This award supports Professor Roger L. Simpson and others in his research group at Virginia Polytechnic Institute and State University (VPI) for collaboration in engineering research with Professor Franz Durst and others of the Fluid Mechanics Group at the University of Erlangen, Federal REpublic of Germany. The objectives of their collaboration are to exchange advanced experimental techniques for turbulent separated flows and to develop improved turbulence models for separated flows based on their collective accumulation of data. Both groups are leaders in research on the turbulent structure of separated flows and in aspects of experimental techniques for separated flow. Their experience and unique facilities are complementary. VPI concentrates on unsteady and three-dimensional external separated flows and has developed rapidly scanning laser anemometry and sensitive pressure fluctuation measuring techniques. The Erlangen group concentrates on internal separated flows, such as in ducts and other flow passages, and is a leader in developing advanced laser anemometry techniques. The micro-LDV designs and developments in Erlangen will allow the VPI group to build and mount units in dynamic wind tunnel models. VPI pressure fluctuation techniques will be applied to internal separated flows in Erlangen. Separated flow is well recognized as the limiting factor to the performance of aircraft and sea vehicles, jet engines, ducted flow systems, and other practical devices. Until the development of laser anemometry, little basic understanding of the nature of separated flow was possible. In the last fifteen years, the VPI and Erlangen groups have made a number of significant contributions to the basic understanding of turbulent separated flow. Work on more complicated separation problems will be continued by these groups under the proposed support.
