Shape optimization of acoustic horns using few design variables

2014 ◽  
Vol 136 (4) ◽  
pp. 2305-2305
Author(s):  
Nilson Barbieri ◽  
Renato Barbieri ◽  
Clebe T. Vitorino ◽  
Key F. Lima
Keyword(s):  
Shape Optimization ◽  
Design Variables ◽  
Acoustic Horns

Shape Optimization of Hydraulic Structures: an Example of an Optimum Design of a Fish Passage

10.29007/2k64 ◽  
2018 ◽  
Author(s):  
Pat Prodanovic ◽  
Cedric Goeury ◽  
Fabrice Zaoui ◽  
Riadh Ata ◽  
Jacques Fontaine ◽  
...  
Keyword(s):  
Numerical Model ◽  
Shape Optimization ◽  
Objective Function ◽  
Optimum Design ◽  
Optimization Problem ◽  
A Priori ◽  
Coupled System ◽  
Fish Passage ◽  
Hydraulic Structures ◽  
Design Variables

This paper presents a practical methodology developed for shape optimization studies of hydraulic structures using environmental numerical modelling codes. The methodology starts by defining the optimization problem and identifying relevant problem constraints. Design variables in shape optimization studies are configuration of structures (such as length or spacing of groins, orientation and layout of breakwaters, etc.) whose optimal orientation is not known a priori. The optimization problem is solved numerically by coupling an optimization algorithm to a numerical model. The coupled system is able to define, test and evaluate a multitude of new shapes, which are internally generated and then simulated using a numerical model. The developed methodology is tested using an example of an optimum design of a fish passage, where the design variables are the length and the position of slots. In this paper an objective function is defined where a target is specified and the numerical optimizer is asked to retrieve the target solution. Such a definition of the objective function is used to validate the developed tool chain. This work uses the numerical model TELEMAC- 2Dfrom the TELEMAC-MASCARET suite of numerical solvers for the solution of shallow water equations, coupled with various numerical optimization algorithms available in the literature.

scholarly journals A Sequential Approach for Aerodynamic Shape Optimization with Topology Optimization of Airfoils

2021 ◽  
Vol 26 (2) ◽  
pp. 34
Author(s):  
Isaac Gibert Martínez ◽  
Frederico Afonso ◽  
Simão Rodrigues ◽  
Fernando Lau
Keyword(s):  
Topology Optimization ◽  
Shape Optimization ◽  
Volume Fraction ◽  
Optimization Techniques ◽  
Free Form ◽  
Aerodynamic Shape Optimization ◽  
Sequential Approach ◽  
Airfoil Surface ◽  
Aerodynamic Shape ◽  
Design Variables

The objective of this work is to study the coupling of two efficient optimization techniques, Aerodynamic Shape Optimization (ASO) and Topology Optimization (TO), in 2D airfoils. To achieve such goal two open-source codes, SU2 and Calculix, are employed for ASO and TO, respectively, using the Sequential Least SQuares Programming (SLSQP) and the Bi-directional Evolutionary Structural Optimization (BESO) algorithms; the latter is well-known for allowing the addition of material in the TO which constitutes, as far as our knowledge, a novelty for this kind of application. These codes are linked by means of a script capable of reading the geometry and pressure distribution obtained from the ASO and defining the boundary conditions to be applied in the TO. The Free-Form Deformation technique is chosen for the definition of the design variables to be used in the ASO, while the densities of the inner elements are defined as design variables of the TO. As a test case, a widely used benchmark transonic airfoil, the RAE2822, is chosen here with an internal geometric constraint to simulate the wing-box of a transonic wing. First, the two optimization procedures are tested separately to gain insight and then are run in a sequential way for two test cases with available experimental data: (i) Mach 0.729 at α=2.31°; and (ii) Mach 0.730 at α=2.79°. In the ASO problem, the lift is fixed and the drag is minimized; while in the TO problem, compliance minimization is set as the objective for a prescribed volume fraction. Improvements in both aerodynamic and structural performance are found, as expected: the ASO reduced the total pressure on the airfoil surface in order to minimize drag, which resulted in lower stress values experienced by the structure.

Structural Shape Optimization Wth Error Control

1994 ◽  
Author(s):  
Pierre Duysinx ◽  
WeiHong Zhang ◽  
HaiGuang Zhong ◽  
Pierre Beckers ◽  
Claude Fleury
Keyword(s):  
Shape Optimization ◽  
Computer Aided Design ◽  
Adaptive Mesh Refinement ◽  
Error Control ◽  
Optimization Procedure ◽  
Adaptive Mesh ◽  
Structural Shape ◽  
Structural Shape Optimization ◽  
Design Variables ◽  
Recent Developments

Abstract A robust and automatic shape optimization procedure is presented in this paper, which incorporates recent developments in the field of computer-aided design (CAD) of mechanical structures, such as geometric modelling, automatic selection of independent design variables, sensitivity analysis using reliable mesh perturbation schemes, error estimation and adaptive mesh refinement. A numerical example is given to show the efficiency of the procedure.

Parameter assessment for virtual Stackelberg game in aerodynamic shape optimization

2018 ◽  
Vol 32 (12n13) ◽  
pp. 1840044
Author(s):  
Jing Wang ◽  
Fangfang Xie ◽  
Yao Zheng ◽  
Jifa Zhang
Keyword(s):  
Shape Optimization ◽  
Stackelberg Game ◽  
Critical Parameters ◽  
Aerodynamic Shape Optimization ◽  
Aerodynamic Optimization ◽  
Aerodynamic Shape ◽  
Design Variables ◽  
Design Cycle ◽  
Parametric Studies ◽  
The Impact

In this paper, parametric studies of virtual Stackelberg game (VSG) are conducted to assess the impact of critical parameters on aerodynamic shape optimization, including design cycle, split of design variables and role assignment. Typical numerical cases, including the inverse design and drag reduction design of airfoil, have been carried out. The numerical results confirm the effectiveness and efficiency of VSG. Furthermore, the most significant parameters are identified, e.g. the increase of design cycle can improve the optimization results but it will also add computational burden. These studies will maximize the productivity of the effort in aerodynamic optimization for more complicated engineering problems, such as the multi-element airfoil and wing-body configurations.

Thermal Optimization of a Microchannel Heat Sink With Trapezoidal Cross Section

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Afzal Husain ◽  
Kwang-Yong Kim
Keyword(s):  
Shape Optimization ◽  
Thermal Resistance ◽  
Objective Function ◽  
Response Surface ◽  
Heat Sink ◽  
Fractional Factorial ◽  
Surface Model ◽  
Microchannel Heat Sink ◽  
Reference Shape ◽  
Design Variables

A microchannel heat sink shape optimization has been performed using response surface approximation. Three design variables related to microchannel width, depth, and fin width are selected for optimization, and thermal resistance has been taken as objective function. Design points are chosen through a three-level fractional factorial design of sampling methods. Navier–Stokes and energy equations for steady, incompressible, and laminar flow and conjugate heat transfer are solved at these design points using a finite volume solver. Solutions are carefully validated with the analytical and experimental results and the values of objective function are calculated at the specified design points. Using the numerically evaluated objective-function values, a polynomial response surface model is constructed and the optimum point is searched by sequential quadratic programming. The process of shape optimization greatly improves the thermal performance of the microchannel heat sink by decreasing thermal resistance of about 12% of the reference shape. Sensitivity of objective function to design variables has been studied to utilize the substrate material efficiently.

Aerodynamic Optimization Design of Airfoil Based on Directly Manipulated FFD Technique

2013 ◽  
Vol 390 ◽  
pp. 121-128 ◽  
Author(s):  
Jun Qiang Bai ◽  
Song Chen
Keyword(s):  
Shape Optimization ◽  
Drag Reduction ◽  
Optimization Design ◽  
High Order ◽  
Control Points ◽  
Aerodynamic Shape Optimization ◽  
Aerodynamic Optimization ◽  
Aerodynamic Shape ◽  
Design Variables ◽  
Geometrical Constraints

The method of applying direct manipulated FFD (DFFD) technique into aerodynamic shape optimization has been proposed and researched. Due to the disadvantage of the original FFD method within which the geometrical manipulation is not direct and intuitive, the DFFD approach has been developed by solving each displacement of the FFD control points with some specified geometry points movements, so that the deformation of the target geometry could be directly manipulated. Besides, it has been illustrated that by DFFD method a relatively small number of design variables together with high order FFD control frame could be accomplished. The study cases has shown that applying this method in aerodynamic shape optimization of airfoil for drag reduction is of good feasibility and result, and could be coupled with effective geometrical constraints like airfoil thickness.

Shape Optimization of a Knuckle using the Design of Experiments

2007 ◽  
Vol 345-346 ◽  
pp. 905-908 ◽  
Author(s):  
Young Chul Park ◽  
Jung Ho Kang ◽  
Dong Hwa Lee ◽  
Seung Hwan Oh ◽  
Won Deg Ko ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Characteristic Function ◽  
Design Of Experiments ◽  
Structural Optimization ◽  
Shape Optimization ◽  
Orthogonal Array ◽  
The Other ◽  
Discrete Variables ◽  
Design Variables ◽  
Constraint Feasibility

DOE (design of experiments) was applied to the design of a knuckle as a part of a suspension system. Specifically, knuckle made of aluminum alloy was optimized considering the strength. On the other hand, design variables were set as shape variables. During structural optimization using DOE, an orthogonal array strategy was developed to determine the optimum design. The relevant discrete variables were treated as levels. Since the conventional orthogonal array did not consider the constraint, however, the characteristic function was defined to include the effect of constraint feasibility. The general DOE was expanded to include problems with constraints related to the new characteristic function.

Evolutionary Structural Shape Optimization Based on Adaptive FEM and Boundary Representation of B-Spline

2012 ◽  
Vol 562-564 ◽  
pp. 1575-1582
Author(s):  
Sheng Li Gu ◽  
Fu Ming Wang
Keyword(s):  
Shape Optimization ◽  
Boundary Representation ◽  
Structural Shape ◽  
B Spline ◽  
B Splines ◽  
Structural Shape Optimization ◽  
Evolutionary Structural Optimization ◽  
Design Variables ◽  
Adaptive Fem ◽  
Element Error

This paper presents a structural shape optimization algorithm based on the evolutionary structural optimization (ESO) method in conjunction with element error estimate and adaptive FEM. B-splines are used to describe the boundary of the design domain; the shape of these B-splines is governed by a set of master nodes which can be taken as the design variables. The optimal shape of the design boundary with constant stress is achieved iteratively by the movement and update of the position of the master nodes based on nodal stress leveling. The result quality, in terms of accuracy and efficiency, is tested and discussed with an analytical solution.

Sign in / Sign up

Export Citation Format

Share Document