# flow enclosed

Computes the radiative heat flow between an enclosing surface and a body found inside it.

Controller: **CodeCogs**

doubleflow_enclosed( | double | A1 | |

double | A2 | ||

double | T1 | ||

double | T2 | ||

double | e1 | ||

double | e2 | )[inline] |

This module calculates the radiative heat flow per unit surface between an enclosing surface and a body found in its interior.
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 enclosed and enclosing surfaces , , the areas of the enclosed and enclosing surfaces, the emissivity constant of the black body and , the corresponding absolute temperatures of the two surfaces.
In the diagram below is shown the radiative heat transfer between a body of temperature which encloses a body of temperature .

### Example 1

- The example below computes the unit radiative heat flow between an enclosing fire brick surface at 1373.16 degrees Kelvin and a spherical oxidated steel body at 873.16 degrees Kelvin, found in its interior.
#include <codecogs/engineering/heat_transfer/radiation/flow_enclosed.h> #include <stdio.h> int main() { // the temperature of the oxidated steel body double T1 = 873.16; // the temperature of the fire brick surface double T2 = 1373.16; // the emission factor of the steel body double e1 = 0.79; // the emission factor of the fire brick surface double e2 = 0.75; // the area of the spherical steel body double A1 = 3.1416; // the area of the fire brick enclosing surface double A2 = 20; // display radiative heat flow between the two enclosed surfaces printf("Radiative heat flow = %.5lf W per sq. meter\n", Engineering::Heat_Transfer::Radiation::flow_enclosed (A1, A2, T1, T2, e1, e2)); return 0; }

### Output

Radiative heat flow = 127904.73453 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

A1 the area of the enclosed body (square meter) A2 the area of the enclosing surface (square meter) T1 the absolute temperature of the enclosed body (Kelvin) T2 the absolute temperature of the enclosing surface (Kelvin) e1 the emissivity factor of the enclosed body e2 the emissivity factor of the enclosing surface

### Returns

- the radiative heat flow between the enclosing surface and the body found in its interior

### Authors

*Grigore Bentea, Lucian Bentea (November 2006)*

##### Source Code

Source code is available when you buy a Commercial licence.

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