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CFD Study of Heat Transfer in Power-law Fluids over Multiple Corrugated Circular Cylinders in a Heat Exchanger
  • Radhe Shyam,
  • Sonam Gopaldasji Rajpuriya
Radhe Shyam
National Institute of Technology Hamirpur

Corresponding Author:rshyam@nith.ac.in

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Sonam Gopaldasji Rajpuriya
National Institute of Technology Hamirpur
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Abstract

The heat transfer in power-law fluids across three corrugated circular cylinders placed in triangular pitch arrangement is studied computationally in a confined channel. Continuity, momentum and energy balance equations were solved using ANSYS FLUENT (Version 18.0). The flow is assumed to be steady, incompressible, 2D and laminar. A square domain of side 300 Dh is selected after detailed domain study. An optimized grid with 98187 cells is used in the study. The convergence criteria of 10 -7 for the continuity, x-momentum and y-momentum balances and 10 -12 for energy equation were used. Constant density and non-Newtonian power-law viscosity modules were used. Diffusive term is discretized using central difference scheme. Convective terms are discretized using Second Order Upwind (SOU) scheme. Pressure-velocity coupling between continuity and momentum equations was implemented using the SIMPLE (Semi-Implicit Method for Pressure Linked Equation) scheme. Streamlines show wake development behind the cylinders, which is much dominant at large ReN and n. Isotherm contours are cramped at higher values of ReN and PrN, implying higher heat transfer. Global parameters like Cd and Nu are computed for the wide ranges of controlling dimensionless parameters, such as power-law index (0.3 ≤ n ≤ 1.5), Reynolds (0.1 ≤ ReN ≤ 40) and Prandtl numbers (0.72 ≤ PrN ≤ 500). The NuLocal plot attains a pitch near corrugation of surface due to abrupt change in velocity and temperature gradients. Nu increases with ReN and/or PrN and decreases with n under otherwise identical situations. Nu is correlated with pertinent parameters, namely, ReN , PrN and n.
Submitted to Heat Transfer
24 Feb 2024Reviewer(s) Assigned
28 Mar 2024Review(s) Completed, Editorial Evaluation Pending
29 Mar 2024Editorial Decision: Revise Minor
26 May 20241st Revision Received
26 Jun 2024Review(s) Completed, Editorial Evaluation Pending
26 Jun 2024Editorial Decision: Revise Minor
02 Jul 20242nd Revision Received
10 Jul 2024Review(s) Completed, Editorial Evaluation Pending
10 Jul 2024Editorial Decision: Accept