Pressure Drop Through Pipe Calculation
- Darcy–Weisbach equation is an empirical equation to determine the head loss, or pressure loss, due to friction for a given length of pipe to the average velocity of the fluid flow for an incompressible fluid
- This formula is directly proportional to the square of the average velocity
Steps to determine the Pressure Drop through the duct
- Known Quantities:
- Density of the fluid, ρ
- Dynamic viscosity of the fluid, μ
- Hydraulic diameter of the duct, D = 2* a* b / (a + b)
- Average fluid velocity, ⟨v⟩
- Determine Reynolds Number: Re = ρ*⟨v⟩* D/μ
- Laminar flow: Re < 2100
- Turbulent Flow: Re > 4000
- Determine the friction factors (Fd) as a function of friction factor and Reynolds number
- Refer to the fluid Mechanics books to get different correlations for friction factor
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- Commonly used the Swamee-Jain Equation for turbulent flow
- Determine Pressure drop per unit length of pipe (ΔP/L) in wg/ft
Pressure Drop Calculator
- Enter values in the column
- For hydraulic diameter:
- Enter the sectional sizes (a x b) for non-circular ducts
- Enter a diameter (D) directly for circular pipe
- Understand the type of flow: laminar or turbulent, however, the turbulent formula has been used
- Note SI or Imperial units