Pressure Drop Calculator
Build a flow path from sequential sections. Add single pipes or identical parallel branch sections, then review pressure drop and heat transfer results.
Fluid and loss assumptions
Flow summary
Model notes
This calculator assumes incompressible flow and identical flow split across each parallel section.
Air properties are estimated for dry air using temperature and standard-atmosphere elevation. Water properties are estimated for liquid water from 0 to 100 deg C.
Rectangular sections use actual rectangular area for velocity and hydraulic diameter for Reynolds number and friction loss.
Laminar Nusselt number uses Nu = 3.66 for fully developed internal flow; turbulent flow uses the Gnielinski correlation with the calculated Darcy friction factor.
For gases at high speed, strong temperature change, or large pressure change, use a compressible-flow model.