Parameter Design of Conformal PML Based on 2D Monostatic RCS Optimization

2021 ◽  
Vol 36 (6) ◽  
pp. 726-733
Author(s):  
Yongjie Zhang ◽  
Xiaofeng Deng

In this study, 2D finite element (FE) solving process with the conformal perfectly matched layer (PML) is elucidated to perform the electromagnetic scattering computation. With the 2D monostatic RCS as the optimization objective, a sensitivity analysis of the basic design parameters of conformal PML (e.g., layer thickness, loss factor, extension order and layer number) is conducted to identify the major parameters of conformal PML that exerts more significant influence on 2D RCS. Lastly, the major design parameters of conformal PML are optimized by the simulated annealing algorithm (SA). As revealed from the numerical examples, the parameter design and optimization method of conformal PML based on SA is capable of enhancing the absorption effect exerted by the conformal PML and decreasing the error of the RCS calculation. It is anticipated that the parameter design method of conformal PML based on RCS optimization can be applied to the cognate absorbing boundary and 3D electromagnetic computation.

2020 ◽  
Vol 20 (03) ◽  
pp. 2050031
Author(s):  
Qiang Han ◽  
Xuan Zhang ◽  
Kun Xu ◽  
Xiuli Du

The optimum design of distributed tuned mass dampers (DTMDs) is normally based on predefined restrictions, such as the location and/or mass ratio of the tuned mass dampers (TMDs). To further improve the control performance, a free parameter optimization method (FPOM) is proposed. This method only restricts the total mass of the DTMDs system and takes the installation position, mass ratio, stiffness and damping of each TMD as parameters to be optimized. An improved hybrid genetic-simulated annealing algorithm (IHGSA) is adopted to find the optimum values of the design parameters. This algorithm can solve the non-convexity and multimodality problems of the objective function and is quite effective in dealing with the large amount of computations in the free parameter optimization. A numerical benchmark model is adopted to compare the control efficiency of FPOM with conventional control scenarios, such as single TMD, multiple TMDs and DTMDs optimized through conventional methods. The results show that the DTMDs system optimized by using FPOM is superior to the other control scenarios for the same value of mass ratio.


2012 ◽  
Vol 190-191 ◽  
pp. 7-10 ◽  
Author(s):  
Yu Guo Wu

In order to raise the design efficiency and get the most excellent design effect, this paper combined Particle Swarm Optimization (PSO) algorithm and put forward a new kind of neural network, based on PSO algorithm and NARMA model. It gives the basic theory, steps and algorithm; The test results show that rapid global convergence and reached the lesser mean square error MSE) when compared with Genetic Algorithm, Simulated Annealing Algorithm, the BP algorithm with momentum term.


2014 ◽  
Vol 1016 ◽  
pp. 256-260
Author(s):  
Ze Yin He ◽  
Teng Jiao Lin ◽  
Wen Liu ◽  
Bo Liu

The Response Surface Method (RSM) and Simulated Annealing Algorithm (SAA) are utilized to analysis and optimize the vibro-acoustic properties of gear system. A simple case is illustrated to demonstrate the capabilities of the acoustic optimization design method. The results show that the method of acoustic optimization design based on RSM and SAA can effectively reduce radiation noise, and provide theoretical fundament and guidance for further study on acoustic optimization design of complicated gear system.


Author(s):  
Yuan Mao Huang ◽  
Bi Shyang Hu

Abstract Many design parameters affect the performance of continuous variable transmissions. This paper presents the optimization of a continuous variable transmission by using the simulated annealing algorithm. The Bessel method of curve fitting and the tensor product method of surface fitting were used to facilitate the discrete fuel consumption, emissions of carbon monoxide (CO) and HC compound of experimental engine data. A compromise method was used to analyze the multi-objective functions. The values for design variables are recommended for further development.


2014 ◽  
Vol 953-954 ◽  
pp. 673-679
Author(s):  
Yang Yang Wang ◽  
Ping Fang Hu ◽  
Fei Lei ◽  
Na Zhu ◽  
Tian Hua Wu ◽  
...  

A design method for ground-coupled heat pump (GCHP) systems with specific constraint conditions is proposed. The total borehole number, borehole depth, borehole space and average velocity of fluid in the U-tube are considered as variables in the optimization problem. The optimization problem of four variables is transformed into that of single decision variable. A case study, which includes different schemes for designing GCHP systems of an office building and the corresponding economic analysis, is performed with the aid of simulation software. The result shows that optimal design parameters could be found in an economic optimization problem with specific constraint conditions. Additionally, design parameters may have a notable influence on the energy consumption of circulating pumps. The optimization method in this paper could be utilized by engineering designers for reference.


2012 ◽  
Vol 2012 ◽  
pp. 1-26 ◽  
Author(s):  
Liming Yao ◽  
Jiuping Xu ◽  
Feng Guo

This paper proposes a bilevel multiobjective optimization model with fuzzy coefficients to tackle a stone resource assignment problem with the aim of decreasing dust and waste water emissions. On the upper level, the local government wants to assign a reasonable exploitation amount to each stone plant so as to minimize total emissions and maximize employment and economic profit. On the lower level, stone plants must reasonably assign stone resources to produce different stone products under the exploitation constraint. To deal with inherent uncertainties, the object functions and constraints are defuzzified using a possibility measure. A fuzzy simulation-based improved simulated annealing algorithm (FS-ISA) is designed to search for the Pareto optimal solutions. Finally, a case study is presented to demonstrate the practicality and efficiency of the model. Results and a comparison analysis are presented to highlight the performance of the optimization method, which proves to be very efficient compared with other algorithms.


Author(s):  
Duccio Bonaiuti ◽  
Mehrdad Zangeneh

Optimization strategies have been used in recent years for the aerodynamic and mechanical design of turbomachine components. One crucial aspect in the use of such methodologies is the choice of the geometrical parameterization, which determines the complexity of the objective function to be optimized. In the present paper, an optimization strategy for the aerodynamic design of turbomachines is presented, where the blade parameterization is based on the use of a three-dimensional inverse design method. The blade geometry is described by means of aerodynamic parameters, like the blade loading, which are closely related to the aerodynamic performance to be optimized, thus leading to a simple shape of the optimization function. On the basis of this consideration, it is possible to use simple approximation functions for describing the correlations between the input design parameters and the performance ones. The Response Surface Methodology coupled with the Design of Experiments (DOE) technique was used for this purpose. CFD analyses were run to evaluate the configurations required by the DOE to generate the database. Optimization algorithms were then applied to the approximated functions in order to determine the optimal configuration or the set of optimal ones (Pareto front). The method was applied for the aerodynamic redesign of two different turbomachine components: a centrifugal compressor stage and a single-stage axial compressor. In both cases, both design and off-design operating conditions were analyzed and optimized.


2012 ◽  
Vol 178-181 ◽  
pp. 2871-2876
Author(s):  
Chao Wang ◽  
Feng Feng ◽  
Xin Chang ◽  
Chun Yu Guo ◽  
Yang Hao Liu

Hydrofoil is the important part of ship design and diverse motion equipment. The optimization design of hydrofoil section on lift-to-drag radio with genetic algorithm (GA) and simulated annealing algorithm are demonstrated, and the method on the hydrofoil section design of the propeller design will be done. Objective function and fitness of every individual are provided by flow solver of panel method. The optimization method on design of hydrofoil section on lift-to-drag is successfully used. The optimization results show the combination of optimization algorithm is feasible at the optimal design of hydrofoil sections. What’s more, a comparison between two different optimization algorithms is made, a conclusion that the simulated annealing algorithm is better then the genetic algorithm is obtained.


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