Approach Based on Analogy between Momentum and Mass Transfer

2 Approach Based on Analogy between Momentum and Mass Transfer 

Osborne Reynolds first noted the similarity between momentum transfer and heat transfer in 1874 (Reynolds 1900). Reynolds stated that in the transport of heat or momentum between a fluid and a solid surface, two mechanisms contributed to the transport process  

The natural internal diffusion of the fluid when at rest. 

The eddy caused by visible motion which mix the fluid up and continuously bring fresh particles into contact with the surface.  

In the case of pipe flow for which Equation 6.28 has been derived, the relation between the bulk fluid velocity, and the friction factor is given by (Bennett and Myers 1962) 

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