Publications
2-D, bluff body drag estimation using a green's function/gram-charlier series approach
In this study, we extend self-similar, far-field, turbulent wake concepts to estimate the 2-d drag coefficient for a range of bluff body problems. The self-similar wake velocity defect that is normally independent of the near field wake (and hence body geometry) is modified using a combined approximate Green's function/Gram-Charlier series approach to retain the body geometry information. Formally a near field velocity defect profile is created using small disturbance theory and the inviscid flow field associated with the body of interest. The defect solution is then used as an initial condition in the approximate Green's function solution. Finally, the Green's function solution is matched to the Gram-Charlier series yielding profiles that are integrated to yield the net form drag on the bluff body. Preliminary results indicate that drag estimates computed using this method are within approximately 15% as compared to published values for flows with large separation. This methodology may be of use as a supplement to CFD and experimental solutions in reducing the heavy computational and experimental burden of estimating drag coefficients for blunt body flows for preliminary design type studies. © 2004 by the American Institute of Aeronautics and Astronautics, Inc.