An investigation of aerothermal loads generated in regions of hypersonic shock interference flows.

摘要

An investigation is conducted to analyze the aerothermal loads generated in regions of hypersonic shock/shock interactions. The principal research method was accomplished through a series of shock tunnel experiments, with Mach 11 freestream conditions simulating the flight regime of both laminar and turbulent interactions. A model configuration was designed, and testing conditions selected, which resemble that of a bow shock impingement to the cowl lip of the engine integrated airframe of a high speed flight vehicle. Experimental methods used in this study regarding the employment of instrumentation and flow visualization, and data acquisition and reduction techniques, represent a unique experimental approach toward the description of key features of these flows.; Three important features of these flowfields, previously not well understood or thoroughly investigated, were targeted for this research. First, the effects of flow pattern variation caused by changes in shock impingement location are examined. A catalogue of highly resolved surface heat transfer and pressure distributions, for a large range of shock wave impingement locations, are presented. From these data, interpretations of flowfield structure, and the phenomenology of a flowfield model based upon these results are offered. Calculations are performed which illustrate the properties of key features and regions of the interference pattern. Second, the effects of Reynolds number and turbulence are examined utilizing comparisons of similar shock interference pattern configurations across the different Reynolds number testing conditions. Calculations of shear layer properties and transition criteria are presented. Correlation techniques for peak heating predictions associated with laminar and turbulent interactions are offered. Third, the presence of large scale unsteadiness upon the aerothermal loads generated by these flows is also investigated, and mechanisms responsible for this unsteadiness are identified. Quantification of the unsteady character of the aerothermal loads is presented.; Throughout this study, comparisons of these experimental data to calculations of current predictive methods, and numerical solutions of laminar and turbulent flows are performed. The extensive set of data presented also provides a definitive set of aerothermal distributions and flowfield measurements for code validation of future numerical studies of these flows.