Flux density imposed (Temperature)
DESCRIPTION
| For all problems in
which temperature is a variable, imposes the heat flux as a function of
the temperature (which remains a variable). The heat flux is the sum of
a constant flux, a convective flux, and a radiative flux. The constant
heat flux is possibly a function of the coordinates.
q = qc + alpha * [ T - Talpha ] + sigma * [ (T + T0) ** 4 - (Tsigma + T0) ** 4 ] , where qc is a temperature independent heat flux, alpha is a heat convection coefficient with a reference temperature Talpha, and sigma is a radiation coefficient with a reference temperature Tsigma. T0 is a scaling factor which vanishes for an absolute temperature scale. By default : q = 0. |
NOTES
-1 Upper level menu 1 Modification of qc The temperature independent contribution to the heat flux. However qc can depend upon coordinates. 2 Modification of alpha The heat convection coefficient must be positive 3 Modification of Talpha The reference temperature for the convective heat exchange 4 Modification of sigma The radiation coefficient must be positive. It is obtained as the product of the Stefan-Boltzman constant (5.6697e-8 W/m2/K4 or 5.6697e-5 erg/cm2/s/K4) by the emissivity on the boundary. 5 Modification of Tsigma The reference temperature for the radiative heat exchange 6 Modification of T0 A non-vanishing value for T0 must be specified when non-absolute temperature scales are used. For example, T0 = 273.15 ?C if temperatures are given in Celsius. This is mandatory when radiative heat fluxes are taken into account.
The units for the various
parameters are :
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| q |
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| qc |
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| alpha |
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| sigma |
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SEE ALSO