered in the blanket design process. This represents a major design challenge because of the lack of a comprehensive design tool capable of considering all these variables to define the optimum blanket design and satisfying all the design constraints for the adopted figure of merit and the blanket design criteria. The blanket design techniques of the First Wall/Blanket/Shield Design and Optimization System (BSDOS) have been developed to overcome this difficulty and to provide the state-of-the-art techniques and tools for performing blanket design and analysis. This report describes some of the BSDOS techniques and demonstrates its use. In addition, the use of the optimization technique of the BSDOS can result in a significant blanket performance enhancement and cost saving for the reactor design under consideration. In this report, examples are presented, which utilize an earlier version of the ITER solid breeder blanket design and a high power density self-cooled lithium blanket design for demonstrating some of the BSDOS blanket design techniques
Steen, H.W.G. van der; Barth, J.E.; Adriaanse, J.P.
An optimization tool for the design of electrostatic lens systems with axial symmetry is presented. This tool is based on the second-order electrode method combined with a multivariable numerical optimization procedure. The second-order electrode method makes a cubic spline approximation to the axial potential for a given electrode shape. With the help of this approximation, a numerical optimization can be done. To demonstrate this optimization tool, a lens system for Auger analyses is optimized. It is shown that variations in the practical constraints imposed on the design, like maximum electrode potential or maximum lens diameter, have strong effects on the obtainable lens quality. It is concluded that a numerical optimization does not take over the lens designer's job, but allows him to thoroughly examine the optical consequences of engineering choices by finding the optimum design for each set of constraints. (orig.)
Ashuri, T.; Van Bussel, G.J.W.; Zaayer, M.B.; Van Kuik, G.A.M.
The purpose of this paper is to integrate the controller design of wind turbines with structure and aerodynamic analysis and use the final product in the design optimization process (DOP) of wind turbines. To do that, the controller design is automated and integrated with an aeroelastic simulation
This paper structures a generic framework to support optimum design for multi-buildings in desert environment. The framework is targeting an environmental friendly design with minimum lifecycle cost, using Genetic Algorithms (Gas). GAs function through a set of success measures which evaluates the design, formulates a proper objective, and reflects possible tangible/intangible constraints. The framework optimizes the design and categorizes it under a certain environmental category at minimum Life Cycle Cost (LCC). It consists of three main modules: (1) a custom Building InformationModel (BIM) for desert buildings with a compatibility checker as a central interactive database; (2) a system evaluator module to evaluate the proposed success measures for the design; and (3) a GAs optimization module to ensure optimum design. The framework functions through three levels: the building components, integrated building, and multi-building levels. At the component level the design team should be able to select components in a designed sequence to ensure compatibility among various components, while at the building level; the team can relatively locate and orient each individual building. Finally, at the multi-building (compound) level the whole design can be evaluated using success measures of natural light, site capacity, shading impact on natural lighting, thermal change, visual access and energy saving. The framework through genetic algorithms optimizes the design by determining proper types of building components and relative buildings locations and orientations which ensure categorizing the design under a specific category or meet certain preferences at minimum lifecycle cost.
Prashant Kumar Patra
Full Text Available The value engineering is the umbrella of the many more sub-system like quality assurance, quality control, quality function design and development for manufacturability. The system engineering & value engineering is two part of the coin. The value engineering is the high level of technology management for every aspect of engineering fields. The value engineering is the high utilization of System Product (i.e. Processor, Memory & Encryption key, Services, Business and Resources at minimal cost. The high end operating system providing highest services at optimal cost & time. The value engineering provides the maximum performance, accountability, reliability, integrity and availability of processor, memory, encryption key and other inter dependency sub-components. The value engineering is the ratio of the maximum functionality of individual components to the optimal cost. VE=k [(P, M, E, C, A]/optimal cost. Where k is the proportionality constant. The VE is directly proportional to performance of individual components and inversely proportional to the minimal cost. The VE is directly proportional to the risk assessment. The VE maximize the business throughput & decision process mean while minimize the risk and down time. We have to develop the dynamic value engineering model & mechanism for risk optimization over a complex real time operating system This proposed composition model definite will be resolve our objective at top high level. Product
Zou, Zheng; Guan, Zhiqiang; Gurgenci, Hal
Highlights: • We proposed a cost model for solar enhanced natural draft dry cooling tower. • We proposed an optimization scheme for this new cooling system. • We optimally designed one for a 50 MW EGS geothermal plant as a demonstration. • Results proved its economic advantages for EGS geothermal application. - Abstract: This paper proposed an optimization scheme for solar enhanced natural draft dry cooling tower design, in which a detailed cost model was proposed including capital, labour, maintenance and operation costs of each component. Based on the developed cost model, the optimal design option can be identified in terms of the relatively lower annual cost and the relatively higher total extra income over the Solar Enhanced Natural Draft Dry Cooling Tower (SENDDCT) lifetime. As a case study, a SENDDCT was optimally designed to meet the cooling demand for a 50 MW geothermal power plant with Engineered Geothermal System (EGS) technology. The results showed that the optimized SENDDCT not only has better cooling performance during the daytime but also is a cost effective option for EGS geothermal power plants
Shilo G. N.
Full Text Available The models of finned radiator are formed by computing aided engineering systems. The relations between sizes of construction elements and boundaries of operability domain are obtained for radiators of minimal mass, minimal volume and minimal overall parameters. Iteration algorithm is used. The non-linear characteristics of weight functions and allowable input heat resistances of radiator are applied in the algorithm. Mass and overall parameters of standard and optimal radiator are defined by different strategies.
Engineers are normally seen as the archetype of people who make decisions in a rational and quantitative way. However, technological design is not value neutral. The way a technology is designed determines its possibilities, which can, for better or for worse, have consequences for human wellbeing.
Monell, Donald W.; Piland, William M.
Past designs of complex aerospace systems involved an environment consisting of collocated design teams with project managers, technical discipline experts, and other experts (e.g. manufacturing and systems operations). These experts were generally qualified only on the basis of past design experience and typically had access to a limited set of integrated analysis tools. These environments provided less than desirable design fidelity, often lead to the inability of assessing critical programmatic and technical issues (e.g., cost risk, technical impacts), and generally derived a design that was not necessarily optimized across the entire system. The continually changing, modern aerospace industry demands systems design processes that involve the best talent available (no matter where it resides) and access to the best design and analysis tools. A solution to these demands involves a design environment referred to as collaborative engineering. The collaborative engineering environment evolving within the National Aeronautics and Space Administration (NASA) is a capability that enables the Agency's engineering infrastructure to interact and use the best state-of-the-art tools and data across organizational boundaries. Using collaborative engineering, the collocated team is replaced with an interactive team structure where the team members are geographically distributed and the best engineering talent can be applied to the design effort regardless of physical location. In addition, a more efficient, higher quality design product is delivered by bringing together the best engineering talent with more up-to-date design and analysis tools. These tools are focused on interactive, multidisciplinary design and analysis with emphasis on the complete life cycle of the system, and they include nontraditional, integrated tools for life cycle cost estimation and risk assessment. NASA has made substantial progress during the last two years in developing a collaborative
Monell, Donald W.; Piland, William M.
Past designs of complex aerospace systems involved an environment consisting of collocated design teams with project managers, technical discipline experts, and other experts (e.g., manufacturing and systems operations). These experts were generally qualified only on the basis of past design experience and typically had access to a limited set of integrated analysis tools. These environments provided less than desirable design fidelity, often led to the inability of assessing critical programmatic and technical issues (e.g., cost, risk, technical impacts), and generally derived a design that was not necessarily optimized across the entire system. The continually changing, modern aerospace industry demands systems design processes that involve the best talent available (no matter where it resides) and access to the best design and analysis tools. A solution to these demands involves a design environment referred to as collaborative engineering. The collaborative engineering environment evolving within the National Aeronautics and Space Administration (NASA) is a capability that enables the Agency's engineering infrastructure to interact and use the best state-of-the-art tools and data across organizational boundaries. Using collaborative engineering, the collocated team is replaced with an interactive team structure where the team members are geographically distributed and the best engineering talent can be applied to the design effort regardless of physical location. In addition, a more efficient, higher quality design product is delivered by bringing together the best engineering talent with more up-to-date design and analysis tools. These tools are focused on interactive, multidisciplinary design and analysis with emphasis on the complete life cycle of the system, and they include nontraditional, integrated tools for life cycle cost estimation and risk assessment. NASA has made substantial progress during the last two years in developing a collaborative
Conway, Erik M
A key issue in history of technology that has received little attention is the use of simulation in engineering design. This article explores the use of both mechanical and numerical simulation in the design of the Mars atmospheric entry phases of the Viking and Mars Pathfinder missions to argue that engineers used both kinds of simulation to develop knowledge of their designs' likely behavior in the poorly known environment of Mars. Each kind of simulation could be used as a warrant of the other's fidelity, in an iterative process of knowledge construction.
Ruiz, David; Díaz-Molina, Alex; Sigmund, Ole
Topology optimization can be used to design piezoelectric actuators by simultaneous design of host structure and polarization profile. Subsequent micro-scale fabrication leads us to overcome important manufacturing limitations: difficulties in placing a piezoelectric layer on both top and bottom...
Pedersen, Niels Leergaard
and the subject of improving the design. The present paper concentrates on the optimization of splines and the predictions of stress concentrations, which are determined by finite element analysis (FEA). Using different design modifications, that do not change the spline load carrying capacity, it is shown...
Ooteghem, van R.J.C.
The research of this thesis was part of a larger project aiming at the design of a greenhouse and an associated climate control that achieves optimal crop production with sustainable instead of fossil energy. This so called solar greenhouse design extends a conventional greenhouse with an improved
Sariyildiz, I.S.; Bittermann, M.S.; Ciftcioglu, O.
A novel approach for performance-based design is presented, where Pareto optimality is pursued. Design requirements may contain linguistic information, which is difficult to bring into computation or make consistent their impartial estimations from case to case. Fuzzy logic and soft computing are
Kumar, P.; Bauer, P.
This work focuses on a design methodology that aids in design and development of complex engineering systems. This design methodology consists of simulation, optimization and decision making. Within this work a framework is presented in which modelling, multi-objective optimization and multi
This monograph presents a tactical planning approach for service network design in metropolitan areas. Designing the service network requires the suitable aggregation of demand data as well as the anticipation of operational relocation decisions. To this end, an integrated approach of data analysis and mathematical optimization is introduced. The book also includes a case study based on real-world data to demonstrate the benefit of the proposed service network design approach. The target audience comprises primarily research experts in the field of traffic engineering, but the book may also be beneficial for graduate students.
Nichols, S.; Kleespies, H.; Wood, K.; Crawford, R.
NASA/USRA is an ongoing sponsor of space design projects in the senior design course of the Mechanical Engineering Department at The University of Texas at Austin. This paper describes the UT senior design sequence, consisting of a design methodology course and a capstone design course. The philosophical basis of this sequence is briefly summarized. A history of the Department's activities in the Advanced Design Program is then presented. The paper concludes with a description of the projects completed during the 1991-92 academic year and the ongoing projects for the Fall 1992 semester.
Full Text Available The method of repeated trial and proofreading is generally used to the convention reducer design, but these methods is low efficiency and the size of the reducer is often large. Aiming the problems, this paper presents an adaptive particle swarm optimization algorithm with foraging behavior, in this method, the bacterial foraging process is introduced into the adaptive particle swarm optimization algorithm, which can provide the function of particle chemotaxis, swarming, reproduction, elimination and dispersal, to improve the ability of local search and avoid premature behavior. By test verification through typical function and the application of the optimization design in the structure of the reducer with discrete and continuous variables, the results are shown that the new algorithm has the advantages of good reliability, strong searching ability and high accuracy. It can be used in engineering design, and has a strong applicability.
Aoki, Takayuki; Mimaki, Hidehito; Oda, Mitsuyuki
In order to deal with the optimization of preservation activities and 'preservation engineering' which makes it possible, the relation between general society and preservation, the content and the structure of preservation activities, and the viewpoint and the approach of the optimization of the preventive preservation are described. The optimization of the preventive preservation is shown respectively in the four stages of planning, implementation, result evaluation and countermeasure. (K. Kato)
Hrishikesh D BACHCHHAV
Full Text Available In this paper, we are present the performance of engine coolant hoses (radiator hoses used in passenger cars by checking various physical behaviours such as hose leakage, hose burst, hose collapse or any mechanical damage as studied-thru design guidelines, CFD analysis and product validation testing and also check pressure drop of the hoses when engine will be running. The design term is more likely used for technical part modelling using CAD tool. Later on, we will focus on the transformation of the part design to process design. The process design term is more likely used for "tooling design" for manufacturing of the product using CAD Tool. Then inlet hose carries coolant from engine to radiator inlet tank, then coolant circulated in radiator and passed through radiator outlet tank to water pump of engine with the help of outlet hose. After that nding any leakage, Burst, damage or collapse of hose and pressure drop of the hose with the help of design checklist, CFD Analysis and product validation testing.
Part 1 of the Electric Utility Engineer`s Flue Gas Desulfurization (FGD) Manual emphasizes the chemical and physical processes that form the basis for design and operation of lime- and limestone-based FGD systems applied to coal- or oil-fired steam electric generating stations. The objectives of Part 1 are: to provide a description of the chemical and physical design basis for lime- and limestone-based wet FGD systems; to identify and discuss the various process design parameters and process options that must be considered in developing a specification for a new FGD system; and to provide utility engineers with process knowledge useful for operating and optimizing a lime- or limestone-based wet FGD system.
Wang, Tao; Gardiner, Bruce S.; Lin, Zhen; Rubenson, Jonas; Kirk, Thomas B.; Wang, Allan; Xu, Jiake; Smith, David W.; Lloyd, David G.; Zheng, Ming H.
Tendon and ligament injury is a worldwide health problem, but the treatment options remain limited. Tendon and ligament engineering might provide an alternative tissue source for the surgical replacement of injured tendon. A bioreactor provides a controllable environment enabling the systematic study of specific biological, biochemical, and biomechanical requirements to design and manufacture engineered tendon/ligament tissue. Furthermore, the tendon/ligament bioreactor system can provide a s...
Turan, Onder [Anadolu University, School of Civil Aviation (Turkey)], e-mail: email@example.com
With the growth of passenger numbers, emissions from the aeronautics sector are increasing and the industry is now working on improving engine efficiency to reduce fuel consumption. The aim of this study is to present the use of genetic algorithms, an optimization method based on biological principles, to optimize the exergetic performance of turbofan engines. The optimization was carried out using exergy efficiency, overall efficiency and specific thrust of the engine as evaluation criteria and playing on pressure and bypass ratio, turbine inlet temperature and flight altitude. Results showed exergy efficiency can be maximized with higher altitudes, fan pressure ratio and turbine inlet temperature; the turbine inlet temperature is the most important parameter for increased exergy efficiency. This study demonstrated that genetic algorithms are effective in optimizing complex systems in a short time.
Długosz, Adam; Klimek, Wiktor
The paper presents an optimal design of UAV wing, made of composite materials. The aim of the optimization is to improve strength and stiffness together with reduction of the weight of the structure. Three different types of functionals, which depend on stress, stiffness and the total mass are defined. The paper presents an application of the in-house implementation of the evolutionary multi-objective algorithm in optimization of the UAV wing structure. Values of the functionals are calculated on the basis of results obtained from numerical simulations. Numerical FEM model, consisting of different composite materials is created. Adequacy of the numerical model is verified by results obtained from the experiment, performed on a tensile testing machine. Examples of multi-objective optimization by means of Pareto-optimal set of solutions are presented.
Shen Wei; Xie Zhongsheng; Yin Banghua
A direct efficient optimization technique has been effected for automatically optimizing the reload of PWR. The objective functions include: maximization of end-of-cycle (EOC) reactivity and maximization of average discharge burnup. The fuel loading optimization and burnable poison (BP) optimization are separated into two stages by using Haling principle. In the first stage, the optimum fuel reloading pattern without BP is determined by the linear programming method using enrichments as control variable, while in the second stage the optimum BP allocation is determined by the flexible tolerance method using the number of BP rods as control variable. A practical and efficient PWR reloading optimization program based on above theory has been encoded and successfully applied to Qinshan Nuclear Power Plant (QNP) cycle 2 reloading design
Jones, E.O.; Freeman, H.D.
A sorbent barrier uses sorbent material such as activated carbon or natural zeolites to prevent the migration of radionuclides from a low-level waste site to the aquifer. The sorbent barrier retards the movement of radioactive contaminants, thereby providing time for the radionuclides to decay. Sorbent barriers can be a simple, effective, and inexpensive method for reducing the migration of radionuclides to the environment. Designing a sorbent barrier consists of using soil and sorbent material properties and site conditions as input to a model which will determine the necessary sorbent barrier thickness to meet contaminant limits. The paper will cover the following areas: techniques for measuring sorption properties of barrier materials and underlying soils, use of a radionuclide transport model to determine the required barrier thickness and performance under a variety of site conditions, and cost estimates for applying the barrier. 8 refs., 6 figs., 1 tab
Jones, E.O.; Freeman, H.D.
A sorbent barrier uses sorbent material such as activated carbon or natural zeolites to prevent the migration of radionuclides from a low-level waste site to the aquifer. The sorbent barrier retards the movement of radioactive contaminants, thereby providing time for the radionuclides to decay. Sorbent barriers can be a simple, effective, and inexpensive method for reducing the migration of radionuclides to the environment. Designing a sorbent barrier consists of using soil and sorbent material properties and site conditions as input to a model which will determine the necessary sorbent barrier thickness to meet contaminant limits. The paper covers the following areas: techniques for measuring sorption properties of barrier materials and underlying soils, use of a radionuclide transport model to determine the required barrier thickness and performance under a variety of site conditions, and cost estimates for applying the barrier
Martins, Joaquim R. R. A.; Kenway, Gaetan K. W.; Burdette, David; Jonsson, Eirikur; Kennedy, Graeme J.
To evaluate new airframe technologies we need design tools based on high-fidelity models that consider multidisciplinary interactions early in the design process. The overarching goal of this NRA is to develop tools that enable high-fidelity multidisciplinary design optimization of aircraft configurations, and to apply these tools to the design of high aspect ratio flexible wings. We develop a geometry engine that is capable of quickly generating conventional and unconventional aircraft configurations including the internal structure. This geometry engine features adjoint derivative computation for efficient gradient-based optimization. We also added overset capability to a computational fluid dynamics solver, complete with an adjoint implementation and semiautomatic mesh generation. We also developed an approach to constraining buffet and started the development of an approach for constraining utter. On the applications side, we developed a new common high-fidelity model for aeroelastic studies of high aspect ratio wings. We performed optimal design trade-o s between fuel burn and aircraft weight for metal, conventional composite, and carbon nanotube composite wings. We also assessed a continuous morphing trailing edge technology applied to high aspect ratio wings. This research resulted in the publication of 26 manuscripts so far, and the developed methodologies were used in two other NRAs. 1
The optimization concepts are described in relation to an overall design process as opposed to a detailed, part-design process where the requirements are firmly stated, the optimization criteria are well established, and a design is known to be feasible. The overall design process starts with the stated requirements. Some of the design criteria are derived directly from the requirements, but others are affected by the design concept. It is these design criteria that define the performance index, or objective function, that is to be minimized within some constraints. In general, there will be multiple objectives, some mutually exclusive, with no clear statement of their relative importance. The optimization loop that is given adjusts the design variables and analyzes the resulting design, in an iterative fashion, until the objective function is minimized within the constraints. This provides a solution, but it is only the beginning. In effect, the problem definition evolves as information is derived from the results. It becomes a learning process as we determine what the physics of the system can deliver in relation to the desirable system characteristics. As with any learning process, an interactive capability is a real attriubute for investigating the many alternatives that will be suggested as learning progresses.
Silva, C. L. M.
The main research objectives of the group are the design and optimization of food processing conditions. Most of the work already developed is on the use of mathematical modeling of transport phenomena and quantification of degradation kinetics as two tools to optimize the final quality of thermally processed food products. Recently, we initiated a project with the main goal of studying the effects of freezing and frozen storage on orange and melon juice pectinesterase activity and q...
Full Text Available Band gap engineering provides an opportunity to not only provide higher overall conversion efficiencies of the reference AM1.5 spectra but also customize PV device design for specific geographic locations and microenvironments based on atmospheric conditions characteristic to that particular location. Indium gallium nitride and other PV materials offer the opportunity for limited bandgap engineering to match spectra. The effects of atmospheric conditions such as aerosols, cloud cover, water vapor, and air mass have been shown to cause variations in spectral radiance that alters PV system performance due to both overrating and underrating. Designing PV devices optimized for spectral radiance of a particular region can result in improved PV system performance. This paper presents a new method for designing geographically optimized PV cells with using a numerical model for bandgap optimization. The geographic microclimate spectrally resolved solar flux for twelve representative atmospheric conditions for the incident radiation angle (zenith angle of 48.1° and fixed array angle of 40° is used to iteratively optimize the band gap for tandem, triple, and quad-layer of InGaN-based multijunction cells. The results of this method are illustrated for the case study of solar farms in the New York region and discussed.
Briggs, Hugh C.
The Aerospace and Defense industry is experiencing an increasing loss of knowledge through workforce reductions associated with business consolidation and retirement of senior personnel. Significant effort is being placed on process definition as part of ISO certification and, more recently, CMMI certification. The process knowledge in these efforts represents the simplest of engineering knowledge and many organizations are trying to get senior engineers to write more significant guidelines, best practices and design manuals. A new generation of design software, known as Product Lifecycle Management systems, has many mechanisms for capturing and deploying a wider variety of engineering knowledge than simple process definitions. These hold the promise of significant improvements through reuse of prior designs, codification of practices in workflows, and placement of detailed how-tos at the point of application.
D. J. Murray-Smith
Full Text Available Artificial neural networks and genetic algorithms are often quoted in discussions about the contribution of biological systems thinking to engineering design. This paper reviews work on the neuromuscular system, a field in which biological systems thinking could make specific contributions to the development and design of automatic control systems for mechatronics and robotics applications. The paper suggests some specific areas in which a better understanding of this biological control system could be expected to contribute to control engineering design methods in the future. Particular emphasis is given to the nonlinear nature of elements within the neuromuscular system and to processes of neural signal processing, sensing and system adaptivity. Aspects of the biological system that are of particular significance for engineering control systems include sensor fusion, sensor redundancy and parallelism, together with advanced forms of signal processing for adaptive and learning control.
Barhm Mohamad; Gabor Szebesi; Betti Bollo
The blending technique used in internal combustion engines can reduce emission of toxic exhaust components and noises, enhance overall energy efficiency and reduce fuel costs. The aim of the study was to compare the effects of dual alcohols (methanol and ethanol) blended in gasoline fuel (GF) against performance, combustion and emission characteristics. Problems arise in the fuel delivery system when using the highly volatile methanol - gasoline blends. This problem is reduced by using specia...
Li Guijiang; Yan Changqi; Wang Jianjun; Liu Chengyang
Genetic algorithm (GA) has been widely applied in nuclear engineering. An improved method, named the mapping crossover genetic algorithm (MCGA), was developed aiming at improving the shortcomings of traditional genetic algorithm (TGA). The optimal results of benchmark problems show that MCGA has better optimizing performance than TGA. MCGA was applied to the reactor coolant pump optimization design. (authors)
Inamdar, S. R.
In this work I present a new type of controller which is an adaptive tracking controller which employs dynamic optimization for optimizing current value of controller action for the temperature control of nonisothermal continuously stirred tank reactor (CSTR). We begin with a two-state model of nonisothermal CSTR which are mass and heat balance equations and then add cooling system dynamics to eliminate input multiplicity. The initial design value is obtained using local stability of steady states where approach temperature for cooling action is specified as a steady state and a design specification. Later we make a correction in the dynamics where material balance is manipulated to use feed concentration as a system parameter as an adaptive control measure in order to avoid actuator saturation for the main control loop. The analysis leading to design of dynamic optimization based parameter adaptive controller is presented. The important component of this mathematical framework is reference trajectory generation to form an adaptive control measure.
Turner, Ken L., Jr.; Kirby, Melissa; Bober, Sue
Engineering design, a framework for studying and solving societal problems, is a key component of STEM education. It is also the area of greatest challenge within the Next Generation Science Standards, NGSS. Many teachers feel underprepared to teach or create activities that feature engineering design, and integrating a lesson plan of core content…
The Journal of Modeling, Design & Management of Engineering Systems publishes original ... systems Electronic/Electrical systems Engineering management systems Fuel and Energy systems Information Technology ... systems Pubic Health systems Software Engineering systems Systems and Industrial Engineering ...
Full Text Available A particle swarm/pattern search hybrid optimizer was used to drive a solid rocket motor modeling code to an optimal solution. The solid motor code models tapered motor geometries using analytical burn back methods by slicing the grain into thin sections along the axial direction. Grains with circular perforated stars, wagon wheels, and dog bones can be considered and multiple tapered sections can be constructed. The hybrid approach to optimization is capable of exploring large areas of the solution space through particle swarming, but is also able to climb “hills” of optimality through gradient based pattern searching. A preliminary method for designing tapered internal geometry as well as tapered outer mold-line geometry is presented. A total of four optimization cases were performed. The first two case studies examines designing motors to match a given regressive-progressive-regressive burn profile. The third case study studies designing a neutrally burning right circular perforated grain (utilizing inner and external geometry tapering. The final case study studies designing a linearly regressive burning profile for right circular perforated (tapered grains.
Jackson, Andrew M.
Engineering design activities are frequently included in technology and engineering classrooms. These activities provide an open-ended context for practicing critical thinking, problem solving, creativity, and innovation---collectively part of the 21st Century Skills which are increasingly needed for success in the workplace. Self-efficacy is a perceptual belief that impacts learning and behavior. It has been shown to directly impact each of these 21st Century Skills but its relation to engineering design is only recently being studied. The purpose of this study was to examine how instructional considerations made when implementing engineering design activities might affect student self-efficacy outcomes in a middle school engineering classroom. Student responses to two self-efficacy inventories related to design, the Engineering Design Self-Efficacy Instrument and Creative Thinking Self-Efficacy Inventory, were collected before and after participation in an engineering design curriculum. Students were also answered questions on specific factors of their experience during the curriculum which teachers may exhibit control over: teamwork and feedback. Results were analyzed using Pearson's correlation coefficients, paired and independent t-tests, and structural equation modeling to better understand patterns for self-efficacy beliefs in students. Results suggested that design self-efficacy and creative thinking self-efficacy are significantly correlated, r(1541) = .783, p classroom strategies for increasing self-efficacy and given specific recommendations related to teamwork and feedback to support students. Finally, although there were weaknesses in the study related to the survey administration, future research opportunities are presented which may build from this work.
Glueckstern, P.; Reed, S.A.; Wilson, J.V.
1 - Description of problem or function: RO75 is a program for the optimization of the design and economics of one- or two-stage seawater reverse osmosis plants. 2 - Method of solution: RO75 evaluates the performance of the applied membrane module (productivity and salt rejection) at assumed operating conditions. These conditions include the site parameters - seawater salinity and temperature, the membrane module operating parameters - pressure and product recovery, and the membrane module predicted long-term performance parameters - lifetime and long flux decline. RO75 calculates the number of first and second stage (if applied) membrane modules needed to obtain the required product capacity and quality and evaluates the required pumping units and the power recovery turbine (if applied). 3 - Restrictions on the complexity of the problem: The program does not optimize or design the membrane properties and the internal structure and flow characteristics of the membrane modules; it assumes operating characteristics defined by the membrane manufacturers
Jones, E J H
Production Engineering: Jig and Tool Design focuses on jig and tool design as part of production engineering and covers topics ranging from inspection and gauging to multiple and consecutive tooling, tool calculation and development of form tools, deep-hole boring, and grinding-wheel form-crushing. Air and oil operated fixtures, negative rake machining, and the economics of jig and fixture practice are also discussed. This text is comprised of 22 chapters; the first of which provides an overview of the function and organization of the jig and tool department. Attention then turns to the subjec
Afaz Uddin Ahmed
Full Text Available A mircostrip antenna is designed for multielement antenna coverage optimization in femtocell network. Interference is the foremost concern for the cellular operator in vast commercial deployments of femtocell. Many techniques in physical, data link and network-layer are analysed and developed to settle down the interference issues. A multielement technique with self-configuration features is analyzed here for coverage optimization of femtocell. It also focuses on the execution of microstrip antenna for multielement configuration. The antenna is designed for LTE Band 7 by using standard FR4 dielectric substrate. The performance of the proposed antenna in the femtocell application is discussed along with results.
A preliminary sensitivity study of the salt repository design has been performed to identify critical site and design parameters to help guide future site characterization and design optimization activities. The study considered the SCP-conceptual design at the Deaf Smith County site in Texas with the horizontal waste package emplacement mode as the base case. Relative to this base case, parameter variations were compared. Limited studies were performed which considered the vertical emplacement mode geometry. The report presents the reference data base and design parameters on which the study was based (including the range of parameters that might be expected). Detailed descriptions of the numerical modeling methods and assumptions are included for the thermal, thermomechanical and hydrogeological analyses. The impacts of parameter variations on the sensitivity of the rock mass response are discussed. Recommendations are provided to help guide site characterization activities and advanced conceptual design optimization activities. 47 refs., 119 refs., 22 tabs
Vinjamuri, Bhavani Prasad; Haware, Rahul V; Stagner, William C
Spray-dried ipratropium bromide (IPB) microspheres for oral inhalation were engineered using Quality by Design. The interrogation of material properties, process parameters, and critical product quality attributes interplay enabled rational product design. A 2 7-3 screening design exhibited the Maillard reaction between L-leucine (LL) and lactose at studied outlet temperatures (OT) >130°C. A response surface custom design was used in conjunction with multicriteria optimization to determine the operating design space to achieve inhalable microparticles. Statistically significant predictive models were developed for volume median diameter (p = 0.0001, adjusted R 2 = 0.9938), span (p = 0.0278, adjusted R 2 = 0.7912), yield (p = 0.0020, adjusted R 2 = 0.9320), and OT (p = 0.0082, adjusted R 2 = 0.8768). An independent verification batch confirmed the model's predictive capability. The prediction and actual values were in good agreement. Particle size and span were 3.32 ± 0.09 μm and 1.71 ± 0.18, which were 4.7 and 5.3% higher than the predicted values. The process yield was 50.3%, compared to the predicted value of 65.3%. The OT was 100°C versus the predicted value of 105°C. The label strength of IPB microparticles was 99.0 to 105.9% w/w suggesting that enrichment occurred during the spray-drying process. The present study can be utilized to initiate the design of the first commercial IPB dry powder inhaler.
Poklonskiy, Alexey A.
Many problems from the fields of accelerator physics and beam theory can be formulated as optimization problems and, as such, solved using optimization methods. Despite growing efficiency of the optimization methods, the adoption of modern optimization techniques in these fields is rather limited. Evolutionary Algorithms (EAs) form a relatively new and actively developed optimization methods family. They possess many attractive features such as: ease of the implementation, modest requirements on the objective function, a good tolerance to noise, robustness, and the ability to perform a global search efficiently. In this work we study the application of EAs to problems from accelerator physics and beam theory. We review the most commonly used methods of unconstrained optimization and describe the GATool, evolutionary algorithm and the software package, used in this work, in detail. Then we use a set of test problems to assess its performance in terms of computational resources, quality of the obtained result, and the tradeoff between them. We justify the choice of GATool as a heuristic method to generate cutoff values for the COSY-GO rigorous global optimization package for the COSY Infinity scientific computing package. We design the model of their mutual interaction and demonstrate that the quality of the result obtained by GATool increases as the information about the search domain is refined, which supports the usefulness of this model. We Giscuss GATool's performance on the problems suffering from static and dynamic noise and study useful strategies of GATool parameter tuning for these and other difficult problems. We review the challenges of constrained optimization with EAs and methods commonly used to overcome them. We describe REPA, a new constrained optimization method based on repairing, in exquisite detail, including the properties of its two repairing techniques: REFIND and REPROPT. We assess REPROPT's performance on the standard constrained
Running-in is a process which can be found in daily lives. This phenomenon occurs after the start of the contact between fresh solid surfaces, resulting in changes in the surface topography, friction and wear. Before the contacting engineering solid surfaces reach a steady-state operation situation this running-n enhances the contact performance. Running-in is very complex and is a vast problem area. A lot of variable occurs in the running-in process, physically, mechanically or chemically. T...
Ruan, Ning; Xing, Wenxun; WCGO-III; Advances in Global Optimization
This proceedings volume addresses advances in global optimization—a multidisciplinary research field that deals with the analysis, characterization, and computation of global minima and/or maxima of nonlinear, non-convex, and nonsmooth functions in continuous or discrete forms. The volume contains selected papers from the third biannual World Congress on Global Optimization in Engineering & Science (WCGO), held in the Yellow Mountains, Anhui, China on July 8-12, 2013. The papers fall into eight topical sections: mathematical programming; combinatorial optimization; duality theory; topology optimization; variational inequalities and complementarity problems; numerical optimization; stochastic models and simulation; and complex simulation and supply chain analysis.
Chaudhary, Kailash; Chaudhary, Himanshu
In this paper, a two stage optimization technique is presented for optimum design of planar slider-crank mechanism. The slider crank mechanism needs to be dynamically balanced to reduce vibrations and noise in the engine and to improve the vehicle performance. For dynamic balancing, minimization of the shaking force and the shaking moment is achieved by finding optimum mass distribution of crank and connecting rod using the equipemental system of point-masses in the first stage of the optimization. In the second stage, their shapes are synthesized systematically by closed parametric curve, i.e., cubic B-spline curve corresponding to the optimum inertial parameters found in the first stage. The multi-objective optimization problem to minimize both the shaking force and the shaking moment is solved using Teaching-learning-based optimization algorithm (TLBO) and its computational performance is compared with Genetic algorithm (GA).
Chaudhary, Kailash; Chaudhary, Himanshu [Malaviya National Institute of Technology, Jaipur (Malaysia)
In this paper, a two stage optimization technique is presented for optimum design of planar slider-crank mechanism. The slider crank mechanism needs to be dynamically balanced to reduce vibrations and noise in the engine and to improve the vehicle performance. For dynamic balancing, minimization of the shaking force and the shaking moment is achieved by finding optimum mass distribution of crank and connecting rod using the equipemental system of point-masses in the first stage of the optimization. In the second stage, their shapes are synthesized systematically by closed parametric curve, i.e., cubic B-spline curve corresponding to the optimum inertial parameters found in the first stage. The multi-objective optimization problem to minimize both the shaking force and the shaking moment is solved using Teaching-learning-based optimization algorithm (TLBO) and its computational performance is compared with Genetic algorithm (GA).
Clark, P. E.; Rilee, M. L.; Curtis, S. A.; Bailin, S.
We are developing Frontier, a highly adaptable, stably reconfigurable, web-accessible intelligent decision engine capable of optimizing design as well as the simulating operation of complex systems in response to evolving needs and environment.
Hoelzel, Robert; Bentley, Phillip M.; Fouquet, Peter
This article describes the design of highly complex physical instruments by using a canonical genetic algorithm (GA). The procedure can be applied to all instrument designs where performance goals can be quantified. It is particularly suited to the optimization of instrument design where local optima in the performance figure of merit are prevalent. Here, a GA is used to evolve the design of the neutron spin-echo spectrometer WASP which is presently being constructed at the Institut Laue-Langevin, Grenoble, France. A comparison is made between this artificial intelligence approach and the traditional manual design methods. We demonstrate that the search of parameter space is more efficient when applying the genetic algorithm, and the GA produces a significantly better instrument design. Furthermore, it is found that the GA increases flexibility, by facilitating the reoptimization of the design after changes in boundary conditions during the design phase. The GA also allows the exploration of 'nonstandard' magnet coil geometries. We conclude that this technique constitutes a powerful complementary tool for the design and optimization of complex scientific apparatus, without replacing the careful thought processes employed in traditional design methods
Hölzel, Robert; Bentley, Phillip M.; Fouquet, Peter
This article describes the design of highly complex physical instruments by using a canonical genetic algorithm (GA). The procedure can be applied to all instrument designs where performance goals can be quantified. It is particularly suited to the optimization of instrument design where local optima in the performance figure of merit are prevalent. Here, a GA is used to evolve the design of the neutron spin-echo spectrometer WASP which is presently being constructed at the Institut Laue-Langevin, Grenoble, France. A comparison is made between this artificial intelligence approach and the traditional manual design methods. We demonstrate that the search of parameter space is more efficient when applying the genetic algorithm, and the GA produces a significantly better instrument design. Furthermore, it is found that the GA increases flexibility, by facilitating the reoptimization of the design after changes in boundary conditions during the design phase. The GA also allows the exploration of "nonstandard" magnet coil geometries. We conclude that this technique constitutes a powerful complementary tool for the design and optimization of complex scientific apparatus, without replacing the careful thought processes employed in traditional design methods.
Full Text Available As a kind of VTOL technology, ducted fan is not only used by many kinds of aircrafts, but also one of the trends of the future aircraft lift system, and attracts more and more attention. For an engine driven ducted fan lift unit, involving the engine and ducted fan matching problem, the form of transmission and transmission ratio are the key design parameters. In order to design and develop a ducted fan aircraft reasonably, a thrust test platform was set up to connect the engine with the ducted fan through the belt driving. The matching relationship between the engine and the transmission system was experimentally studied and the optimal transmission ratio was determined. The results showed that the optimal transmission ratio for the engine 1 is 2.2:1, and for the engine 2, the optimal transmission ratio should be 2.95:1 based on the current ducted and movable blade aerofoil design. At this time, the lift will exceed 130 kg•f, meeting the aircraft's original design requirements.
The Universities Space Research Association (USRA) Advanced Design Program (ADP) program promotes engineering education in the field of design by presenting students with challenging design projects drawn from actual NASA interests. In doing so, the program yields two very positive results. Firstly, the students gain a valuable experience that will prepare them for design problems with which they will be faced in their professional careers. Secondly, NASA is able to use the work done by students as an additional resource in meeting its own design objectives. The 1994 projects include: Universal Test Facility; Automated Protein Crystal Growth Facility; Stiffening of the ACES Deployable Space Boom; Launch System Design for Access to Space; LH2 Fuel Tank Design for SSTO Vehicle; and Feed System Design for a Reduced Pressure Tank.
Hwang, Shun-Fa; Wu, Jen-Chih; He, Rong-Song
To balance the robustness and the convergence speed of optimization, a novel hybrid algorithm consisting of Taguchi method and the steepest descent method is proposed in this work. Taguchi method using orthogonal arrays could quickly find the optimum combination of the levels of various factors, even when the number of level and/or factor is quite large. This algorithm is applied to the inverse determination of elastic constants of three composite plates by combining numerical method and vibration testing. For these problems, the proposed algorithm could find better elastic constants in less computation cost. Therefore, the proposed algorithm has nice robustness and fast convergence speed as compared to some hybrid genetic algorithms.
Tkachenko, A. Yu; Kuz'michev, V. S.; Krupenich, I. N.
The article describes a method for simulating the flight of the aircraft along a predetermined path, establishing a functional connection between the parameters of the working process of gas turbine engine and the efficiency criteria of the aircraft. This connection is necessary for solving the optimization tasks of the conceptual design stage of the engine according to the systems approach. Engine thrust level, in turn, influences the operation of aircraft, thus making accurate simulation of the aircraft behavior during flight necessary for obtaining the correct solution. The described mathematical model of aircraft flight provides the functional connection between the airframe characteristics, working process of gas turbine engines (propulsion system), ambient and flight conditions and flight profile features. This model provides accurate results of flight simulation and the resulting aircraft efficiency criteria, required for optimization of working process and control function of a gas turbine engine.
Papila, Nilay; Shyy, Wei; Griffin, Lisa; Huber, Frank; Tran, Ken; McConnaughey, Helen (Technical Monitor)
In this study, we present a method for optimizing, at the preliminary design level, a supersonic turbine for rocket propulsion system application. Single-, two- and three-stage turbines are considered with the number of design variables increasing from 6 to 11 then to 15, in accordance with the number of stages. Due to its global nature and flexibility in handling different types of information, the response surface methodology (RSM) is applied in the present study. A major goal of the present Optimization effort is to balance the desire of maximizing aerodynamic performance and minimizing weight. To ascertain required predictive capability of the RSM, a two-level domain refinement approach has been adopted. The accuracy of the predicted optimal design points based on this strategy is shown to he satisfactory. Our investigation indicates that the efficiency rises quickly from single stage to 2 stages but that the increase is much less pronounced with 3 stages. A 1-stage turbine performs poorly under the engine balance boundary condition. A portion of fluid kinetic energy is lost at the turbine discharge of the 1-stage design due to high stage pressure ratio and high-energy content, mostly hydrogen, of the working fluid. Regarding the optimization technique, issues related to the design of experiments (DOE) has also been investigated. It is demonstrated that the criteria for selecting the data base exhibit significant impact on the efficiency and effectiveness of the construction of the response surface.
Wang, Tao; Gardiner, Bruce S; Lin, Zhen; Rubenson, Jonas; Kirk, Thomas B; Wang, Allan; Xu, Jiake; Smith, David W; Lloyd, David G; Zheng, Ming H
Tendon and ligament injury is a worldwide health problem, but the treatment options remain limited. Tendon and ligament engineering might provide an alternative tissue source for the surgical replacement of injured tendon. A bioreactor provides a controllable environment enabling the systematic study of specific biological, biochemical, and biomechanical requirements to design and manufacture engineered tendon/ligament tissue. Furthermore, the tendon/ligament bioreactor system can provide a suitable culture environment, which mimics the dynamics of the in vivo environment for tendon/ligament maturation. For clinical settings, bioreactors also have the advantages of less-contamination risk, high reproducibility of cell propagation by minimizing manual operation, and a consistent end product. In this review, we identify the key components, design preferences, and criteria that are required for the development of an ideal bioreactor for engineering tendons and ligaments.
… intended for use as a textbook for an advanced course in software design. Each chapter ends with review questions and references. … provides an overview of the software development process, something that would not be out of line in a course on software engineering including such topics as software process, software management, balancing conflicting values of stakeholders, testing, quality, and ethics. The author has principally focused on software design though, extracting the design phase from the surrounding software development lifecycle. … Software design strategies are addressed
Tiradani, Tiradani,Anthony [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Altunay, Mine [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Dagenhart, David [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Kowalkowski, Jim [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Litvintsev, Dmitry [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Lu, Qiming [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Mhashilkar, Parag [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Moibenko, Alexander [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Paterno, Marc [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Timm, Steven [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
The Decision Engine is a critical component of the HEP Cloud Facility. It provides the functionality of resource scheduling for disparate resource providers, including those which may have a cost or a restricted allocation of cycles. Along with the architecture, design, and requirements for the Decision Engine, this document will provide the rationale and explanations for various design decisions. In some cases, requirements and interfaces for a limited subset of external services will be included in this document. This document is intended to be a high level design. The design represented in this document is not complete and does not break everything down in detail. The class structures and pseudo-code exist for example purposes to illustrate desired behaviors, and as such, should not be taken literally. The protocols and behaviors are the important items to take from this document. This project is still in prototyping mode so flaws and inconsistencies may exist and should be noted and treated as failures.
We study the design and optimization of statically sound and materially efficient space structures constructed by connected beams. We propose a systematic computational framework for the design of space structures that incorporates static soundness, approximation of reference surfaces, boundary alignment, and geometric regularity. To tackle this challenging problem, we first jointly optimize node positions and connectivity through a nonlinear continuous optimization algorithm. Next, with fixed nodes and connectivity, we formulate the assignment of beam cross sections as a mixed-integer programming problem with a bilinear objective function and quadratic constraints. We solve this problem with a novel and practical alternating direction method based on linear programming relaxation. The capability and efficiency of the algorithms and the computational framework are validated by a variety of examples and comparisons.
Jiang, Caigui; Tang, Chengcheng; Seidel, Hans-Peter; Wonka, Peter
We study the design and optimization of statically sound and materially efficient space structures constructed by connected beams. We propose a systematic computational framework for the design of space structures that incorporates static soundness, approximation of reference surfaces, boundary alignment, and geometric regularity. To tackle this challenging problem, we first jointly optimize node positions and connectivity through a nonlinear continuous optimization algorithm. Next, with fixed nodes and connectivity, we formulate the assignment of beam cross sections as a mixed-integer programming problem with a bilinear objective function and quadratic constraints. We solve this problem with a novel and practical alternating direction method based on linear programming relaxation. The capability and efficiency of the algorithms and the computational framework are validated by a variety of examples and comparisons.
Full Text Available Outdoor lighting is an essential service for modern life. However, the high influence of this type of facility on energy consumption makes it necessary to take extra care in the design phase. Therefore, this manuscript describes an algorithm to help light designers to get, in an easy way, the best configuration parameters and to improve energy efficiency, while ensuring a minimum level of overall uniformity. To make this possible, we used a particle swarm optimization (PSO algorithm. These algorithms are well established, and are simple and effective to solve optimization problems. To take into account the most influential parameters on lighting and energy efficiency, 500 simulations were performed using DIALux software (188.8.131.52, DIAL, Ludenscheid, Germany. Next, the relation between these parameters was studied using to data mining software. Subsequently, we conducted two experiments for setting parameters that enabled the best configuration algorithm in order to improve efficiency in the proposed process optimization.
The purpose of this study is to clarify the meaning of the trendy concept in engineering ethics education that ethical problems should be comprehended from the viewpoint of design. First, I present two objections against the concept and the content of it. Second, I examine the concept and show that the essence of it is pragmatic methods. That is, we should understand ethical problems and design problems pragmatically. Finally, I point out that the objections are not true of this pragmatic understanding.
Presents the application of engineering design and analysis based on the approach of understanding the physical characteristics of a given problem and then modeling the important aspects of the physical system. This book covers such topics as contact stress analysis, singularity functions, gear stresses, fasteners, shafts, and shaft stresses.
Buede, Dennis M
The ideal introduction to the engineering design of systems-now in a new edition. The Engineering Design of Systems, Second Edition compiles a wealth of information from diverse sources to provide a unique, one-stop reference to current methods for systems engineering. It takes a model-based approach to key systems engineering design activities and introduces methods and models used in the real world. Features new to this edition include: * The addition of Systems Modeling Language (SysML) to several of the chapters, as well as the introduction of new terminology * Additional material on partitioning functions and components * More descriptive material on usage scenarios based on literature from use case development * Updated homework assignments * The software product CORE (from Vitech Corporation) is used to generate the traditional SE figures and the software product MagicDraw UML with SysML plugins (from No Magic, Inc.) is used for the SysML figures This book is designed to be an introductory reference ...
Love, Tyler S.; Ryan, Larry
Crab cakes and football, that's what Maryland does!" (Abrams, Levy, Panay, & Dobkin, 2005). Although the Old Line State is notorious for harvesting delectable blue crabs, the movie "Wedding Crashers" failed to highlight something else Maryland does well: engineering design competitions. This article discusses how a multistate…
Full Text Available The investigation aims at optimization of gas ejector operation. The goal consists in the improvement of the inflator design so that to enable 50 liters of gas inflation within ~30 milliseconds. For that, an experimental facility was developed and fabricated together with the measurement system to study pressure patterns in the inflator path.
Jensen, Jakob Søndergaard; Sigmund, Ole
In this paper we use topology optimization to design phononic band gap structures. We consider 2D structures subjected to periodic loading and obtain the distribution of two materials with high contrast in material properties that gives the minimal vibrational response of the structure. Both in...
Pedersen, Pauli; Pedersen, Niels Leergaard
For thermoelastic structures the same optimal design does not simultaneously lead to minimum compliance and maximum strength. Compliance may be a questionable objective and focus for the present paper is on the important aspect of strength, quantified as minimization of the maximum von Mises stre...... loads are appended....
Jones, C.; Mount, R. E.
The power section for an advanced rotary stratified-charge general aviation engine has been designed under contract to NASA. The single-rotor research engine of 40 cubic-inches displacement (RCI-40), now being procured for test initiation this summer, is targeted for 320 T.O. horse-power in a two-rotor production engine. The research engine is designed for operating on jet-fuel, gasoline or diesel fuel and will be used to explore applicable advanced technologies and to optimize high output performance variables. Design of major components of the engine is described in this paper.
He, Lu; Friedman, Alan M.; Bailey-Kellogg, Chris
In developing improved protein variants by site-directed mutagenesis or recombination, there are often competing objectives that must be considered in designing an experiment (selecting mutations or breakpoints): stability vs. novelty, affinity vs. specificity, activity vs. immunogenicity, and so forth. Pareto optimal experimental designs make the best trade-offs between competing objectives. Such designs are not “dominated”; i.e., no other design is better than a Pareto optimal design for one objective without being worse for another objective. Our goal is to produce all the Pareto optimal designs (the Pareto frontier), in order to characterize the trade-offs and suggest designs most worth considering, but to avoid explicitly considering the large number of dominated designs. To do so, we develop a divide-and-conquer algorithm, PEPFR (Protein Engineering Pareto FRontier), that hierarchically subdivides the objective space, employing appropriate dynamic programming or integer programming methods to optimize designs in different regions. This divide-and-conquer approach is efficient in that the number of divisions (and thus calls to the optimizer) is directly proportional to the number of Pareto optimal designs. We demonstrate PEPFR with three protein engineering case studies: site-directed recombination for stability and diversity via dynamic programming, site-directed mutagenesis of interacting proteins for affinity and specificity via integer programming, and site-directed mutagenesis of a therapeutic protein for activity and immunogenicity via integer programming. We show that PEPFR is able to effectively produce all the Pareto optimal designs, discovering many more designs than previous methods. The characterization of the Pareto frontier provides additional insights into the local stability of design choices as well as global trends leading to trade-offs between competing criteria. PMID:22180081
Herbst, L.; Hinz, W.
The concept for modern plant control rooms is primary influenced by: The automation of protection, binary control and closed loop control functions; organization employing functional areas; computer based information processing; human engineered design. Automation reduces the human work load. Employment of functional areas permits optimization of operational sequences. Computer based information processing makes it possible to output information in accordance with operating requirements. Design based on human engineering principles assures the quality of the interaction between the operator and the equipment. The degree to which these conceptional features play a role in design of power plant control rooms depends on the unit rating, the mode of operation and on the requirements respecting safety and availability of the plant. (orig.)
Rony Baskoro Lukito
Full Text Available The purpose of this research is how to optimize a web design that can increase the number of visitors. The number of Internet users in the world continues to grow in line with advances in information technology. Products and services marketing media do not just use the printed and electronic media. Moreover, the cost of using the Internet as a medium of marketing is relatively inexpensive when compared to the use of television as a marketing medium. The penetration of the internet as a marketing medium lasted for 24 hours in different parts of the world. But to make an internet site into a site that is visited by many internet users, the site is not only good from the outside view only. Web sites that serve as a medium for marketing must be built with the correct rules, so that the Web site be optimal marketing media. One of the good rules in building the internet site as a marketing medium is how the content of such web sites indexed well in search engines like google. Search engine optimization in the index will be focused on the search engine Google for 83% of internet users across the world using Google as a search engine. Search engine optimization commonly known as SEO (Search Engine Optimization is an important rule that the internet site is easier to find a user with the desired keywords.
Sluder, C. Scott [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Moriarty, Kristi [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jehlik, Forrest [Argonne National Lab. (ANL), Argonne, IL (United States); West, Brian H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
This report examines diesel/gasoline misfueling, leaded/unleaded gasoline misfueling, E85/E15/E10 misfueling, and consumer selection of regular grade fuel over premium grade fuel in an effort to evaluate misfueling technologies that may be needed to support the introduction of vehicles optimized for a new fuel in the marketplace. This is one of a series of reports produced as a result of the Co-Optimization of Fuels & Engines (Co-Optima) project, a Department of Energy-sponsored multi-agency project to accelerate the introduction of affordable, scalable, and sustainable biofuels and high-efficiency, low-emission vehicle engines.
Jones, Daniel Ray
Liquid rocket engines are highly reliable, controllable, and efficient compared to other conventional forms of rocket propulsion. As such, they have seen wide use in the space industry and have become the standard propulsion system for launch vehicles, orbit insertion, and orbital maneuvering. Though these systems are well understood, historical optimization techniques are often inadequate due to the highly non-linear nature of the engine performance problem. In this thesis, a Particle Swarm Optimization (PSO) variant was applied to maximize the specific impulse of a finite-area combustion chamber (FAC) equilibrium flow rocket performance model by controlling the engine's oxidizer-to-fuel ratio and de Laval nozzle expansion and contraction ratios. In addition to the PSO-controlled parameters, engine performance was calculated based on propellant chemistry, combustion chamber pressure, and ambient pressure, which are provided as inputs to the program. The performance code was validated by comparison with NASA's Chemical Equilibrium with Applications (CEA) and the commercially available Rocket Propulsion Analysis (RPA) tool. Similarly, the PSO algorithm was validated by comparison with brute-force optimization, which calculates all possible solutions and subsequently determines which is the optimum. Particle Swarm Optimization was shown to be an effective optimizer capable of quick and reliable convergence for complex functions of multiple non-linear variables.
Engineers are normally seen as the archetype of people who make decisions in a rational and quantitative way. However, technological design is not value neutral. The way a technology is designed determines its possibilities, which can, for better or for worse, have consequences for human wellbeing. This leads various scholars to the claim that engineers should explicitly take into account ethical considerations. They are at the cradle of new technological developments and can thereby influence the possible risks and benefits more directly than anybody else. I have argued elsewhere that emotions are an indispensable source of ethical insight into ethical aspects of risk. In this paper I will argue that this means that engineers should also include emotional reflection into their work. This requires a new understanding of the competencies of engineers: they should not be unemotional calculators; quite the opposite, they should work to cultivate their moral emotions and sensitivity, in order to be engaged in morally responsible engineering. © The Author(s) 2010. This article is published with open access at Springerlink.com
Tajima, Hiroyasu; Hayashi, Masahito
The optimal efficiency of quantum (or classical) heat engines whose heat baths are n-particle systems is given by the strong large deviation. We give the optimal work extraction process as a concrete energy-preserving unitary time evolution among the heat baths and the work storage. We show that our optimal work extraction turns the disordered energy of the heat baths to the ordered energy of the work storage, by evaluating the ratio of the entropy difference to the energy difference in the heat baths and the work storage, respectively. By comparing the statistical mechanical optimal efficiency with the macroscopic thermodynamic bound, we evaluate the accuracy of the macroscopic thermodynamics with finite-size heat baths from the statistical mechanical viewpoint. We also evaluate the quantum coherence effect on the optimal efficiency of the cycle processes without restricting their cycle time by comparing the classical and quantum optimal efficiencies.
This book presents the theoretical details and computational performances of algorithms used for solving continuous nonlinear optimization applications imbedded in GAMS. Aimed toward scientists and graduate students who utilize optimization methods to model and solve problems in mathematical programming, operations research, business, engineering, and industry, this book enables readers with a background in nonlinear optimization and linear algebra to use GAMS technology to understand and utilize its important capabilities to optimize algorithms for modeling and solving complex, large-scale, continuous nonlinear optimization problems or applications. Beginning with an overview of constrained nonlinear optimization methods, this book moves on to illustrate key aspects of mathematical modeling through modeling technologies based on algebraically oriented modeling languages. Next, the main feature of GAMS, an algebraically oriented language that allows for high-level algebraic representation of mathematical opti...
Miyauchi, S; Matsumoto, H; Sano, M; Kassai, N; Zhu, B; Luo, X; Piao, B
As for pump impellers, the meridional flow channel and blade-to-blade flow channel, which are relatively independent of each other but greatly affect performance, are designed in parallel. And the optimization design is used for the former and the inverse design is used for the latter. To verify this new design method, a mixed-flow impeller was made. Next, we use Tani's inverse design method for the blade loading of inverse design. It is useful enough to change a deceleration rate freely and greatly. And it can integrally express the rear blade loading of various methods by NACA, Zangeneh and Stratford. We controlled the deceleration rate by shape parameter m, and its value became almost same with Tani's recommended value of the laminar airfoil.
Harding, D.C.; Witkowski, W.R.
Since the design of transportation packages involves a complex coupling of structural, thermal and radiation shielding analyses and must follow very strict design constraints, numerical optimization provides the potential for more efficient container designs. In numerical optimization, the requirements of the design problem are mathematically formulated through the use of an objective function and constraints. The objective function(s), e.g., package weight, cost, volume, or combination thereof, is the function to be minimized or maximized by altering a set of design variables that define the package's shape and dimensions. Constraints are limitations on the performance of the system, such as resisting structural and thermal accident environments. Two constraints defined for an example wire mesh composite Type B package are: 1) deformation in the containment vessel seal region remains small enough throughout the 10 CFR-71 accident conditions to meet containment criteria, and 2) the elastomeric seal region remains below its operational temperature limit to guarantee seal integrity in the fire environment. The first constraint of a minimum energy absorbing layer thickness is evaluated with finite element analyses of the proposed dynamic crush accident criteria. The second constraint is evaluated with a 1-D transient thermal finite difference code parametrized for variable composite layer thicknesses, and is integrated with the optimization process. (J.P.N.)
Blasques, José Pedro Albergaria Amaral
model for the analysis of laminated composite beams is proposed. The structural analysis is performed in a beam finite element context. The development of a finite element based tool for the analysis of the cross section stiffness properties is described. The resulting beam finite element formulation...... is able to account for the effects of material anisotropy and inhomogeneity in the global response of the beam. Beam finite element models allow for a significant reduction in problem size and are therefore an efficient alternative in computationally intensive applications like optimization frameworks...... design of laminated composite beams. The devised framework is applied in the optimal design of laminated composite beams with different cross section geometries and subjected to different load cases. Design criteria such as beam stiffness, weight, magnitude of the natural frequencies of vibration...
systems engineering process models (Blanchard & Fabrycky, 1990) and the majority of engineering design education (Dym et al., 2005). The waterfall model ...Engineering Career Competency Model Clifford Whitcomb, Systems Engineering Professor, NPS Corina White, Systems Engineering Research Associate, NPS...Postgraduate School (NPS) in Monterey, CA. He teaches and conducts research in the design of enterprise systems, systems modeling , and system
Herbst, L.; Hinz, W.
Automation reduces the human work load. Employment of functional areas permits optimization of operational sequences. Computer based information processing makes it possible to output information in accordance with operating requirements. Design based on human engineering principles assures the quality of the interaction between the operator and the equipment. The degree to which these conceptional features play a role in design of power plant control rooms depends on the unit rating, the mode of operation and on the requirements respecting safety and availability of the plant. (orig./RW)
Konstantinos V. Katsikopoulos
Full Text Available I show how the coherence/correspondence distinction can inform the conversation about decision methods for engineering design. Some engineers argue for the application of multi-attribute utility theory while others argue for what they call heuristics. To clarify the differences among methods, I first ask whether each method aims at achieving coherence or correspondence. By analyzing statements in the design literature, I argue that utility theory aims at achieving coherence and heuristics aim at achieving correspondence. Second, I ask if achieving coherence always implies achieving correspondence. It is important to provide an answer because while in design the objective is correspondence, it is difficult to assess it, and coherence that is easier to assess is used as a surrogate. I argue that coherence does not always imply correspondence in design and that this is also the case in problems studied in judgment and decision-making research. Uncovering the conditions under which coherence implies, or does not imply, correspondence is a topic where engineering design and judgment and decision-making research might connect.
Prabir K. Basudhar
Full Text Available The study pertains to the optimal cost-analysis and design of a circular footing subjected to generalized loadings using sequential unconstrained minimization technique (SUMT in conjunction with Powell’s conjugate direction method for multidimensional search and quadratic interpolation method for one dimensional minimization. The cost of the footing is minimized satisfying all the structural and geotechnical engineering design considerations. As extended penalty function method has been used to convert the constrained problem into an unconstrained one, the developed technique is capable of handling both feasible and infeasible initial design vector. The net saving in cost starting from the best possible manual design ranges from 10 to 20 %. For all practical purposes, the optimum cost is independent of the initial design point. It was observed that for better convergence, the transition parameter should be chosen at least 100 times the initial penalty parameter kr .
Gu, Yuanxian; Chen, Biaosong; Zhang, Hongwu; Zhao, Guozhong
The numerical method of design optimization for structural thermally induced vibration is originally studied in this paper and implemented in application software JIFEX. The direct and adjoint methods of sensitivity analysis for thermal induced vibration coupled with both linear and nonlinear transient heat conduction is firstly proposed. Based on the finite element method, the structural linear dynamics is treated simultaneously with coupled linear and nonlinear transient heat structural linear dynamics is treated simultaneously with coupled linear and nonlinear transient heat conduction. In the thermal analysis model, the nonlinear heat conduction considered is result from the radiation and temperature-dependent materials. The sensitivity analysis of transient linear and nonlinear heat conduction is performed with the precise time integration method. And then, the sensitivity analysis of structural transient dynamics is performed by the Newmark method. Both the direct method and the adjoint method are employed to derive the sensitivity equations of thermal vibration, and there are two adjoint vectors of structure and heat conduction respectively. The coupling effect of heat conduction on thermal vibration in the sensitivity analysis is particularly investigated. With coupling sensitivity analysis, the optimization model is constructed and solved by the sequential linear programming or sequential quadratic programming algorithm. The methods proposed have been implemented in the application software JIFEX of structural design optimization, and numerical examples are given to illustrate the methods and usage of structural design optimization on thermally induced vibration
Full Text Available Expedience of probabilistic durability concepts and approaches in advanced engineering design of building materials, structural members and systems is considered. Target margin values of structural safety and serviceability indices are analyzed and their draft values are presented. Analytical methods of the cumulative coefficient of correlation and the limit transient action effect for calculation of reliability indices are given. Analysis can be used for probabilistic durability assessment of carrying and enclosure metal, reinforced concrete, wood, plastic, masonry both homogeneous and sandwich or composite structures and some kinds of equipments. Analysis models can be applied in other engineering fields.
Ashok, Amit; Neifeld, Mark A
Undersampling in the detector array degrades the performance of iris-recognition imaging systems. We find that an undersampling of 8 x 8 reduces the iris-recognition performance by nearly a factor of 4 (on CASIA iris database), as measured by the false rejection ratio (FRR) metric. We employ optical point spread function (PSF) engineering via a Zernike phase mask in conjunction with multiple subpixel shifted image measurements (frames) to mitigate the effect of undersampling. A task-specific optimization framework is used to engineer the optical PSF and optimize the postprocessing parameters to minimize the FRR. The optimized Zernike phase enhanced lens (ZPEL) imager design with one frame yields an improvement of nearly 33% relative to a thin observation module by bounded optics (TOMBO) imager with one frame. With four frames the optimized ZPEL imager achieves a FRR equal to that of the conventional imager without undersampling. Further, the ZPEL imager design using 16 frames yields a FRR that is actually 15% lower than that obtained with the conventional imager without undersampling.
This paper investigates the role of constraints in limiting and enhancing creativity in engineering design. Based on a review of literature relating constraints to creativity, the paper presents a longitudinal participatory study from Coloplast A/S, a major international producer of disposable...... and ownership of formal constraints played a crucial role in defining their influence on creativity – along with the tacit constraints held by the designers. The designers were found to be highly constraint focused, and four main creative strategies for constraint manipulation were observed: blackboxing...
Campbell, C. Warren
The purpose of this effort was to develop a finite element code for the analysis and design of permanent magnet electric motors. These motors would drive electromechanical actuators in advanced rocket engines. The actuators would control fuel valves and thrust vector control systems. Refurbishing the hydraulic systems of the Space Shuttle after each flight is costly and time consuming. Electromechanical actuators could replace hydraulics, improve system reliability, and reduce down time.
Roth, Brian Douglas
Significant progress has been made toward the development of multidisciplinary design optimization (MDO) methods that are well-suited to practical large-scale design problems. However, opportunities exist for further progress. This thesis describes the development of enhanced collaborative optimization (ECO), a new decomposition-based MDO method. To support the development effort, the thesis offers a detailed comparison of two existing MDO methods: collaborative optimization (CO) and analytical target cascading (ATC). This aids in clarifying their function and capabilities, and it provides inspiration for the development of ECO. The ECO method offers several significant contributions. First, it enhances communication between disciplinary design teams while retaining the low-order coupling between them. Second, it provides disciplinary design teams with more authority over the design process. Third, it resolves several troubling computational inefficiencies that are associated with CO. As a result, ECO provides significant computational savings (relative to CO) for the test cases and practical design problems described in this thesis. New aircraft development projects seldom focus on a single set of mission requirements. Rather, a family of aircraft is designed, with each family member tailored to a different set of requirements. This thesis illustrates the application of decomposition-based MDO methods to aircraft family design. This represents a new application area, since MDO methods have traditionally been applied to multidisciplinary problems. ECO offers aircraft family design the same benefits that it affords to multidisciplinary design problems. Namely, it simplifies analysis integration, it provides a means to manage problem complexity, and it enables concurrent design of all family members. In support of aircraft family design, this thesis introduces a new wing structural model with sufficient fidelity to capture the tradeoffs associated with component
Mellish, J. A.
The performance optimization of expander cycle engines at vacuum thrust levels of 10K, 15K, and 20K lb is discussed. The optimization is conducted for a maximum engine length with an extendible nozzle in the retracted position of 60 inches and an engine mixture ratio of 6.0:1. The thrust chamber geometry and cycle analyses are documented. In addition, the sensitivity of a recommended baseline expander cycle to component performance variations is determined and chilldown/start propellant consumptions are estimated.
Sun, Chunling; Ma, Susu; Zhong, Weichao
Quota design is one of the effective methods of cost control in real estate development project and widely used in the current real estate development project to control the engineering construction cost, but quota design have many deficiencies in design process. For this purpose, this paper put forward a method to achieve investment control of real estate development project, which combine quota design and value engineering(VE) at the stage of design. Specifically, it’s an optimizing for the structure of quota design. At first, determine the design limits by investment estimate value, then using VE to carry on initial allocation of design limits and gain the functional target cost, finally, consider the whole life cycle cost (LCC) and operational problem in practical application to finish complex correction for the functional target cost. The improved process can control the project cost more effectively. It not only can control investment in a certain range, but also make the project realize maximum value within investment.
Janes, Kevin A; Chandran, Preethi L; Ford, Roseanne M; Lazzara, Matthew J; Papin, Jason A; Peirce, Shayn M; Saucerman, Jeffrey J; Lauffenburger, Douglas A
Measuring and modeling the integrated behavior of biomolecular-cellular networks is central to systems biology. Over several decades, systems biology has been shaped by quantitative biologists, physicists, mathematicians, and engineers in different ways. However, the basic and applied versions of systems biology are not typically distinguished, which blurs the separate aspirations of the field and its potential for real-world impact. Here, we articulate an engineering approach to systems biology, which applies educational philosophy, engineering design, and predictive models to solve contemporary problems in an age of biomedical Big Data. A concerted effort to train systems bioengineers will provide a versatile workforce capable of tackling the diverse challenges faced by the biotechnological and pharmaceutical sectors in a modern, information-dense economy.
Rasdorf, W. J.
Various perspectives are given of the knowledge currently used in engineering design, specifically dealing with knowledge-based expert systems (KBES). Constructing an expert system often reveals inconsistencies in domain knowledge while formalizing it. The types of domain knowledge (facts, procedures, judgments, and control) differ from the classes of that knowledge (creative, innovative, and routine). The feasible tasks for expert systems can be determined based on these types and classes of knowledge. Interpretive tasks require reasoning about a task in light of the knowledge available, where generative tasks create potential solutions to be tested against constraints. Only after classifying the domain by type and level can the engineer select a knowledge-engineering tool for the domain being considered. The critical features to be weighed after classification are knowledge representation techniques, control strategies, interface requirements, compatibility with traditional systems, and economic considerations.
Richard P. TING
Full Text Available A study designed, fabricated, and optimized performance of a jatropha sheller, consisting of mainframe, rotary cylinder, stationary cylinder, transmission system. Evaluation and optimization considered moisture content, clearance, and roller speed as independent parameters while the responses comprised of recovery, bulk density factor, shelling capacity, energy utilization of sheller, whole kernel recovery, oil recovery, and energy utilization by extruder.Moisture content failed to affect the response variables. The clearance affected response variables except energy utilization of the extruder. Roller speed affected shelling capacity, whole kernel recovery, and energy utilization of the extruder. Optimization resulted in operating conditions of 9.5%wb moisture content, clearance of 6 mm, and roller speed of 750 rpm.
Perwaiz, A.; Khan, S.A.
This paper proposes a technique custom to the optimization requirements suited for a particular family of Field Programmable Gate Arrays (FPGAs). As FPGAs have introduced re configurable black boxes there is a need to perform optimization across FPGAs slice fabric in order to achieve optimum performance. Though the Register Transfer Level (RTL) Hardware Descriptive Language (HDL) code should be technology independent but in many design instances it is imperative to understand the target technology especially once the target device embeds dedicated arithmetic blocks. No matter what the degree of optimization of the algorithm is, the configuration of target device plays an important role as far as the device utilization and path delays are concerned Index Terms: Field Programmable Gate Arrays (FPGA), Compression Tree, Bit Width Reduction, Look Ahead Pipelining. (author)
Moody, Mia; Bates, Elizabeth
Enough evidence is available to support the idea that public relations professionals must possess search engine optimization (SEO) skills to assist clients in a full-service capacity; however, little research exists on how much college students know about the tactic and best practices for incorporating SEO into course curriculum. Furthermore, much…
Willems, F.P.T.; Donkers, M.C.F.; Kupper, F.
This study presents an integrated energy and emission management strategy for a Euro-VI diesel engine with Waste Heat Recovery (WHR) system. This Integrated Powertrain Control (IPC) strategy optimizes the CO2-NOx trade-off by minimizing the operational costs associated with fuel and AdBlue
Willems, F.P.T.; Donkers, M.C.F.; Kupper, F.; Waschl, H.; Kolmanovsky, I.; Steinbuch, M.; Del Re, L.
This study presents an integrated energy and emission management strategy for a Euro-VI diesel engine with Waste Heat Recovery (WHR) system. This Integrated Powertrain Control (IPC) strategy optimizes the CO 2 - NO x trade-off by minimizing the operational costs associated with fuel and AdBlue
Clarke, Theresa B.; Clarke, Irvine, III
Despite an increase in ad spending and demand for employees with expertise in search engine optimization (SEO), methods for teaching this important marketing strategy have received little coverage in the literature. Using Bloom's cognitive goals hierarchy as a framework, this experiential assignment provides a process for educators who may be new…
Miskimin, P.A.; Shepard, M.
The purpose of this presentation is to describe a fully optimized application of systems engineering methods and philosophy to the management of a large nuclear waste repository project. Knowledge gained from actual experience with the use of the systems approach on two repository projects is incorporated in the material presented. The projects are currently evaluating the isolation performance of different geologic settings and are in different phases of maturity. Systems engineering methods were applied by the principal author at the Waste Isolation Pilot Plant (WIPP) in the form of a functional analysis. At the Basalt Waste Isolation Project (BWIP), the authors assisted the intergrating contractor with the development and application of systems engineering methods. Based on this experience and that acquired from other waste management projects, an optimized plan for applying systems engineering techniques was developed. The plan encompasses the following aspects: project organization, developing and defining requirements, assigning work responsibilities, evaluating system performance, quality assurance, controlling changes, enhancing licensability, optimizing project performance, and addressing regulatory issues. This information is presented in the form of a roadmap for the practical application of system engineering principles to a nuclear waste repository project
Punnathanam, Varun; Kotecha, Prakash
Highlights: • Multi-objective optimization of three recent Stirling engine models. • Use of efficient crossover and mutation operators for real coded Genetic Algorithm. • Demonstrated supremacy of the strategy over the conventionally used algorithm. • Improvements of up to 29% in comparison to literature results. - Abstract: In this article we demonstrate the supremacy of the Non-dominated Sorting Genetic Algorithm-II with Simulated Binary Crossover and Polynomial Mutation operators for the multi-objective optimization of Stirling engine systems by providing three examples, viz., (i) finite time thermodynamic model, (ii) Stirling engine thermal model with associated irreversibility and (iii) polytropic finite speed based thermodynamics. The finite time thermodynamic model involves seven decision variables and consists of three objectives: output power, thermal efficiency and rate of entropy generation. In comparison to literature, it was observed that the used strategy provides a better Pareto front and leads to improvements of up to 29%. The performance is also evaluated on a Stirling engine thermal model which considers the associated irreversibility of the cycle and consists of three objectives involving eleven decision variables. The supremacy of the suggested strategy is also demonstrated on the experimentally validated polytropic finite speed thermodynamics based Stirling engine model for optimization involving two objectives and ten decision variables.
Man, Jun [Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou China; Zhang, Jiangjiang [Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou China; Li, Weixuan [Pacific Northwest National Laboratory, Richland Washington USA; Zeng, Lingzao [Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou China; Wu, Laosheng [Department of Environmental Sciences, University of California, Riverside California USA
The ensemble Kalman filter (EnKF) has been widely used in parameter estimation for hydrological models. The focus of most previous studies was to develop more efficient analysis (estimation) algorithms. On the other hand, it is intuitively understandable that a well-designed sampling (data-collection) strategy should provide more informative measurements and subsequently improve the parameter estimation. In this work, a Sequential Ensemble-based Optimal Design (SEOD) method, coupled with EnKF, information theory and sequential optimal design, is proposed to improve the performance of parameter estimation. Based on the first-order and second-order statistics, different information metrics including the Shannon entropy difference (SD), degrees of freedom for signal (DFS) and relative entropy (RE) are used to design the optimal sampling strategy, respectively. The effectiveness of the proposed method is illustrated by synthetic one-dimensional and two-dimensional unsaturated flow case studies. It is shown that the designed sampling strategies can provide more accurate parameter estimation and state prediction compared with conventional sampling strategies. Optimal sampling designs based on various information metrics perform similarly in our cases. The effect of ensemble size on the optimal design is also investigated. Overall, larger ensemble size improves the parameter estimation and convergence of optimal sampling strategy. Although the proposed method is applied to unsaturated flow problems in this study, it can be equally applied in any other hydrological problems.
Zhu, Ning Ke
the development of BIM technology and application in the field of architecture design has produced results, but BIM technology and application in the field of interior design is still immaturity because of construction and decoration engineering separation. The article analyzes the problems that BIM technology lead to the interior design work mode optimization, from the 3D visualization work environment, real-time collaborative design mode, physical analysis design mode, information integration design mode state the application in interior design.
The Defense Waste Processing Facility (DWPF) takes radioactive defense waste sludge and the radioactive nuclides, cesium and strontium, from the salt solution, and incorporates them in borosilicate glass in stainless steel canisters, for subsequent disposal in a deep geologic repository. The facility was designed by Bechtel National, Inc. under a subcontract from E.I. DuPont de Nemurs and Co., the prime contractor for the Department of Energy, for the design, construction and commissioning of the plant. The design criteria were specified by the DuPont Company, based upon their extensive experience as designer, and operator since the early 1950's, of the existing Savannah River Plant facilities. Some of the design criteria imposed unusual or new requirements on the detailed design of the facilities. This paper describes some of these criteria, encompassing several engineering disciplines, and discusses the solutions and designs which were developed for the DWPF
Full Text Available We consider the optimal design of a sequence of quantum barriers, in order to manufacture an electronic device at the nanoscale such that the dependence of its transmission coefficient on the bias voltage is linear. The technique presented here is easily adaptable to other response characteristics. There are two distinguishing features of our approach. First, the transmission coefficient is determined using a semiclassical approximation, so we can explicitly compute the gradient of the objective function. Second, in contrast with earlier treatments, manufacturing uncertainties are incorporated in the model through random variables; the optimal design problem is formulated in a probabilistic setting and then solved using a stochastic collocation method. As a measure of robustness, a weighted sum of the expectation and the variance of a least-squares performance metric is considered. Several simulations illustrate the proposed technique, which shows an improvement in accuracy over 69% with respect to brute-force, Monte-Carlo-based methods.
Bo Zhao; Haldar, Justin P; Setsompop, Kawin; Wald, Lawrence L
Magnetic resonance (MR) fingerprinting is an emerging quantitative MR imaging technique that simultaneously acquires multiple tissue parameters in an efficient experiment. In this work, we present an estimation-theoretic framework to evaluate and design MR fingerprinting experiments. More specifically, we derive the Cramér-Rao bound (CRB), a lower bound on the covariance of any unbiased estimator, to characterize parameter estimation for MR fingerprinting. We then formulate an optimal experiment design problem based on the CRB to choose a set of acquisition parameters (e.g., flip angles and/or repetition times) that maximizes the signal-to-noise ratio efficiency of the resulting experiment. The utility of the proposed approach is validated by numerical studies. Representative results demonstrate that the optimized experiments allow for substantial reduction in the length of an MR fingerprinting acquisition, and substantial improvement in parameter estimation performance.
Michael R. Levot
Full Text Available The Minimalist Program in generative syntax has been the subject of much rancour, a good proportion of it stoked by Noam Chomsky’s suggestion that language may represent “a ‘perfect solution’ to minimal design specifications.” A particular flash point has been the application of Minimalist principles to speculations about how language evolved in the human species. This paper argues that Minimalism is well supported as a plausible approach to language evolution. It is claimed that an assumption of minimal design specifications like that employed in MP syntax satisfies three key desiderata of evolutionary and general scientific plausibility: Physical Optimism, Rational Optimism, and Darwin’s Problem. In support of this claim, the methodologies employed in MP to maximise parsimony are characterised through an analysis of recent theories in Minimalist syntax, and those methodologies are defended with reference to practices and arguments from evolutionary biology and other natural sciences.
Reynoso Meza, Gilberto; Sanchis Saez, Javier; Herrero Durá, Juan Manuel
This book is devoted to Multiobjective Optimization Design (MOOD) procedures for controller tuning applications, by means of Evolutionary Multiobjective Optimization (EMO). It presents developments in tools, procedures and guidelines to facilitate this process, covering the three fundamental steps in the procedure: problem definition, optimization and decision-making. The book is divided into four parts. The first part, Fundamentals, focuses on the necessary theoretical background and provides specific tools for practitioners. The second part, Basics, examines a range of basic examples regarding the MOOD procedure for controller tuning, while the third part, Benchmarking, demonstrates how the MOOD procedure can be employed in several control engineering problems. The fourth part, Applications, is dedicated to implementing the MOOD procedure for controller tuning in real processes.
Coroneos, Rula M.; Pai, Shantaram S.
Nonlinear programming algorithms play an important role in structural design optimization. Several such algorithms have been implemented in OpenMDAO framework developed at NASA Glenn Research Center (GRC). OpenMDAO is an open source engineering analysis framework, written in Python, for analyzing and solving Multi-Disciplinary Analysis and Optimization (MDAO) problems. It provides a number of solvers and optimizers, referred to as components and drivers, which users can leverage to build new tools and processes quickly and efficiently. Users may download, use, modify, and distribute the OpenMDAO software at no cost. This paper summarizes the process involved in analyzing and optimizing structural components by utilizing the framework s structural solvers and several gradient based optimizers along with a multi-objective genetic algorithm. For comparison purposes, the same structural components were analyzed and optimized using CometBoards, a NASA GRC developed code. The reliability and efficiency of the OpenMDAO framework was compared and reported in this report.
Full Text Available The paper presents applications of modern techniques of CAD (Computer Aided Design and CAE (Computer Aided Engineering to design and optimize the mechanisms used in mechanical engineering. The use exemplification of these techniques was achieved by designing and optimizing parts of a drawing installation for horizontal continuous casting of metals. By applying these design methods and using finite element method at simulations on designed mechanisms results a number of advantages over traditional methods of drawing and design: speed in drawing, design and optimization of parts and mechanisms, kinematic analysis option, kinetostatic and dynamic through simulation, without requiring physical realization of the part or mechanism, the determination by finite element method of tension, elongations, travel and safety factor and the possibility of optimization for these sizes to ensure the mechanical strength of each piece separately. Achieving these studies was possible using SolidWorks 2009 software suite.
Meyn, Larry A.
One of the goals of NASA's Revolutionary Vertical Lift Technology Project (RVLT) is to provide validated tools for multidisciplinary design, analysis and optimization (MDAO) of vertical lift vehicles. As part of this effort, the software package, RotorCraft Optimization Tools (RCOTOOLS), is being developed to facilitate incorporating key rotorcraft conceptual design codes into optimizations using the OpenMDAO multi-disciplinary optimization framework written in Python. RCOTOOLS, also written in Python, currently supports the incorporation of the NASA Design and Analysis of RotorCraft (NDARC) vehicle sizing tool and the Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics II (CAMRAD II) analysis tool into OpenMDAO-driven optimizations. Both of these tools use detailed, file-based inputs and outputs, so RCOTOOLS provides software wrappers to update input files with new design variable values, execute these codes and then extract specific response variable values from the file outputs. These wrappers are designed to be flexible and easy to use. RCOTOOLS also provides several utilities to aid in optimization model development, including Graphical User Interface (GUI) tools for browsing input and output files in order to identify text strings that are used to identify specific variables as optimization input and response variables. This paper provides an overview of RCOTOOLS and its use
Zhao, Bo; Haldar, Justin P.; Setsompop, Kawin; Wald, Lawrence L.
Magnetic resonance (MR) fingerprinting is an emerging quantitative MR imaging technique that simultaneously acquires multiple tissue parameters in an efficient experiment. In this work, we present an estimation-theoretic framework to evaluate and design MR fingerprinting experiments. More specifically, we derive the Cram��r-Rao bound (CRB), a lower bound on the covariance of any unbiased estimator, to characterize parameter estimation for MR fingerprinting. We then formulate an optimal experi...
Zhang Yuanbin; Pan Wanjiang
With the help of ANSYS FEA technique, high voltage and cryogenic proper- ties of the SST-1 Tokamak insulators were obtained, and the structure of the insulators was designed and modified by taking into account the simulation results. The simulation results indicate that the optimization structure has better high voltage insulating property and cryogenic mechanics property, and also can fulfill the qualification criteria of the SST-1 Tokamak insulators. (authors)
Liu, Zhihong; Hu, Yongming [INET, Tsinghua university, Beijing 100084 (China)
PWR in-core loading (reloading) pattern optimization is a complex combined problem. An excellent fuel management optimization code can greatly improve the efficiency of core reloading design, and bring economic and safety benefits. Today many optimization codes with experiences or searching algorithms (such as SA, GA, ANN, ACO) have been developed, while how to improve their searching efficiency and engineering usability still needs further research. CSA (Characteristic Statistic Algorithm) is a global optimization algorithm with high efficiency developed by our team. The performance of CSA has been proved on many problems (such as Traveling Salesman Problems). The idea of CSA is to induce searching direction by the statistic distribution of characteristic values. This algorithm is quite suitable for fuel management optimization. Optimization code with CSA has been developed and was used on many core models. The research in this paper is to improve the engineering usability of CSA code according to all the actual engineering requirements. Many new improvements have been completed in this code, such as: 1. Considering the asymmetry of burn-up in one assembly, the rotation of each assembly is considered as new optimization variables in this code. 2. Worth of control rods must satisfy the given constraint, so some relative modifications are added into optimization code. 3. To deal with the combination of alternate cycles, multi-cycle optimization is considered in this code. 4. To confirm the accuracy of optimization results, many identifications of the physics calculation module in this code have been done, and the parameters of optimization schemes are checked by SCIENCE code. The improved optimization code with CSA has been used on Qinshan nuclear plant of China. The reloading of cycle 7, 8, 9 (12 months, no burnable poisons) and the 18 months equilibrium cycle (with burnable poisons) reloading are optimized. At last, many optimized schemes are found by CSA code
Das, Manas Ranjan; Das, Sarat Kumar
Sheet pile wall is a type of flexible earth retaining structure used in waterfront offshore structures, river protection work and temporary supports in foundations and excavations. Economy is an essential part of a good engineering design and needs to be considered explicitly in obtaining an optimum section. By considering appropriate embedment depth and sheet pile section it may be possible to achieve better economy. This paper describes optimum design of both cantilever and anchored sheet pile wall penetrating clay using a simple optimization tool Microsoft Excel ® Solver. The detail methodology and its application with examples are presented for cantilever and anchored sheet piles. The effects of soil properties, depth of penetration and variation of ground water table on the optimum design are also discussed. Such a study will help professional while designing the sheet pile wall penetrating clay.
This Engineering Report (Conceptual Design) addresses remediation of the plutonium-bearing solutions currently in inventory at the Plutonium Finishing Plant (PFP). The recommendation from the Environmental Impact Statement (EIS) is that the solutions be treated thermally and stabilized as a solid for long term storage. For solutions which are not discardable, the baseline plan is to utilize a denitration process to stabilize the solutions prior to packaging for storage.
This Engineering Report (Conceptual Design) addresses remediation of the plutonium-bearing solutions currently in inventory at the Plutonium Finishing Plant (PFP). The recommendation from the Environmental Impact Statement (EIS) is that the solutions be treated thermally and stabilized as a solid for long term storage. For solutions which are not discardable, the baseline plan is to utilize a denitration process to stabilize the solutions prior to packaging for storage
Involvement of the European industry promoted elaboration of the ITER engineering design. The EFDA is responsible for coordination of the industry involvement under the signed contracts the total amount of which is about 70 MEURO. Diversified remote handling equipment is available to replace internal structures and to transfer them to and back from hot cell. The contribution of the European industry consists mainly of divertor equipment, of air cushion transfer system and transfer casks [ru
Adegas, Fabiano Daher; Stoustrup, Jakob
This paper presents a new procedure for discrete-time robust structured control design. Parameter-dependent nonconvex conditions for stabilizable and induced L2-norm performance controllers are solved by an iterative linear matrix inequalities (LMI) optimization. A wide class of controller...... structures including decentralized of any order, ﬁxed-order dynamic output feedback, static output feedback can be designed robust to polytopic uncertainties. Stability is proven by a parameter-dependent Lyapunov function. Numerical examples on robust stability margins shows that the proposed procedure can...
Mamlouk, M.S.; Zaniewski, J.P.; He, W.
A project-level optimization approach was developed to minimize total pavement cost within an analysis period. Using this approach, the designer is able to select the optimum initial pavement thickness, overlay thickness, and overlay timing. The model in this approach is capable of predicting both pavement performance and condition in terms of roughness, fatigue cracking, and rutting. The developed model combines the American Association of State Highway and Transportation Officials (AASHTO) design procedure and the mechanistic multilayer elastic solution. The Optimization for Pavement Analysis (OPA) computer program was developed using the prescribed approach. The OPA program incorporates the AASHTO equations, the multilayer elastic system ELSYM5 model, and the nonlinear dynamic programming optimization technique. The program is PC-based and can run in either a Windows 3.1 or a Windows 95 environment. Using the OPA program, a typical pavement section was analyzed under different traffic volumes and material properties. The optimum design strategy that produces the minimum total pavement cost in each case was determined. The initial construction cost, overlay cost, highway user cost, and total pavement cost were also calculated. The methodology developed during this research should lead to more cost-effective pavements for agencies adopting the recommended analysis methods.
Garcia V, M.A.
In the present thesis, the modifications made to the axial optimization system based on Tabu Search (BT) for the axial design of BWR fuel type are presented, developed previously in the Nuclear Engineering Group of the UNAM Engineering Faculty. With the modifications what is mainly looked is to consider the particular characteristics of the mechanical design of the GE12 fuel type, used at the moment in the Laguna Verde Nucleo electric Central (CNLV) and that it considers the fuel bars of partial longitude. The information obtained in this thesis will allow to plan nuclear fuel reloads with the best conditions to operate in a certain cycle guaranteeing a better yield and use in the fuel burnt, additionally people in charge in the reload planning will be favored with the changes carried out to the system for the design and axial optimization of nuclear fuel, which facilitate their handling and it reduces their execution time. This thesis this developed in five chapters that are understood in the following way in general: Chapter 1: It approaches the basic concepts of the nuclear energy, it describes the physical and chemical composition of the atoms as well as that of the uranium isotopes, the handling of the uranium isotope by means of the nuclear fission until arriving to the operation of the nuclear reactors. Chapter 2: The nuclear fuel cycle is described, the methods for its extraction, its conversion and its enrichment to arrive to the stages of the nuclear fuel management used in the reactors are described. Beginning by the radial design, the axial design and the core design of the nuclear reactor related with the fuel assemblies design. Chapter 3: the optimization methods of nuclear fuel previously used are exposed among those that are: the genetic algorithms method, the search methods based on heuristic rules and the application of the tabu search method, which was used for the development of this thesis. Chapter 4: In this part the used methodology to the
Laursen, Esben Skov; Møller, Louise
This paper describes a case study comparing the understanding of design intent between industrial designers and design engineers. The study is based on the hypothesis that it is not all aspects of the design intent that are equally difficult to share between industrial designers and design engineers in the product development process. The study builds on five semi-structured interviews, where two industrial designers and three design engineers were interviewed about different aspects of the design intent. Based on our results, there seem to be indications that the more complex and abstract elements of industrial design knowledge such as the meaning, semantics, values, emotions and social aspects of the product are less shared by the design engineers. Moreover, the results also indicate that the different aspects of the design intent are perceived separately, rather than as part of a whole by the design engineers. The connection between the different aspects of the design intent is not shared between the industrial designer and design engineer making the shared knowledge less meaningful to the design engineers. The results of this study cannot be claimed to be conclusive due to the limited empirical material. Further investigation and analytically richer data are required in order to verify and broaden the findings. More case studies have therefore been planned in order to understand the area better.
Grasso, F. [ECN Wind Energy, Petten (Netherlands)
In order to increase the ratio of energy capture to the loading and thereby to reduce cost of energy, the use of specially tailored airfoils is needed. This work is focused on the design of an airfoil for marine application. Firstly, the requirements for this class of airfoils are illustrated and discussed with reference to the requirements for wind turbine airfoils. Then, the design approach is presented. This is a numerical optimization scheme in which a gradient based algorithm is used, coupled with RFOIL solver and a composite Bezier geometrical parameterization. A particularly sensitive point is the choice and implementation of constraints; in order to formalize in the most complete and effective way the design requirements, the effects of activating specific constraints are discussed. Particularly importance is given to the cavitation phenomenon. Finally, a numerical example regarding the design of a high efficiency, tidal turbine airfoil is illustrated and the results are compared with existing turbine airfoils.
Tan, Chee Wee; Miao, Jianmin
A well-designed condenser microphone backplate is very important in the attainment of good frequency response characteristics--high sensitivity and wide bandwidth with flat response--and low mechanical-thermal noise. To study the design optimization of the backplate, a 2(6) factorial design with a single replicate, which consists of six backplate parameters and four responses, has been undertaken on a comprehensive condenser microphone model developed by Zuckerwar. Through the elimination of insignificant parameters via normal probability plots of the effect estimates, the projection of an unreplicated factorial design into a replicated one can be performed to carry out an analysis of variance on the factorial design. The air gap and slot have significant effects on the sensitivity, mechanical-thermal noise, and bandwidth while the slot/hole location interaction has major influence over the latter two responses. An organized and systematic approach of designing the backplate is summarized.
Waldron, W.L., E-mail: WLWaldron@lbl.gov [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Abraham, W.J.; Arbelaez, D. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Friedman, A. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Galvin, J.E. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Gilson, E.P. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Greenway, W.G. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Grote, D.P. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Jung, J.-Y.; Kwan, J.W.; Leitner, M.; Lidia, S.M.; Lipton, T.M.; Reginato, L.L.; Regis, M.J.; Roy, P.K. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Sharp, W.M. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Stettler, M.W.; Takakuwa, J.H.; Volmering, J. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); and others
The Neutralized Drift Compression Experiment (NDCX-II) is a user facility located at Lawrence Berkeley National Laboratory which is uniquely designed for ion-beam-driven high energy density laboratory physics and heavy ion fusion research. Construction was completed in March 2012 and the facility is now in the commissioning phase. A significant amount of engineering was carried out in order to meet the performance parameters required for a wide range of target heating experiments while making the most cost-effective use of high-value hardware available from a decommissioned high current electron induction accelerator. The technical challenges and design of this new ion induction accelerator facility are described.
Organ, Allan J
Some 200 years after the original invention, internal design of a Stirling engine has come to be considered a specialist task, calling for extensive experience and for access to sophisticated computer modelling. The low parts-count of the type is negated by the complexity of the gas processes by which heat is converted to work. Design is perceived as problematic largely because those interactions are neither intuitively evident, nor capable of being made visible by laboratory experiment. There can be little doubt that the situation stands in the way of wider application of this elegant concep
IntroductionBroad Context and MotivationConcurrent Engineering: A Road Map for EnergyQuantitative Robust ControlNovel CAD Toolbox for QFT Controller DesignOutline Part I: Advanced Robust Control Techniques: QFT and Nonlinear SwitchingIntroduction to QFTQuantitative Feedback TheoryWhy Feedback? QFT OverviewInsight into the QFT TechniqueBenefits of QFTMISO Analog QFT Control SystemIntroductionQFT Method (Single-Loop MISO System)Design Procedure OutlineMinimum-Phase System Performance SpecificationsJ LTI Plant ModelsPlant Templates of P?(s), P( j_i )Nominal PlantU-Contour (Stability Bound)Trackin
Full Text Available The backtracking search optimization algorithm (BSA is a population-based evolutionary algorithm for numerical optimization problems. BSA has a powerful global exploration capacity while its local exploitation capability is relatively poor. This affects the convergence speed of the algorithm. In this paper, we propose a modified BSA inspired by simulated annealing (BSAISA to overcome the deficiency of BSA. In the BSAISA, the amplitude control factor (F is modified based on the Metropolis criterion in simulated annealing. The redesigned F could be adaptively decreased as the number of iterations increases and it does not introduce extra parameters. A self-adaptive ε-constrained method is used to handle the strict constraints. We compared the performance of the proposed BSAISA with BSA and other well-known algorithms when solving thirteen constrained benchmarks and five engineering design problems. The simulation results demonstrated that BSAISA is more effective than BSA and more competitive with other well-known algorithms in terms of convergence speed.
Patanè, Andrea; Santoro, Andrea; Costanza, Jole; Carapezza, Giovanni; Nicosia, Giuseppe
Recent advances in synthetic biology call for robust, flexible and efficient in silico optimization methodologies. We present a Pareto design approach for the bi-level optimization problem associated to the overproduction of specific metabolites in Escherichia coli. Our method efficiently explores the high dimensional genetic manipulation space, finding a number of trade-offs between synthetic and biological objectives, hence furnishing a deeper biological insight to the addressed problem and important results for industrial purposes. We demonstrate the computational capabilities of our Pareto-oriented approach comparing it with state-of-the-art heuristics in the overproduction problems of i) 1,4-butanediol, ii) myristoyl-CoA, i ii) malonyl-CoA , iv) acetate and v) succinate. We show that our algorithms are able to gracefully adapt and scale to more complex models and more biologically-relevant simulations of the genetic manipulations allowed. The Results obtained for 1,4-butanediol overproduction significantly outperform results previously obtained, in terms of 1,4-butanediol to biomass formation ratio and knock-out costs. In particular overproduction percentage is of +662.7%, from 1.425 mmolh⁻¹gDW⁻¹ (wild type) to 10.869 mmolh⁻¹gDW⁻¹, with a knockout cost of 6. Whereas, Pareto-optimal designs we have found in fatty acid optimizations strictly dominate the ones obtained by the other methodologies, e.g., biomass and myristoyl-CoA exportation improvement of +21.43% (0.17 h⁻¹) and +5.19% (1.62 mmolh⁻¹gDW⁻¹), respectively. Furthermore CPU time required by our heuristic approach is more than halved. Finally we implement pathway oriented sensitivity analysis, epsilon-dominance analysis and robustness analysis to enhance our biological understanding of the problem and to improve the optimization algorithm capabilities.
Ghasemi, Abdollah; Ghasemi, Farshid
Propagation Engineering in Radio Link Design covers the basic principles of radiowaves propagation in a practical manner. This fundamental understanding enables the readers to design radio links efficiently. This book elaborates on new achievements as well as recently developed propagation models. This is in addition to a comprehensive overview of fundamentals of propagation in various scenarios. It examines theoretical calculations, approaches and applied procedures needed for radio links design. The authors study and analysis of the main propagation phenomena and its mechanisms based on the recommendations of International Telecommunications Union, (ITU). The book has been organized in 9 chapters and examines the role of antennas and passive reflectors in radio services, propagation mechanisms related to radar, satellite, short distance, broadcasting and trans-horizon radio links, with two chapters devoted to radio noise and main parameters of radio link design. The book presents some 278 illustration...
Savageau, Michael A
Modern systems biology and synthetic bioengineering face two major challenges in relating properties of the genetic components of a natural or engineered system to its integrated behavior. The first is the fundamental unsolved problem of relating the digital representation of the genotype to the analog representation of the parameters for the molecular components. For example, knowing the DNA sequence does not allow one to determine the kinetic parameters of an enzyme. The second is the fundamental unsolved problem of relating the parameters of the components and the environment to the phenotype of the global system. For example, knowing the parameters does not tell one how many qualitatively distinct phenotypes are in the organism's repertoire or the relative fitness of the phenotypes in different environments. These also are challenges for biomedical engineers as they attempt to develop therapeutic strategies to treat pathology or to redirect normal cellular functions for biotechnological purposes. In this article, the second of these fundamental challenges will be addressed, and the notion of a "system design space" for relating the parameter space of components to the phenotype space of bioengineering systems will be focused upon. First, the concept of a system design space will be motivated by introducing one of its key components from an intuitive perspective. Second, a simple linear example will be used to illustrate a generic method for constructing the design space in which qualitatively distinct phenotypes can be identified and counted, their fitness analyzed and compared, and their tolerance to change measured. Third, two examples of nonlinear systems from different areas of biomedical engineering will be presented. Finally, after giving reference to a few other applications that have made use of the system design space approach to reveal important design principles, some concluding remarks concerning challenges and opportunities for further development
Mechanisms of incorporating machine learning paradigms in design optimization have been investigated in the current research. The primary focus of the work is on machine learning algorithms which use computational models that are analogous to the hypothesized principles of natural or biological learning. Examples from structural and aerodynamic optimization have been used to demonstrate the potential of the proposed schemes. The first strategy examined in the current work seeks to improve the convergence of optimization problems by pruning the search space of weak variables. Such variables are identified by learning from a database of existing designs using neural networks. By using clustering techniques, different sets of weak variables are identified in different regions of the design space. Parameter sensitivity information obtained in the process of identifying weak variables provides accurate heuristics for formulating design rules. The impact of this methodology on obtaining converged designs has been investigated for a turbine design problem. Optimization results from a three-stage power turbine and an aircraft engine turbine are presented in this thesis. The second scheme is an evolutionary design optimization technique which gets progressively 'smarter' during the optimization process by learning from computed domain knowledge. This technique employs adaptive learning mechanisms (classifiers) which recognize the influence of the design variables on the problem solution and then generalize them to dynamically create or change design rules during optimization. This technique, when applied to a constrained optimization problem, shows progressive improvement in convergence of search, as successive generations of rules evolve by learning from the environment. To investigate this methodology, a truss optimization problem is solved with an objective of minimizing the truss weight subject to stress constraints in the truss members. A distinct convergent trend is
Azfanizam Ahmad, Siti; Sunthiram, Devaraj
Biodiesel recently has been receiving a great attention in the world market due to the depletion of the existing fossil fuels. Biodiesel also becomes an alternative for diesel No. 2 fuel which possesses characteristics such as biodegradable and oxygenated. However, there are facts suggested that biodiesel does not have the equivalent features as diesel No. 2 fuel as it has been claimed that the usage of biodiesel giving increment in the brake specific fuel consumption (BSFC). The objective of this study is to find the maximum brake power and brake torque as well as the minimum BSFC to optimize the condition of diesel engine when using the biodiesel fuel. This optimization was conducted using the Bees Algorithm (BA) under specific biodiesel percentage in fuel mixture, engine speed and engine load. The result showed that 58.33kW of brake power, 310.33 N.m of brake torque and 200.29/(kW.h) of BSFC were the optimum value. Comparing to the ones obtained by other algorithm, the BA produced a fine brake power and a better brake torque and BSFC. This finding proved that the BA can be used to optimize the performance of diesel engine based on the optimum value of the brake power, brake torque and BSFC.
Priyadarshi, Pankaj; Sharma, Abhishek; Mukherjee, Swarnadip; Muralidharan, Bhaskaran
We consider the design of an optimal superlattice thermoelectric generator via the energy bandpass filter approach. Various configurations of superlattice structures are explored to obtain a bandpass transmission spectrum that approaches the ideal ‘boxcar’ form, which is now well known to manifest the largest efficiency at a given output power in the ballistic limit. Using the coherent non-equilibrium Green’s function formalism coupled self-consistently with the Poisson’s equation, we identify such an ideal structure and also demonstrate that it is almost immune to the deleterious effect of self-consistent charging and device variability. Analyzing various superlattice designs, we conclude that superlattice with a Gaussian distribution of the barrier thickness offers the best thermoelectric efficiency at maximum power. It is observed that the best operating regime of this device design provides a maximum power in the range of 0.32–0.46 MW/m 2 at efficiencies between 54%–43% of Carnot efficiency. We also analyze our device designs with the conventional figure of merit approach to counter support the results so obtained. We note a high zT el = 6 value in the case of Gaussian distribution of the barrier thickness. With the existing advanced thin-film growth technology, the suggested superlattice structures can be achieved, and such optimized thermoelectric performances can be realized.
Cheng, Chin-Hsiang; Yang, Hang-Suin
In the present study, optimization of rhombic drive mechanism used in a beta-type Stirling engine is performed based on a dimensionless theoretical model toward maximization of shaft work output. Displacements of the piston and the displacer with the rhombic drive mechanism and variations of volumes and pressure in the chambers of the engine are firstly expressed in dimensionless form. Secondly, Schmidt analysis is incorporated with Senft's shaft work theory to build a dimensionless thermodynamic model, which is employed to yield the dimensionless shaft work. The dimensionless model is verified with experimental data. It is found that the relative error between the experimental and the theoretical data in dimensionless shaft work is lower than 5.2%. This model is also employed to investigate the effects of the influential geometric parameters on the shaft work, and the optimization of these parameters is attempted. Eventually, design charts that help design the optimal geometry of the rhombic drive mechanism are presented in this report. - Highlights: • Specifically dealing with optimization of rhombic-drive mechanism used in Stirling engine based on dimensionless model. • Propose design charts that help determine the optimal geometric parameters of the rhombic drive mechanism. • Complete study of influential factors affecting the shaft work output
Rodriguez, Marco A.
Fuel cell is one of the most dependable "green power" technologies, readily available for immediate application. It enables direct conversion of hydrogen and other gases into electric energy without any pollution of the environment. However, the efficient power generation is strictly stationary process that cannot operate under dynamic environment. Consequently, fuel cell becomes practical only within a specially designed hybridization scheme, capable of power storage and power management functions. The resultant technology could be utilized to its full potential only when both the fuel cell element and the entire hybridization scheme are optimally designed. The design optimization in engineering is among the most complex computational tasks due to its multidimensionality, nonlinearity, discontinuity and presence of constraints in the underlying optimization problem. this research aims at the optimal utilization of the fuel cell technology through the use of genetic optimization, and advance computing. This study implements genetic optimization in the definition of optimum hybridization rules for a PEM fuel cell/supercapacitor power system. PEM fuel cells exhibit high energy density but they are not intended for pulsating power draw applications. They work better in steady state operation and thus, are often hybridized. In a hybrid system, the fuel cell provides power during steady state operation while capacitors or batteries augment the power of the fuel cell during power surges. Capacitors and batteries can also be recharged when the motor is acting as a generator. Making analogies to driving cycles, three hybrid system operating modes are investigated: 'Flat' mode, 'Uphill' mode, and 'Downhill' mode. In the process of discovering the switching rules for these three modes, we also generate a model of a 30W PEM fuel cell. This study also proposes the optimum design of a 30W PEM fuel cell. The PEM fuel cell model and hybridization's switching rules are postulated
Carlucci, Antonio Paolo; Ficarella, Antonio; Trullo, Gianluca
Highlights: • A Two-Stroke diesel engine for aircraft propulsion was modeled with a 0D/1D approach. • The results of the 0D/1D model are compared with those resulting from a 3D model. • The effect of several design and thermodynamic parameters have been analyzed. • Guidelines for the optimization of engine performance are provided. - Abstract: In Two-Stroke engines, the cylinder filling efficiency is antithetical to the cylinder scavenging efficiency; moreover, both of them are influenced by geometric and thermodynamic parameters characterizing the design and operation of both the engine and the related supercharging system. Aim of this work is to provide several guidelines about the definition of design and operation parameters for a Two-Stroke two banks Uniflow diesel engine, supercharged with two sequential turbochargers and an aftercooler per bank, with the goal of either increasing the engine brake power at take-off or decreasing the engine fuel consumption in cruise conditions. The engine has been modeled with a 0D/1D modeling approach. Then, the model capability in describing the effect of several parameters on engine performance has been assessed comparing the results of 3D simulations with those of 0D/1D model. The validated 0D/1D model has been used to simulate the engine behavior varying several design and operation engine parameters (exhaust valves opening and closing angles and maximum valve lift, scavenging ports opening angle, distance between bottom edge of the scavenging ports and bottom dead center, area of the single scavenging port and number of ports, engine volumetric compression ratio, low and high pressure compressor pressure ratios, air/fuel ratio) on a wide range of possible values. The parameters most influencing the engine performance are then recognized and their effect on engine thermodynamic behavior is discussed. Finally, the system configurations leading to best engine power at sea level and lowest fuel consumption in cruise
James A. Wills
Full Text Available This paper presents the exergy analysis and optimization of the Stirling engine, which has enormous potential for use in the renewable energy industry as it is quiet, efficient, and can operate with a variety of different heat sources and, therefore, has multi-fuel capabilities. This work aims to present a method that can be used by a Stirling engine designer to quickly and efficiently find near-optimal or optimal Stirling engine geometry and operating conditions. The model applies the exergy analysis methodology to the ideal-adiabatic Stirling engine model. In the past, this analysis technique has only been applied to highly idealized Stirling cycle models and this study shows its use in the realm of Stirling cycle optimization when applied to a more complex model. The implicit filtering optimization algorithm is used to optimize the engine as it quickly and efficiently computes the optimal geometry and operating frequency that gives maximum net-work output at a fixed energy input. A numerical example of a 1,000 cm3 engine is presented, where the geometry and operating frequency of the engine are optimized for four different regenerator mesh types, varying heater inlet temperature and a fixed energy input of 15 kW. The WN200 mesh is seen to perform best of the four mesh types analyzed, giving the greatest net-work output and efficiency. The optimal values of several different engine parameters are presented in the work. It is shown that the net-work output and efficiency increase with increasing heater inlet temperature. The optimal dead-volume ratio, swept volume ratio, operating frequency, and phase angle are all shown to decrease with increasing heater inlet temperature. In terms of the heat exchanger geometry, the heater and cooler tubes are seen to decrease in size and the cooler and heater effectiveness is seen to decrease with increasing heater temperature, whereas the regenerator is seen to increase in size and effectiveness. In
Ridluan, Artit; Danchus, William; Tokuhiro, Akira
With steady increase in energy consumption, the vulnerability of the fossil fuel supply, and environmental concerns, the U.S. Department of Energy (DOE) has initiated the Next Generation Nuclear Power Plants (NGNP), also known as Very High Temperature Reactor (VHTR). The VHTR is planned to be operational by 2021 with possible demonstration of a hydrogen generating plant. Various engineering design studies on both the reactor plant and energy conversion system are underway. For this and related Generation IV plants, it is the goal to not only meet safety criteria but to also be efficient, economically competitive, and environmentally friendly (proliferation resistant). Traditionally, heat exchanger (HX) design is based on two main approaches: Log-Mean Temperature Difference (LMTD) and effectiveness-NTU (ε-NTU). These methods yield the dimension of the HX under anticipate condition and vice-versa. However, one is not assured that the dimension calculated give the best performing HX when economics are also considered. Here, we develop and show a specific optimization algorithm (exercise) using LMTD and simple (optimal) design theory to establish a reference case for the Printed Circuit Heat Exchanger (PCHE). Computational Fluid Dynamics (CFD) was further used as a design tool to investigate the optimal design of PCHE thermohydraulic flow. The CFD results were validated against the Blasius correlation before being subjected to optimal design analyses. Benchmark results for the pipe flow indicated that the predictive ability of SST k-ω is superior to the other (standard and RNG k-ε and RSM) turbulence models. The difference between CFD and the empirical expression is less than 10%. (author)
Kekaelaeinen, Teemu; Mattila, Jouni; Virvalo, Tapio
This paper describes one of the research projects carried out in The Preparation of Remote Handling Engineers for ITER (PREFIT) program within the European Fusion Training Scheme (EFTS). This research project is focusing on the design and optimization of water hydraulic manipulators used to test several remote handling tasks of ITER at Divertor Test Platform 2 (DTP2), Tampere, Finland, and later in ITER. In this project, a water hydraulic manipulator designed and build by Department of Intelligent Hydraulics and Automation in Tampere University of Technology, Finland (TUT/IHA) is further optimized as a case study for a given manipulator requirement specification in order to illustrate and verify developed comprehensive design guidelines and performance metrics. Without meaningful manipulator performance parameters, the evaluation of alternative robot manipulators designs remains ad hoc at best. Therefore, more comprehensive design guidelines and performance metrics are needed for comparing and improving different existing manipulators versus task requirements or for comparing different digital prototypes at early design phase of manipulators. In this paper the description of the project, its background and developments are presented and discussed.
Grasso, F. [ECN Wind Energy, Petten (Netherlands)
To increase the ratio of energy capture to the loading and, thereby, to reduce cost of energy, the use of specially tailored airfoils is needed. This work is focused on the design of an airfoil for marine application. Firstly, the requirements for this class of airfoils are illustrated and discussed with reference to the requirements for wind turbine airfoils. Then, the design approach is presented. This is a numerical optimization scheme in which a gradient-based algorithm is used, coupled with the RFOIL solver and a composite Bezier geometrical parameterization. A particularly sensitive point is the choice and implementation of constraints .A section of the present work is dedicated to address this point; particular importance is given to the cavitation phenomenon. Finally, a numerical example regarding the design of a high-efficiency hydrofoil is illustrated, and the results are compared with existing turbine airfoils, considering also the effect on turbine performance due to different airfoils.
Peng, Xuebing, E-mail: firstname.lastname@example.org [Institute of Plasma Physics, Chinese Academy of Sciences, Shushanhu Road 350, 230031 Hefei Anhui (China); Ye, Minyou [School of Nuclear Science and Technology, University of Science and Technology of China, Jinzhai Road 96, 230026 Hefei Anhui (China); Institute of Plasma Physics, Chinese Academy of Sciences, Shushanhu Road 350, 230031 Hefei Anhui (China); Song, Yuntao [Institute of Plasma Physics, Chinese Academy of Sciences, Shushanhu Road 350, 230031 Hefei Anhui (China); School of Nuclear Science and Technology, University of Science and Technology of China, Jinzhai Road 96, 230026 Hefei Anhui (China); Mao, Xin [Institute of Plasma Physics, Chinese Academy of Sciences, Shushanhu Road 350, 230031 Hefei Anhui (China); Chen, Peiming; Qian, Xinyuan [School of Nuclear Science and Technology, University of Science and Technology of China, Jinzhai Road 96, 230026 Hefei Anhui (China)
Highlights: • Three divertor structures for two plasma configurations, ITER-like and snowflake. • Property of enlarging wet area for all three divertors is analyzed. • The divertor accommodating with both the plasma configurations is unfeasible. • Divertor cooling system is developed. - Abstract: The China Fusion Engineering Test Reactor (CFETR), which is in conceptual design phase, aims at producing fusion power of 50–200 MW with tritium breeding ratio of ∼1.2 and duty cycle time of 0.3–0.5. Its designed main parameters are major/minor radii of 5.7 m/1.6 m and plasma current of 10 MA. Although the fusion power is lower than the one of ITER, the relative smaller machine dimensions and planed much higher auxiliary heating power of 100–140 MW make that the power exhausting for the CFETR divertor is a very critical issue. To solve this issue, the divertor should be better designed with advanced physical operation mode, advanced configuration/geometry or high efficient cooling structure. In the paper, much effort was put on the divertor configuration and geometry. With designed magnet system, three divertor configurations can be realized, ITER-like, snowflake and super-X. However, considering structural design feasibility and remote handling compatibility, only the first two configurations were selected for the first step of engineering design. Three divertors were designed. They have different first wall geometries to accommodate with different plasma configurations, one for the ITER-like, one for the snowflake and the third one for both the configurations. All three divertors employ the same cassette body as the support and the cooling water manifold for the first wall. This feature simplifies the interface of the divertor to other components in the vacuum vessel. Besides, the cooling structure and the remote maintenance concept are also introduced in the paper.
Boks, C.; Diehl, J.C.; Wever, R.
Developments in the field of sustainable product design are manifold, which means that education in this field is rapidly evolving as well. In this paper, the continuously evolving portfolio of courses offered at Delft University of Technology’s Industrial Design Engineering faculty is
Pierce, Jeff G.
This dissertation develops and applies an integrated framework for embedding flexibility in an engineered system architecture. Systems are constantly faced with unpredictability in the operational environment, threats from competing systems, obsolescence of technology, and general uncertainty in future system demands. Current systems engineering and risk management practices have focused almost exclusively on mitigating or preventing the negative consequences of uncertainty. This research recognizes that high uncertainty also presents an opportunity to design systems that can flexibly respond to changing requirements and capture additional value throughout the design life. There does not exist however a formalized approach to designing appropriately flexible systems. This research develops a three stage integrated flexibility framework based on the concept of architecture options embedded in the system design. Stage One defines an eight step systems engineering process to identify candidate architecture options. This process encapsulates the operational uncertainty though scenario development, traces new functional requirements to the affected design variables, and clusters the variables most sensitive to change. The resulting clusters can generate insight into the most promising regions in the architecture to embed flexibility in the form of architecture options. Stage Two develops a quantitative option valuation technique, grounded in real options theory, which is able to value embedded architecture options that exhibit variable expiration behavior. Stage Three proposes a portfolio optimization algorithm, for both discrete and continuous options, to select the optimal subset of architecture options, subject to budget and risk constraints. Finally, the feasibility, extensibility and limitations of the framework are assessed by its application to a reconnaissance satellite system development problem. Detailed technical data, performance models, and cost estimates
Feola, M.; Bella, G.; Pelloni, P.; Casoli, P.; Toderi, G.; Cantore, G.
This paper describes how different timing and shape of the injection law can influence pollutant emission of a direct injection diesel engine. The study was carried out making use of a multizone thermodynamic model as regards the closed valve phase, and a filling-emptying one as regards the open valve phase. After being calibrated by comparison with experimental data, the abovementioned model was used for injection law optimization as regards minimum pollutant concentration (NO x and soot) in the exhaust gases with the smallest engine performance reduction possible
Bhunia, Uttam; Saha, Subimal; Chakrabarti, Alok
A novel multi-objective optimization design approach for sectored toroidal superconducting magnetic energy storage coil has been developed considering the practical engineering constraints. The objectives include the minimization of necessary superconductor length and torus overall size or volume, which determines a significant part of cost towards realization of SMES. The best trade-off between the necessary conductor length for winding and magnet overall size is achieved in the Pareto-optimal solutions, the compact magnet size leads to increase in required superconducting cable length or vice versa The final choice among Pareto optimal configurations can be done in relation to other issues such as AC loss during transient operation, stray magnetic field at outside the coil assembly, and available discharge period, which is not considered in the optimization process. The proposed design approach is adapted for a 4.5 MJ/1 MW SMES system using low temperature niobium-titanium based Rutherford type cable. Furthermore, the validity of the representative Pareto solutions is confirmed by finite-element analysis (FEA) with a reasonably acceptable accuracy.
Koszalka, Tiffany A.; Wu, Yiyan
Changes in engineering practices have spawned changes in engineering education and prompted the use of distributed learning environments. A distributed collaborative engineering design (CED) course was designed to engage engineering students in learning about and solving engineering design problems. The CED incorporated an advanced interactive…
This book discusses performance-based seismic and wind-resistant design for high-rise building structures, with a particular focus on establishing an integrated approach for performance-based wind engineering, which is currently less advanced than seismic engineering. This book also provides a state-of-the-art review of numerous methodologies, including computational fluid dynamics (CFD), extreme value analysis, structural optimization, vibration control, pushover analysis, response spectrum analysis, modal parameter identification for the assessment of the wind-resistant and seismic performance of tall buildings in the design stage and actual tall buildings in use. Several new structural optimization methods, including the augmented optimality criteria method, have been developed and employed in the context of performance-based design. This book is a valuable resource for students, researchers and engineers in the field of civil and structural engineering.
Qiu, Jiaheng; Chen, Ray-Bing; Wang, Weichung; Wong, Weng Kee
Particle swarm optimization (PSO) is an increasingly popular metaheuristic algorithm for solving complex optimization problems. Its popularity is due to its repeated successes in finding an optimum or a near optimal solution for problems in many applied disciplines. The algorithm makes no assumption of the function to be optimized and for biomedical experiments like those presented here, PSO typically finds the optimal solutions in a few seconds of CPU time on a garden-variety laptop. We apply PSO to find various types of optimal designs for several problems in the biological sciences and compare PSO performance relative to the differential evolution algorithm, another popular metaheuristic algorithm in the engineering literature.
There are many things that I like about James Shapiro's new book "Evolution: A View from the 21st Century" (FT Press Science, 2011). He begins the book by saying that it is the creation of novelty, and not selection, that is important in the history of life. In the presence of heritable traits...... function. Shapiro argues that what we see in genomes is 'Natural Genetic Engineering', or designed evolution: "Thinking about genomes from an informatics perspective, it is apparent that systems engineering is a better metaphor for the evolutionary process than the conventional view of evolution...... as a select-biased random walk through limitless space of possible DNA configurations" (page 6). In this review, I will have a look at four topics: 1.) why I think genomics is not the whole story; 2.) my own perspective of E. coli genomics, and how I think it relates to this book; 3.) a brief discussion...
Pedersen, Søren Juhl; Geoffrey Vining, G.
This work looks at the application of Design of Experiments (DoE) to Food Engineering (FE) problems in relation to quality. The field of Quality Engineering (QE) is a natural partnering field for FE due to the extensive developments that QE has had in using DoE for quality improvement especially...... in manufacturing industries. In the thesis the concepts concerning food quality is addressed and in addition how QE proposes to define quality. There is seen a merger in how QE’s definition of quality has been translated for food. At the same time within FE a divergence has been proposed in the literature...... that the fundamental principles of DoE have as much importance and relevance as ever for both the food industry and FE research....
Dixon, Raymond A.; Johnson, Scott D.
A cognitive construct that is important when solving engineering design problems is executive control process, or metacognition. It is a central feature of human consciousness that enables one "to be aware of, monitor, and control mental processes." The framework for this study was conceptualized by integrating the model for creative design, which…
The development of control systems for jet engines requires a real-time computer simulation. The simulation provides an effective tool for evaluating control concepts and problem areas prior to actual engine testing. The development and use of a real-time simulation of the Pratt and Whitney F100-PW100 turbofan engine is described. The simulation was used in a multi-variable optimal controls research program using linear quadratic regulator theory. The simulation is used to generate linear engine models at selected operating points and evaluate the control algorithm. To reduce the complexity of the design, it is desirable to reduce the order of the linear model. A technique to reduce the order of the model; is discussed. Selected results between high and low order models are compared. The LQR control algorithms can be programmed on digital computer. This computer will control the engine simulation over the desired flight envelope.
Kusnowo, Roni; Gunara, Sophiadi
Centrifugal casting is a metal casting process in which metal liquid is poured into a rotating mold at a specific temperature. Given round will generate a centrifugal force that will affect the outcome of the casting. Casting method is suitable in the manufacture of the casting cylinder to obtain better results. This research was performed to design a prototype machine by using the concept of centrifugal casting. The design method was a step-by-step systematic approach in the process of thinking to achieve the desired goal of realizing the idea and build bridges between idea and the product. Design process was commenced by the conceptual design phase and followed by the embodiment design stage and detailed design stage. With an engineering design process based on the method developed by G. E. Dieter, draft prototype of centrifugal casting machine with dimension of 550×450×400 mm, ¼ HP motor power, pulley and belt mechanism, diameter of 120-150mm, simultaneously with the characteristics of simple casting product, easy manufacture and maintenance, and relatively inexpensive, was generated.
Bonderup Dohn, Niels
The aim of the present mixed-method study was to investigate task-based situational interest of sixth grade students (n = 46), between 12 and 14 years old, during an eight-week engineering design programme in a Science & Technology-class. Students' interests were investigated by means of a descriptive interpretative analysis of qualitative data from classroom observations and informal interviews. The analysis was complemented by a self-report survey to validate findings and determine prevalence. The analysis revealed four main sources of interest: designing inventions, trial-and-error experimentation, achieved functionality of invention, and collaboration. These sources differ in terms of stimuli factors, such as novelty, autonomy (choice), social involvement, self-generation of interest, and task goal orientation. The study shows that design tasks stimulated interest, but only to the extent that students were able to self-regulate their learning strategies.
Dohn, Niels Bonderup
The aim of the present mixed-method study was to investigate task-based situational interest of sixth grade students (n=46), between 12 and 14 years old, during an eight-week engineering design programme in a Science & Technology-class. Students’ interests were investigated by means...... of a descriptive interpretative analysis of qualitative data from classroom observations and informal interviews. The analysis was complemented by a self-report survey to validate findings and determine prevalence. The analysis revealed four main sources of interest: designing inventions, trial......-and-error experimentation, achieved functionality of invention, and collaboration. These sources differ in terms of stimuli factors, such as novelty, autonomy (choice), social involvement, self-generation of interest, and task goal orientation. The study shows that design tasks stimulated interest, but only to the extent...
Journal of Modeling, Design and Management of Engineering Systems. ... Journal Home > Vol 5, No 1 (2007) ... or mathematical modeling, computing, simulation, design and/or operations research tools for solving engineering problems.
Ribeiro, R; Dias-Rodrigues, J; Vaz, M
Future High Energy Physics experiments require the use of light and stable structures to support their most precise radiation detection elements. These large structures must be light, highly stable, stiff and radiation tolerant in an environment where external vibrations, high radiation levels, material aging, temperature and humidity gradients are not negligible. Unforeseen factors and the unknown result of the coupling of environmental conditions, together with external vibrations, may affect the position stability of the detectors and their support structures compromising their physics performance. Careful optimization of static and dynamic behavior must be an essential part of the engineering design. Genetic Algorithms ( GA) belong to the group of probabilistic algorithms, combining elements of direct and stochastic search. They are more robust than existing directed search methods with the advantage of maintaining a population of potential solutions. There is a class of optimization problems for which Ge...
Keski-Rahkonen, J. K.
Probabilistic methods have gradually gained ground within engineering practices but currently it is still the industry standard to use deterministic safety margin approaches to dimensioning components and qualitative methods to manage product risks. These methods are suitable for baseline design work but quantitative risk management and product reliability optimization require more advanced predictive approaches. Ample research has been published on how to predict failure probabilities for mechanical components and furthermore to optimize reliability through life cycle cost analysis. This paper reviews the literature for existing methods and tries to harness their best features and simplify the process to be applicable in practical engineering work. Recommended process applies Monte Carlo method on top of load-resistance models to estimate failure probabilities. Furthermore, it adds on existing literature by introducing a practical framework to use probabilistic models in quantitative risk management and product life cycle costs optimization. The main focus is on mechanical failure modes due to the well-developed methods used to predict these types of failures. However, the same framework can be applied on any type of failure mode as long as predictive models can be developed.
Full Text Available This paper consists of two parts: aerodynamic and mechanical multi-objective optimization for centrifugal compressor impeller through combining the three dimensional fluid dynamic simulation module CFX 16.1, the static structure in the ANSYS Workbench and the optimization software optiSLang; and a comparison and analysis of the effects of the optimized compressor on the engine performance by the one dimensional simulation tool GT-Power. In the process of optimization, the compressor design point is regarded as the optimizing point, while impeller blades and hub line were parameterized through the Bezier curve. Pressure ratio, isentropic efficiency, quality and maximum deformation and maximum internal stress of the impeller were defined as the output conditions. MOP module was then adopted in optiSLang for the parameters sensitivity analysis and mapping relationship modeling between the impeller parameters and the objective functions. The genetic algorithm is applied to find out and validate the optimal design. Through 1D simulation tool GT-Power, the influence of the optimized compressor on rotational speed of the turbocharger, backpressure and pumping loss under different engine operating conditions is analyzed and compared.