The present work quantifies numerically the systematic errors present in experimental
infrared heat flux studies of boiling surfaces. A transient conduction model for multilayer
structures is proposed to describe the periodic heat fluxes encountered on boiling surfaces. The
results of the current work show that the systematic error behavior of the infrared method is
not uniform but dependent on the frequency of the heat flux signal of the boiling surface; which
is a novel finding. As the frequency of the heat flux signal increases, the errors in the measured
phase of heat flux signals are expected to increase. The errors in the amplitude of heat flux
signals sharply increase at low frequencies (1-10 Hz) and decrease as the frequency increases.
The maximum errors in the phase and amplitude of heat flux signals are 9% and 23%,
respectively in the frequency range of nucleate boiling (10-80 Hz). Based on the current
analysis, it is concluded that the systematic errors found arise from assuming that thermal
contact resistances of such systems are negligible. This is an assumption universally adopted
2
by the field. By considering and correcting for the thermal contact resistance in the
measurement of heat fluxes, the maximum errors in the phase and the amplitude of heat flux
signals can be reduced to 7% and 9%, respectively. The results are applied to experimental data
ensembles from the published public domain. Finally, the current work provides general
guidelines to improve systematic errors in the measurement of heat flux for the study of boiling
using infrared thermography found in the literature.