Algorithmic developments for the computation of turbulent steady and unsteady compressible flow on moving geometries

Algorithmic developments for the computation of turbulent steady and unsteady compressible flow on moving geometries
By Milan Zaloudek

PhD Thesis from the von Karman Institute / Czech Technical University, December 2012, ISBN 978-2-87516-045-4, 219 pgs

Abstract

The main target of this work is to simulate and describe the flow around the exhaust valve of a reciprocating engine during an exhaust stroke. The computations are performed with two independent in-house numerical codes. Both the codes are based on the finite volume method, using the modern numerical schemes and the Arbitrary Lagrangian-Eulerian formulation for the simulations with moving geometries. In order to perform the simulations, some substantial developments (with the main focus on the turbulence modelling) were neccessary and have been accomplished within the scope of this work. Some one- and two-equations turbulence models of the first and second order closure have been taken from the literature and implemented. The properties of the mathematical model are tested together with the sensitivity analysis of the simulation parameters (including geometry changes) on the results obtained, respectively on the processes over the exhaust stroke.