Data Summary from the First AIAA Computational Fluid Dynamics Drag Prediction Workshop

The results from the first AIAA Computational Fluid Dynamics (CFD) Drag Prediction Workshop are summarized. The workshop was designed specifically to assess the state of the art of CFD methodsfor force and moment prediction. An impartial forum was provided to evaluate the effectiveness of existing computer codes and modeling techniques and to identify areas needing additional research and development. The subject of the study was the German Aerospace Research Center DLR-F4 wing-body configuration, which is representative of transport aircraft designed for transonic flight. Specific test cases were required so that valid comparisons could be made. Optional test cases included constant CL drag-rise predictions typically used in airplane design by industry. Results are compared to experimental data from three wind-tunnel tests. A total of 18 international participants using 14 different codes submitted data to the workshop. No particular grid type or turbulence model was more accurate, when compared to each other, or to wind tunnel data. Most of the results overpredicted CL0 and CD0 , but induced drag (dCD /dC2L ) agreed fairly well. Drag rise at high Mach number was underpredicted, however, especially at high CL . On average, the drag data were fairly accurate, but the scatter was greater than desired. The results show that well-validated Reynolds averaged Navier-Stokes CFD methods are sufficiently accurate to make design decisions based on predicted drag.