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
Numerical Study of Heat Transfer Characteristics in Helical Coils with Sinusoidal Wavy Walls
Thermo-hydraulic performance analysis of a helical coil made up of a sinusoidal wavy wall channel is presented. Steady, laminar, incompressible flow in this novel helical coil has been carried out using SIMPLE algorithm- based finite volume solver. A comprehensive parametric study has been performed to investigate the influence of aspect ratio and waviness (3 or 4 periodic modules) of the channel on the thermo-hydraulic behavior. A sinusoidal wavy wall is provided on a helical coil with a mean helix diameter 0.2 m having a hydraulic diameter of 0.024 m has been chosen for the numerical study for 50≤Re≤300 with water as the working fluid. Asymmetry of the Dean vortices plays a vital role in performance enhancement. A helical channel with 3 periodic module wave units exhibits better heat transfer characteristics with less pressure drop for Re<200; whereas 4-periodic module perform better for Re>200. This unique helical path mechanism attributes additional fluid advection, boundary layer thinning, and sharper temperature gradients near boundaries that favors heat transfer.