立轴旋涡多圈螺旋流场特性研究

为描述进水口前立轴旋涡多圈螺旋的流场特性,运用数值模拟、试验研究和理论公式3种方法。其中,数模采用VOF法追踪自由水面,试验中用有色颜料作为示踪介质,3个方向速度的理论公式中增加了随轴向的变化。结果表明,在轴对称条件下,对数模、理论计算的速度分布进行对比分析,证实了旋涡流场不仅是径向的函数,而且还是轴向的函数。运用数值模拟具有能模拟各种不同边界条件的优势,还对非对称来流条件下形成的立轴旋涡进行了模拟。

Research on Flow Field Characteristics of Vertical Vortex with Multi-circle Spiral Flow

The flow field characteristics of vertical vortex with multi-circle spiral flow at hydraulic intakes are described by numerical simulation,experimental investigation,and theoretical equations.VOF method is used to deal with the free water surface in the numerical simulation.The coloring tracer is employed as tracker particles in the test.The theoretical equations for 3-D velocities add the change of vertical vortex in the axial direction,which on other model does.The velocity distribution of the numerical simulation and the theoretical equations calculation are compared on the condition of axial symmetry.It shows that flow field of vertical vortex is not only the function of the radial coordinate but also the function of the axial coordinate.Taking the advantage of numerical simulation that can simulate the different types of boundary conditions,the vertical vortex induced by the asymmetric initial flow is simulated too.