Sweden, G¨oteborg, Chalmers University of Technology, 2010. 53 p.
Master’s Thesis in Automotive EngineeringAbstract
This report presents the methodology and the results of simulations of the flow in a
Stratified charged two-stroke engine. The focus is put on the process and performance
of the scavenging. To simulate the flow through the engine the finite volume method
in three dimensions is used. The OpenFOAM-1.5-dev computational fluid dynamics
software is used to perform the calculations. The performance and possibilities that
OpenFOAM-1.5-dev gives for this kind of applications is evaluated.Contents
Abstract
Contents
Nomenclature
Preface
Acknowledgements
Introduction
Background
Aim and purpose
Theory
The two-stroke engine
Conventional two-stroke engine
Stratified charged two-stroke engine
The governing equations
The RANS-equations and turbulence modeling
The finite volume method
Fluids
Approach
Limitations
Method
Engine geometry
Engine geometry medications
Mesh generation
The H576 engine geometry
The block geometry
Dynamic mesh with topology changes
Liner and ports
Deforming mesh
Layer addition and removal
Sliding interfaces
Mesh quality
In data from 1-D software
Discretisation schemes
Time derivatives
Gradient terms
Divergence terms
Laplacian terms
Boundary conditions
Walls
Inlets and outlets
Time step and convergence criterion
Setup for calculations in parallel
Layer addition and removal in parallel
Sliding interfaces in parallel
Domain decomposition
Assumptions and approximations
Fluids and combustion
Initial field values
Results
Scavenging and trapping efficiency
Validation
Commercial 1-D software
Turbulence modeling
Commercial 3-D software
Conclusions
Discussion and recommendations
