Control of water hammer suppression via time-scaling technique
CHEN Te-huan
REN Zhi-gang
Abstract：During the fluid pipeline running, sudden closure of an open valve in the pipeline network causes a huge pressure shock toward the valve and pipeline wall.This phenomenon,called water hammer,threatens the healthy operation of the fluid pipeline. Thus, an optimal boundary control problem of water hammer suppression during valve closure is studied. The water hammer model can be described as a set of nonlinear spatio-temporal equations,including a boundary control at the end of the pipeline. First, the method of lines (MOL) is applied to reduce the water hammer model to a finite dimensional model. Then,the piecewise-linear control parameterization method and sensitivity analysis method combined with the time-scaling technique are proposed to derive the gradients of the objective function.Finally,nonlinear optimization techniques are used to solve the optimal control problem. Numerical results show the time-scaling technique can suppress water hammer more effectively. Since the practical control input is the degree of the valve opening, the optimal changes of valve relative opening with time evolution are given based on the optimal boundary control and the corresponding pressure changes.
Keywords：water hammer modelpiecewise-linear control parameterizationtime-scaling techniquesensitivity analysis
Publication Date：2018-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：9( 198-206 )