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convection calculation
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Natural Convection Heat Transfer Coefficient Correlations (S.I. units)
4. With an isothermal horizontal cylinder Fluid = air
Inputs Calculations
30 30
60 318
45 0.7
1.10.E+09
0.7 m
7.60E+08
1.1
0.0000187
106
1
4.08
1000
Fluid Thermal
0.027 J/s-m-K
Fluid Thermal
0.003143
* For an Excel spreadsheet that can be downloaded to calculate the density of a gas
"Excel Templates for Venturi and Orifice Flow Meter Calculations," at:
Fluid Temp, T¥ = oC Temp Diff, DT = oC
Surface Temp, Tw = oC Abs. Film Temp, Tf = oK
Film Temp., Tf = oC Prandtl Number, Pr =
[ Tf = (T¥ + Tw)/2 ]
Grashof Number, Gr =
Cylinder Diam., D =
Rayleigh No., Ra =
Fluid Density, r* = kg/m3
Fluid viscosity, m = N-s/m2
Nu =
Fluid Sp. Heat, Cp = J/g-oK
h = W/m2-K
Fluid Sp. Heat, Cp = J/kg-oK
Conductivity, k =
Expans. Coeff, b = oK-1
with known molecular weight and specified temperature and pressure, see:
http://www.brighthub.com/engineering/civil/articles/83825.aspx