Optimizing the system structure and introducing beam splitting technology are effective strategies for enhancing the operational performance of concentrating solar photovoltaic/thermal (PV/T) systems. In this study, a...
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Optimizing the system structure and introducing beam splitting technology are effective strategies for enhancing the operational performance of concentrating solar photovoltaic/thermal (PV/T) systems. In this study, a twostage concentrating PV/T system based on beam splitting is proposed, and the system is analyzed using a fully coupled optical-thermal-electrical method. First, the reliability of the established discrete ordinates (DO) radiation model is verified using the Monte Carlo Ray Tracing (MCRT) method. Next, the obtained quantitative results are applied as a volumetric heat source in a 3D flow heat transfer model. Finally, the operational characteristics of the two-stage concentrating nanofluid PV/T system under various operating conditions are investigated parametrically. The results demonstrate that the radiative fluxes obtained from the 2D DO radiation model are in good agreement with those derived from the MCRT method. Under the series operating condition of the 3D flow heat transfer model, the electrical efficiency of the PV subsystem is 22.13 %, the thermal efficiency of the integrated system is 71.85 %, and the exergy efficiency is 20.77 %, with a nanofluid inlet temperature of 25 degrees C and an inlet mass flow rate of 0.03 kg/s. This study also evaluates the system's operating efficiency under series and parallel configurations, showing that the series configuration achieves higher exergy efficiency, while the parallel configuration enhances the thermal efficiency of the system.
The photothermal self-driving process of Janus microparticles has wide application prospects in the fields of *** silica and gold have good biocompatibility and high photothermal conversion efficiency,the SiO_(2)@Au J...
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The photothermal self-driving process of Janus microparticles has wide application prospects in the fields of *** silica and gold have good biocompatibility and high photothermal conversion efficiency,the SiO_(2)@Au Janus microparticles are widely used as drug *** on the multiphysics coupling method,the photothermal self-driving process of SiO_(2)@Au Janus microparticles was investi-gated,wherein the substrate was SiO_(2)particles and one side of the particles was coated with gold *** a continuous wave laser with irradiation of 20 W/cm^(2),the distance covered by the Janus particles was increased by increasing the thickness of the gold film and reducing the size of the SiO_(2)particles;the self-driving characteristics of the Janus particles were controlled substantially by increasing the intensity of the incident *** on the simulation results,the thermophoretic motion and Brownian motion of particles can be measured by comparing the absolute values of the thermophoretic force impulse,Brownian force impulse,and drag force *** Brownian force acting on Janus microparticles under low laser power cannot be ***,the minimum laser power required for Janus particles to overcome Brownian motion was *** results can effectively guide the design of Janus particles in biomedicine and systematically analyze the mechanism of particle thermophoretic motion during drug delivery.
During the flight of a hypersonic vehicle, a plasma sheath will be produced around the vehicle due to the effect of the shock layer. Because the plasma sheath will absorb, reflect, and scatter electromagnetic waves, w...
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During the flight of a hypersonic vehicle, a plasma sheath will be produced around the vehicle due to the effect of the shock layer. Because the plasma sheath will absorb, reflect, and scatter electromagnetic waves, which causes the communication signal to be attenuated or even interrupted, forming a communication "blackout." In this article, the plasma sheath is illuminated by a high-power microwave (HPM) when the hypersonic vehicle is in the state of thermodynamic equilibrium and chemical nonequilibrium. Thus, the parameters of the plasma sheath change because of absorbing the energy of the HPM and then affect the electromagnetic characteristics of the plasma sheath. Aiming at the interaction between the HPM and the plasma sheath, we propose a multiphysicscoupling model of fluid field and electromagnetic field, which provides a way of thinking for the interaction of electromagnetic and fluid coupling. Furthermore, through this multiphysics coupling method, it is found that the HPM illuminates into the plasma sheath, the ability of low-frequency electromagnetic waves to pass through the plasma sheath will be improved within a specific time window, which provides a possibility to enhance the communication blackout problem. Since the primary purpose of this article is to reveal the multiphysics field method and its related phenomena, both theoretical derivations and numerical examples are only presented in the 2-D space.
The realistic numerical modelling of multiphysics applications is an efficient way to precisely predict the operation of concentrated solar systems. Although many multiphysics conjugating approaches have been proposed...
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The realistic numerical modelling of multiphysics applications is an efficient way to precisely predict the operation of concentrated solar systems. Although many multiphysics conjugating approaches have been proposed in the literature, it is difficult to adopt such methods into simulating complex concentrated solar technologies. Consequently, this study introduces a novel 2D:3D numerical optical, thermal and electric coupling approach for a hybrid compound parabolic concentrator photovoltaic/thermal (CPC-PV/T) collector using a nanofluid as a spectral beam filter. In this approach, the volumetric absorbed radiation in each component of the system obtained from the non-gray 2D model is patched into the 3D model as a volumetric heat source using sophisticated computational tools. The main features of the full couplingmethod (FCM) are extensively analyzed and compared with the other two couplingmethods previously adopted. Further, the module performance has been investigated employing both the nanofluid and base-fluid spectrum filters (BF-filter) compared with a stand-alone concentrated PV cell. From findings, the FCM can be applied to reveal more realistic operation characteristics of the proposed system compared with the other approaches, since the FCM can take into account the non-uniformity of solar illumination and the direction of reflected solar beams upon the receiver, along with the variation in the optical characteristics of utilized materials over the solar irradiance. Additionally, suspending indium tin oxide (ITO) nanoparticles into the Therminol VP1 oil raises the absorption rate over the thermal-bands with 62.5% higher than the use of BF-filter, whilst the cell temperature and the transmitted irradiance within the PV-band are obviously declined.
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