Reynolds Analogy (cont.)
The Reynolds analogy related the flow parameters to the thermal parameters. If a given flow field can be determined, the heat transfer characteristics can be found by using the Reynolds analogy.
A modified Reynolds analogy has been obtained to take into consideration of the fact that Prandtle number Pr is usually not equal to one:
Note: The Reynolds analogy should only be used when the pressure gradient is zero. However, in turbulent flow, this condition is not that important. Therefore, the analogy can be applied even when the pressure gradient is nonzero for turbulent flows.