VISUALIZATION AND SIMULATION OF THE NATURAL-CONVECTION FLOW ABOVE HORIZONTAL WAVY PLATES

Abstract

An experimental and numerical study of internal laminar natural convection above horizontal wavy plates subject to a uniform and constant heat flux density is performed in this article. The flow movements are visualized by using the laser tomography technique. Surface temperature are measured by using the infrared thermography technique. Amplitudes and periods of the sinusoidal protuberances vary respectively from 6 to 24 mm and from 18 to 54 mm, and the modified Rayleigh numbers vary between 10 6 and 4 2 10 8 . Two structures of the flow movement are noticeable. They are respectively characterized by the presence or by the absence of recirculating movement of the air above the heated plate. The occurrence of each type of structure is correlated with the surface parameters and with the modified Rayleigh number values.