I am now trying to make hydraulic model of a complex open channel by swmm, this channel as the one of main collector of urban storm water system (man-made flood way). The purpose of the simulation is determined the channel capacity and flood warning systems to create, etc.
The main problem is that the longitudinal channels of high slope (more than 35-15 percent) and the channel bottom made step stairs.
Channel dimension is 3*4 meter (box) with high frequency stair stepped along the bottom of channel. Drop heights between 30 to 120 cm and the distance each other from 2-10meter (short drop of about 30cm (height) at 2-3 length mostly been implemented.) Therefore, very high frequency Stairs should be informed to the model.
If the location of each step we consider the node, very short distance is Links. (With inlet or outlet offset) Therefore minimal models converge, instability, continuity error and many problem accrued
So what can I do, please? Any suggestion?
If the dynamic wave method is used, do you recommend I focus on the methods for determining time step, and other techniques ……? I think that any of the links leads to the drop with minor loss, what a way to determine this loss is available?