2413 半開放形プロペラファンにおける三次元渦流れ構造(S41-1 流体機械に関連した複雑内部流動の解析と計測(圧縮機・ファン),S41 流体機械に関連した複雑内部流動の解析と計測)  [in Japanese] 2413 Three-Dimensional Structure of Vortical Flow Field in a Half-Ducted Propeller Fan  [in Japanese]

Three-dimensional structure of vortical flow field has been investigated by numerical analysis on a half-ducted propeller fan. Complicated flow phenomena in the fan were captured by Reynolds-averaged Navier-Stokes flow simulation (RANS) and vortex structure identification based on the critical point theory. The tip leakage vortex starts to be formed near the blade mid-chord and grows nearly in the tangential direction, impinging on the pressure surface of the adjacent blade. In the blade passage, the breakdown inception of the tip leakage vortex occurs by interaction between the leading-edge separation vortex and the tip leakage vortex. It is expected that the behavior of the tip leakage vortex plays a major role in characteristics of the fan noise.