Department of Mathematics, Bangladesh University of Engineering & Technology, Dhaka-1000, Bangladesh.
This work compares heat loss characteristics across a riser pipe of a flat plate solar collector filled water based nanofluid of double nanoparticles (alumina and copper) with single nanoparticle (alumina). Also this study compares heat transfer phenomena among four nanofluids namely water-copper oxide, water-alumina, water-copper and water-silver nanofluids. Comparisons are obtained by numerically solving assisted convective heat transfer problem of a cross section of flat plate solar collector. Governing partial differential equations are solved using the finite element simulation with Galerkin’s weighted residual technique. The average Nusselt number (Nu) at the top hot wall, average temperature (θav), mean velocity (Vav), percentage of collector efficiency (η), mid-height dimensional temperature (T) for both nanofluid and base fluid through the collector pipe are presented graphically. The results show that the better performance of heat loss through the riser pipe of the flat plate solar collector is found by using the double nanoparticles (alumina and copper) than single nanoparticle (only alumina). When comparing the four nanofluids considering the same solid volume fraction ( = 5%), this study claims that the average Nusselt number for water-Ag nanofluid is higher than others.