Characteristic of TiO2-SiO2 Nanofluid With Water/Ethylene Glycol Mixture for Solar Application

Solar energy is a sustainable energy supply technology due to the renewable nature of solar radiation and the ability of solar energy conversion systems to generate greenhouse gas-free heat and electricity during their lifetime. In this study, an experimental investigation was conducted to explore the effect of hybrid nanofluids on heat transfer for solar application. An experiment was conducted for hybrid nanofluid concentrations starting from 0.3, 0.5, 0.7 and 1.0%. Each setup was exposed to short wavelength radiation under a solar simulator with 300, 500 and 700 W/m2 for 30 minutes, of which 15 minutes is the heating period and the next 15 minutes is for cooling. For solar radiation of 300 W/m2 within 15 minutes of charging process are 51.9 °C, 52.8 °C, 53.4 °C and 54.2 °C for concentration of nanofluids 0.3, 0.5, 0.7 and 1.0% respectively. The results for solar radiation of 500 and 700 W/m2 within 15 minutes almost the same pattern which is increasing during the charging process. It can be concluded that the higher concentrations of nanofluid give ample time to the test tube to transfer the heat and thus increased its temperature during the charging process.

Empirical Study of Solar Absorber Metamaterial Characterization in GHz and THz Regime

Advanced material such as composite material, metamaterial, nanomaterials and smart materials plays a significant role in degree of performance of any system as compared to conventional material and hence, they are commonly used in diverse applications such as aerospace, medical devices, sensor detection, smart solar application etc. Metamaterial is one of such artificial sub-wavelength materials to exhibit electromagnetic and optical properties that surpass or complement those accessible in nature. In this research paper, three structure of metamaterials are simulated for the solar application as an absorber to increase solar efficiency as well as to increase negative refractive index to represent wave propagation in different directions. From this study it can be concluded that all the three materials have reached maximum point of absorption in a narrow bandwidth and it is possible to obtain transverse magnetic wave if the materials are stacked. These materials can be used as frequency detector for THz applications.