TURBULENCE RADIATION INTERACTION IN CONFINED COMBUSTION SYSTEMS

A new approach for modeling turbulence-radiation inter action is propo sed. The formulation is based upon equations for statistical moments. Additional to the balance equations for the velocity and mixture fr ac tion, equations for the mean, variance, covariance of heat release rat e, and mixture fraction is solved. The coupling with the chemistry mod el is formulated by means of a two dimensional pdf of mixture fraction and heat release race. The proposed approach is open for improvement by more sophisticated submodels. A natural gas fired combustion chambe r is designed and constructed, and the temperature field measured by C ARS spectroscopy. The main features of the modified combustion system are discussed. The comparison of experimental temperatures with the nu merical simulation of the combustion system shows the good quality of our approach. The modeling of the two dimensional pdf is found to be m ost suitable for the hot region near the burner, where most radiation effects take place.