AIAA 2003-0923 RECOMMENDATIONS FOR CFD PROCEDURES FOR PREDICTING ABRUPT WING STALL

This paper summarizes the lessons learned from the computational fluid dynamics (CFD) effort of the joint NASA/Navy/Air Force Abrupt Wing Stall (AWS) Program, discusses the results, and makes recommendations for approaches to be used in future aircraft programs to identify uncommanded lateral characteristics early in the design phase of an aircraft development program. The discussion also suggests CFD procedures and figures of merit for use in predicting and quantifying AWS tendencies and vulnerabilities of the proposed designs. Topics addressed include critical parameters that can be used to identify uncommanded lateral activity in the transonic flow regime, and the geometric parameters that were the primary contributors to the adverse lateral activity observed on pre-production F/A-18E/F aircraft. In addition, differences in steady-state and averaged time-accurate CFD solutions for the F/A18E in the AWS region of interest are analyzed and compared with existing unsteady experimental data to determine the utility and accuracy of the unsteady approach. Lastly, proposed CFD figures of merit are critically evaluated as indicators of possible AWS tendencies, and screening procedures for the identification of AWS are suggested.