Numerical and Experimental Tests of Supersonic Inlet Utilizing a Pylon Set for Mixing, Combustion and Thrust Enhancement

Abstract

A pylon set is proposed for installation in the supersonic inlet of an air-breathing propulsion system. For rectangular and axisymmetric inlets, the pylon set is installed near the cowl front edge. This set contains 3 – 4 airfoil-shaped strips or cross-section rings depending on the type of inlet. The pylons are located at different distances (tiers) from the forebody. Fuel injection takes place through these pylons, which provides uniform mixing downstream. The mutual locations, sizes and angles of these pylons are very important for efficient application. Optimal values of geometrical parameters were determined from multi-parametric Navier-Stokes Equations (NSE) numerical simulations of the laminar and turbulent external/internal flows. These simulations have shown substantial benefits for mixing, combustion and thrust of the proposed approach by comparison with traditional well-known designs. In this paper, numerical simulation and experimental test results are presented for the cases with and without the pylon set installed in a supersonic inlet without fuel injection through the pylons. These tests are intended for examination of several phenomena. First, if a supersonic flow regime can be reached with the installed pylon set in the NASA LaRC Mach 4 Blowdown Facility. Second, comparison of inlet performance with and without pylons. Third, comparison of numerical simulation and experimental test results. And finally, improved inlet design based on results obtained in this preliminary stage of our research project. The experimental tests at the NASA LaRC were conducted in September, 2004. Some numerical simulation results for the case with fuel injection (hydrogen and helium) were obtained using the NASA VULCAN code. Details of these numerical simulation results and experimental test results obtained at the NASA LaRC Mach 6 Facility will be presented at the next appropriate AIAA Conferences. Preliminary numerical simulation results have shown the efficiency of this approach for mixing, combustion and thrust enhancement. Mach 4 numerical simulations and experimental tests results are illustrated in Figures 3 – 11 and a numerical simulation result for Mach 6 with helium injection is shown in Figure 12. _________________________________________________________ ** Research Professor, Hampton University, Senior AIAA Member ** Research Assistant, Hampton University Aeropropulsion Center *** Professor, Hampton University Aeropropulsion Center **** Professor, Hampton University Aeropropulsion Center ♦ Aerospace Engineer, NASA Langley Research Center ♦♦ Aerospace Engineer, NASA Langley Research Center ♦♦♦ Aerospace Engineer, NASA Langley Research Center + Senior Technologist, NASA Glenn Research Center, AIAA Associate Fellow 43rd AIAA Aerospace Sciences Meeting and Exhibit 10 13 January 2005, Reno, Nevada AIAA 2005-21