Performance prediction procedures of the supersonic spiked intakes

The supersonic flow approaching the intake of a supersonic aero engine must be brought to subsonic state before reaching the compressor face stage. The velocity reduction is combined with reduction in the total pressure of the flow which is not preferred by the designer of the supersonic gas turbine. In the present paper, analytical and two different numerical techniques were coupled to analyze the flow field in 2-D, compressible, supersonic spiked intake. The analyses were carried out at Mach number between 1.8 to 2.2 and spike angles of 12 and 20°. The flow field was subdivided into external part which was solved analytically and internal part which was solved numerically. The numerical analyses ware carried out under two assumptions; method I: non viscous flow and method II: viscous flow. The results are presented and compared based on the predicted values of the pressure recovery at the face of the compressor. The procedure was verified by comparing with previous experimental works. It was found that the pressure recovery is slightly influenced by the viscosity up to 2.14 Mach. The pressure recovery values predicted from the non viscous assumption were higher than the corresponding values obtained from the viscous solution. The viscosity contribution becomes more significant as the spike angle is increased from 12 to 20° where noticeable differences in the pressure recovery values were predicted. Accordingly, the diffusion analysis of compressible flow in such conditions assuming viscous, is essential. © 2011 Asian Network for Scientific Information.

Author Keywords
Aero engine compressible flow; Diffuser; Numerical analysis; Supersonic flow; Supersonic intake