The Chair of Fluid Mechanics and the Institute of Aerodynamics belongs to the department of mechanical engineering of the RWTH Aachen University. The experimental and numerical units plus the laboratory for bio-medical flows constitute the main departments of the institute. Several subsonic, transonic and supersonic wind tunnels and water tunnels are the essential experimental facilities. In addition, there are special test rigs to study flow fields, e.g., within piston engines, through safety valves, and artificial heart valve prosthesis. The measurement methods consist of, e.g., particle-image and particle-tracking velocimetry, laser-doppler and hot-wire anemometry, multi-sensor hot films, differential and Mach-Zehnder interferometry, and schlieren-methods. Continuous as well as pulse lasers and high-speed cameras are part of the experimental setups. Measuring equipment such as hot wires and hot films is in-house manufactured. Workstations and PCs are connected to form a parallel cluster on which computational fluid dynamics simulations are run. Furthermore, the Institute has access to the massively parallel machine of the university's scientific computing center to perform numerical analyses of internal and external, steady and unsteady, laminar and turbulent flows for complex geometries.