A NEW NUMERICAL METHOD FOR RADIATION IN PARTICIPATING MEDIA IN COMBINATION WITH CFD CALCULATION FOR OTHER MODES OF HEAT TRANSFER A

A new radiation met hod is proposed for modeling the radiative heat transfer within combustion chambers. This method can obtain temperature profiles and heat transfer in an emitting, absorbing and scattering media of non-uniform absorptivity. In this study, the method has been tested in a two-dimensional geometry, but the approach can be applied also in three-dimensional cases. The information of the velocity field and gas composition is provided by CFD calculation (i.e. FLUENT software). Due to the demands of the theory, a new exchange factor is defined between each pair of the volume and surface cells in the system. A new set of equations for these exchange factors between infinitely long narrow surfaces and an infinite line source of gas has been provided and used during the new method calculation. The new radiation source values, which have been calculated by using the new approach, will replace old ones in the FLUENT for attaining more accurate results until a certain convergence limit is reached. This new approach can be fitted with other modern numerical methods of computation fluid dynamics. Giving a good understanding of the angular behavior of radiative intensity in each point of the gas will be another advantage of using this approach. The results of the method have been confirmed by comparing them with the results of other numerical methods in radiation modeling, such as the Discrete Ordinate Method, Direct Transfer Radiation Method, etc.

Keywords:

Radiation Heat Transfer , Numerical Modeling , Computational Fluid Dynamics , Furnace