scholarly journals Performance Optimization of a Diesel Engine with a Two-Stage Turbocharging System and Dual-Loop EGR Using Multi-Objective Pareto Optimization Based on Diesel Cycle Simulation

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4223 ◽  
Author(s):  
Heecheong Yoo ◽  
Bum Park ◽  
Honghyun Cho ◽  
Jungsoo Park
Keyword(s):  
Performance Optimization ◽  
Fuel Efficiency ◽  
Test Procedure ◽  
Dilution Effect ◽  
Optimization Method ◽  
Pareto Optimization ◽  
Design Parameters ◽  
Cylinder Pressure ◽  
Multi Objective ◽  
Cycle Simulation

The effects of an electric supercharger (eS) and a dual-loop exhaust gas recirculation (EGR) system on a passenger car’s diesel engine’s emissions and fuel efficiency under various worldwide harmonized light-duty vehicles test procedure (WLTP) reference operation points were investigated using a one-dimensional engine cycle simulation, called GT-Power. After heavy EGR application, the in-cylinder pressure and temperature declined due to a dilution effect. As eS power and rpm increased, the brake-specific fuel consumption (BSFC) decreased because the effects of the air flow rate increased. However, it was unavoidable that nitrogen oxide (NOx) emissions also increased due to the higher in-cylinder pressure and temperature. To induce more EGR to the intake system, a dual-loop EGR system was applied with eS at different low-pressure EGR (LP-EGR) fractions (0, 0.25, 0.5, 0.75, and 1.0). Under these conditions, a design of experiment (DoE) procedure was carried out and response surface plots of the BSFC and brake-specific NOx (BSNOx) were prepared. A multi-objective Pareto optimization method was used to improve the trade-off in results between the BSFC and BSNOx. Through optimization, optimal Pareto fronts were obtained, which suggested design parameters for eS power and rpm to control the engine under various LP fraction conditions.

scholarly journals Multi-objective performance optimization of ORC cycle based on improved ant colony algorithm

Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 48-59 ◽  
Author(s):  
Rong He ◽  
Xinli Wei ◽  
Nasruddin Hassan
Keyword(s):  
Performance Optimization ◽  
Ant Colony Algorithm ◽  
Optimal Solution ◽  
Second Law Of Thermodynamics ◽  
Optimization Method ◽  
Ant Colony ◽  
Multi Objective ◽  
Objective Performance ◽  
Performance Evaluation Index ◽  
Improved Ant Colony Algorithm

Abstract To solve the problem of multi-objective performance optimization based on ant colony algorithm, a multi-objective performance optimization method of ORC cycle based on an improved ant colony algorithm is proposed. Through the analysis of the ORC cycle system, the thermodynamic model of the ORC system is constructed. Based on the first law of thermodynamics and the second law of thermodynamics, the ORC system evaluation model is established in a MATLAB environment. The sensitivity analysis of the system is carried out by using the system performance evaluation index, and the optimal working parameter combination is obtained. The ant colony algorithm is used to optimize the performance of the ORC system and obtain the optimal solution. Experimental results show that the proposed multi-objective performance optimization method based on the ant colony algorithm for the ORC cycle needs a shorter optimization time and has a higher optimization efficiency.

scholarly journals Development of a Drive Cycle Simulation Model for Hybrid Powertrains

2012 ◽  
Author(s):  
Johan Vingbäck ◽  
Peter Jeppsson
Keyword(s):  
Simulation Model ◽  
Fuel Efficiency ◽  
Design Parameters ◽  
Vehicle Performance ◽  
Simulation Tools ◽  
Cycle Simulation ◽  
Hybrid Powertrains ◽  
Different Types ◽  
Main Model ◽  
Simulation Time

In this paper a modular numerical simulation model for hybrid powertrains is presented. The simulation model is based on common design parameters and measurements for fuel efficiency and vehicle performance. Implemented in Simulink, the main model is expandable to combine the strengths of different types of simulation tools. As the design process proceeds, parts of the model can gradually be replaced with instances containing one or more subsystem modelled in the appropriate tool, including CAD, FEA and MBD, incrementally increasing the accuracy of the model of the overall system yet keeping the simulation time reasonable. Subsystems can be replaced to support hardware input and/or output, resulting in a so-called hardware-in-the-loop simulation. The presented system has shown to be modular as all the components contain their physical properties and can be modified, replaced or reorganized without the modification of any other subsystem. The simulation model of the powertrain is easily modified in order to allow the simulation of multiple designs with the same components. The systeam also has the same information flow as would be observed in a physical powertrain.

Multi-Objective Optimization for the Efficiency and Weight of Helicopter Transmission Planetary Gear Train

2014 ◽  
Vol 635-637 ◽  
pp. 177-180
Author(s):  
Kang Huang ◽  
Xiao Hui Zhu ◽  
Xiang Chen ◽  
Gong Chuan Xia
Keyword(s):  
Planetary Gear ◽  
Optimization Method ◽  
Gear Train ◽  
Transmission Ratio ◽  
Design Parameters ◽  
Multi Objective Optimization ◽  
Planetary Gear Train ◽  
Multi Objective ◽  
Critical Design ◽  
Helicopter Transmission

A multi-objective optimization method for the optimization of the efficiency and weight of helicopter transmission planetary gear train was established. Taking the transmission ratio, efficiency weight, and reliability as critical design parameters, taking the conditions of the planetary gear train itself and the strength check constraint for the gear train as constraint functions, making the weight and efficiency of the planetary gear train asoptimization targets and using the Matlab function fgoalattain, a multi-objective optimization has been made. Comparison between the initial and the optimized results showed the success of the optimized planetary gear train in reducing the weight and increasing the efficiency.

scholarly journals Multi-Objective Optimization Design of Permanent Magnet Torque Motor

2021 ◽  
Vol 12 (3) ◽  
pp. 131
Author(s):  
Jiawei Chai ◽  
Tianyi Zhao ◽  
Xianguo Gui
Keyword(s):  
Permanent Magnet ◽  
Optimization Method ◽  
Torque Ripple ◽  
Numerical Control ◽  
Design Parameters ◽  
Support Vector ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Output Torque ◽  
Low Torque

Permanent magnet torque motor (PMTM) is widely used in aerospace, computer numerical control (CNC) machine tools, and industrial robots with many advantages such as high torque density, strong overload capacity, and low torque ripple. With the upgrading of industrial manufacturing, the requirements for the performance of torque motors have become more stringent. At present, how to achieve high output torque and low torque ripple has become a research hotspot of torque motors. In the optimization process, it is necessary to increase the output torque while the torque ripple can be reduced, and it is difficult to get a good result with the single-objective optimization. In this paper, a multi-objective optimization method based on the combination of design parameter stratification and support vector machine (SVM) is proposed. By analyzing the causes of torque ripple, the output torque, efficiency, cogging torque, and total harmonic distortion (THD) of back electromotive force (EMF) are selected as the optimization objectives. In order to solve the coupling problem between the motor parameters, the calculation formula of Pearson correlation coefficient is used to analyze the relationship between the design parameters and the optimization objectives, and the design parameters are layered ac-cording to the sensitivity. In order to shorten the optimization cycle of the motor, SVM is used as a fitting method of the mathematical model. The performance between initial and optimal motors is compared, and it can be found that the optimized motor has a higher torque and lower torque ripple. The simulation results verify the effectiveness of the proposed optimization method.

scholarly journals Weight-Vibration Pareto Optimization of a Triple Mass Flywheel for Heavy-Duty Truck Powertrains

Machines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 50
Author(s):  
Viktor Berbyuk
Keyword(s):  
Total Mass ◽  
Optimization Method ◽  
Pareto Optimization ◽  
Design Parameters ◽  
Vibration Absorber ◽  
Optimized Design ◽  
Heavy Duty ◽  
Mean Values ◽  
Input Shaft ◽  
Heavy Duty Truck

Enhanced efficiency of heavy-duty truck powertrains with constraints imposed on noise, vibration, and harshness requires novel solutions for torsion vibrations attenuation. In the paper, the weight-vibration Pareto optimization problem for a novel vibration absorber, a triple mass flywheel, for application in heavy-duty truck powertrains is considered. Global sensitivity analysis and Pareto optimization method are used to design a novel vibration absorber. The optimization method attempts to minimize oscillations of the torque at the transmission input shaft as well as to minimize total mass inertia of the absorber. It is shown that there exists a Pareto front between the measure of the attenuation of oscillations of the torque and the total mass inertia of a triple mass flywheel. The optimized design parameters for the absorber are obtained that provide the best attenuation of oscillations of the torque at the transmission input shaft for different mean values of the engine driving torque. The analysis shows real evidence of the feasibility of the application of this concept of vibration absorbers in heavy-duty truck powertrains. It is also shown that optimized design parameters of a triple mass flywheel put this concept in a superior position in comparison with a dual mass flywheel.

scholarly journals Multi-objective optimization of flexure hinge mechanism considering thermal–mechanical coupling deformation and natural frequency

2017 ◽  
Vol 9 (1) ◽  
pp. 168781401668791 ◽  
Author(s):  
Lufan Zhang ◽  
Xueli Li ◽  
Jiwen Fang ◽  
Zhili Long
Keyword(s):  
Finite Element ◽  
Natural Frequency ◽  
Element Model ◽  
Optimization Method ◽  
Design Parameters ◽  
Flexure Hinge ◽  
Multi Objective Optimization ◽  
Motion Platform ◽  
Mechanical Coupling ◽  
Multi Objective

Flexure hinge mechanism plays a key part in realization of terminal nano-positioning. The performance of flexure hinge mechanism is determined by its positioning design. Based on the actual working conditions, its finite element model is built and calculated in ANSYS. Moreover, change trends of deformation and natural frequency with positioning design parameters are revealed. And sensitivity analysis is performed for exploration response to these parameters. These parameters are used to build four objective functions. To solve it conveniently, the multi-objective optimization problem is transferred to the form of single-objective function with constraints. An optimal mechanism is obtained by an optimization method combining ANSYS with MATLAB. Finite element numerical simulation has been carried out to demonstrate the superiority of the optimal flexure hinge mechanism, and the superiority can be further verified by experiment. Measurements and tests have been conducted at varying accelerations, velocities, and displacements, to quantify and characterize the amount of acceleration responses obtained from flexure hinge mechanism before and after optimization. Both time- and frequency-domain analyses of experimental data show that the optimal flexure hinge mechanism has superior effectiveness. It will provide a basic for realizing high acceleration and high precision positioning of macro–micro motion platform.

Computational Fluid Dynamics–Based Optimization of a Surface Combatant

2004 ◽  
Vol 48 (04) ◽  
pp. 273-287
Author(s):  
Y. Tahara ◽  
F. Stern ◽  
Y. Himeno
Keyword(s):  
Fluid Dynamics ◽  
Free Surface ◽  
Wave Field ◽  
Performance Optimization ◽  
High Performance ◽  
Optimization Method ◽  
Design Parameters ◽  
Design Constraints ◽  
Hull Form ◽  
Surface Combatant

Computational fluid dynamics (CFD)-based optimization of a surface combatant is presented with the following main objectives:development of a high-performance optimization module for a Reynolds averaged Navier-Stokes (RANS) solver for with-free-surface condition; anddemonstration of the capability of the optimization method for flow- and wave-field optimization of the Model 5415 hull form. The optimization module is based on extension of successive quadratic programming (SQP) for higher-performance optimization method by introduction of parallel computing architecture, that is, message passing interface (MPI) protocol. It is shown that the present parallel SQP module is nearly m(= 2k+ 1; k is number of design parameters) times faster than conventional SQP, and the computational speed does not depend on the number of design parameters. The RANS solver is CFDSHIP-IOWA, a general-purpose parallel multiblock RANS code based on higher-order upwind finite difference and a projection method for velocity-pressure coupling; it offers the capability of free-surface flow calculation. The focus of the present study is on code development and demonstration of capability, which justifies use of a relatively simple turbulence model, a free-surface model without breaking model, static sinkage and trim, and simplified design constraints and geometry modeling. An overview is given of the high-performance optimization method and CFDSHIP-IOWA, and results are presented for stern optimization for minimization of transom wave field disturbance; sonar dome optimization for minimization of sonar-dome vortices; and bow optimization for minimization of bow wave. In conclusion, the present work has successfully demonstrated the capability of the CFD-based optimization method for flow- and wave-field optimization of the Model 5415 hull form. The present method is very promising and warrants further investigations for computer-aided design (CAD)-based hull form modification methods and more appropriate design constraints.

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