Finite volume solutions of 1D Euler equations for high spped flows with finite-rare chemistry

Erdem, Birşen
In this thesis, chemically reacting flows are studied mainly for detonation problems under 1D, cylindrical and spherical symmetry conditions. The mathematical formulation of chemically reacting, inviscid, unsteady flows with species conservation equations and finite-rate chemistry is described. The Euler equations with finite-rate chemistry are discretized by Finite-Volume method and solved implicitly by using a time-spliting method. Inviscid fluxes are computed using Roe Flux Difference Splitting Model. The numerical solution is implemented in parallel using domain decomposition and PVM library routines for inter-process communication. The solution algorithm is validated first against the numerical and experimental data for a shock tube problem with and without chemical reactions and for a cylindrical and spherical propagation of a shock wave. 1D, cylindrically and spherically symmetric detonations of H2:O2:Ar mixture are studied next.


YAPICI, KERİM; Uludağ, Yusuf (FapUNIFESP (SciELO), 2013-10-01)
In this work, computer simulation results of steady incompressible flow in a 2-D square lid-driven cavity up to Reynolds number (Re) 65000 are presented and compared with those of earlier studies. The governing flow equations are solved by using the finite volume approach. Quadratic upstream interpolation for convective kinematics (QUICK) is used for the approximation of the convective terms in the flow equations. In the implementation of QUICK, the deferred correction technique is adopted. A non-uniform st...
Numerical solution of nonlinear reaction-diffusion and wave equations
Meral, Gülnihal; Tezer, Münevver; Department of Mathematics (2009)
In this thesis, the two-dimensional initial and boundary value problems (IBVPs) and the one-dimensional Cauchy problems defined by the nonlinear reaction- diffusion and wave equations are numerically solved. The dual reciprocity boundary element method (DRBEM) is used to discretize the IBVPs defined by single and system of nonlinear reaction-diffusion equations and nonlinear wave equation, spatially. The advantage of DRBEM for the exterior regions is made use of for the latter problem. The differential quad...
Excitonic effects on the nonlinear optical properties of small quantum dots
KARABULUT, İBRAHİM; Safak, H.; Tomak, Mehmet (IOP Publishing, 2008-08-07)
The excitonic effects on the nonlinear optical properties of small quantum dots with a semiparabolic confining potential are studied under the density matrix formalism. First, within the framework of the strong confinement approximation, we present the excitonic states and then calculate the excitonic effects on the nonlinear optical properties, such as second harmonic generation, third harmonic generation, nonlinear absorption coefficient and refractive index changes. We find the explicit analytical expres...
Hybrid CFIE-EFIE solution of composite geometries with coexisting open and closed surfaces
Ergül, Özgür Salih (2005-07-08)
The combined-field integral equation (CFIE) is employed to formulate the electromagnetic scattering and radiation problems of composite geometries with coexisting open and closed conducting surfaces. Conventional formulations of these problems with the electric-field integral equation (EFIE) lead to inefficient solutions due to the ill-conditioning of the matrix equations and the internal-resonance problems. The hybrid CFIE-EFIE technique introduced in this paper, based on the application of the CRE on the ...
Numerical Modeling of Electromagnetic Scattering from Periodic Structures by Transformation Electromagnetics
ÖZGÜN, ÖZLEM; Kuzuoğlu, Mustafa (2016-09-22)
The transformation electromagnetics is applied to the modeling of electromagnetic scattering from periodic structures in conjunction with the finite element method with periodic boundary conditions. In a unit cell of periodic structure, a uniform mesh is used over a flat surface and the arbitrary periodic surface is modeled by a coordinate transformation. The major advantage of this approach is that arbitrary geometries can be handled by using a single and simple mesh. Therefore, repeated computations (such...
Citation Formats
B. Erdem, “Finite volume solutions of 1D Euler equations for high spped flows with finite-rare chemistry,” M.S. - Master of Science, Middle East Technical University, 2003.