Aerodynamics: On–track Flow Visualisation

M13′s aerodynamic package saw huge gains over its predecessors, mostly due to the implementation of a drag reduction system allowing for a more aggressive design for downforce.

Using ANSYS CFX software to undertake computational fluid dynamics (CFD) analysis, the aerodynamics team were able to compare over 180 different configurations through during the design period. But a problem with computational simulation is knowing the error between the simulation results and on track results.

In order to compare flow structures from the CFD results to on-track flow, flow visualisation paint (flow vis) was used. Flow vis is used in a number of industries, from Formula 1 to scale building aerodynamics, in order to analyse streamlines on the surface of the object.

After research was completed into viscosity, size of particles and other properties, the team tested different mixtures to determine which paint would give the best way to compare results.

The team sprayed the paint onto the car and the car was driven until the paint dried. The car was then brought into a darkened area where a UV light was placed to increase the definition of the streamlines and photos were taken.

The aerodynamics team has been able to compare these results with CFD for validation of the M13’s aerodynamic package and find possible improvements for both future designs and areas to increase accuracy in CFD.