Large-Scale Multifidelity, Multiphysics, Hybrid Reynolds-Averaged Navier–Stokes/Large-Eddy Simulation of an Installed Aeroengine

The aerodynamics and noise produced by aeroengines are critical topics in engine design. Hybrid Reynolds-averaged Navier–Stokes/large-eddy simulation are used to investigate the influence of upstream internal geometry on jet flow and noise. The methods are validated using an isolated nozzle. The internal geometry is added by using approximated immersed boundary methods and body force methods, reducing grid complexity and cost. Installed coaxial nozzles, including an intake, wing, and flap, as well as (internally) the fan, outlet guide vanes, and other large features, are modeled. These large-scale multifidelity, multiphysics calculations are shown to reveal substantial new aeroacoustic insights into an installed aeroengine. The turbulence generated internally introduces a complex unsteady nozzle exit flow. This accelerates inner shear layer development, moving it one jet diameter upstream; and it reduces the potential core length by 5%. For the more intense outer shear layer, the effect appears secondary.