Supersonic, Inviscid, Conical Corner Flowfields

A computational procedure has been developed to predict the inviscid supersonic/hypersonic flowfield of conical internal corners. The prediction of internal corner flowfields can be important in the design of supersonic "box"-type inlets. The computational procedure utilizes a second-order finite-difference marching technique to approach the conical corner flow solution of Euler's equations asymptotically. These flowfields are dominated by complex shock interactions. All discontinuities, shocks, and slip surfaces are fitted with the appropriate jump conditions. The "triple" points (the interaction of three shocks and a slip surface) are also computed exactly. Computed results are compared with experimental data and the computational results of other investigators. In addition, the sensitivity of these flowfields to a number of geometric parameters is studied, and the impact of these flows on inlet performance is assessed. N the development of supersonic and hypersonic engine inlets, a detailed prediction of the internal flowfield is critical. Inlet designers are concerned mainly with total pressure losses, flowfield nonuniformities, and flow angularities at the compressor face or flame holders (in the case of ram/scramjets ). These conditions require a detailed description of the shock wave structure in three-dimensi onal internal flows. This paper deals with the prediction of the inviscid, supersonic flow in two-dimension al or "box"-type inlets, as shown in Fig. 1. In particular, this paper discusses the flowfields which are generated at the four corners of this inlet (Fig. 1, station 2). The corner flowfields generate large variations in all flowfield parameters (particularly in total pressure). In the case of ram/scramjets, these corner flows are carried to the combustion chamber where they can cause nonuniform combustion, while in the case of external compression inlets (typical of Mach 2 vehicles), a normal shock will be located before the inlet lower lip so that the corner flows will interact with this shock. Here, again, the nonuniformities in total pressure generated at the inlet corners will be preserved and eventually affect the combustion. The corner flowfields are conical if the two intersecting walls remain planar. In this situation, all flowfield variables (pressure, velocities, and entropy) are independent of the spherical radial coordinate centered at the origin of the corner flow (Fig. 1) rendering these flowfields dependent only on two space dimensions. Any fully three-dimensional computation will require conical corner flow solutions as initial conditions. In addition, the knowledge gained in a study of the conical flow problem is essential to the success of three-dimensi onal computations. This paper deals with conical corner flowfields of the type generated by two compressing wedges, since this configuration is typical of supersonic inlet flows. Two possible shock configurations could be generated by the intersection of two compressive wedges. One is called a regular reflection configuration, the other a Mach disk configuration. These terms refer to the shock conditions at the