This special volume contains several articles written in honour of Professor IngolfTeipel on the occasion of his 65th birthday. Professor Teipel was born on March 15th, 1933 in Wissen/Sieg. He started his school career in Betzdorf/Sieg. From 1943 to 1951 he went to the Gymnasium in Betzdorf, where he obtained his school-leaving exam after only 8 years. In 1951 Professor Teipel started his studies in Mechanical Engineering at the Technical University of Aachen and got his diploma at the Aerodynamic Institute in 1956. Then Professor Teipel decided to join the research group of the Institute of Theoretical Gasdynamics at the Deutsche Versuchsanstalt fiir Luft- und Raumfahrt (DVL), the famous institute of Professor Oswatitsch, where he spent about 13 years until 1968. At the Technical University of Aachen he finished his dissertation devoted to spherical-symmetric shock waves and he obtained his doctorate in Mechanical Engineering in 1960. Some years later he went as a guest scientist to the Aerospace Laboratories of Dayton, Ohio, USA.
In 1965 Professor Teipel fmished his habilitation work with a paper on unsteady transonic pressure forces at the Technical University of Aachen, where he recieved the venia legendi in fluid mechanics. In this year, Professor Teipel was given the freedom of the state Tennessee, USA.