The scope of the Master Thesis was a better understanding of turbulent flow fields inside vehicles. Different degrees and spectra of turbulence are produced by different setups of turbulence generators located in a test wind tunnel. First, several steady CFD simulations were performed for each turbulence generator to investigate the characteristics of the fluid flow, then unsteady CFD simulations for the quantitative analysis of the turbulent flow fields. Transient simulations have been performed to provide frequency spectra which show that prominent features of the spatial frequency behavior are well captured. The comparison of the experimentally and numerically generated frequency spectra offer the possibility to find out where CFD simulations are effective. It has been shown that the simulations give results approximately equivalent to the experimental results.