Comparison of Wide Band, Narrow Band, and SLW Models with HITRAN and HITEMP for Predicting Radiative Heat Transfer

摘要

Accurate modeling of radiative heat transfer is critical to atmospheric science applications, as well as propulsion systems, including combustion chambers and rocket plumes. The objectives of this study are to: (1) predict radiative heat transfer using the wide band, narrow band, and global property models, and (2) compare the results obtained with those from line-by-line (LBL) simulations performed using HITRAN and HITEMP databases. The five radiative property models considered in the current study are the Exponential Wide Band Model (EWBM), Spectrally-Resolved Exponential Wide Band Model (SR-EWBM), Elsasser Narrow Band Model (Elsasser NBM), Malkmus Narrow Band Model (Malkmus NBM), and the Spectral Line Weighted-Sum-of-Gray-Gases (SLW) model. The problem considered consists of a non-gray, one-dimensional (1-D) enclosure containing H_2O with uniform temperature and species mass fraction. The radiative transfer equation (RTE) was solved using the Discrete Ordinates Method (DOM). First, the spectral absorption coefficients computed from these models are compared with the LBL data obtained using the HITRAN and HITEMP databases. The effects of varying the medium temperature and pressure, as well as the wall temperature, on the model predictions of radiative heat flux and its divergence are studied through comparison with the corresponding data obtained using HITRAN and HITEMP. For all of the medium temperatures and pressures considered, the SLW model predictions showed excellent agreement and Malkmus NBM showed reasonable agreement with the HITEMP data. At lower temperatures (and at constant pressure), the two wide band models and the Elsasser NBM showed reasonable agreement with HITEMP. At high temperatures (and at constant pressure), the SR-EWBM and the Elsasser NBM showed poor agreement with HITEMP. At low pressures (and at constant temperature), the two wide band models and the Elsasser NBM showed reasonable agreement with HITEMP. However, at high pressures, the EWBM showed poor agreement with HITEMP. Finally, we investigate DOM for a variety of cases, including isothermal, homogeneous, non-isothermal, inhomogeneous, and mixture cases for HITRAN and HITEMP. Two-dimensional domains, as well as additional spatial inhomogeneities in temperature and species concentrations, will also be considered in the near future.