Week 11- Broadband Noise modelling over Ahmed body

1) Ahmed body and its importance

The Ahmed body is a generic car body (a simplified vehicle model). The airflow around the Ahmed body captures the essential flow features around an automobile and was first defined and characterized in the experimental work of Ahmed [1]. Although it has a very simple shape, Ahmed body allows us to capture characteristic features that are relevant to bodies in the automobile industry.

2) Aim

To setup the domain and assuming the ahmed body is travelling at 110 kmph and also to study about the acoustic field over Ahmed body.

Procedure

1) Import the cad model to spaceclaim, since the boundaries are set we can proceed to nest step.

2) Mesh the enclosure with the element size of 59 mm and give body sizing around the ahmed body as 10 mm so it can capture the flow physics near the ahmed body properly.

3) Give inflation layer for the road and the ahmed body to capture all the separation flow near to the boundaries.

4) For the road the inflation layer values are

5) For the ahmed body the inflation layer values are

6)

Models used

Solver - Pressure based

Velocity formulation - Absolute

Time - Steady

2D space - Plannar

Viscous - k-Epsilon - Realizable

Boundary conditions

Inlet - Velocity Inlet

Outlet - Pressure Outlet

Farfeild - Symmetry

Results