Performance Evaluation of the Numerical Flux Jacobians in Flow Solution and Aerodynamic Design Optimization

Ezertas, Alper
Eyi, Sinan
A direct sparse matrix solver is utilized for the flow solution and the analytical sensitivity analysis. The effects of the accuracy of the numerical Jacobians on the accuracy of sensitivity analysis and on the performance of the Newton's method flow solver are analyzed in detail. The gradient based aerodynamic design optimization is employed to demonstrate those effects.


Numerical analysis of radio frequency inductively coupled ion thruster and computation of its performance parameters
Bozkurt, Erdal; Alemdaroğlu, Nafiz.; Department of Aerospace Engineering (2019)
The main goal of this thesis is geometric and parametric analysis of a simulated cylin-drical two-gridded Radio Frequency Inductively Coupled (RF-ICP) ion thruster. Inaddition, instrumental performance of this thruster and the effects of a fixed shapeof the electrodes on ion trajectories are investigated. The simulations of the plasmaand the ion optics are performed by using COMSOL Multiphysics software. The firststep is checking the reliability of the software. Radial and axial simulation parametricresults...
Image segmentation and smoothing via partial differential equations
Özmen, Neslihan; Leblebicioğlu, Mehmet Kemal; Department of Scientific Computing (2009)
In image processing, partial differential equation (PDE) based approaches have been extensively used in segmentation and smoothing applications. The Perona-Malik nonlinear diffusion model is the first PDE based method used in the image smoothing tasks. Afterwards the classical Mumford-Shah model was developed to solve both image segmentation and smoothing problems and it is based on the minimization of an energy functional. It has numerous application areas such as edge detection, motion analysis, medical i...
Error analysis and feasibility study of dynamic stiffness matrix-based damping matrix identification
Özgen, Gökhan Osman (Elsevier BV, 2009-02-06)
Developing a method to formulate a damping matrix that represents the actual spatial distribution and mechanism of damping of the dynamic system has been an elusive goal. The dynamic stiffness matrix (DSM)-based damping identification method proposed by Lee and Kim is attractive and promising because it identifies the damping matrix from the measured DSM without relying on any unfounded assumptions. However, in ensuing works it was found that damping matrices identified from the method had unexpected forms ...
A two-dimensional vibrational system with a strong nonlinear coupling is studied using a quantum-classical mixed mode self-consistent-field approach. The classical equations of motion as well as the time-dependent Schrodinger equation are solved for respective modes under the influence of the average fields generated by the other modes. This vibrational system was previously shown to be chaotic under classical mechanical treatment but quantum mechanical observations pointed out to highly regular behaviour...
Transformation Electromagnetics Based Analysis of Waveguides With Random Rough or Periodic Grooved Surfaces
Ozgun, Ozlem; Kuzuoğlu, Mustafa (Institute of Electrical and Electronics Engineers (IEEE), 2013-02-01)
A computational model is introduced which employs transformation-based media to increase the computational performance of finite methods (such as finite element or finite difference methods) for analyzing waveguides with grooves or rough surfaces. Random behavior of the roughness is taken into account by utilizing the Monte Carlo technique, which is based on a set of random rough surfaces generated from Gaussian distribution. The main objective of the proposed approach is to create a single mesh, and to ana...
Citation Formats
A. Ezertas and S. Eyi, “Performance Evaluation of the Numerical Flux Jacobians in Flow Solution and Aerodynamic Design Optimization,” 2010, Accessed: 00, 2020. [Online]. Available: