Accession Number : ADA563731


Title :   Yip-08 Hypervelocity Boundary Layer Studies for Axisymmetric Engine Flowpaths


Descriptive Note : Final rept. Dec 2007-Nov 2010


Corporate Author : ILLINOIS UNIV AT URBANA DEPT OF AEROSPACE ENGINEERING


Personal Author(s) : Austin, Joanna M ; Flaherty, William P


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a563731.pdf


Report Date : 25 Feb 2011


Pagination or Media Count : 78


Abstract : An experimental and analytical study of boundary layer response to concave surface curvature in a high-stagnation enthalpy, hypersonic flow is reported. Data for models with cubic, quadratic and blended concave surface curvature were compared with two baseline models: a flat plate and a linear compression ramp. Diagnostic capabilities for surface heat transfer and two-dimensional surface pressure measurements were developed. For all models, concave surface curvature was shown to produce significant destabilization of the boundary layer and increase in the heat flux over flat plate laminar and tripped boundary layer values. We have demonstrated that the laminar heat flux has a functional form that is very similar to the surface equation, and therefore that a reasonable estimate for the increase in heat transfer may be made from the surface geometry at the conditions of these experiments. Imposed vortex structures exhibited significant differences in the response to surface curvature. Spanwise pressure gradients were measured in the presence of the vortex structures, but not in their absence. The vortex structures were observed to interact with the pressure gradient. The distance to vortex breakdown was quantified and found to depend strongly on the surface curvature.


Descriptors :   *BOUNDARY LAYER , AXISYMMETRIC , COMPRESSION , CURVATURE , FREE STREAM , GEOMETRY , HEAT TRANSFER , HYPERSONIC FLOW , PRESSURE MEASUREMENT


Subject Categories : Fluid Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE