Film Cooling in Gas Turbines—Exploring Physics and Uncertainties
Modern gas turbine airfoils are subject to gas temperatures in excess of 30000 F that are well above the material limits for reliable operation. The airfoils have to be therefore actively cooled to prevent engine failure. Film cooling is commonly used and involves pushing the coolant air (by-passed from the compressor) through inclined holes drilled on the airfoil surface. In this talk, attention is focused on the flow physics of film cooling flows, and Large Eddy Simulation (LES) results from a finite-volume code are analyzed to understand the origin and development of flow structures. The spectral characteristics of both the flow and thermal fields will be studied in order to identify the frequencies associated with these structures and to examine which of these play an important role on the temperature distributions near the surface (or the cooling effectiveness). These results indicate that low frequency modes play an important role in near wall mixing and temperature distributions. The talk will also explore the role of uncertainties in boundary conditions (such as coolant inflow velocity) on the film cooling distribution. A polynomial chaos approach combined with a spectral code is used for this purpose.
Research in our lab focuses on the evolution and population genetics of herbivorous insects, many of which are crop pests. Current projects include adaptations to genetically modified crops, responses to plant defensive compounds and the effect of alternative food plans on population structure. Computation aspects of our research include the analysis of high-throughput sequencing data and simulating large genetic data sets under different evolutionary scenarios.