Incorporating computational fluid dynamics into a virtual engineering environment

Abstract

This thesis develops a process for integrating computational fluid dynamics (CFD) models into a virtual engineering environment. The goal of this research is to enable a non-CFD expert to readily incorporate changes to a reduced CFD model and to view the results of those changes in an intuitive and natural manner. There are five steps in this process. These steps are (1) construct the complete CFD model, (2) validate the complete model, (3) reduce the model by focusing on the questions that the model needs to answer, (4) integrate the model into an interactive virtual environment, and (5) validate the reduced model with the complete model. This thesis elaborates on the third and fourth steps, specifically model reduction, by examining the questions being answered and addressing the integration of the CFD model into an interactive virtual engineering environment. These methods are implemented on a complex CFD model used for practical engineering decision making. The CFD model is of an underhood engine compartment of a vehicle. The complete CFD model consists of approximately eight million cells and requires approximately three days of computational time to determine the results of a design change. The complete CFD model of the vehicle is reduced to encompass the underhood engine compartment. Boundary conditions are then mapped to the outside surface of the reduced model to replicate the flow conditions of the complete model. The reduced model is able to develop a converged solution in approximately five percent of the original model's time, thereby making the model more feasible for interactive design. This reduced model is then integrated with a virtual engineering software package which allows the user to add a flow-deflecting baffle into the model, run the model, and view the results in a virtual environment. This environment allows human interaction with the CFD models and the associated geometric representations. The integration of the model with interactive design tools creates a more holistic approach to engineering and brings CFD results of a design change into a more collaborative tool in the design process.