Enter the pipe diameter, pipe material, pipe length, and total elevation change to calculate the flow velocity and mass flow rate of a gravity-fed pipe flow.

Pipe Flow Formula

The following formula is used to calculate the volumetric flow of water through a pipe of a certain diameter, length, and height.

v = k * C * R0.63 * S0.54

  • Where k is a constant (.849)
  • C is the roughness coefficient (dependent on the material of pipe)
  • R is the hydraulic radius
  • S is the slope of the pipe
  • v is the velocity of water (m/s)

From this, the mass flow rate can be determined by multiplying the volume flow rate times the density.

m= p * v

  • Where p is the density of the fluid
  • v is the volumetric flow rate

Pipe Flow Definition

The pipe flow is defined as either the total mass or total volume of fluid moving through a pipe section at any point.

How to calculate pipe flow velocity?

How to calculate pipe flow velocity.

  1. First, determine the roughness coefficient.

    This should be available based on the material used.

  2. Next, determine the hydraulic radius.

    Calculate the hydraulic radius.

  3. Next, determine the slope of the pipe.

    Calculate the slope of the pipe.

  4. Finally, calculate the flow velocity.

    Using the formula above, calculate the flow velocity.

FAQ

What is pipe flow?

Pipe flow is defined as either the total mass or total volume of fluid moving through a pipe section at any point.