On CFD and Transient Flow in Vehicle Aerodynamics

The accuracy of computational fluid dynamics, CFD, has improved considerably over the years but still, large errors are present and vehicle parameters such as drag and lift are often poorly predicted.

The current work is investigating how transient CFD would cope with a very complex flow structure around a surface mounted cube. A transient Reynolds averaged Navier Stokes model, RANS model, is presented together with a large eddy simulation model, LES model. Furthermore, two “industrial like” test cases have been simulated using a transient RANS model.