Numerical simulation of turbulent flow inside the cylinder of a new two-stroke grail engine design
Abstract
This work presents a novel way of implementing Autodesk computational fluid
dynamics (CFD) software for internal combustion (IC) engine application. The main
objective of this research is to develop a high fidelity simulation methodology for a state
of art hybrid two-stroke Grail engine and to investigate the complex motion of piston and
intake valve of the engine. Grail engine design is unique due to presence of single
intake valve within the piston itself. Thus, the intake valve moves with the piston which
makes the motion much more complex to study in the present work. Since the efficiency
of combustion and the production of pollutants in the internal combustion engine are
strongly dependent on the turbulent flow field in the engine cylinder. The focus is put in
the analysis of the in-cylinder flow field dynamics and turbulence within the cylinder and
through the complete engine cycle in the initial stages of development of the Grail
engine. Finally, the scavenging process of the Grail engine with mixing and scavenging
efficiency was also numerically investigated. In most engines, turbulent kinetic energy
(TKE) is almost exclusively generated during the intake stroke and enhances greatly the
mixing of air and fuel to give better mixing during compression stoke. The 3-D
simulation of the flow through the engine is performed by using finite element method.
Autodesk Reynold's-averaged Navier-Stokes (RANS) K ?? model is used to perform
the calculations of the flow. The performance and possibilities that Autodesk CFD gives
for this kind of application is evaluated.
Description
Thesis (Ph.D.)-- Wichita State University, College of Engineering, Dept. of Aerospace Engineering