Week 11- Broadband Noise modelling over Ahmed body

Describe Ahmed's body and its importance.

-->As the burning of fossil fuels becomes a more pressing issue, manufacturers are introducing more fuel efficient cars to the market. One main contributor to fuel burn is the car’s aerodynamic drag. Complexly shaped, cars are very challenging to model and it’s difficult to quantify the aerodynamic drag computationally. 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.

The Ahmed Body was first created by S.R. Ahmed in his research “Some Salient Features of the Time-Averaged Ground Vehicle Wake” in 1984. Since then, it has become a benchmark for aerodynamic simulation tools. The simple geometrical shape has a length of 1.044 meters, height of 0.288 meters, and a width of 0.389 meters. It also has 0.5-meter cylindrical legs attached to the bottom of the body and the rear surface has a slant that falls off at 40 degrees.

Domain and setup assuming body is travelling at 110 kmph (31 m/s)

a.The setup was copied into Spaceclaim.

b.Meshing

Nodes = 126656

Elements = 510690

Plot for static pressure and coefficient of drag and lift.

Broadband- modelling and detail the acoustic field study over Ahmed body.

Result

The required literature review was done on the Ahmed boddy & the required plots for coefficient of drag and lift were obtained with plots for the acoustic field study for the ahmed body is also added.Where we can see that the noise is the most at first contact and there is a wake region on the other side of the Ahmed body.