Week 3 - External flow simulation over an Ahmed body.

AIM : External flow simulation over an Ahmed body.

OBJECTIVE:

1. To Describe Ahmed's body and its importance.

2. To Explain the reason for the negative pressure in the wake region.

3. To Explain the significance of the point of separation.

The Ahmed body is a benchmark model widely used in the automotive industry for validating simulation tools. The Ahmed body shape is simple enough to model, while maintaining car-like geometry features. Importance of Ahmed Body : The drag coefficient quantifies the resistance of an object in a fluid environment.

1. The A recirculation region that is formed as the flow separates at the top of the vertical back surface of the model

2. The B recirculation region that is formed due to the separation at the base of the model.

3. The c-pillar vortices that form as the vorticity in the side boundary layers roll up over the slant edges.

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for case II

i worked it by step by step.

Conclusion.

There is a variation of pressure across the Ahmed body. The pressure in front of the body is positive because that's the location where the flow first comes in contact with the body and comes to rest. At the corner, the flow accelerates, thereby decreasing the pressure.

The reason behind negative pressure in the wake region is due to flow separation, recirculating flow. It's a phenomenon that generally happens as the air moving past the body isn't able to pass through the immediate backside of the body creating a region, where there is no movement of air and thereby creating a pressure gradient.