Comparison of Measured and Simulated Flow Features for the Full-Scale F-16XL Aircraft

Abstract

Accurate and cost-effective Computational Fluid Dynamics (CFD) methods play an increasingly important role, even in the support of fighter aircraft operations. Prior to the deployment of such CFD methods they should be well validated and evaluated against stateof-the-art wind tunnel and/or flight test data. The Cranked-Arrow Wing Aerodynamics Project (CAWAP) provided the CFD community with an excellent database for validation and evaluation. Initiated by NASA, the Cranked-Arrow Wing Aerodynamics Project International (CAWAPI) was started as a follow-on project of CAWAP. The National Aerospace Laboratory NLR participated in this project using the in-house developed flow simulation system ENFLOW, which includes both grid generation tools and a flow solver. NLR applied (semi-automatic) grid generation tools to generate a structured (multi-block) grid. Steady flow simulations for all seven CAWAPI flight conditions are performed employing the flow solver ENSOLV. Results obtained for flight condition 7, 19 and 25 are discussed. The focus of this discussion is on a com parison of the measured and simulated flow features. It is shown that the understanding o f NLR’s structured (multi-block) grid generation algorithm and the confidence in the appl ication of its flow simulation method to complex fighter configurations increased significan tly by participating in CAWAPI.