Page 395 - Modelling in Transport Phenomena A Conceptual Approach
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9.3. HEAT TRANSFER WITH CONVECTION 375
1.2
1
0.8
e
0.6
0.4
0.2
0
0 0.2 0.4 0.6 0.8
5
Figure 9.13 Variation of 8 as a function of with Br as a parameter.
In dimensionless form, Eq. (9.3-88) becomes
fl
(9.3-89)
Jo
where
(9.3-90)
Substitution of Eqs. (9.3-71) and (9.3-87) into Eq. (9.3-89) gives
(9.3-91)
Calculation of the Nusselt number for the bottom plate
The heat flux at the bottom plate is expressed as
(9.3-92)
Therefore, the Nusselt number becomes
(9.3-93)