Pulsating flow effects on convection heat transfer in a corrugated channel: A LBM approach

At the present study, the effects of the pulsating flow on forced convection in a corrugated channel are investigated using Lattice Boltzmann Method (LBM) based on Boundary Fitting Method (BFM). The dimensionless frequency of pulsating velocity (at a form of Strouhal number) and oscillation amplitude are studied at a wide range (0.05 ≤ St ≤ 1 and 0 ≤ Apulse ≤ 0.25) which Apulse = 0 represents the steady constant flow. The study is carried out for different Reynolds numbers (50, 100 and 150) when the Prandtl number is equal to 3.103. Temporal variations of streamlines, isotherms, and relative pressure drop and Nusselt number are presented for appropriate dimensionless groups. Also, the time-averaged values of Nusselt number and relative pressure drop along a pulse period time are calculated and presented in the form of relevant correlations aspect to the Strouhal number. The results show that the role of flow pulsation on the heat transfer enhancement on the target surface is highly dependent on pulsating velocity parameters. It is found that the variation of heat transfer rate according to Strouhal number has an extremum peak. In this extremum value pulsating velocity gradient has best effects on heat transfer rate and heat transfer rate start to drop for higher frequencies.