Radiative heat transfer by solid suspension turbulent flow with radiating fluid in a circular tube with constant wall temperature

While the solid suspension medium acquires superior heat transfer characteristics under the condition of high temperature and high heat flux such as encountered with HTGR, a clear knowledge of the heat transfer mechanism and the quantitative evaluation of heat transfer seem to be insufficient. In the current study, an analysis has been performed on the heat transfer by a turbulent flow of radiating gaseous suspension in a circular tube with constant wall temperature, taking account of the thermal radiation to both particulate and carrier phases simultaneously. The complexities of the geometry and the flow mechanics are described by introducing plausible assumptions. The results reveal greatly improved heat transfer on account not only of the increased heat capacity of the flowing medium but also of the enhanced radiative heat transfer caused by the increment of the optical thickness for radiation. The results obtained here are also compared with those of a single phase flow of radiating medium, and a simplified treatment of heat transfer by gaseous suspension flow is presented to facilitate practical calculations. (author)