| Since careful design of primary engine components such as the inlet is necessary to exploit effectively the potential of propulsion-airframe integration, a combined computational and experimental parametric study of the internal aerodynamics of a generic three-dimensional sidewall compression scramjet inlet configuration has been performed. The study was designed to demonstrate the utility of computational fluid dynamics as a design tool in hypersonic inlet flow fields, to provide a detailed account of the nature and structure of the internal flow interactions, and to provide a comprehensive surface property and flow field database to determine the effects of contraction ratio, cowl position, and Reynolds number on the performance of a hypersonic scramjet inlet configuration. The work proceeded in several phases: the initial inviscid assessment of the internal shock structure, the preliminary computational parametric study, the coupling of the optimized configuration with the physical limitations of the facility, the wind tunnel blockage assessment, and the computational and experimental parametric study of the final configuration. A total of 256 channels of pressure data, including static pressure orifices, pilot pressures, and entrance and exit flow rates, along with oil flow and infrared thermography provided a detailed experimental description of the flow. Generally good agreement is obtained between the computation and experiment. For the higher contraction ratios, a large forward separation of the inflow boundary layer is observed. The dominant effect of forward cowl placement is an increase in mass capture, while the principle effect of decreased Reynolds number is an increase in internal shock strength due to increased sidewall displacement thicknesses. |
