How to calculate mass flow rate and flow velocity?

Question

What is the equation for calculating mass flow rate and flow velocity in a pipe.
the known values i have are diameter, relative density of the liquid, flow velocity at the entry of the pipe, and the density of water.

Answer 1

Since the fluid is a liquid, the flow velocity is constant in the pipe from one end to the other. Using the formula:



quantity = cross sectional area X flow velocity



You can determine the flow rate in terms of cubic volume



Knowing the volumetric rate and the density you can calculate the mass flow rate.



The key is to keep all of your dimensions consistent,

Answer 2

By knowing the properties of the pumps (pumps power and rotating velocity), you can calculate the mass flow rate which is pumped to the pipes. Then by the following formula the velocity can be calculated: Mass flow = Density * Velocity * Pipe Area

Answer 3

m_dot = rho*v*Pi*d^2/4