The FIA has finalised the details regarding the unrestricted CFD for the teams for simulations related to the 2021 regulations. Before running the simulation, the teams must submit details of the solver being used, boundary conditions and geometry.
Boundary conditions are such things as setting an inlet and the velocity the fluid has at the inlet, setting a moving ground condition and so on. These are used to solve the equations by the software. There are also initial conditions, these are calculated from the boundary conditions and also used to solve the equations. Initial conditions are required so that a turbulence model can be used. Without this, things such as wheel wake wouldn’t be calculated and accounted for.
All teams will have custom solvers which take a mathematical model of fluid flow, usually a simplified version of the Navier-Stokes equations, and turn them into something the computer can apply. The solver then applies the equations that make up the mathematical model at points throughout the mesh. Usually the more points the more accurate. The computer solves these equations iteratively, which means it ‘guesses’ a solution and each subsequent guess is closer to the real solution. It does this until it converges on a solution.
If approved by the FIA, the simulation can be competed with the results also being submitted. However, no teams will have access to another teams data. The purpose of this is to assist the FIA in creating the 2021 technical regulations.