Accession Number : ADA267656


Title :   An Experimental Investigation of the Effects of Leading Edge Geometry on the Dynamics of Blunt Fin-Induced Shock Wave Turbulent Boundary Layer Interaction


Descriptive Note : Master's thesis,


Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH


Personal Author(s) : Kleifges, Kelly


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a267656.pdf


Report Date : May 1993


Pagination or Media Count : 101


Abstract : Fluctuating wall pressure measurements have been made on centerline upstream of blunt fins in a Mach 5 flow. Standard time series analysis and conditional sampling algorithms have been used to examine the effects of leading edge sweep, leading edge shape, and fin root modifications on the RMS level and spectral content of fluctuating pressures. Results show that the fluctuating loads can be reduced significantly by appropriate modification of the fin leading edge. Leading edge sweep considerably reduces the mean and RMS pressure loading at the fin root, the extent of the region of unsteady separation shock motion (i.e. the intermittent region), and the separation length. The spectral content of pressure fluctuations in the intermittent region shifts to higher frequencies with leading edge sweep, while the spectral content of pressure fluctuations in the separated region is virtually unchanged by leading edge sweep. Of the different fin leading edge geometries which induce the same size interaction, the 'blunter' configurations produce smaller intermittent regions and larger separated regions. While the use of a strake at the fin leading edge root has virtually no effect, a swept hemicylindrically blunted root fillet reduces the centerline upstream influence and intermittent region length by 50%, and reduces the mean and RMS pressure loading at the fin root by 75% and 95% respectively.


Descriptors :   *TURBULENT FLOW , *TURBULENT BOUNDARY LAYER , *LEADING EDGES , *FINS , ALGORITHMS , INTERACTIONS , SHOCK WAVES , SAMPLING , WIND TUNNEL TESTS , UNSTEADY FLOW , HYPERSONIC FLOW , STRAKES , FLOW SEPARATION , SUPERSONIC FLOW , MACH NUMBER , WALLS , PRESSURE , CONFIGURATIONS , SHAPE , TIME SERIES ANALYSIS , MOTION


Subject Categories : Fluid Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE