Comparison of Numerical Procedures for Gate Stroking

Abstract

A study was conducted to compare three existing solution methods for the inverse problem of unsteady open-channel flow (i.e., gate stroking). Both the accuracy of the results and the robustness of the methods were examined. Similar solutions were computed with a method-of-characteristics and an implicit finite-difference model, except under extreme transients, in which case the method-of-characteristics model performed better. However, the characteristic model was unable to find a solution for some proposed examples. An explicit finite-difference model was also examined and, although it produced satisfactory results for some examples, it is inherently unstable. A nonlinear, implicit finite-difference gate-stroking method was developed, which was sufficiently accurate and more robust than the existing methods.