cfd simulation and experimental validation for wall effects on heat transfer of finite cylindrical catalyst

in this paper, heat transfer of single cylindrical particle affected by wall has been investigated numerically and experimentally for reynolds number range 2000 to 6000. the heat transfer in two different orientations, axial and cross flow over the particle has been considered in simulation with multiphysics software femlab version 2.3. the heat and mass transfer analogy technique has been applied for validation of the simulation results. the coated particle with naphthalene was sublimated to obtain the corresponding sherwood numbers. the results show that the cfd model can predict the particle-to-fluid heat transfer for two situations due to trivial error (an average error of 6%) compared to experimental values. influence of wall on heat transfer of particle in seven different bed-to-cylinder diameter ratio (n = 1.66, 2.65, 2.75, 5, 6.66, 12, and 18) have been discussed in different velocities. according to obtaining results, with increasing the bed-to-cylinder diameter ratio over the 12 wall have no significant consequence on nusselt number. due to this fact, a cfd based correlation has been proposed to consider the wall effects on particle-to-fluid nusselt number with an average error of 2.19%.