Accounting for Sensor Errors in Estimation of Surface Heat Flux by an Inverse Method
Jonathan W. Woolley and Keith A. Woodbury
ASME Summer Heat Transfer Conference
Jacksonville, Florida, August 10 - 14, 2008
ABSTRACT
Thermocouples or
other measuring devices are often embedded into a solid to provide data for an
inverse calculation. It is well-documented that such installations will result
in erroneous (biased) sensor readings, unless the thermal properties of the
measurement wires and surrounding insulation can be carefully matched to those
of the parent domain. Since this rarely can be done, or doing so is
prohibitively expensive, an alternative is to account for the sensor dynamics
with an appropriate model.
In this paper we simulate a thermocouple embedded
in a sand mold near the interface of a solidifying aluminum casting.The effect of sensor errors is accounted for
by generating correction kernels from a detailed model of the embedded
thermocouple. The corrected sensor readings are used in the inverse heat
conduction solution. The magnitude of the effect is shown by comparing surface
heat fluxes computed with measured temperatures to the heat fluxes computed
with corrected temperatures.
