基于水气两相流的海拔高程对某电站溢洪道泄洪雾化的影响分析

Analysis of Influence of Altitude on a Hydropower Station Spillway Flood Discharge Atomization Based on Water Air Two-phase Flow

海拔高程增加所引起的气象条件的改变会对泄洪水舌的运动产生影响,进而影响泄洪雾化风场及雨场的时空分布。为此,基于水气两相流理论,考虑不同海拔高度的环境压强、温度、粘滞性及空气密度等参数的变化,采用数值模拟的方法研究了海拔高程对泄洪雾化的影响。结果表明,相同泄洪条件下,泄洪稳定后的压强值随海拔升高无明显增加趋势,然而海拔越高,水舌空中运动所受空气阻力越小,相同条件下落水点压强增幅越大;温度降低带来的水的粘滞性增加对水雾运动影响较小,海拔高程越高,雾化风速到达最大值的时间越早,所能达到的最大值也越大;泄洪稳定时近地表雾化降雨强度随海拔高程的增加而增大,与海拔高程呈近似线性关系,此外强降雨范围随海拔的升高而逐渐扩大。

The change of meteorological conditions caused by the increase of altitude elevation will affect the movement of the flood tongue,which in turn affects the temporal and spatial distribution of the flood fogging wind field and rain field.Based on the theory of water air two-phase flow,considering the changes of environmental pressure,temperature,viscosity and air density at different altitudes,the influence of altitude on flood discharge atomization was studied by numerical simulation.The results show that under the same flood discharge conditions,the pressure value after stable flood discharge does not increase significantly with the increase of altitude,but the higher the altitude,the smaller the air resistance of the water tongue in the air is,and the greater the increase of pressure at the falling point under the same conditions.Through the analysis of wind speed at characteristic points,the increase in water viscosity brought by temperature reduction has less impact on water mist movement,and the higher the altitude,the earlier the atomization wind speed reaches the maximum value,and the greater the maximum value that can be reached.When the flood discharge is stable,the intensity of near-surface fog rainfall increases with the increase of altitude,which is approximately linear with the elevation,and the range of heavy rainfall gradually expands with the increase of altitude.