In this paper, we report on the results of numerical experiments in the field of computational fluid dynamics (CFD) on Amazon's HPC cloud. To this end, we benchmarked our MPI-parallel fluid solver NaSt3DGPF on several HPC compute nodes of the cloud system. Our solver can use CPUs and GPUs to calculate the simulation results. With a pre-requested number of instances we observe for both, CPUs and GPUs, good scalability even for a larger number of parallel processes, provided that the GPUs run in the non-ECC mode. Furthermore, we see a high potential for medium sized parallel compute problems which are typically present in industrial engineering applications.