有压管道水力计算的显式计算式

有压管道水力计算比较复杂,通过对原隐式计算式进行处理和数值拟合,给出了紊流流动中的有压管道各类水力计算的显式计算式.求解流量的计算式是直接对原计算方程组进行推导所得,所得出的有压管道紊流流动的流量显式计算式与原隐式计算式成果完全一致.对水头损失及管道直径,通过对原隐式计算式进行处理和数值拟合,给出了相应的显式计算式.由此得出,对于有压管道中的水力计算问题,均可采用显式计算式直接计算,而不需要进行反复试算.管道水力计算显式计算式使有压管道的水力计算更为方便.

Explicitformulaeof pipe-flowproblems

The hydraulic computations of the pipe-flows have been a little complicated for they have encountered a problem of the implicit form of the Colebrook-Write equation. By transforming the Colebrook-Write equation or choosing the proper dimensionless variables and fitting the suitable curves to the Colebrook-Write equation, some corresponding explicit formulae of the pipe-flow problems are given.The explicit formula of discharge is transformed directly from the Colebrook-Write equation. The explicit formulae for determining pipe diameter and head loss are obtained by choosing the proper dimensionless variables and fitting the suitable curves to the Colebrook-Write equation. Thus,for all the pipe-flow problems we can use the explicit formulae calculation directly instead of many trials. The explicit formulae of the pipe-flow problems bring quite convenience for their hydraulic computations.