Flowfield Surveys in the Leading Edge Region of a Sharp Flat Plate.
Final scientific rept. Jan 70-Jan 71,
CORNELL AERONAUTICAL LAB INC BUFFALO N Y
Pagination or Media Count:
Data obtained in the hypersonic viscous shock layer of a sharp flat plate are presented. These were obtained with speed-ratio probes operating under free-molecule conditions, and the measurements are interpreted with the theory for free-molecule flows as the local speed-ratio, and the local value of the product. These show that the initial disturbance from the plate extends about twelve ambient mean-free-paths ahead of the leading edge. In the immediate vicinity of the leading edge vertically less than five ambient mean-free-paths the disturbance causes a decrease in the speed ratio, and no change in the product. Beyond five mean-free-paths from the surface, the disturbance produces a simultaneous increase in the local value of the product and a decrease in speed-ratio. The data obtained within the viscous shock layer show there is a well-defined boundary where the measurements of the local value of the product show a pronounced decrease. This is identified as the boundary where viscous heating dominates, and its location is found to be in good agreement with the position of the shock wave determined from low-density schlieren observations. This is because viscous heating in the flowfield produces a stronger density gradient than the upstream compression process. Lateral profiles of the speed-ratio are in good agreement with other temperature data. Author
- Fluid Mechanics