ISSN Online: 2688-7231
ISBN Online: 978-1-56700-524-0
Proceedings of the 26thNational and 4th International ISHMT-ASTFE Heat and Mass Transfer Conference December 17-20, 2021, IIT Madras, Chennai-600036, Tamil Nadu, India
Forced Convection from Chains of Spheres
Operations involving clusters of particles moving together as agglomerates in fluid media are encountered in a plethora of industrial processes like drying operations, fluidized transportation, continuous thermal treatment of food stuff etc. to name a few. These agglomerates move through such fluids, affect the flow field and in turn, are affected by it in ways different than in the case of an individual particle. The present study is an idealization of the aforementioned situation in which a linear chain of heated spheres (1 ≤ N ≤ 20) is moving in a pool of air (Pr = 0.72) in laminar steady state flow (1 ≤ Re ≤ 100) conditions. The governing mathematical equations have been solved numerically employing finite element methodology subjected to appropriate boundary conditions. The effect of number of spheres in chain (N) as well as flow conditions (Re) on the hydrodynamics and thermal behaviour of the flow have been studied in detail. Developed flow field with increasing Re has been visualized by mapping vorticity contours and streamlines in the vicinity of the chain. The results on shape factor (λ) and average Nusselt Number (Nu) have been reported over the range of parameters considered in the present work. Finally, the functional dependence of drag correction factor λ and Nu on Reynolds number (Re) and number of spheres in the chain (N) have been established by simple expressions to facilitate interpolation to intermediate values of Re and N to enable a priory estimation in a new application.