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An experimental investigation was carried out in a wind tunnel in order to study the turbulent flow over a flat plate that is a scaledown of a photovoltaic (PV) panel. By inducing turbulence in the flow over a PV panel, its convective heat loss can be increased. The turbulence was generated by a plate with diamond-shaped perforations (grid), which was mounted vertically at the leading edge of the flat plate. Fourier and wavelet transforms are utilized to study the turbulence downstream of the grid at specific points. Results showed that at the height of the upper edge of the grid, turbulence has a higher kinetic energy than at the points behind the grid. For the points behind the grid, at all eddy size ranges, turbulence energy decayed significantly with downstream distance. For the points at grid height, it seems that for large eddies (frequency lower than 100 Hz) the energy increased in the downstream direction and for other ranges it decreased very slightly. This analysis may influence the design of passive flow devices meant to enhance the heat transfer from a PV panel’s surface.Copyright © 2014 by ASME |
