A multiple grid algorithm for one-dimensional transient open channel flows

Numerical modeling of open channel flows with shocks using explicit finite difference schemes is constrained by the choice of time step, which is limited by the CFL stability criteria. To overcome this limitation, in this work we introduce the application of a multiple grid algorithm to the field of computational hydraulics. By coupling this algorithm to a second-order accurate MacCormack scheme, we demonstrate that the solution can be accelerated to the desired transient state. The present formulation has been tested to simulate shocks arising from sudden closure of a sluice gate and for flows accompanied with a hydraulic jump. The close agreement between the obtained results and the theoretical findings indicates the reliability of the proposed algorithm. (C) 2000 Elsevier Science Ltd. All rights reserved.