Week 10: Modeling and Simulation of flow around an Ahmed Body

Modeling and Simulation of flow around an Ahmed Body

Aim :

• To create a CAD model of Ahmed body.
• To perform a simulation in coarse mesh.
• To perform a simulation in refined mesh.

CAD Model:

General Setup:

Case setup:

Refined Mesh

Application Type:-

• Time based

Material:-

• Gas simulation
• Global transport parameters
  1.Turbulent Prandtl number - 0.9
  2.Turbulent schmidt number - 0.78
• Species
  1.N2
  2.O2

Simulation Parameters:-

• Run Parameters
  1.Solver - Steady
  2.Simulation mode - Full hydrodynamic
  3.Gas flow solver - Compressible
• Simulation Time Parameters:
  1.Start time - 0 s
  2.End time - 1 s
  3.Initial time step - 0.0001 s
  4.Minimum time step - 1e-9 s
  5.Maximum time step - 0.01 s.
• Solver Parameters:
  1.Navier stokes solver scheme - PISO
  2.Navier stokes solver type - Density based solver
• Boundary Conditions :
  1.Inlet - Inflow
  Velocity -40m/s
  Species - Air
  2.Outlet - Outflow
  Pressure - 101325 pa
  Species - Air
  3.Symmetry - Symmetry
  4.Wall - Wall
  5.car_wall- wall
• Initial conditions and events:
  1.Initial pressure - 101325 pa
  2.Initial Velocity - 40m/s
  3.Initial Temperature - 300K
  4.Species - Air
• Physical Models:
  1.Turbulence modelling - RNG-K-epsilon
• Grid control:
  1.Base Grid - (x-0.02m) (y-0.02m) (z-0.02m)

Results:

CFD Results:

Experimental results: