Correcting lateral heat conduction effect in image-based heat flux measurements as an inverse problem

Liu, Tianshu; Wang, Bo; Rubal, Justin; Sullivan, John P.

doi:10.1016/j.ijheatmasstransfer.2010.10.027

Cited by 23 publications

(2 citation statements)

References 38 publications

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“…The Image Processing Toolbox includes built-in functions that deconvolve an image with a pointspread function (PSF) that describes the blur in order to produce a deblurred image; the deconvwnr function was employed here [24]. Reference [25] describes the mathematics of image deconvolution for a similar application, heat diffusion in temperature-sensitive paint modeled by a Gaussian PSF. The PSF for the blurred rotor was constructed as follows.…”

Section: Image Deblurringmentioning

confidence: 99%

Motion-deblurred, fast-response pressure-sensitive paint on a rotor in forward flight

Juliano

Disotell

Gregory

et al. 2012

Meas. Sci. Technol.

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A pressure-sensitive paint (PSP) system capable of measuring the global, unsteady pressure distribution on a rotating surface without resorting to phase averaging is applied to a two-bladed model propeller in edgewise freestream flow. A gated lifetime-based technique captures the paint luminescence after a single pulse of high-energy laser excitation, yielding a signal-to-noise ratio sufficient to avoid image averaging. The selection of a porous polymer/ceramic matrix base with platinum tetra(pentafluorophenyl) porphyrin (PtTFPP) as the luminophore afforded high frequency response and pressure sensitivity, but the long lifetime of PtTFPP caused blurring in the long-exposure image of the rotating blade. An approach to deblurring based on the lifetime of the paint and surface motion is described and validated by results obtained from a disc of 17.8 cm diameter spinning at 70 Hz. An infrared camera recorded wind-on and -off temperature maps to provide a temperature correction for the PSP. The single-shot PSP technique with motion deblurring and temperature correction is then applied to a vertically mounted model propeller with a 25.4 cm diameter and 10.2 cm pitch. Surface pressure maps for the advancing and retreating blades are presented for a spin rate of 70 Hz and advance ratio of 0.3. The higher suction peak and other features on the advancing blade due to its larger effective velocity are detected by the paint system, while the retreating blade shows a qualitatively different distribution.

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Section: Image Deblurringmentioning

confidence: 99%

Motion-deblurred, fast-response pressure-sensitive paint on a rotor in forward flight

Juliano

Disotell

Gregory

et al. 2012

Meas. Sci. Technol.

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“…The method based on the discrete Fourier law for a data reduction model [20] is relatively accurate for a base with high thermal conductivity, assuming that the base temperature equals the initial temperature after a short amount of time. In contrast with the above data reduction model, Liu et al [21][22][23][24] offered a systematic analysis for determining surface heat flux in TSP measurements by developing an exact one-dimensional analytical inverse solution as well as a series of correction methods for the effects of lateral heat conduction, temperature-dependent thermal diffusivity and other factors. Cai et al [25] proposed a numerical method based on an iterative algorithm to solve inverse problems with temperature-dependent thermal properties.…”

Section: Introductionmentioning

confidence: 99%

Apparent temperature in temperature-sensitive paint measurement and its effect on surface heat flux determination for hypersonic flows

Liu

Shao

Zhou

et al. 2020

Meas. Sci. Technol.

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Non-zero temperature gradients in temperature-sensitive paint (TSP) cause the apparent temperature (the temperature measured by the TSP) to correspond to the temperature somewhere inside the TSP, which does not equal the top surface temperature. Treating the apparent temperature as the average temperature across the TSP layer is not always accurate, especially when there is a large temperature gradient in the TSP. In this paper, the apparent temperature is theoretically derived by integrating the luminescent intensity across the TSP layer and numerically determined using a Monte Carlo ray-tracing method. The results of a simulation show that the difference between the apparent and average temperatures increases with the temperature gradient in the TSP layer, which leads to a non-negligible error when determining the surface heat flux based on the average temperature. A modified Levenberg–Marquardt algorithm is used to accurately recover the surface heat flux based on the apparent temperature for typical optical conditions in the measurement system. The results are compared with those obtained using the average temperature of the TSP. The effects of heat flux, TSP thickness and base material on the errors in the determination of the heat flux are investigated in detail.

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Applications of TSP

Liu

Sullivan

Asai

et al. 2021

Experimental Fluid Mechanics

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Correcting lateral heat conduction effect in image-based heat flux measurements as an inverse problem

Cited by 23 publications

References 38 publications

Motion-deblurred, fast-response pressure-sensitive paint on a rotor in forward flight

Motion-deblurred, fast-response pressure-sensitive paint on a rotor in forward flight

Apparent temperature in temperature-sensitive paint measurement and its effect on surface heat flux determination for hypersonic flows

Applications of TSP

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