The explanation is clear and easy for a non engineering student... You really help me a lot since I am doing internship with an engineer🥰 Keep it up bro.
I have a doubt if s in Manning equation represent the slope of energy line .so it should be total head loss /horizontal length.but in slope area method we take this slope as hf/L where hf is head loss due to friction why we donot consider head loss due to eddy in calculating the slope of energy line ?
good question. Manning's equation is primarily used to compute the major (friction) loss. There are ways to incorporate other minor losses in HEC-RAS by editing minor loss coefficients. Hope this helps.
I understand the equation of hydraulic radius(or hydraulic mean depth) but how to visualise it i mean for example i can visualise area is π/4D² so it covers whole pipe area but what is hydraulic radius in practical point of view? which part or section of the pipe it represents!?
Dear, we need to consider only flow area for calculating hydraulic radius (R = Flow Area/ Wetted Parameter), So practically you may say that it is length when multiplied by wetted parameter gives the flow Area
Just one question. Why we take chezzys and manning coefficient independent of fluid viscosity. i.e. According to my thinking, there will always be a fluid layer sticking to the bed (no slip condition) and the effect of bed roughness is propagated to other layers of fluid via viscosity. But both these coefficients doesn't have viscosity component in them. For example if I apply the Mannings equation for hot areas where water temp is at 30 Centigrade and in cold areas where the temperature is 5-10Centrigrade. In both, the case Mannings equation will yield the same Flow rate but I think the flow rate will be different in both cases for the same channel.. Please help me with this.
Good question! Manning's equation is an empirical equation derived specifically for open channels where the flow is turbulent and is mostly used for the flow of water. Calculation of Reynolds number which is used to find whether the flow is turbulent or laminar does include fluid properties (density and viscosity) so we could say that these properties are implicitly included in the application of Manning's equation, but you are right these properties do not explicitly appear in the equation. Hope this helps!
Open channel flow is basically based on gravitational force unlike pipe flow where viscous force plays a major role and infact viscous damping reduces the turbulence in flow and when turbulence force over comes the viscous damping turbulent flow is initiated (Refer to my explanation of Reynolds number). On the other hand in open channel flow viscous damping does not play role, so, these roughness coefficients do not have viscosity factor
Hey, you referred to a previous video regarding unit hydrograph but I couldn’t find it on your channel. Could you please guide me where I can find the previous videos leading out to this . Cheers, Ash
