Wide-band k distribution model for radiative characteristics of carbon dioxide

A novel wide-band k distribution model was established. The spectrum radiative characteristic parameters of carbon dioxide were obtained from a high-temperature gas database HITEMP. A correlation formula was used to perform a fitting of the absorption coefficient of main carbon dioxide spectrum band. The model in question was used to calculate the radiative heat flux of the carbon dioxide. A comparison was made with a line-by-line calculation method, statistical narrowband model, a narrow-band and a full-spectrum k distribution model. The results of the comparison show that for isothermal gases, the results obtained by using the wide-band k distribution model are in very good agreement with those obtained by using the line-by-line calculation method, even more accurate than those obtained by using the full-spectrum k distribution model. If the integration format is properly chosen, the wide-band k distribution model can attain a calculation accuracy higher than that of the statistical narrow-band model, but comparable to that of the narrow-band k distribution model. For non-isothermal gases between ash wall plates, the calculation error of the wide-band k distribution model is about 10% when its calculation results are compared with those of the line-by-line calculation method, thus greatly enhancing the calculation accuracy and speed of gas radiative characteristics.