RANS Technology for Transonic Drag Prediction; A Boeing Perspective of the 4th Drag Prediction Workshop

The Common Research Model utilized by the fourth Drag Prediction Workshop was employed to investigate the accuracy of three primary codes used at Boeing for transonic aerodynamic ow analysis. The codes used in this study are CFL3D (block structured), OVERFLOW (overset structured), and BCFD (unstructured). Solutions were obtained for the wing-body con guration with the horizontal tail at incidence angles of 0◦, +2◦, −2◦ and with the tail removed. Grid convergence and resolution, mesh topology, and turbulence models were considered the primary factors in this study for accurate predictions of cruise drag, pitching moments, and Reynolds number e ects. Also, these factors were considered in wing and tail side-of-body ow separation predictions. In this study, all three cases (one required and two optional) were completed with all three codes. The solutions were obtained with the one-equation turbulence model of Spalart & Allmaras and the twoequation SST turbulence model of Menter. For the trim drag and Reynolds number e ect studies (optional cases), OVERFLOW and BCFD were run only with the Spalart-Allmaras turbulence model.