Buoyancy effects on automotive engine compartment airflow

This thesis presents a computational investigation of a two-dimensional, automotive engine compartment. Three primary objectives were considered in this investigation. The first objective was to develop an insight of buoyancy effects on the airflow in an engine compartment of an automobile. The second objective was to develop a general understanding of the basic flow through an engine compartment. The last objective was to study the effects of repositioning the engine in its compartment on the underhood airflow.

The computational procedure utilized was tested by comparing predictions with experimental measurements. This comparison indicated that the computational procedure was capable of predicting the overall flow field in a simplified engine compartment reasonably well.

This study showed that buoyancy forces, due to temperature gradients present, do not significantly affect the overall airflow in an automotive engine compartment. However, localized areas of flow can be affected by buoyancy, especially hot, stagnant areas.