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Influence of participating media on the Radiation Thermometry for Surface Temperature Measurement

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Journal of Thermal Science 2005年第4期14卷 368-373,381页

作者： Yuying LIU Xinxin ZHANG Department of Thermal Engineering School of Jet Propulsion Beijing University of Aeronautics andAstronautics Beijing 100083 Department of Thermal Engineering School of Mechanical Engineering University of Science andTechnology Beijing Beijing 100083

A temperature measurement model of radiation thermometry for the surface covered by participating media was developed. The model was based on the radiation heat transfer of participating media and principles of radiation pyrometers, and solved by integral formulation of discrete ordinate method on spectral waveband. The influence of water mist on the indicated temperature of Raytek MR1SB one/two color pyrometer was discussed. Mie theory was used to calculate the radiative properties of water mist. In order to verify the model, a laboratory temperature measurement experiment was executed. The result shows that temperature of radiation thermometry is sensitive to the spectral response wavelength of pyrometer, and the simulated temperature of pyrometer agrees well with the experimental measurements on a suitable wavelength. The simulated temperature was lower than the real temperature of surface for one-color pyrometer, and it could be higher or lower than the real one for two-color pyrometer with the influence of participating media.

关键词： participating media radiation thermometry surface temperature measurement discrete ordinatemethod.

Efficient participating media rendering with differentiable regularization

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Computational Visual media 2024年第5期10卷 937-948页

作者： Wenshi Wu Beibei Wang Milos Hasan Lei Zhang Zhong Jin Ling-Qi Yan School of Computer Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China Adobe Research San JoseCA 95110-2704USA Department of Computing Hong Kong PolytechnicUniversityHong Kong 999077China Department of ComjouterScience University of California Santa BarbaraCA 93106USA.

Highly scattering media,such as milk,skin,and clouds,are common in the real *** participating media is challenging,especially for highorder scattering dominant media,because the light may undergo a large number of scattering events before leaving the *** Carlo-based methods typically require a long time to produce noise-free *** on the observation that low-albedo media contain less noise than high-albedo media,we propose reducing the variance of the rendered results using differentiable *** first render an image with low-albedo participating media together with the gradient with respect to the albedo,and then predict the final rendered image with a low-albedo image and gradient image via a novel prediction *** achieve high quality,we also consider the gradients of neighboring frames to provide a noise-free gradient ***,our method can produce results with much less overall eror than equal-time path tracing methods.

关键词： participating media differentiable regularization differentiable rendering volumetric path tracing temporal denoising

A survey on rendering homogeneous participating media

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Computational Visual media 2022年第2期8卷 177-198页

作者： Wenshi Wu Beibei Wang Ling-Qi Yan School of Computer Science and Engineering Nanjing University of Science and TechnologyNanjingChina University of California Santa BarbaraUSA

participating media are frequent in real-world scenes,whether they contain milk,fruit juice,oil,or muddy water in a river or the *** light interacts with these participating media in complex ways:refraction at boundaries and scattering and absorption inside *** radiative transfer equation is the key to solving this *** are several categories of rendering methods which are all based on this equation,but using different *** this paper,we introduce these groups,which include volume density estimation based approaches,virtual point/ray/beam lights,point based approaches,Monte Carlo based approaches,acceleration techniques,accurate single scattering methods,neural network based methods,and spatially-correlated participating media related *** well as discussing these methods,we consider the challenges and open problems in this research area.

关键词： participating media Monte Carlo methods rendering volume density estimation

Prediction of the coupled heat radiation and conduction parameters and boundary condition using the unscented Kalman filter

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Science China(Technological Sciences) 2020年第3期63卷 422-433页

作者： WEN Shuang QI Hong WANG YiFei REN YaTao WEI LinYang RUAN LiMing School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China Key Laboratory of Aerospace Thermophysics Ministry of Industry and Information TechnologyHarbin 150001China

The boundary emissivity, thermal conductivity, and boundary time-varying heat flux in the participating media are retrieved in this work. In the forward model, the coupled radiation-conduction heat transfer in the participating medium is resolved by the finite volume method combined with discrete ordinates method. The inverse model utilizes the temperature signals at the appropriate position of the medium as the known information and uses the unscented Kalman filter(UKF) as an optimization tool to reconstruct the boundary emissivity, thermal conductivity, and boundary time-varying heat flux. It is found that when the emissivity, thermal conductivity, and boundary time-varying heat flux are reconstructed simultaneously, only the temperature information of two locations is required. The influence of the measurement noise, sampling interval, absorption coefficient,process noise covariance, measurement noise covariance on the accuracy and stability of the retrieval results is investigated in detail. All the reconstruction results indicate that the UKF technique is effective and robust for estimating the photothermal parameters and boundary condition of the radiation-conduction heat transfer problems.

关键词： inverse heat transfer thermal conductivity boundary emissivity time-varying heat flux unscented Kalman filter participating media