Vom albatros zur „idealen windmühle”: Zum vorsprung dänischer aerodynamik um die jahrhundertwende

Abstract

The science of aerodynamics was in a desolate state around the turn of the century. Phenomena like resistance or updrift in a flow were known and studied, but not understood properly. The theoretical understanding was still dominated by the Newtonian resistance theory, which had already proved insufficient since the 18th century. The Danish scientists Hans Christian Vogt, Johan Irminger and Poul la Cour provided significant contributions to aerodynamics around the turn of the century and belonged to the first to break with the traditional understanding. Vogt studied a large variety of natural aerodynamic phenomena like the flight of birds or the movement of fishes. He recognized that updrift and resistance are interrelated phenomena and explained updrift by a reduced air pressure on the upper side of a wing, fin or blade. His friend Johan Irminger provided careful measurements of the air pressure around a body in an air flow, which confirmed Vogts ideas. Poul la Cour made even more precise measurements in a wind tunnel and provided the best experimental understanding of aerodynamic phenomena hitherto available. Based on his investigations he concluded the design features of an „ideal windmill”-which proved to be exactly those of the traditional windmill.