Development of Smoothed Particle Hydrodynamics for Flow in Complex Geometries and Application of Open Source Software for the Simulation of Turbulent Flow

摘要

Turbulence modelling is a key issue in many industrial application, as the com-putational power of direct numerical simulation (DNS) is insuÿcient to deal with complex flow structures with high Reynolds number. Also in Industrial applications often involve turbulent flow in complex geometries. Thus devel-oping a computational method which can deal with complex fluid structure, simulate complex geometers that change topology is particular challenging as the connectivity of the computational domain may change dynamically, and still eÿcient is important.In this thesis we are presenting a remeshed particle-mesh method, the method involves three-dimensional compressible turbulent flow modelling, and coupled with an immersed boundary technique to deal with the complex solid obstacles.This dissertation is composed of three parts.In combustion engines the scavenging process in two-stroke marine diesel engines removes combustion gases from the engine cylinder and fills up the cylinder with the fresh air charge for the next cycle. Understanding the scavenging flow is crucial for the development of such engines, since it a˙ects fuel consumption, engine cooling and production of pollutants.We consider a state-of-the art eulerian methods to study the turbulent flow in a model diesel engine. the goals of this study include validation of large eddy simulations (LES) turbulence models.