TCP-UQ: two-color pyrometry uncertainty quantification using high speed color cameras

Abstract In this study, an uncertainty quantification method is developed for two-color pyrometry (TCP-UQ), using high-speed color cameras. A NIST traceable calibrated light source is used and the relative exposure is determined using spectrometer measurements and color camera response functions. The inherent digitization and noise uncertainty is estimated from a set of calibration images and characterized with probability distribution functions. These uncertainties are then propagated during TCP to two quantities of interest: the temperature and soot volume fraction measurements. TCP-UQ is applied to a polymethyl methacrylate slab burner experiment to determine the temperature and the soot volume fraction fields. Temperature measurements ranged from 2300 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">K</mml:mi> </mml:mrow> </mml:mrow> </mml:math> to 2800 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">K</mml:mi> </mml:mrow> </mml:mrow> </mml:math> , soot volume fractions are recorded between 0.5 and 10 ppm and are in good agreement with prior measurements reported in the literature. The newly developed TCP-UQ allows for uncertainty estimations in the temperature and the soot volume fraction measurements to be associated with variations in the pixel intensities. For the slab burner experiment, the average uncertainty in the temperature is between 120–140 K and the average uncertainty in the soot volume fraction is around 0.1 ppm. Generally, higher pixel intensities corresponded to lower uncertainty in the temperature measurement.