节流管孔流动参数与雷诺数关系的数值研究

对初始静止状态的流体，在其压力差为阶跃变化的情况下，通过节流孔的流动过程进行了数值解析计算。特别注目于再附着点距离zats、流量系数cd、惯性长，以及时间常数τq、τz与雷诺数Re的关系。做出了流动参数与雷诺数Re的关系图，并给出了用雷诺数计算时间常数的计算式。数值计算结果说明了对应于流量变化的时间常数τq随着Re数的增加而减少，而对应于流场变化的时间常数τz几乎为一定值。

Numerical analysis for fluid parameters of pipe orifice with respect to Re

The numericalanalysisoffluid through apipe orifice has beenperformedfrom the initial stationary stateunder asuddenlyim- posed pressure gradient. Particularly, the relationships of Reynolds number Re with the distance of the reattachment point , the discharge coefficient , the inertial length , the time constants , and so on have been studied. The figures of the fluid parameters with respect to Re are shown. And then the formulae of the time constants with respect to Re are given. The numerical calculation has shown that the corresponding to the flow rate change deceases with the increasing Re, the corresponding to the variation of the flow structure is independent on the Re.