Mathematical model of Heat Transfer Coefficient through the annulus gap between concentric pipes filled with fluid:
(1) | U = \frac{\lambda}{d_h} \, {\rm Nu}_h |
where
\lambda | thermal conductivity of flowing fluid |
d_h | annular hydraulic diameter |
{\rm Nu}_h | dimensionless Nusselt number (Nu) |
The Nusselt number (Nu) correlations are:
Stagnant fluid | Natural Convection | Forced Convection | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
OEIS sequence A282581 | J. DIRKER & J. P. MEYER | |||||||||
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where | where | |||||||||
\epsilon({\rm Ra}) | Natural Convection Heat Transfer Multiplier | \displaystyle \mbox{Pr} = \frac{\nu}{a} | ||||||||
{\rm Ra} | Rayleigh number | \nu | ||||||||
a | thermal diffusivity | |||||||||
\zeta = r_{out}/r_{in} | ||||||||||
p = 1.013 \cdot\exp \left[ -0.067 \cdot \zeta \right] | ||||||||||
\displaystyle c = \frac{0.03 \, \zeta^{1.86}}{0.063 \, \zeta^3 -0.674 \, \zeta^2 +2.225 \, \zeta - 1.157 } |
See also
Physics / Thermodynamics / Heat Transfer / Heat Transfer Coefficient (HTC) / Heat Transfer Coefficient (HTC) @model
[ Thermal conductivity ] [ Nusselt number (Nu) ]