A comparative study on thermal and flow fields in glazed wavy and flat plate solar collectors utilizing nanofluid

الملخص EN

A numerical investigation of steady two dimensional laminar natural convection heat transfer in plain and wavy solar collector is presented in this work.

The parameters adopted are Rayleigh number range (103 to 106), aspect ratios (2, and 4) for wavy enclosure with number of undulation (1 to 4), and nanofluid volume fraction range (0 to 10%).

The continuity, Navier-Stokes and the energy equations are solved by utilizing (FLUENT 6.3) software which is based on the finite volume method.

SIMPLE algorithm with upwind scheme is adopted to compute the velocity components, temperature, pressure and Nusselt number (local and average).

This study considers the effect of different boundary conditions on the heat transfer within the air space above the absorber and base fluid or nanofluid below the absorber.

It is found that, the heat transfer rate increases with increasing Rayleigh number.

The Nusselt number increases with increasing volume fraction in plain enclosure.

Nu No.

increases with increasing volume fraction.

It is found that the heat transfer in plain enclosure decreases as aspect ratio increasing, while it increases in wavy enclosure.

The maximum heat transfer occurs when the wavy is designed with two undulations for pure fluid and one undulations for nanofluid.

The results show that the Nusselt number in wavy collector is higher than that of flat collector.