VM106

VM106
Radiant Energy Emission

Overview

Reference:	F. Kreith, Principles of Heat Transfer, 2nd Printing, International Textbook Co., Scranton, PA, 1959, pg. 22, problem 1-8(b).
Analysis Type(s):	Thermal Analysis (ANTYPE = 0)
Element Type(s):	Radiation Link Elements (LINK31)
Input Listing:	vm106.dat

Test Case

Determine the rate of radiant heat emission q in Btu/hr from a black body of unit area A at a temperature T, when ambient temperature is T_a.

Figure 152: Radiant Energy Emission Problem Sketch

Material Properties

Geometric Properties

ε = emissivity = 1.0

A = 1 ft²

F = form factor = 1.0

T = 3000°F

T_a = 0°F

Analysis Assumptions and Modeling Notes

A conversion factor of 144 in²/ft² is included in the area input to convert the default Stefan-Boltzmann constant to feet units. The temperature offset of 460°F is required to convert the input Fahrenheit temperature to an absolute (Rankine) temperature. The node locations are arbitrarily selected as coincident.

Results Comparison

	Target	Mechanical APDL [1]	Ratio
q, Btu/hr	2.4559 x 10⁵	2.4552 x 10⁵	1.000

Element heat rate