基于VOF模型的排洪竖井底板脉动压力数值模拟与分析

Numerical Simulation and Analysis on Fluctuating Pressure on Floor of Flood Discharge Shaft Based on VOF Model

竖井排洪是火电厂储灰场及选矿厂尾矿库常用的泄洪方式,排洪竖井底板脉动压力变化是确定排洪竖井底板合理高程的重要参数。采用VOF法和RNG k紊流计算方法对排洪竖井底板脉动压力变化进行数值模拟分析,分析结果与物理模型实测值结果吻合较好,说明基于VOF法和RNG k紊流计算方法的数值模拟对排洪竖井脉动压力分析是可行的;分析也同时表明了竖井底板振动的优势频率主要集中在05Hz,属于低频振动,不会对排洪竖井产生共振破坏。但对于水库水位较低、排泄流量较小的排洪竖井可在考虑经济成本的情况下,适当降低竖井底板高程、加深水垫,以减轻水流对竖井底板的垂直冲击作用。

Flood discharge shaft is a common way of flood discharge used in ash storage yard of thermal power plant and tailings reservoir of mineral processing plant.The Variation of fluctuating pressure on floor of flood discharge shaft is an important parameter determining its reasonable elevation.In this paper,the authors carried out numerical simulation and analysis on variation of fluctuating pressure on floor of flood discharge shaft by using VOF method and RNG k~εturbulence calculating method,the analysis results are better identical with those of actual measurement value by physical model,this shows that the numerical simulation based the two method is feasible for the analysis on the fluctuating pressure on floor of flood discharge shaft.The analysis also shows that the dominant frequency of the fluctuating pressure vibrating on the floor of shaft is mainly concentrated in the scope 0~5Hz,and which belongs to low frequency vibration,not resulting in resonance failure in flood discharge shaft.However,for the flood discharge shaft that the water level of reservoir is lower and the discharge of flood discharge is less,under the condition of considering economic cost,it is possible properly decreasing the elevation of shaft floor and deepening the water cushion,to lighten the vertical impact action coming from water flow on the floor of shaft.