VM107

VM107
Thermocouple Radiation

Overview

Reference:A. J. Chapman, Heat Transfer, The Macmillan Co, New York, NY, 1960, pg. 396, article 13.5.
Analysis Type(s):Thermal analysis (ANTYPE = 0)
Element Type(s):
Radiation Link Elements (LINK31)
Convection Link Elements (LINK34)
Input Listing:vm107.dat

Test Case

A thermocouple is used to measure the temperature Tg of a gas flowing within a duct. The duct wall temperature is Tw and the thermocouple is placed at right angles to the flow. If the conduction effects are negligible, determine the thermocouple reading Tt and the heat flow rate q due to convection and radiation.

Figure 153: Thermocouple Radiation Problem Sketch

Thermocouple Radiation Problem Sketch

Material PropertiesLoading
ε = emissivity = 0.5
h = 11.85 Btu/hr-ft2-°F
Stefan-Boltzmann constant[1]
= 0.174 x 10-8 Btu/hr-ft2-°R4
Tw = 300°F
Tg = 1309°F

  1. As given in A. J. Chapman, Heat Transfer.

Analysis Assumptions and Modeling Notes

The temperature offset of 460°F is required to convert the input Fahrenheit temperatures to absolute (Rankine) temperatures. The node locations are arbitrarily selected (coincident).

Results Comparison

TargetMechanical APDL [1]Ratio
Tt, °F1000.00999.951.000
q, Btu/hr3661.653662.24 [2]1.000

  1. At node 2

  2. From solution output