Internal Flow — Ducts, Pipes & HVAC
Pressure drop, developing flow, secondary flows in bends, flow distribution in manifolds, and HVAC system CFD simulation.
Articles in This Section
Quick Explainer
Why does flow in a pipe bend create secondary flows, and why does it matter?
Centrifugal force throws high-momentum fluid to the outer wall, driving counter-rotating Dean vortices perpendicular to the main flow. These enhance mixing and heat transfer but increase pressure drop. Important in compact heat exchangers, biomedical devices, and HVAC ductwork design.
How does a CFD simulation of an HVAC system differ from a network model?
Network models (1D) are fast — they use pressure-drop correlations at nodes and branches. CFD resolves 3D velocity and temperature fields, capturing local hot spots, dead zones, and short-circuit flows that 1D models miss. Engineers use 1D for system-level sizing, 3D CFD for critical components.