An improved model to calculate radiative heat transfer in hot combustion gases

Abstract

Radiative heat transfer plays an important role in the chemical reactions in the combustor. The widely used WSGG model proposed by Smith is established for normal pressure, which shows inevitable computational errors when dealing with radiative heat transfer problems at reduced or elevated pressures. In this paper, an improved global model is established to calculate the radiant energy exchanges between combustion gases and combustor chamber walls. Compared with the Smith model, the new model shows better performance in a wide range of pressure regions. The model accuracy is examined by computing the emissivity, radiative heat flux as well as the radiative source of H₂O–CO₂ gas mixtures at different pressure values. Finally, the radiative heat transfer inside a 3D TBCC(turbine-based combined cycle) engine exhaust system where strong gradients of pressure and temperature exist, is also addressed. The computational results show that the developed model provides approximate results at much less computational costs than the high-precision MSMGFSK-c8 model, which makes it competitive in complicated combustion systems.

Keywords:

• thermal radiation
• heat flux
• heat source
• combustion gas
• pressure region

Acknowledgements

The authors are grateful to the good study environment in Science and Technology on Optical Radiation Laboratory as well as the school of energy and power engineering of Beihang University.

Disclosure statement

No potential conflict of interest was reported by the author(s).