Week 11- Broadband Noise modelling over Ahmed body

                                                            Broadband Noise modelling over Ahmed body

Aim: To run simulation for Ahmed body with acoustic field.

Objective: 

1. Describe Ahmed's body and its importance.
2. Setup the domain and setup assuming body is travelling at 110 kmph
3. Run the setup till convergence and plot for static pressure and coefficient of drag and lift to check for convergence
4. Turn on Broadband- modelling and detail the acoustic field study over Ahmed body.

Theory:

Ahmed Body:

The Ahmed body has the form of a highly simplified car, consisting of a blunt nose with rounded edges fixed onto a box-like middle section and a rear end that has an upper slanted surface. The model is supported on circular-sectioned legs or stilts, rather than wheels. 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. Although it has a very simple shape, Ahmed body allows us to capture characteristic features that are relevant to bodies in the automobile industry.

Procedure:

Import the file in Geometry.

 Mesh:

Body sizing - 59 mm

Create 2 inflation layers.

Setup:

Solver:

Pressure-based.

Steady state.

Viscous - Realizable K-epsilon

Inlet velocity - 31 m/s

Acoustics - On

Acoustic Power:

Velocity contour:

Pressure contour:

Co-effecient of drag:

Co-effecient of lift:

Conclusion:

Acoustic waves for the Ahmed body has been obtained.

Static pressure and Co-effecient of lift and drag is converged.