TRANSITION PREDICTION FOR TRANSPORT AIRCRAFT CONFIGURATIONS BASED ON OVERSET GRID

Laminar-flow aerodynamic design receives great importance by the civil aviation field in recent years. Complex flight conditions and complex configurations give challenges to present CFD techniques especially the transition prediction method and grid generation. This work adopted γ - (Equation presented)e_θt local correlation-based transition model and overset meshing strategy to conduct flow simulations of typical civil transport aircraft configurations. A locally helicity-based modeling method for crossflow instability was introduced to extend the three-dimensional transition prediction ability. Results have shown well behavior of the crossflow-extended transition model on surface pressure and force prediction at transonic cruise Mach number. Combining structured overset grid, crossflow-extended transition model can also give better prediction on transition characteristics of the high-lift configuration compared to the baseline transition model. However, high Reynolds number of actual flight condition seemed to exceed the application boundary of present local transition model. Although the predicted pressure coefficient distributions were in good agreement with the experiment results, the predicted transition line was far forward to the leading edge.