A nongray-wall emissivity model for the full-spectrum correlated k-distribution method based on uniform media assumption. (November 2021)

• Record Type: Journal Article
• Authors: Liu, Guanghai; Liu, Yuying; Liu, Fengshan; Consalvi, Jean-Louis; Xu, Jiale
• Is Part Of: International journal of heat and mass transfer. Volume 179(2021)
• Publication Date: 2021-11
• Subjects: Radiative heat transfer -- Full-spectrum correlated k-distribution -- Nongray-wall; FSCK full-spectrum correlated k-distribution -- HAPI HITRAN, application programming interface -- LBL line-by-line -- MSMGFSK multi-scale multi-group FSK -- NBCK narrow-band correlated k-distribution -- RTE radiative transfer equation -- SLW spectral-line-based weighted-sum-of-gray-gases -- SNBCK statistical narrow-band correlated-k -- SNB statistical narrow-band -- WBCK wide-band correlated k-distribution -- WSGG weighted-sum-of-gray-gases; Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Electronic journals; 621.4022
• DOI: 10.1016/j.ijheatmasstransfer.2021.121660
• Languages: English
• ISSNs: 0017-9310

Abstract

Abstract: The walls of high-temperature combustion devices are usually assumed to be black or gray in radiative heat transfer calculations to save computing resources; however, this simplification may introduce large errors. To improve the accuracy of the Full-Spectrum Correlated K -distribution (FSCK) method in calculations of nongray-wall radiative heat transfer problems without reducing the computational efficiency, a nongray-wall emissivity model for the FSCK method is proposed based on uniform-medium assumption. The accuracy of this nongray-wall emissivity model and the commonly used Planck-function-weighted gray-wall emissivity model is evaluated in 1D isothermal and homogeneous cases, 1D non-isothermal and inhomogeneous cases, and 3D flames bounded by walls coated with fly-ash deposit or soot deposit. The results show that the nongray-wall emissivity model for FSCK demonstrates much better accuracy than the gray-wall one, especially for cases of low wall temperatures. The nongray-wall emissivity model provides good accuracy over a wide range of optical depth, while the accuracy of the gray-wall emissivity model is highly dependent on the optical depth. The nongray-wall emissivity model based on the uniform-medium assumption can be applied to non-isothermal and inhomogeneous radiative heat transfer problems involving nongray walls.