Abstract：

The turbine section of gas turbine engines operate at very high temperatures, often with mainstream temperatures that are larger than melting point of the metal used to construct vanes and blades in turbine section.  Consequently, active cooling of these engine components is crucial.  Current technology relies heavily on use of film cooling techniques.  Film cooling involves ejection of coolant air from channels within the turbine airfoil through small holes to the surface such that the coolant flows along the external surface.  This “film” of cooler air flowing along the surface provides and insulating barrier between the surface and the hot mainstream gases.  Because of the importance of film cooling to turbine operations, there have been numerous experimental and computational studies of film cooling performance.  Most all of these studies used a generic plenum feed of coolant into the film cooling hole. However, in actual engine operation, the coolant holes are often fed from internal channels which have a significant cross-flow velocity.  We have done numerous studies at the University of Texas at Austin to investigate how this internal cross-flow affects the performance of film cooling, and have found that for many operating conditions the internal cross-flow causes significant degradation of performance. This presentation will review results from these studies including correlations for predicting film cooling effectiveness, and thermal and velocity field measurements which provide insight on the physical mechanisms that lead to decreased film cooling effectiveness.

Brief Biography:

David G. Bogard

Professor

Associate Chair for Administration and Research

Baker Hughes Incorporated Centennial Professorship in Mechanical Engineering

Department of Mechanical Engineering, The University of Texas at Austin

Dr. David G. Bogard is a professor of Mechanical Engineering at The University of Texas at Austin. He earned his Ph.D. in mechanical engineering from Purdue University in 1982 and joined the faculty of The University of Texas at Austin that same year. He is affiliated with the Thermal/Fluid Systems research program. Dr. Bogard currently directs research programs in turbine blade cooling and advanced drag reduction techniques for turbulent wall flows. In April, 2002, Dr. Bogard was named the Outstanding Graduate Advisor at the University of Texas at Austin. He has published more than 130 technical articles and reports, and awarded the ASME Heat Transfer Committee Outstanding Paper Award in 2003 and 2013. He is a member and fellow of ASME, the associate editor of ASME Journal of Turbomachinery, and the reviewer for 12 journals.