抵抗要素分解を用いた遷音速流れ空力解析

In this paper, advanced drag prediction method based on the momentum conservation theorem was applied to CFD computational results of transonic flows. This method can decompose total drag into drag components such as wave, profile, induced and spurious drag which is due to the effect of the numerical diffusion and error. In this method, drag components are computed by the volume integration of entropy production or vorticity terms in the flow field around the aircraft. Therefore, wave/profile drag can be computed by the partial volume integration of the entropy terms around the shock waves/boundary layer and wake, respectively. Then, spurious drag can be computed by the volume integration of the entropy terms at the remaining flow field. It is because the entropy production in the flow field should occurred within shock, wake and boundary layer regions from the viewpoint of physics. Induced drag can be computed by the integration of the vorticity terms related to the wingtip vortex. This drag decomposition method was applied to structured/unstructured mesh computational results. The computational results showed that the drag decomposition method had good capability of the drag prediction and meaningful drag decomposition. Moreover, the more accurate drag prediction was realized by the elimination of the spurious drag component from the total drag.
資料番号: AA0049212002
レポート番号: JAXA-SP-05-017