Wall-Modeled Large Eddy Simulation of an Aircraft in Landing Configuration
Konrad Goc, Sanjeeb Bose, Parviz Moin
Abstract
Wall-Modeled Large Eddy Simulations (WMLES) are carried out for a realistic aircraft model in landing configuration. The validation case considered is that of the Japanese Aerospace Exploration Agency (JAXA) Standard Model (JSM), which was the focus of the recent Third AIAA High-Lift Prediction Workshop (AIAA HLPW-3). The CharLES solver with Voronoi gridding technology developed at Cascade Technologies is leveraged for the current study. An Equilibrium Wall-Modeling (EQWM) approach which assumes that the sum of the turbulent and viscous stresses between the wall and the wall-model/LES exchange location is invariant is employed. The exchange location is at the first cell centroid and no time filtering of the LES input to the wall model is applied. Two JSM configurations are simulated, one with a nacelle/pylon and one without. Good agreement with experimental C_L data is obtained across the flight envelope for both cases at similar computational cost to some Reynolds-Averaged Naver Stokes (RANS) calculations of the same configuration, indicating that WMLES technology is ready for routine use in industry. The coefficient of lift at maximum lift, C_{L,max}, is predicted to within 5 lift counts, or 1.5%, of the uncorrected experimental value for both nacelle/pylon on and off configurations. Evaluation of sectional pressures at a post-stall alpha corroborates the accuracy of the lift predictions. The grids required to achieve this agreement number less than 50 million control volumes (Mcv) and include the wind tunnel geometry. For the nacelle/pylon off case, the effect of the tunnel mounting system on the prediction of quantities of interest (QOI’s) is evaluated. WMLES shows that it can identify wind tunnel effects, including the appearance of an inboard separation at the wing/body junction absent in many free air calculations of the same configuration.