Absortivity Correlation for CO₂ at Elevated Pressures by Employing Tree Regression Analysis and Logistic Dose Functions

Gas turbine inlet temperatures have reached, for special applications, values near to 1700K, as a result, radiative effects must be considered in heat transfer studies. In consequence, optical properties estimation has to be faced, which has increased the complexity of the correlation currently used. An absortivity correlation for CO₂ at low resolution spectra, available from literature, for high pressure by employing a tree regression analysis and logistic dose function approach is presented therein. The model applied for the spectral range of 2μm to 15μm and for pressures in the range of 0.5 atm to 10 atm and for temperatures in the range of 294K to 1390K. Associated error is compared with Hottel emissivity and high resolution line spectra data base (HITRAN).