Coupled Viscous/Inviscid Analysis of Powered-Lift Airfoils and Wings

This proposal is in response to NASA SBIR Topic A2.08 in the area of "Variable Fidelity, Physics-Based Design/Analysis Tools". The development of a coupled viscous/inviscid analysis tool for powered-lift airfoils and wings is presented. In this context, powered-lift airfoils are taken to be airfoils under the influence of a high-energy jet, and include jet-flaps, augmenter-flaps, upper surface blowing, and circulation control airfoils. This methodology consists of coupling a viscous jet analysis, using a finite-difference approach, with a potential flow panel calculation. The method uses an iterative procedure to capture the effects of viscous mixing and determine the correct jet shape. The goal in developing 2-D powered-lift predictions is to couple this analysis with a pre-existing modified Weissinger method to accurately predict 3-D wing performance based on sectional data. In this manner, high-lift wing characteristics can be determined at a fraction of the computational cost of CFD. An MDAO framework for aircraft-level optimization will be developed with the goal of integrating the powered-lift analysis such that ESTOL concepts and technologies can be incorporated at the conceptual and preliminary design stages.