Week 3 - External flow simulation over an Ahmed body.

                                                               External flow simulation over an Ahmed body

Aim: To run external flow simulation over Ahmed body.

Objective: 

Run the simulation for the velocity of 25 m/sec with the default air properties in fluent.

Theory:

Ahmed body is a simplified car model, the flow of air around the Ahmed body captures the essential flow features to examine the quantities varying around it.

The negative pressure in wake region is due to the turbulent flow, and boundary layer seperation.

Point of seperation is region where fluid gets seperated from the body due to adverse pressure gradient.

Procedure:

Geometry:

Open the file in Space claim of Ansys Fluent 

Create the enclosure around the Ahmed body

Meshing:

 

First layer thickness = 5 mm

 

Setup:

Solver:

Density - based

Steady state

K-epsilon model 

Inlet velocity= 25 m/s

Drag co-effecient:

Velocity contour

Pressure contour around car wall

Velocity vector plot:

Conclusion:

Velocity, pressure and co-effecient of drag is obtained.

Wake region is captured behind the body