Aerodynamic Prediction of High-Lift Configuration Using Turbulence Model

Abstract

The aerodynamic performance of the high-lift configuration greatly influences the safety and economy of commercial aircraft. Accurately predicting the aerodynamic performance of the high-lift configuration, especially the stall behavior, is important for aircraft design. However, the complex flow phenomena of high-lift configurations pose substantial difficulties to current turbulence models. In this paper, an eddy-viscosity turbulence model is used to compute the stall behavior of high-lift configurations. A separated shear layer fixed function is implemented in the turbulence model to better capture the nonequilibrium characteristics of turbulence. Different high-lift configurations, including the two-dimensional multi-element NLR7301 and Omar airfoils and a complex full-configuration model (JAXA Standard Model), are numerically tested. The simulations show engineering accurate results and indicate that the effect of the nonequilibrium characteristics of turbulence is significant in the free shear layer, which is key to accurately predicting the stall behavior of high-lift devices. The modified shear layer fixed model is more accurate in predicting stall behavior than the Spalart–Allmaras, shear stress transport, and original models for the full high-lift configuration. The relative errors in the predicted maximum lift coefficients are within 3% of the experimental data.