摘要 : This study is motivated by applications to near-wall shear flow (ⅰ) as a longitudinal wall shaping starts, (ⅱ) around a surface obstacle, or (ⅲ) through a pipe bend. All are shown to be governed, at relatively high flow rates, ... 展开 This study is motivated by applications to near-wall shear flow (ⅰ) as a longitudinal wall shaping starts, (ⅱ) around a surface obstacle, or (ⅲ) through a pipe bend. All are shown to be governed, at relatively high flow rates, by essentially the same theoretical problem. This concerns three-dimensional nonlinear longitudinal vortex-like motion under a prescribed displacement which continues to increase with distance downstream. Symmetry-plane solutions are obtained mainly through forward marching computation followed by analysis of the far-downstream response. The behaviour far downstream is found to involve either a strengthening attachment or an increasing three-dimensional separation (lift-off) with no backflow. 收起