Computes the total energy radiated by a body with given parameters.

Contents

Interface Function Documentation Page Comments

Interface

#include <codecogs/engineering/heat_transfer/radiation/energy.h>

using namespace Engineering::Heat_Transfer::Radiation;

	double	energy (double T, double e = 1.0)[inline] Computes the total energy radiated by a body with given parameters.
	Real	cc_energy (Real T, Real e) This function is available as a Microsoft Excel add-in.

Function Documentation

This module calculates the total energy radiated by a body per unit surface area in unit time.

The total radiative energy of a black body is given by the Stefan-Boltzmann law where is the radiative intensity of the black body.

In practice, the following formula due to Kirchoff is used where is the emissivity constant of the black body , is the emissivity factor of the body and is its absolute temperature.

Example 1:

The following example calculates the total radiative energy emitted by the Wolfram filament of an incandescent light bulb at 3573.16 degrees Kelvin.

#include <codecogs/engineering/heat_transfer/radiation/energy.h>
#include <stdio.h>
 
int main()
{
  // the temperature of the Wolfram filament
  double T = 3573.16;
 
  // emissivity factor of the filament
  double e = 0.39;
 
  // display the total radiative energy
  printf("Energy = %.5lf kW per sq. meter\n",
  Engineering::Heat_Transfer::Radiation::energy(T, e)/1000.0);
 
  return 0;
}

Output:

Energy = 3603.96794 kW 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:

T	the absolute temperature of the body (Kelvin)
e	Default value = 1.0

Returns:

the total radiative energy emitted by the body (Watt per square meter)

Authors:

Grigore Bentea, Lucian Bentea (November 2006)