Modeling of Engine Processes

The Engine Research Center (ERC) of University of Wisconsin-Madison has worked on the numerical model development and computer simulations of engine processes for many years. The numerical models range from the simplified phenomenological model to the comprehensive fluid dynamics-based model to study the engine flow and combustion process in details. The Computer models developed at ERC are categorized into the following:

• Zero-Dimensional: uses a simple model to estimate the residual gas fraction
• One-Dimensional: uses the method of characteristics to study the flow exchange process within the entire engine system.
• Multi-Dimensional: includes the flow, spray and combustion model development and applications using KIVA, KIVA3V_lite and STAR-CD.

It has proven to be successful to combine the use of two or more of these models. For instance, the zero-dimensional model may be used to estimate initial values for a multi-dimensional simulation. The one-dimensional model, which uses the method of characteristics, gives higher accuracy than the zero-dimensional model but is more difficult to use. Multi-dimensional models, such as the spray and combustion models, give a detailed picture of the engine processes of interest for improving engine performance and reducing emissions.