Combined turbulent forced convection and thermal radiation in a curved pipe with uniform wall temperature

摘要

This paper describes numerically investigated combined turbulent forced convective and radiative heat transfer of a participating medium in the entrance region of a curved pipe. The P-1 radiation model was applied to the combined convection-radiation simulations. The renormalization group (RNG) k-ε model was used to account for the turbulent flow and heat transfer in the curved pipe at a constant wall temperature. A control volume finite element method (CVFEM) with second-order accuracy was used to solve the three-dimensional full-elliptic governing equations. An unstructured (block-structured) nonuniform grid system was used to discrete the computation domain in this study. The numerical results for forced convective flow were in agreement with previous experiment data. This study explored the interaction phenomena between turbulent forced convection and thermal radiation in a participating medium inside a curved pipe at different temperature ratio, optical thickness, and wall emissivity. Based on the results of this research, the flow and thermal fields and Nusselt number distributions were presented graphically and analyzed.