Aerothermodynamic shape optimization using DSMC and POD-RBF methods

Download

index.pdf

Date

2018

Author

Kutkan, Halit

Metadata

Show full item record

Item Usage Stats

310
views

123
downloads

This thesis study presents a hybrid method based on Proper Orthogonal Decomposition (POD) with Radial Basis Function (RBF), on Direct Simulation Monte Carlo (DSMC) solutions for aerothermodynamic front surface optimization of Stardust re-entry. Gaussian and multiquadric RBFs are implemented for comparison, and multiquadric functions are chosen due to their insensitivity to diverse shape parameters. Cubic uniform B-spline curves are used innovatively for parameterization of the geometry change, instead of curve fitting the geometry itself. This makes possible to reduce the number of design variables. Gradient based optimization strategy is implemented by regarding the distributions of pressure, shear stress and heat flux along the surface of the geometries. DS2V two dimensional axisymmetric DSMC solver is used as the physics solver, and 11 species air model are chosen with 41 chemical reactions according to atmospheric conditions of the re-entry. Different geometries are obtained via deviating the design variables arbitrarily to form a snapshot pool. In this manner, the approximation success of the POD-RBF methodology is tested on highly nonlinear flow conditions with arbitrarily chosen design of experiment. Finally, the optimized geometries are simulated via DSMC code and the solutions are compared with the solutions of POD-RBF Reduced Order Model (ROM). Method lowered the optimization time extraordinarily and provided satisfactory results.

Subject Keywords

Aerothermodynamics., Hypersonic planes.

URI

http://etd.lib.metu.edu.tr/upload/12622398/index.pdf
https://hdl.handle.net/11511/27420

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Aerothermodynamic Shape Optimization of Reentry Capsules Using DSMC and POD Methods Kutkan, Halit; Eyi, Sinan (null; 2018-07-09) This paper presents a hybrid method based on proper orthogonal decomposition (POD) with a trained radial basis function (RBF) network, on direct simulation monte carlo (DSMC) solutions for aerothermodynamic front surface optimization of Stardust re-entry. Gaussian and multiquadric RBFs are implemented for comparison, and multiquadric functions are chosen due to their insensitivity to diverse shape parameters. Cubic uniform B-spline curves are used ...
Aerothermodynamic Shape Optimization of Reentry Capsule Kutkan, Halit; Eyi, Sinan (2018-06-25) This paper presents a hybrid method based on proper orthogonal decomposition (POD) with a trained radial basis function (RBF) network, on direct simulation monte carlo (DSMC) solutions for aerothermodynamic front surface optimization of Stardust reentry. Gaussian and multiquadric RBFs are implemented for comparison, and multiquadric functions are chosen due to their insensitivity to diverse shape parameters. Cubic uniform B-spline curves are used innovatively for parameterization of t...
LASP Local adaptive super pixels İNCE, Kutalmış Gökalp; Çığla, Cevahir; Alatan, Abdullah Aydın (2015-09-30) In this study, a novel gradient ascent approach is proposed for super-pixel extraction in which spectral statistics and super-pixel geometry are utilized to obtain an optimal Bayesian classifier for pixel to super-pixel label assignment. Utilization of the spectral variances and super-pixel areas reduces the dependency on user selected global parameters, while increasing robustness and adaptability. Proposed Local Adaptive Super-Pixels (LASP) approach exploits hexagonal tiling, while achieving some refineme...
Evaluation of Hypersingular Integrals on Curvilinear Surface Elements Selcuk, Gokhun; Koç, Seyit Sencer (2016-04-15) In this study finite part integrals are utilized for evaluation of hypersingular and nearly-hypersingular surface integrals on curvilinear elements. These integrals are related to the second derivative of the free space Green' function and arise in the solution of electric field integral equation (EFIE) via locally corrected Nystriim (LCN) method. The curvilinear elements are represented by the Taylor series expansion of the surface function around the observation point. The hypersingular integral, defined ...
Time-domain simulation of directive sources in 3-D digital waveguide mesh-based acoustical models Hacıhabiboğlu, Hüseyin; Günel Kılıç, Banu (2008-07-01) Digital waveguide mesh (DWM) models offer a simple, accurate, time-domain, numerical solution of the wave equation. A specific case where such accurate and computationally simple solutions are needed is the acoustical modeling of open or closed volumes. It is possible to model 3-D propagation of waves in enclosures such as rooms using DWM models. Generally, idealized omnidirectional sources are used for obtaining the impulse response in the DWM. However, real-life sound sources are never completely isotropi...

Citation Formats

H. Kutkan, “Aerothermodynamic shape optimization using DSMC and POD-RBF methods,” M.S. - Master of Science, Middle East Technical University, 2018.