论文标题
角动量平衡和壁构成的涡流产生
Angular momentum balance and vortex production in wall-bounded flows
论文作者
论文摘要
要产生涡流，必须将扭矩施加到流体上。在粘性流体中，一旦粘性摩擦超过了流体的剪切应力抗性，产生湍流的扭矩是由于应力张量的对称性而导致的。特别是在壁结合的流中，湍流涡旋形成在墙壁附近的薄层流体中形成，实际上与所谓的粘性子层相吻合，那里的粘性摩擦达到最大的值。本文确定了该子层的涡旋结构，与该区域平均流向速度的平均流向速度图的线性线性一致。该分析使我们能够在稳态条件下计算粘性子层中涡旋的直径，角速度和涡流中的直径。确定了使涡流从壁向主流流迁移到主流流的起重力，并讨论了陀螺式进动作用在涡旋轴重新定位中所起的关键作用。
To produce a vortex, a torque must be applied to the fluid. In viscous fluids, the torques that produce turbulent vortices result from the loss of symmetry of the stress tensor, once the viscous friction exceeds the shear stress resistance of the fluid. In wall-bounded flows, in particular, the turbulent vortices form in a thin layer of fluid adjacent to the wall, practically coinciding with the so-called viscous sublayer, where the viscous friction reaches the largest values. The present paper determines a vortex structure for this sublayer, consistent with the well-known linearity of the diagram of the mean streamwise velocity of this region. The analysis enables us to calculate the diameter, angular velocity, and interaxis of the vortices in the viscous sublayer in steady-state conditions. The lifting force that makes the vortices migrate from the wall towards the mainstream flow is determined, and the crucial role played by gyroscopic precession in the reorientation of the vortex axis is discussed.
