Summary Data from the Sixth AIAA CFD Drag Prediction Workshop: CRM Cases

TLDR

The workshop examined force, moment, and pressure predictions for NASA’s Common Research Model wing–body and wing–body–nacelle–pylon configurations, using a geometry deformed to the appropriate static aeroelastic twist and deflection at each angle of attack. The study employed a common set of overset, unstructured, and multiblock structured grids to perform grid refinement and drag increment predictions for the wing–body and wing–body–nacelle–pylon at fixed Mach number and lift coefficient, while also conducting a static aeroelastic/buffet sweep, optional grid adaptation, and coupled aerostructural solutions. Results demonstrate progress since the previous workshop but highlight the need for further CFD improvement, particularly for conditions with significant flow separation, and indicate that enhanced experimental diagnostics are required to guide future development.

Abstract

Results from the Sixth AIAA CFD Drag Prediction Workshop Cases 2 to 5 are presented. These cases focused on force/moment and pressure predictions for the NASA Common Research Model wing–body and wing–body–nacelle–pylon configurations. The Common Research Model geometry differed from previous workshops in that it was deformed to the appropriate static aeroelastic twist and deflection at each specified angle of attack. The grid refinement study and nacelle–pylon drag increment prediction (Case 2) used a common set of overset and unstructured grids, as well as user-created multiblock structured, unstructured, and Cartesian-based grids. Solutions were requested for both the wing–body and wing–body–nacelle–pylon at a fixed Mach number and lift coefficient. The wing–body static aeroelastic/buffet study (Case 3) specified an angle-of-attack sweep at finely spaced intervals through the zone where wing separation was expected to begin. The optional Case 4 requested grid adaption solutions of the wing–body at a specified flight condition. Optional Case 5 requested coupled aerostructural wing–body solutions. Results from this workshop highlight the progress made since the last workshop, and the continuing need for computational fluid dynamics (CFD) improvement, particularly for conditions with significant flow separation. These comparisons also suggest the need for improved experimental diagnostics to guide future CFD development.