The Study For The Application Of Narrow Band Model On Gas Radiation

Generally, we account the gas medium transparent, so gas radiation is always ignored. However, under high temperature combustion conditions, gas radiation is very important in the total heat transfer. The purpose of this dissertation is to study the application of narrow band model on gas radiation.The main points in the dissertation are as follows:(1) The dissertation Analyses the properties of gas radiation, and the computation of optical depth and Planck function. The dissertation analyses the agency of the rate of radiation convection in heat transfer as well.(2) The dissertation analyses the applicability of three models of gas radiation computation: the gray model, the narrow band model and the wide band model, and analyses the normal method of using them.(3) The dissertation calculating the spectral intensity and transmittance along the wavelength, using narrow band model, according to the physical property, as well as the total directional radiated energy flux. While the gas medium is isothermal uniformed, the dissertation calculates the effective absorption coefficient, the Planck-mean absorption coefficient and the wall-incident mean coefficient.(4) The dissertation outlines the volume, unit and style of input and output parameter in the program, and plots curves according to the output parameter, illustrates the fine of the study. The dissertation also plots curves after changing the temperature or the volume fraction of soot, and compares to the one before changed. And the dissertation compares the outcome to the data of Hottel and Ludwig.