ACCURACY OF KINEMATIC WAVE AND DIFFUSION WAVE APPROXIMATIONS FOR TIME-INDEPENDENT FLOW WITH MOMENTUM EXCHANGE INCLUDED

✍ Scribed by V. P. SINGH; V. ARAVAMUTHAN

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 338 KB
• Volume: 11
• Category: Article
• ISSN: 0885-6087
• DOI: 10.1002/(sici)1099-1085(199704)11:5<511::aid-hyp444>3.0.co;2-z

✦ Synopsis

Errors in the kinematic wave and diusion wave approximation for time-independent (or steady-state) cases of channel ¯ow with momentum exchange included were derived for three types of boundary conditions: zero ¯ow at the upstream end, and critical ¯ow depth and zero depth gradient at the downstream end. The diusion wave approximation was found to be in excellent agreement with the dynamic wave approximation, with errors of less than 1% for KF 2 0 5 7Á5 and up to 12% for KF 2 0 4 0Á75 for the upstream boundary condition of zero discharge and ®nite depth, where K is the kinematic wave number and F 0 is the Froude number. The kinematic wave approximation was reasonably accurate except at the channel boundaries and for small values of KF 2 0 41. The accuracy of these approximations was signi®cantly in¯uenced by the downstream boundary condition both in terms of the error magnitude and the segment of the channel reach for which these approximations would be applicable.