# flow noshield

Computes the radiative heat flow between two plane surfaces that are separated by a non-absorptive medium.

Controller: **CodeCogs**

doubleflow_noshield( | double | T1 | |

double | T2 | ||

double | e1 | ||

double | e2 | )[inline] |

This module calculates the radiative heat flow per unit surface between two plane surfaces, considering the case when these are separated by a non-absorptive medium.
On account of the Stefan-Boltzmann law, the unit radiative heat flow between the two surfaces is given by
where
with , the emissivity factors of the first and second surface , the emissivity constant of the black body and , the corresponding absolute temperatures of the two plane surfaces.
In the diagram below is show the radiative heat transfer between two plane surfaces, in which is the radiative energy emitted by the first surface, is the radiative energy emitted by the second surface, is the energy emitted by the first surface and absorbed by the second, is the energy emitted by the second surface and absorbed by the first, is the radiative energy emitted by the first surface and reflected by the second and is the radiative energy emitted by the second surface and reflected by the first.

### Example 1

- The example below computes the unit radiative heat flow between an oxidated aluminium plane surface at 873.16 degrees Kelvin and an oxidated copper plane surface at 403.16 degrees Kelvin, separated by a non-absorptive medium.
#include <codecogs/engineering/heat_transfer/radiation/flow_noshield.h> #include <stdio.h> int main() { // the temperature of the oxidated aluminium surface double T1 = 873.16; // the temperature of the oxidated copper surface double T2 = 403.16; // the emission factor of the aluminium surface double e1 = 0.19; // the emission factor of the copper surface double e2 = 0.76; // display radiative heat flow between the two plane surfaces printf("Radiative heat flow = %.5lf W per sq. meter\n", Engineering::Heat_Transfer::Radiation::flow_noshield(T1, T2, e1, e2)); return 0; }

### Output

Radiative heat flow = 5638.04033 W per sq. meter

### Note

- A table with the emissivity factors of various materials at different temperatures can be found at the following link http://www.monarchserver.com/TableofEmissivity.pdf

### References

- Dan Stefanescu, Mircea Marinescu - "Termotehnica"

### Parameters

T1 the absolute temperature of the first surface (Kelvin) T2 the absolute temperature of the second surface (Kelvin) e1 the emissivity factor of the first surface e2 the emissivity factor of the second surface

### Returns

- the radiative heat flow between the two plane surfaces (Watt per square meter)

### Authors

*Grigore Bentea, Lucian Bentea (November 2006)*

##### Source Code

Source code is available when you buy a Commercial licence.

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