Article ID Journal Published Year Pages File Type
670156 International Journal of Thermal Sciences 2011 13 Pages PDF
Abstract
This work compares experimentally the effectiveness of substituting the water-based suspensions of Al2O3 nanoparticles (nanofluid) and of micro-encapsulated phase change material particles (PCM suspension) for the pure water for laminar forced convective cooling through an iso-flux heated circular horizontal tube. Convection heat transfer experiments have been undertaken for the tube using the pure water, the PCM suspensions (ωPCM = 2, 5, and 10 wt.%) and the nanofluids (ωnp = 2, 6, and 10 wt.%) as the working fluids under the following operating conditions: the volume flow rate Q = 25-240 cm3/min (the Reynolds number Ref = 195-1801), the heating power applied at the outer wall of the tube qo = 20, 30, 40 W, and the inlet fluid temperature Tin = 32.8-33.2 °C. In addition, a scale analysis together with integral energy balance is presented concerning thermally developing heat transfer characteristics of the water-based suspension flow in the tube. The convective cooling performance of the water-based suspensions was gauged in terms of local and surface-averaged temperature control effectiveness along the tube wall compared with that obtained for the pure water. Furthermore, the water-based suspensions were compared based on the figures of merit for their heat transfer performances against the corresponding pressure drop penalty.
Related Topics
Physical Sciences and Engineering Chemical Engineering Fluid Flow and Transfer Processes
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