水煤浆流经局部管件阻力特性的研究

在水煤浆综合输送试验台上研究了水煤浆流经渐缩管、突缩管以及90°水平弯管的局部阻力特性，分析了渐缩角、管径比以及弯径比对上述局部管件阻力损失的影响。结果表明，增加渐缩角使得渐缩管的局部阻力损失减少；较小的管径比变化对突缩管的局部阻力损失没有较大影响；存在一个最佳弯径比，使得水平弯管的局部阻力损失最小。随着雷诺数的增加，渐缩管、突缩管以及水平弯管的阻力系数先迅速下降然后逐渐趋于稳定，而渐缩管当量长度与管径的比值Le/D逐渐下降然后趋于稳定；突缩管的Le/D先下降再增加，对于弯管的Le/D则成线性增加。

Research on Resistance Characteristic of Coal-water Slurry Flowing Through the Local Fittings

The local resistance characteristics of coal-water slurry (CWS) flowing through three types of local fittings, namely, the gradual contraction, sudden contraction and 90° horizontal bend, were investigated at a comprehensive transportation test facility of CWS. The effect of experimental parameters such as contract degree，diameter ratio and bend diameter ratio on the local resistance loss of local fittings was measured. The results show that the local friction loss of gradual contraction decreases as the contract degree increases. When the pipe diameter ratio varies a little，the local resistance loss of sudden contraction changes insignificantly. There is an optimal value of bend diameter ratio, where the local resistance loss of horizontal bend is least. As Reynolds number increases，the friction loss coefficients of three fittings decline fast at first, and then gradually tend to be constant values, while the three pipes have different ratio of equivalent length to pipe diameter Le/D behaviors that is Le/D of the gradual contraction decreases gradually and then keeps stable, that of the sudden contraction reduces at first and then increases, and that of the horizontal bend increases linearly.