Natural Heat Transfer Check
Accessory component to check the heat transfer coefficient of Natural convection
Description
Equations
Variables
Connections
Parameters
See Also
The Natural Heat Transfer Check component models the heat transfer coefficient calculation of Natural convection.
Before using HeatConvection component, you can check how to calculate the heat transfer coefficient internally.
Average temperature is :
T=Tin1−Tin22
Heat transfer coefficient of Natural convection is calculated with :
h=`HeatTransfer.Properties.Fluid.AirNaturalHeatTransferpin, Tin1,Tin2,9.81,X,C__lam,n__lam,C__tur,n__tur,Threshold
( h=Nu⋅kX )
( Nu={C__lam⋅Ran__lamRa≤ThresholdC__tur⋅Ran__turotherwise__)
( Ra=Gr⋅Pr )
( Gr and Pr and k is calculated from pin and T )
Output is :
out=h
For details about the calculation of Fluid properties, see Fluid Properties Check.
Symbol
Units
Modelica ID
T__
K
Averaged temperature between Tin[1] and Tin[2]
h
Wm2⋅K
Heat transfer coefficient
Nu
Nusselt number
Pr
Prandtl number
Gr
Grashof number
Ra
Rayleigh number
k
Wm⋅K
Thermal conductivity
Name
pin
Pa
Pressure input
Tin2
Temperature inputs
Tin[2]
out
Heat transfer coefficient of Natural convection
Default
X
0.1
m
Streamwise length
Clam
0.59
Gain parameter for Reynolds number in the generalized experimental equation of Natural convection generalized equation when Fluid is laminar.
C_lam
nlam
14
Exponent parameter for Reynolds number in the generalized experimental equation of Natural convection generalized equation when Fluid is laminar.
n_lam
Ctur
Gain parameter for Reynolds number in the generalized experimental equation of Natural convection generalized equation when Fluid is Turbulent.
C_tur
ntur
13
Exponent parameter for Reynolds number in the generalized experimental equation of Natural convection generalized equation when Fluid is Turbulent.
n_tur
Threshold
109
Threshold value for Reynolds number to define Laminar or Turbulent.
TH
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