Heat Transfer Prediction in Transitional Hypersonic Flow

Our Phase I program will extend and validate a high-speed engineering transitional model (ETM) using new CUBRC data sets (such as HIFIRE-1) of interest to the Air Force. The ETM is responsive to tunnel noise and wall heating, and predicts the overshoot in heat transfer observed in transitional data. The model solves PDEs for transition onset as well as for an intermittency parameter that blends the viscosity from laminar to turbulent levels. The ETM has full 3D capabilities, viz., the PDEs solved generate a swept onset curve and variable transitional lengths downstream of the onset curve, and it is incorporated into Navier-Stokes codes in a manner akin to the inclusion of 2-equation turbulence models. Validation using fundamental high-speed data sets has been limited to axisymmetric or planar geometries. In this program, ETM predictions will be compared with those of the STABL parabolized stability (PSE) code to examine differences in their onset predictions emphasizing tunnel noise and surface temperature effects. Studies using the ETM will be performed for several basic 3D flows and modeling refinements will be incorporated to improve overall performance. Phase II experimental planning will be performed in collaboration with Holden / CUBRC to support ETM model improvements. BENEFIT: From CRAFT Techs perspective, commercialization potential results from having a validated engineering-oriented CFD code that can predict transitional processes for complex 3D flowfields. Having this unique capability permits CRAFT Tech to provide additional system and design support to varied DOD and NASA government agencies and their contractors, as well as to expanding the licensing of our CFD codes. CRAFT Tech is developing a scramjet web-based building-block data base (BBDB) for the Air Force that is being commercialized and licensed to varied research facilities. Unique to this data base is the inclusion of both data as well the CFD solutions, synchronized via specialized scripts so that external users can try out their codes on varied data sets and compare with existing CFD solutions in an automated black-box manner. The extension of this data base to include transitional data sets has significant commercial potential. From CUBRCs perspective, the use of their data sets to firmly establish transitional modeling capabilities in an engineering-oriented code should lead to additional experimental programs in the transitional arena. In addition, having their data sets linked into the new BBDB will enhance their utility by the research community.)