Order Description
Computational fluid dynamics (CFD) is often used to evaluate the external aerodynamics of a vehicle and to investigate how aerodynamic devices on that vehicle interact. This often involves highly
turbulent flow regimes which are inherently a 3D phenomena.

Develop a 3D simulation of the external aerodynamics of a simplified vehicle geometry and conduct an aerodynamic investigation.

Task 1 : Create Fluid Domain Geometry

Create the Ahmed geometry in ANSYS and create a suitable fluid domain to analyse the external aerodynamics around this geometry. To do this you may wish to utilise the ANSYS tutorial for guidance.
You should discuss the reasoning behind your domain geometry choices, referencing expected flow patterns and mesh strategy.

Task 2 : Create Mesh and appraise quality

Create a 3D mesh of the fluid domain again using the tutorial for guidance. Apply mesh controls to create mesh density in regions where you expect significant flow regimes to occur. Appraise the
mesh quality by assessing skew, orthoganality and aspect ratio. Setup boundary conditions to simulate the vehicle travelling at 30m/s. Clearly explain and justify your meshing decisions.

Task 3 : Solve and Analyse Results

Setup the solver and obtain an initial solution. Analyse the results by producing vector and contour plots.

Task 4 : Compare turbulence models

Compare how turbulence models and wall functions affect the results obtained and suggest which model is the most appropriate for the simulation.

Task 5 : Refine mesh and evaluate solution

Refine the mesh and/or boundary conditions and domain. Review the resulting solutions and compare with your initial solution.

Task 6 : Aerodynamic investigation

Investigate how the top rear slant angle (?) affects lift and drag for the body. Produce graphs illustrating these results and comment on their validity.

Task 7 : Report

Write a report documenting the modelling processes, results and conclusions.