Numerical Investigations of S-Shaped Air Inlet for Embedded Engines

Abstract

In this paper, compressible Reynolds-averaged Navier–Stokes computations are conducted for an S-shaped duct, in a clean configuration and also with a single row of vortex generators. The numerical simulations are performed using a hybrid unstructured grid. The influence of including the geometric representation of the probe instrumentation is investigated by considering the rake fairing geometry and also the geometry of the complete rake with the probes. Some aspects of the probe modeling are also discussed. A direct comparison of the numerical simulation results with the experimental values is performed for the wall static pressure along the duct, total pressure recovery, and distortion indices at the aerodynamic interface plane. Three different eddy-viscosity turbulence models are evaluated: the one-equation Spalart–Allmaras, and the two-equation realizable and shear stress transport. A virtual 200-probe rake is also proposed, beyond the standard 40-probe rake, to enrich the total pressure and distortion indices comparisons. An overall good agreement is observed among experimental results and the numerical wall static pressure and the total pressure topology at the aerodynamic interface plane. Some discrepancies for the distortion indices are verified and discussed in detail.