An experimental study to show the effect of forced vertical vibrations on the thermal heat transfer coefficient of a flat plate

Abstract

AbstractThe objective of this study is to conduct an experiment that considers the influence of vertical oscillations on the heat transfer coefficient of free convection in an aluminum flat plate component measuring 3 × 100 × 300 mm. The plate is subject to a steady-state heat transfer; whereby it experiences a sustained heat flux ranging from (250–1500) W/m2. The orientation of the flat plate can be either horizontal or inclined at particular angles, specifically at 0°, 30°, 45°, 60°, and 90°. The experimental tests conducted were characterized by an expanded frequency spectrum ranging from 2 to 16 Hz, a variable amplitude range spanning from 1.63 to 7.16 mm, and a range of Rayleigh number values upon activation of the system, with minimum and maximum thresholds of 138.991 and 487.275, respectively. The impact of vibration frequency upon both the amplitude and velocity of vibrations for a heat flow of 250 W/m2, situated at an angle of θ = 0°, was examined. The impact of the Reynolds number upon the total vibrational heat transfer coefficient, as well as the total Nusselt number, was investigated with and without the presence of angle vibration θ = 0°, across diverse degrees of heat flux. This study investigates the impact of the Rayleigh number on the overall Nusselt number under varying conditions of thermal flux, with and without the application of vibration at angles of θ = 30°, 45°, 60°, and 90°. The findings of this analysis demonstrate that there exists a discernible correlation between the incremental amplitude of vibration and the coefficient of heat transfer, manifesting as a negative slope within the range of 0° to 60°. Such correlation reaches its optimal magnitude of 13.2894% under the condition of flat vibration mode, whereas the coefficient of heat transfer declines progressively as vertical vibration is augmented, culminating in a maximum decline of 7.6475%. The present study reports a decrease in the overall vibrational heat transfer coefficient with increasing vibrational Reynolds number. The total Nusselt number was found to increase with or without vibration as the Rayleigh number increased.