A method to measure heat flux in convection using Gardon gauge

Abstract

Heat flux measurements are widely used in thermal environment analyses. The Gardon gauge is an excellent heat flux sensor with a wide measurement range and long lifespan in harsh environments. However, the Gardon gauge is usually calibrated for radiation heat transfer and is not good for convective heat transfer. This paper introduces a method to measure heat flux for convective heat transfer using the Gardon gauge by relating the measurement sensitivity for convection to that for radiation. The heat flux and convective heat-transfer coefficient can then be simultaneously determined by the standard thermo-electromotive voltage output of the Gardon gauge. The method was demonstrated for convective heat-transfer coefficient ranging from 200 to 3000 W/(m 2 K). The analysis illustrates that the measurement sensitivity for convection decreases with increasing convective heat-transfer coefficient. A correction is necessary especially for higher convective heat-transfer coefficient. The corrected convective heat-transfer coefficients and heat fluxes agree well with the actual values. The relative uncertainty in heat flux is within 0.64%. The method not only greatly improves the measurement accuracy of the Gardon gauge for convection applications, but also provides a reference for evaluating convective heat transfer coefficients in convection environments.

Transient analysis of a circular foil gage in a convective and radiative environment

“…(34), have the same form. Equation (34) is also analogous to the results given in Kuo and Kulkarni [9] and Fu et al [10].…”

“…A one-dimensional transient heat conduction model was developed by Keltner and Wildin [7] to examine transient response of the gages. Borell and Diller [8], Kuo and Kulkani [9], and Fu et al [10] expanded the steady-state analysis of Gardon [1] by including convective heat transfer at the foil surface and provided calibration corrections for convective heat transfer. Recently, Fu et al [11] applied the Duhamel theorem to study Gardon gage exposed to fast heat flux transients.…”

A Mixed Radiative-Convective Technique for the Calibration of Heat Flux Sensors in Hypersonic Flow

“…The use of oxyacetylene flames to obtain very high heat flux has already been attempted in the past; only recently, however, some experimental results have appeared where their performances could be characterized with an acceptable level of accuracy [14,15].…”

“…9. With regard to these, we wish to highlight that a 'correction' has been applied to such measures (obtained using the aforementioned reference sensors GG01) following the theoretical-numerical arguments elaborated by Fu et al [15]. As sensor characteristic parameters to be used as an input for the application of such corrections, we have estimated d = 0.2 mm, R = 2.15 mm, and a heat sink temperature of T 0 = 30°C.…”

Analysis of Heat Gains from Flat Plate Heater Measured using Multi-Axis Heat Flux Sensors

“…Their objective is to improve the sensitivity and accuracy of heat flux sensors. In addition, another research work by Tairan Fu et al 6) measure convection heat flux with a radiometer. They used the Gardon gauge sensor as their heat flux sensor.…”