Department of Mechanical Engineering, IIT Ropar, Rupnagar-140001, India; Department of Mechanical Engineering, Manipal University Jaipur, Jaipur-303007, India
Department of Mechanical Engineering, IIT Ropar, Rupnagar-140001, India
Sarit K. Das
Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India
The present study focused on simultaneously hydrodynamically and thermally developing regime of laminar mixed convection for the investigation. Numerical simulations of buoyancy- aiding and -opposing flow have been performed to understand the heat transfer, pressure drop and flow characteristics of air in a vertical channel subjected to uniform heat flux from the side walls. Two-dimensional steady state simulations are performed in ANSYS-Fluent for a length-to-width (L/H) ratio of 50. The structured mesh was generated with uniform grids in axial and non-uniform in transverse directions. The effects of Reynolds number (100 ≤ Re ≤ 2300), Grashof number (103 ≤ Gr ≤ 5.29 * 105) on fluid flow and heat transfer respectively are studied. The corresponding range of Richardson number (Ri) is 1 to 1.5. In case of assisting flow, it has been observed that the velocity is accelerated near the wall compared to the center of the channel. In contrast, velocity is accelerated at the center as compared to the wall in case of opposing flow. The pressure drops as well as heat transfer is higher in assisting flow as that of the opposing flow for a fixed Ri and Re. Further, it has been inferred from the results that the hydrodynamic and thermal entry length are dependent on Gr.