【作者】 陈云祥； 陈科； 尤云祥； 胡天群；

【Author】 CHEN Yun-xiang,CHEN Ke,YOU Yun-xiang~+,HU Tian-qun State Key Laboratory of Ocean Engineering,Shanghai Jiao Tong University,Shanghai 200240,China

【机构】 上海交通大学海洋工程国家重点实验室；

【摘要】 本研究基于实验和数值方法研究了层流圆管潜射流生成蘑菇形涡结构的演化机理与表现特征,定量研究了蘑菇形涡结构无量纲射流长度L^*、螺旋型涡环半径R^*及其包络外形长度d^*等几何特征参数随时间t^*的变化规律。结果表明,实验与数值模拟吻合良好,二者都揭示出蘑菇形涡结构的形成与演化过程存在启动、发展和衰退三个不同阶段。在启动阶段,L^*和d^*随t^*线性变化而R^*则近似为一个常数;在发展阶段,蘑菇形涡结构的演化具有自相似性,L^*、R^*和d^*与t^*1/2均为同一正比关系;在衰退阶段,L^*和R^*正比于t^*1/5巧而d^*则近似为一个常数。更多还原

【Abstract】 This paper investigates the formation mechanism and evolution characteristics of the mushroom-like vortex structure generated by a submerged laminar round jet based on experimental and numerical methods.The experimental results agree well with the computational ones and both reveal that three distinct stages,the starting stage,the developing stage and the decaying stage,exist in the formation and evolution processes of the mushroom-like vortex structure.Three non-dimensional parameters for the mushroom-like vortex structure,including the length of the jet L^*,the radius of the mushroom-like vortex R^* and the length of vortex circulation d^*,are introduced and the variation characteristics of these parameters with the non-dimensional time t^* are quantitatively analyzed. In the starting stage,L^* and d^* increase linearly with t^* while R^* approximately remains a constant; in the developing stage,a considerable self-similarity is confirmed and L^*,R^*,d^* display the same proportional relationships to t^*1/2;in the decaying stage,L^* and R^* are approximately proportional to t^*1/5,while d^* nearly levels off at a constant.更多还原