Abstract
In Automobile field, CFD can be more effective for selection of the body shape than conventional wind tunnel, which needs much less time and can be repeated without the limitation of experiment. The essential matter of CFD analysis is solving 3-dimentional N-S equations by numerical methods. This paper applied FEM to analyze the external flow field and worked out its drag coefficient (Cd), which had quite conformability to that of wind tunnel test. Additionally it has been found that for fastback model the drag shows a sharp peak at certain windscreen angle, which verifies that rear configuration can greatly influence the aerodynamics.