Natural convection induced by absorption of solar radiation in the near shore region of lakes and reservoirs: Experimental results

Natural convection induced by absorption of solar radiation in the near shore of lakes and reservoirs with a sloping bed is investigated experimentally utilising an open top triangular tank and a light source to simulate solar radiation. The present experimental investigation aims to examine the flow quantitatively for experimental parameters up to Rayleigh numbers one order of magnitude greater than that reported by Lei and Patterson (2002). Concurrent shadowgraph/Particle Image Velocimetry (PIV) technique is used to characterise the flow quantitatively for a number of experimental cases. Three temporal flow stages, initiation, transitional and quasi steady are identified and three spatial sub-regions, conductive, stable convection and unstable convective, are observed, consistent with previous scaling and numerical results. Scales for the onset of instability, velocities along the slope and the movement of the plumes are also verified by the experiments.