As is common with fluid mechanics analysis, a number of dimensionless parameters are employed to describe convective heat transfer. A summary of these variables is included in the following tables: |
General Convection (Forced and Free) |
Parameter | Formula | Interpretation |
Prandtl Number: | ![]() |
Ratio of fluid velocity boundary layer thickness to the fluid temperature boundary layer thickness. |
Nusselt Number: | ![]() |
Ratio of heat transfered from surface to heat conducted away by fluid. |
Forced Convection Only |
Parameter | Formula | Interpretation |
Reynolds Number: | ![]() |
Ratio of fluid inertia stress to viscous stress (for flow over flat plates). |
Reynolds Number: | ![]() |
(Reynolds Number for pipe flow). |
Stanton Number: | ![]() |
Free Convection Only |
Parameter | Formula | Interpretation |
Grashof Number: | ![]() |
Ratio of fluid buoyancy stress to viscous stress. |
Rayleigh Number: | ![]() |