关阀过程中管内瞬变流一二维数值模拟对比

One-Dimensional and Two-Dimensional Numerical Simulation Contrast of Transient Flow with Valve Closing in a Water Pipeline

应用动网格技术对输水管内不同关阀速度时的瞬变流进行了二维数值模拟,并将其计算结果与经典一维特征线法计算结果进行了对比,探讨了关阀速度、进口压力水头、管径三个主要因素取值不同对两种方法计算结果相对偏差值的影响。算例结果表明:两种方法计算结果在阀前管段的最大偏差值约10%,而阀后管段的最大偏差值可能接近100%;与阀门距离越远该偏差值越小,这种衰减趋势在5倍管径距离范围内尤为明显,但对于阀后管段,即使在与阀门10倍管径距离处,该偏差值仍可能为10%以上;关阀速度或进口压力水头越大,该相对偏差值越大;而管径越大,该相对偏差值越小。

Dynamic mesh was introduced to simulate the transient flow of valve closure in waler pipeline, and the calculation results were comparcd with the classical one-dimensional method of characteristics（ MOC）, the effects of thrce main factors including closnre speed, inlet pressure and valve diameter were investigated to the relative deviation of the calculated results of the two methods. The results show that the maximum deviation for upstream of the valve is about 10% , and the value is close to 100% for downstream of the valve; the deviation value deerease as the distance from the valve increases, and the attenuation trend is particularly evident when the distanee frum the valve is less than 5 times of the valve diameler, but for downstream pile of the valve, the deviation value is still larger than 10% even the distance is hmger than 10 times of the valve diameter; the deviation value increases as the clnsure speed or inlet pressure head increases while it deereases as the valve diameter increases.