旋转弯曲管内流动的数值模拟

Numerical simulation of flow through rotating curved duct

为了分析弯曲管内流动的稳定性、解的分支产生以及流动类型的变化,对正方形断面弯曲管内的流动进行了数值模拟计算。这个流动除了外墙以外的其他墙壁随着弯曲管中心轴旋转,沿着管的轴向具有压力梯度。使用波谱分析法对内圆筒旋转和由压力综合作用下所产生的流动进行了计算。流动是以螺旋泵为模型的。获得了断面二次流动的变化规律,相对于断面中心线得到了2涡流,4涡流,8涡流以及非对称的流动类型,并获得了多重解。对得到的解,进行了线性稳定性分析,并且求解了流量的变化特性。

To analyze the stability of flow in curved duct,multiple solutions,bifurcation of the flow,various types of the secondary flow,etc,the Taylor-Dean flow through a curved duct of square cross-section was investigated numerically by using spectral method,in which the walls of the duct except the outer wall rotate around the centre of curvature and an azimuthal pressure gradient was imposed.The flow may be considered as a model of the screw pump.The steady flow patterns of the induced secondary flow and the flux through duct were obtained.It shows that the secondary flow in a cross-section consists of two-vortex,four-vortex,eight-vortex or even non-symmetric vortex with respect to the centre line of the cross-section.The multiple solutions of the flow were also obtained in certain regions of the flow parameters.The linear stability analysis of the flow was carried out,and the solutions for flow variation were obtained,which may be realized in an actual flow.