S. Harikrishnan and Shaligram Tiwari* Pages 326 - 331 ( 6 )
Background: Wavy channels are considered to be an effective passive method for heat transfer enhancement and are widely used in different heat exchanger devices. Various relevant papers and patents report significant increase in convective mixing of the fluid in the wavy channel when it is operated in unsteady flow regime. Consequently, a significant amount of research has been devoted to unsteady flow regimes of wavy channels to better understand the physical mechanism behind the enhancement in heat transfer.
Objective: To find the role of monitoring point in predicting flow regimes for periodically fully developed flow conditions in a biconvex module of sinusoidal wavy channel.
Methods: In the present study, two-dimensional numerical investigations are carried out to identify the flow regimes for periodically fully developed flow in sinusoidal wavy channels. Computations are carried out using commercial software ANSYS Fluent 17.2. Time signal analysis is carried out for four different points in the flow domain to understand the flow regimes indicated by the points.
Results: Detailed temporal variation of x-velocity, its power spectral density and phase space trajectories are presented to understand the flow regimes indicated by the four different points. Even though power spectral density shows difference in nature of velocity signals at the four locations considered, for the three different Re values, phase trajectories illustrate near similar flow regimes.
Conclusion: Phase space trajectories of four different points indicate that monitoring velocity at any point in the domain is enough to predict the flow regimes in periodically fully developed flow.
Fast Fourier Transform, flow transition, phase space trajectories, sinusoidal wavy channel, time signal analysis, unsteady flow.
Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai-600036, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai-600036