Errors of Kinematic-Wave and Diffusion-Wave Approximations for Time-IndependentFlows in Infiltrating Channels

摘要

Time independent (or steady state) cases of channel flow were treated and errorsof the kinematic wave and diffusion wave approximations derived for finite flow at the upstream end. The diffusion wave approximation was found to be in excellent agreement with the dynamic wave representation, with error magnitudes of 0.2% for values of KF-sq sub 0 >or= 7.5, where K is the kinematic wave number and F sub 0 is the Froude number. Even for small values of KF-sq sub 0(e.g., O.75), the errors were typically in the range of 1.3 to 3.7%. The approximate analytical diffusion wave solution performed poorly with error magnitudes greater than 30% even for large values of KF-sq sub 0. The kinematic wave approximation was also found to be in good agreement with the dynamic wave representation with errors of about 1.2% for KF-sq sub 0=7.5 and varying from 15 to 44% for KF-sq sub 0=O.75.