Nanofluids are a potential alternative to significantly improving the performance of heat transfer applications. In this work, a numerical analysis to examine the eff ect of dispersing copper(Cu), copper oxide(CuO), a...Nanofluids are a potential alternative to significantly improving the performance of heat transfer applications. In this work, a numerical analysis to examine the eff ect of dispersing copper(Cu), copper oxide(CuO), and aluminum(Al2O3) nanoparticles in pure water on the performance of a flat plate solar collector(FPSC) and a numerical model was proposed. The influence of the nanofluid type on the thermal efficiency was critically investigated and discussed. The eff ect of the mass flow rate on the performance was also analyzed and discussed. Based on correlations of the thermophysical properties of nanofluids, a sensitivity analysis was used to analyze the impact of the nanoparticles on the base fluid. The results indicate that the performance of the FPSC with Cu/water nanofluid was better than that of FPSCs using CuO/water or Al2O3/water nanofluids. When the mass flow rate of the nanofluids was 8.0 L/min, the efficiency of the FPSC was much greater than those at the flow rates of 5.0 L/min and 2.0 L/min. Mean enhancements in thermal efficiency of 4.44%, 4.27%, and 4.21% were observed when 2.0 L/min was applied using Cu/water, Cu O/water, and Al2O3/water nanofluids, respectively. Improvements in thermal efficiency of 2.76%, 2.53%, and 2.47% occurred when 8.0 L/min was applied.展开更多
The characteristics of two different kinds of lignocellulosic materials(vegetable fillers)with two morphologies as Argania nut-shells(ANS)particles and Coir Fibers(CF)were used as reinforcement for phenolic resin(Bake...The characteristics of two different kinds of lignocellulosic materials(vegetable fillers)with two morphologies as Argania nut-shells(ANS)particles and Coir Fibers(CF)were used as reinforcement for phenolic resin(Bakelite)in this work,and the composite are studied as a function of filler types,shape,content(10,20,and 30%wt.percent)and manufacturing loading force(1500 and 3000 LBs).Compression molding was used to create the composites,which were then evaluated using Scanning electronic microscopy(SEM),Fourier-transform infrared spectroscopy(FTIR),bending,dynamic-mechanical-thermal and rheological studies.The morphology of broken samples demonstrates that both fillers are well dispersed and distributed.When fillers are added to the matrix,the flexural characteristics improve,and the optimal values are attained in the case of Argania nut-shells.The results showed that the kind and shape of the fillers had a direct influence on the dynamic mechanical characteristics of the composites due to the reinforcement's modulus augmentation.It was noticed that,the increment of manufacturing loading force decreased the mechanical and dynamical properties of composites.The optimum properties obtained indicate that the composites can only be manufactured at low manufacturing loading force(1500 LBs).展开更多
文摘Nanofluids are a potential alternative to significantly improving the performance of heat transfer applications. In this work, a numerical analysis to examine the eff ect of dispersing copper(Cu), copper oxide(CuO), and aluminum(Al2O3) nanoparticles in pure water on the performance of a flat plate solar collector(FPSC) and a numerical model was proposed. The influence of the nanofluid type on the thermal efficiency was critically investigated and discussed. The eff ect of the mass flow rate on the performance was also analyzed and discussed. Based on correlations of the thermophysical properties of nanofluids, a sensitivity analysis was used to analyze the impact of the nanoparticles on the base fluid. The results indicate that the performance of the FPSC with Cu/water nanofluid was better than that of FPSCs using CuO/water or Al2O3/water nanofluids. When the mass flow rate of the nanofluids was 8.0 L/min, the efficiency of the FPSC was much greater than those at the flow rates of 5.0 L/min and 2.0 L/min. Mean enhancements in thermal efficiency of 4.44%, 4.27%, and 4.21% were observed when 2.0 L/min was applied using Cu/water, Cu O/water, and Al2O3/water nanofluids, respectively. Improvements in thermal efficiency of 2.76%, 2.53%, and 2.47% occurred when 8.0 L/min was applied.
文摘The characteristics of two different kinds of lignocellulosic materials(vegetable fillers)with two morphologies as Argania nut-shells(ANS)particles and Coir Fibers(CF)were used as reinforcement for phenolic resin(Bakelite)in this work,and the composite are studied as a function of filler types,shape,content(10,20,and 30%wt.percent)and manufacturing loading force(1500 and 3000 LBs).Compression molding was used to create the composites,which were then evaluated using Scanning electronic microscopy(SEM),Fourier-transform infrared spectroscopy(FTIR),bending,dynamic-mechanical-thermal and rheological studies.The morphology of broken samples demonstrates that both fillers are well dispersed and distributed.When fillers are added to the matrix,the flexural characteristics improve,and the optimal values are attained in the case of Argania nut-shells.The results showed that the kind and shape of the fillers had a direct influence on the dynamic mechanical characteristics of the composites due to the reinforcement's modulus augmentation.It was noticed that,the increment of manufacturing loading force decreased the mechanical and dynamical properties of composites.The optimum properties obtained indicate that the composites can only be manufactured at low manufacturing loading force(1500 LBs).
