Thermal radiaton effects of a high-temperature developing laminar flow in a tube

The thermal radiation effects of a high-temperature developing laminar flow in a tube are investigated numerically. The two-dimensional steady flow and heat transfer are considered for an absorbing-emitting gray medium, whose density is dependent on the temperature. The governing equations of the coupled process are simultaneously solved by the discrete ordinate method combined with the control volume method. For a moderate optical thickness, the velocity distribution, the temperature distribution, and the radial heat flux distribution in the medium as well as the heat flux distribution oil the tube wall are presented and discussed. The results show that the thermal radiation effects of a high-temperature medium are significant under a moderate optical thickness. The flow and convective heat transfer are weakened, and the development of temperature distribution is accelerated noticeably.