Numerical Study Of Radiative Transfer In Aero-Engine Combustor

Radiative heat transfer accounts for a large proportion of total heat flux from flame heat transfer in aero-engine combustion chamber with high-temperature and high-pressure. The accurate prediction of radiative heat transfer play an important role in designing, improving performance and combustion efficiency, prolonging liner life of aero-engine combustion chamber, and guarantee a highly efficient operation and flight security of an aero-engine. In this paper the radiative heat transfer is calculated using a numerical simulation in an aero-engine combustion chamber, the influences of operating parameters and liner wall oxidation of combustion chamber on radiative heat transfer and liner wall temperature are investigated.The research background and development status quo of radiative heat transfer in combustor were reviewed, the related theories and research methods of combustion phenomenon and flame radiation are simply introduced. The effects of combustor operating pressure, inlet air temperature, fuel property and fuel/air ratio on flame radiative property and wall radiative property of combustor on radiative heat flux and liner wall temperature are respectively discussed. Meanwhile, the change trend of combustor pollutant emissions is presented. The combustion phenomenon of combustor in this paper is a three-dimension two-phase turbulent non-premixed combustion, which is simulated by integrating Realizable k–εequations turbulent model with fast chemistry simplified PDF model. P-1 and DO radiation model are adopted respectively to predict the influence of operating parameters and wall radiative property of combustor on radiation heat flux. As for the formation models of pollutant, thermal NO and prompt NO are taken into consideration to evaluate NOx formation, and Khan and Greeves model is utilized to estimate soot formation.The results indicate that the changes of combustor operating pressure, inlet air temperature, fuel property and fuel/air ratio have significant influences on soot concentration and flame temperature, and lead radiation heat flux of combustor and liner wall temperature to increase drastically. Wall radiative property of combustor exerts a negligible influence on soot concentration and flame temperature, while radiation heat flux of combustor and liner wall temperature rise gradually with increasing wall oxidation, which are attributed to increasing absorptivity and decreasing reflectivity of liner wall.