Computational-Reach Length for Prismatic Channels

In this paper, we present a methodology for the selection of reach length in unsteady, onedimensional models of open channel flow. Using computational experiments, we determined an appropriate reach length for 425 combinations of channel and flow parameters. For each combination of parameters, we refined the finite difference grid until numerical error was reduced to 1.0% of a high resolution solution. We generated a set of dimensionless parameters and used regression analysis to relate channel and flood properties to an appropriate computational reach length.