Computational and PIV Analysis of the Fluid Flow in a Channel With an Oscillating Finned Surface

Experimental and CFD studies were performed to investigate the kinematics of flow resulting from oscillation of a finned surface in a duct. The experiments were performed with working fluid with a kinematic viscosity of 1.8×10⁻⁶ m²/s. A steady flow Reynolds number in the laminar range of 0 < Re < 400 was studied. The oscillation Reynolds number Re_osc was between the range of 50 and 1000. Oscillation amplitude range of 0.2 mm < A < 1.0 mm together with oscillation frequency in the range of 5 Hz < f < 90 Hz were employed. The acquired images were analysed using the particle image velocimetry (PIV) software. Three experimental conditions were studied, i.e. oscillating finned surface in a fluid at rest, steady finned flow and oscillating finned flow. CFD simulations were performed using the software suit CFX11 from ANSYS GmbH, Germany. The simulation results were compared with the PIV measurements using the time averaged velocity. The results of the visualization reveal periodic recirculation eddies around the fins which enhances the fluid mixing. The flow patterns and the crossflow effects depend on the geometries of the fins and the oscillation parameters. CFD results allow for performance predictions of different geometries and flow conditions. Enhanced heat transfer was obtained at moderate flow rates when applied in cooling system. Triangular finned geometry gives better performance.