How to Iterate for a Solution with an Excel Macro: The Manning Formula for Open-Channel Flow
The Manning formula for open-channel flow is: whereV= Velocityn = Manning’s “n”,r = Hydraulic radius = area / wetted perimeter = b*y / (2*y + b) for a rectangular channel (where y = depth and b = width), ands = slope of channel (m/m). Discharge Q = V*A = V*b*y. We cannot solve this…