Calculating Water Flow Using a Venturi Meter

[HethensEnd25]

Homework Statement

A 4 inch to 1 inch diameter venturi meter is used to measure water flow and it
has a mercury manometer deflection of 1 inch. What is the discharge
through the four inch diameter pipe?

Homework Equations

Bernoulli Equation, manometer formula

The Attempt at a Solution

Thus far my attempt at a solution is using the Reynolds Transport Theorem. I know that for a steady flow process that there will be no change in volume for the control volume. Thus that term will be zero. So now I am left with

∫ρV*dA

I have two diameters given and I know that it is a in-compressible fluid. So my flow in must equal my flow out. I am confused however upon the given information regarding the mercury deflection. Am I to use that deflection to give myself a pressure? Or is that a piece of information that is nonessential in approaching this problem?

Best Regards,

D

 

[billy_joule]

Am I to use that deflection to give myself a pressure? Or is that a piece of information that is nonessential in approaching this problem?

The pressure differential is absolutely essential information.
You can use Bernoulli's equation and the continuity equation to solve for flow rate.

 

[HethensEnd25]

Thank you for your insight. I have solved the problem. I will post my answer once I am home to double check.

Best Regards,
D