Mechanical Engineering, University of Tabriz
The interaction of thermal radiation with conduction and laminar natural convection in a vertical circular pin, situated at participating gas, is numerically investigated. An absorbing and emitting gas is considered, and treated to be a gray participating media. Under the idealizing of gray gas, the Rosselan4 approximation is employed to describe the radiative heat flux in the energy equation. The modified box method with unequal grid spacing is used to perform the numerical computation of the coupled boundary layer conservation equations and pin conduction equation. The effects of buoyancy and radiation on the temperature, velocity, heat flux, and Nusselt number are examined in detail. The Nusselt number variation shows that heat transfer is enhanced by thermal radiation. Also, the local Nusselt number is found to be strongly dependent on the temperature ratio YT, radiation-conduction parameter YR, and conventional Gr and Pr numbers. Furthermore, the results are comparable with the available data in the literature for pure natural convection.