Whether propellers, pumps, fans, or wind turbines - when new products are developed in the fields of automotive, energy, or food technology, it is imperative to examine the flow behaviour of the air or fluids. With the help of software designed by the Hessian Engineering office for technical-scientific computing TWB, small and medium-sized businesses without their own simulation departments can virtually optimise or test their products. Together with the University of Applied Sciences in Frankfurt am Main, the TWB developed a wind flow tunnel with whose help operators can find economically worthwhile sites for smaller wind turbines.