Research on the Optimization Design of the Acoustic Stealth Shape of a Bottom Object

2021 ◽  
pp. 2150009
Author(s):  
Bing Li ◽  
Fulin Zhou ◽  
Jun Fan ◽  
Bin Wang ◽  
Zilong Peng
Keyword(s):  
Optimization Design ◽  
Weighting Function ◽  
Design Method ◽  
Acoustic Scattering ◽  
Optimization Method ◽  
Physical Acoustics ◽  
Optimal Method ◽  
Optimal Shapes ◽  
Grid Topology ◽  
Grazing Angles

This paper presents an optimal design method for the acoustic stealth shape for a bottom object with relatively lower echo strength (ES), based on the physical acoustics method (PAM) and genetic algorithm (GA). Specifically, the performance of the PAM was evaluated with acoustic scattering from a Manta-like object, using two-dimensional (2D) axisymmetric calculation method. In the optimization method, GA, the object shape represented by the Bernstein polynomial, grid topology acquired by using the MATLAB-COMSOL module and the scattering calculation are combined into a process. The optimization objective function is given as the weighting function of the ES of the bottom object with different grazing angles and frequencies. Finally, the two optimal shapes of the bottom object under different conditions are given, in which the ES and the angle detection rate after optimization are greatly reduced. This optimal method provides guidance for the lower ES shape design of bottom targets.

A new jig-shape optimization method for the high aspect ratio wing

2018 ◽  
Vol 91 (1) ◽  
pp. 124-133
Author(s):  
Zhe Yuan ◽  
Shihui Huo ◽  
Jianting Ren
Keyword(s):  
Aspect Ratio ◽  
Shape Optimization ◽  
High Aspect Ratio ◽  
Optimization Design ◽  
Design Method ◽  
Aircraft Design ◽  
Optimization Method ◽  
Attack Angle ◽  
Structural Deformation ◽  
Content Type

Purpose Computational efficiency is always the major concern in aircraft design. The purpose of this research is to investigate an efficient jig-shape optimization design method. A new jig-shape optimization method is presented in the current study and its application on the high aspect ratio wing is discussed. Design/methodology/approach First, the effects of bending and torsion on aerodynamic distribution were discussed. The effect of bending deformation was equivalent to the change of attack angle through a new equivalent method. The equivalent attack angle showed a linear dependence on the quadratic function of bending. Then, a new jig-shape optimization method taking integrated structural deformation into account was proposed. The method was realized by four substeps: object decomposition, optimization design, inversion and evaluation. Findings After the new jig-shape optimization design, both aerodynamic distribution and structural configuration have satisfactory results. Meanwhile, the method takes both bending and torsion deformation into account. Practical implications The new jig-shape optimization method can be well used for the high aspect ratio wing. Originality/value The new method is an innovation based on the traditional single parameter design method. It is suitable for engineering application.

Shape Optimization Design of Gravity Buttress of Arch Dam Based on Asynchronous Particle Swarm Optimization Method

2014 ◽  
Vol 662 ◽  
pp. 160-163
Author(s):  
Lei Xu
Keyword(s):  
Particle Swarm Optimization ◽  
Optimization Design ◽  
Design Method ◽  
Particle Swarm ◽  
Optimization Method ◽  
Arch Dam ◽  
Swarm Optimization ◽  
Safety Coefficient ◽  
Parametric Description ◽  
Particle Swarm Optimization Method

The optimization design method was rarely used to design the gravity buttress of arch dam in the past. With this in mind, the parametric description of gravity buttress is given, and the auto-calculation of its exerting loads and the safety coefficient of anti-slide stability are realized subsequently. Then, the optimization design model of gravity buttress and the procedures of optimization design are presented using the asynchronous particle swarm optimization method. Finally, ODGB software, which is short for Optimization Design of Gravity Buttress software, is developed and verified.

Improving the Robustness of Adjoint-Based Airfoil Drag Reduction Design

2013 ◽  
Vol 444-445 ◽  
pp. 259-263
Author(s):  
Yan Hong Fan
Keyword(s):  
Drag Reduction ◽  
Optimization Design ◽  
Line Search ◽  
Optimization Problem ◽  
Design Method ◽  
Optimization Method ◽  
Search Method ◽  
Linear Search

The effect of steps in the line search on the consistence of adjoint-based drag reduction of airfoil is investigated in this paper. Constant step adopted in drag reduction design usually gives different optimization results and choice of constant step often depends on designers experience and optimization problem. Bracket method is applied to automatically give the optimal step in performing drag reduction design of airfoils RAE2822 and S73613 and the consistent optimal results are obtained. The results illustrate that the linear search method can automatically find the optimal step, and overcome the restriction on choice of user-defined constant step which is used in the traditional adjoint-based optimization method. That is, it reduces the dependence of step in the drag reduction design, and improves the robustness of the adjoint-based airfoil drag reduction optimization design method.

An Optimization Design Method of Geometric Parameters of Skid Shoe Referring to Subject Weight of Marine Structures

2014 ◽  
Vol 678 ◽  
pp. 325-332
Author(s):  
Feng Yan Yang ◽  
Xiang Zhen Yan ◽  
Zheng Rong Song ◽  
Ming Wang Yang ◽  
Zi Kun Zhao ◽  
...  
Keyword(s):  
Optimization Design ◽  
Design Method ◽  
Plate Thickness ◽  
Optimization Method ◽  
Geometric Parameters ◽  
Frame Structure ◽  
Complex Method ◽  
Optimized Design ◽  
Original Design ◽  
Marine Structures

The optimization design method of geometric parameters of skid shoe which is used to subject weight of marine structures is proposed. Considering skid shoe as steel frame structure, total weight and the bearing capacity of the skid shoe are selected as optimal objectives, and geometric parameters of the skid shoe are taken as design variables. Taking the strength, stiffness, local stability of the skid shoe as the constraint conditions, multi-objectives constraints optimization model of geometric parameters is established, and solved based on complex method. According to research results, a computer program has been developed using VC language. Then geometric optimum parameters of skid shoe in service of CNOOC are analyzed by the program. The results show that optimized design decreases steel volume, steel plate thickness by 28.7%, 18.4%, respectively, compared with original design. The optimization method has a series of advantages, such as simple model, fast calculating speed, high calculation accuracy.

Intelligent Optimization Design of the Cutting Unit’s Transmission System of a Shearer Based on Robustness

2021 ◽  
pp. 2158009
Author(s):  
Hongbin Gao ◽  
Junjun Chen
Keyword(s):  
Optimization Design ◽  
Design Method ◽  
Harmonic Balance Method ◽  
Optimization Method ◽  
Transmission System ◽  
Gear Transmission ◽  
Manufacturing Cost ◽  
Tooth Width ◽  
Gear Transmission System ◽  
Cutting Unit

To improve the robustness of the shearer cutting part and reduce the manufacturing cost, in this study, the gear transmission system of a shearer’s cutting unit can be divided into three basic components: single-gear-on-one-shaft form, the planetary reduction form, and double-gears-on-one-shaft form. The dynamic differential equations of each structure are established in this study, and the volume functions of the three basic components are obtained. The characteristics of the internal excitation of the gear transmission system are analyzed, and a scheme for solving the motion parameters of each component is formulated based on the harmonic balance method. Based on the parameters, such as tooth width, tooth number, and modulus, as optimized variables, a robust optimization method minimizing the multi-parameter evaluation function, which is weighted linearly by dimensionless vibration and volume of the gear transmission system, is presented. The gear transmission system of a sample shearer’s cutting unit is optimized using the proposed method. The results show that the transmission system’s size decreases by 5.4%, the drum’s maximum torsional acceleration decreases by 17.8%, and the first gear’s maximum torsional acceleration decreases by 9.6%. Thus, we conclude that the optimum design method decreases a shearer’s manufacturing cost and decreases the cutting unit’s failure rate.

Study on Optimization Design of a Hoist Roller

2011 ◽  
Vol 415-417 ◽  
pp. 460-463
Author(s):  
Li Liu ◽  
Hong Xia Liu
Keyword(s):  
Optimization Design ◽  
Design Method ◽  
Plate Thickness ◽  
Optimization Method ◽  
Practical Significance ◽  
Application Software ◽  
Side Plate ◽  
Design Variables ◽  
Programming Software ◽  
Set Up

In the design of wrapping hoist, the roller strength is always a larger problem. In this paper, diameter, wall thickness and side plate thickness of the roller were selected as design variables, and volume of the roller acts as object function. Through analyzing its inner stresses, the mechanical model and mathematical model were set up. Adopting the optimization method of covering complex and VB programming software, an application software of a hoist roller optimization design was got. An example is used to verify correctness and practicability of the software. This optimization design method has practical significance on reducing the weight and material of a hoist roller.

Optimization, design and testing for morphing leading edge

2020 ◽  
pp. 095440622094188
Author(s):  
Yu Yang ◽  
Zhigang Wang ◽  
Binwen Wang ◽  
Shuaishuai Lyu
Keyword(s):  
Optimization Design ◽  
Design Method ◽  
Leading Edge ◽  
Optimization Method ◽  
Collaborative Optimization ◽  
Noise Abatement ◽  
Deformation Control ◽  
Design Variables ◽  
Weight Penalty

Wing's morphing leading edge, drooping in a seamless way, has significant potential for noise abatement and drag reduction. Innovative design methods for compliant skin and internal actuating mechanism, respectively, are proposed and validated through a mockup in this paper. For the skin, a collaborative optimization method is presented, which takes all design variables, continuous and discrete, into account simultaneously. Moreover, to overcome the drawback of conventional algorithm, which is insufficient for deformation control in critical regime, weight penalty is imposed on present objective function. On the other hand, an internal kinematic actuating mechanism is designed from an improved concept, of which positions of level-rod hinges are optimized in a larger zone to fit the deflection requirement. The test of mockup validates the above methods, and excellent morphing quality of the compliant skin proves the advancement of the collaborative optimization method. However, the design method of internal actuating mechanism needs further improvement, and the error induced deteriorates the final morphing quality of the mockup.

Optimization Design of Crank Rocker Mechanism for a Torque Exciter

2011 ◽  
Vol 88-89 ◽  
pp. 592-595
Author(s):  
Xu Zhang ◽  
Guo Jun Bi ◽  
Li Wei Li ◽  
Wei Wei Cui ◽  
Ji Jun Cui ◽  
...  
Keyword(s):  
Optimization Design ◽  
Performance Test ◽  
Design Method ◽  
Angular Displacement ◽  
Dynamic Performance ◽  
Optimization Method ◽  
Existence Condition ◽  
Condition Optimization ◽  
Transmission Angle ◽  
Design Function

The dimension synthesis of crank rocker mechanism used in torque exciter was carried out with known angular displacement of rocker swing. Optimization method based on minimum kinetic energy of whole mechanism was adopted under constraint condition of minimum transmission angle and mechanism bar existence condition. Optimization design function was applied in solution and a design method of crank rocker mechanism was developed. The torque exciter has been in operation, achieving scheduled function for dynamic performance test, and all testing data are exact and valid.

The Research of Dynamic Optimization Method on Automobile Shock Absorption Twist Bar Spring Design

2009 ◽  
Vol 16-19 ◽  
pp. 415-419
Author(s):  
Gui Qiu Song
Keyword(s):  
Dynamic Optimization ◽  
Optimization Design ◽  
Optimization Methods ◽  
Optimization Method ◽  
Random Load ◽  
Optimal Method ◽  
New Approach ◽  
Recent Developments ◽  
Spring System ◽  
Automobile Components

This paper presents recent developments in the study of optimization methods for industrial product design, and provides a method of dynamic optimization design to calculate the optimal loading property of automobile twist bar spring system. This is a different approach to traditional systems that is based on dynamic and random load, applying the basic theory and methods of dynamic design, according to the multi-goal characteristic of automobile twist bar spring. This paper presents a thorough analysis dynamic quadratic fuzzy optimal method of double-goal and the method to determine paper optimal gene. This method is used to automobile twist bar spring design, the result shows that the ability of spring loading is improved; the weight of structure is reduced. The new approach makes the vibration absorbing system more reliable and comfortable. The results presented in this paper are not only applicable to automobile twist bar spring systems but all systems that possess dynamic, random and fuzzy characteristics. This work finds applications in automobile components design and dynamic character analysis.

scholarly journals Efficiency Optimization Design of L-LLC Resonant Bidirectional DC-DC Converter

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3123
Author(s):  
Jing Lu ◽  
Xiangqian Tong ◽  
Jianwu Zeng ◽  
Ming Shen ◽  
Jun Yin
Keyword(s):  
Parameter Optimization ◽  
Optimization Design ◽  
High Efficiency ◽  
Design Method ◽  
Optimization Method ◽  
Switching Loss ◽  
Intrinsic Mechanism ◽  
Parasitic Parameters ◽  
New Type ◽  
Parameter Optimization Design

The new type of L-LLC resonant bidirectional DC-DC converter (L-LLC-BDC) has merits of high efficiency, high-power density and wide gain and power ranges, and it is suitable for energy interface between energy storage systems and DC micro grid. However, the resonances are sensitive to the parasitic parameters, which will deteriorate the efficiency. This paper investigates the intrinsic mechanism of parasitic parameters on the L-LLC-BDC operating principle and working characteristics based on the analysis of working modes and resonance tank. By taking the oscillation of parasitic parameters produced in the stage for the freewheeling stage into consideration, a parameter optimization method is proposed to reduce the resonant current oscillation while maintaining the characteristic of the natural soft switching. The experiment results not only validated the proposed parameter optimization design method, but also testified to the improvement of the efficiency through the minimization of the conduction and switching loss.

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