VM125

VM125
Radiation Heat Transfer Between Concentric Cylinders

Overview

Reference:F. Kreith, Principles of Heat Transfer, 2nd Printing, International Textbook Co., Scranton, PA, 1959, pg. 260.
Analysis Type(s):
Thermal Analysis (ANTYPE = 0)
AUX12 (Radiation View Factor Utility)
Element Type(s):
3D Conduction Bar Elements (LINK33)
Superelement (or Substructure) (MATRIX50)
Input Listing:vm125.dat

Test Case

Two long concentric cylinders are held at constant temperatures T1 and T2. Determine the rate of radiative heat transfer between the cylinders.

Figure 177: Concentric Cylinders Problem Sketch

Concentric Cylinders Problem Sketch

Material PropertiesGeometric PropertiesLoading
ε1 = 0.7
ε2 = 0.5
r1 = 1 in
r2 = 2 in
T1 = 1000°R
T2 = 460°R

Analysis Assumptions and Modeling Notes

The cylinders are assumed to be sufficiently long enough to neglect end losses. A 2D model is used to determine the heat transfer rate per unit depth. The thermal conductivity and cross-sectional areas of the conducting bars are arbitrarily set equal to 1. The Stefan-Boltzmann constant defaults to 0.119 x 10-10 Btu/hr-in2-°R4 (value given in reference).

Results Comparison

TargetMechanical APDLRatio
Q, Btu/hr-in37.0[1]36.40.984

  1. Based on two cylinders 100 inches long.