# [Conceptual Question] Fluid Mechanics Analysis of Pipe Flow

1. Nov 24, 2014

### aerograce

1. The problem statement, all variables and given/known data
As shown in the figure, if the pipe net work is shifted bodily by 10m vertically up the tank, and all the other conditions remain the same as the previous figure. Will the volume flow rate change?

Or I rephrase it as, in the calculation of elevation head of pipe flow, is the elevation head related to free surface height of the water in tank, or the entrance/exit position of the pipes from the tank?

2. Relevant equations
Relevant Equations are:
Hf=f L/d V^2/g
Hl= K V^2/g

3. The attempt at a solution
The attempt at this problem is:
I think it is related to free surface height of the water in tank only since in calculation we usually draw a line from one water tank free surface to another.

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2. Nov 25, 2014

### OldEngr63

You are correct (if I understand you correctly). The flow entrance distance below the free surface is the key factor since it is this head that drives the flow. In the first figure, the entrance appears to be somewhat close to the tank bottom, and that could have a minor effect on the nature of the flow around the entrance, but the big factor is the head.