Paper presented at the 7th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Turkey, 19-21 July, 2010.
An S-duct inlet used in aircraft gas turbine engines is computationally studied for the effects of inlet icing and wall heat transfer. A Reynolds-Averaged Navier-Stokes (RANS) code with k-ω turbulence model is used to simulate the compressible viscous flow in the duct. Engine face distortion is analyzed with particular emphasis on the static temperature distortion. The glaze-ice accretion on the inlet lip, which can significantly impact engine face distortion, is modeled using the numerical icing shape. Inlet lip separation, increased internal blockage, and internal shocks do appear in the S-duct as a result of glaze-inlet icing at freestream Mach numbers of 0.475 and 0.85. The additional flow separation that is induced by the shock-boundary layer interaction due to the inlet icing creates a stronger secondary flow pattern at the engine face. The wall thermal boundary condition for zero heat transfer and the heated wall boundary condition allow for the simulation of realistic temperature distortion at the engine face under inlet icing conditions. Stall margin deterioration as a result of both total pressure and static temperature distortion is presented.