- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2018 IEEE 8th International Conference on Consumer Electronics - Berlin - Berlin (2018.9.2-2018.9.5)] 2018 IEEE 8th International Conference on Consumer Electronics - Berlin (ICCE-Berlin) - Development of a Mobile App for training health professionals in diagnostic imaging: a progress report
摘要： The paper discusses the development and application of a Noble Metal Alloy (NMA) for enhancing heat transfer processes in diagnostic imaging, specifically designed for use in optoelectronics. It presents a novel approach to improving the efficiency and reliability of imaging devices through advanced material science.
关键词： Noble Metal Alloy,Heat Transfer,Optoelectronics,Material Science,Diagnostic Imaging
更新于2025-09-23 15:22:29
-
Uncertainty Analysis and Experimental Design in the Monte Carlo Ray-Trace Environment
摘要： Despite the dominant role of the Monte Carlo ray-trace (MCRT) method in modern radiation heat transfer analysis, the contemporary literature remains surprisingly reticent on the uncertainty of results obtained using it. After first identifying the radiation distribution factor as a population proportion, standard statistical procedures are used to estimate its mean uncertainty, to a stated level of confidence, as a function of the number of surface elements making up the enclosure and the number of rays traced per surface element. This a priori statistical uncertainty is then shown to compare favorably with the observed variability in the distribution factors obtained in an actual MCRT-based analysis. Finally, a formal approach is demonstrated for estimating, to a prescribed level of confidence, the uncertainty in predicted heat transfer. This approach provides a basis for determining the minimum number of rays per surface element required to obtain the desired accuracy.
关键词： Monte Carlo ray-trace,uncertainty analysis,experimental design,radiation heat transfer,distribution factor
更新于2025-09-23 15:22:29
-
A Theoretical Extension of AH FDTD Method and Applications in Various Physical Fields
摘要： In this paper we extended the Associated Hermite (AH) FDTD method theoretically and used it to analyze various physical fields, which are electromagnetic field, acoustic field and heat-transfer field. The AH differential transformation operator is developed theoretically as a basic element for setting a time-frequency bridge, where several common operators such as differential, second-order differential and integral linear operator, etc. on the concept of signal processing and analyzing can be expediently transformed, which leads to a unified and much simpler derivation to construct the previous AH FDTD formula. Therefore, it gives a reconsideration for AH FDTD to calculate a more general or even arbitrary liner physic field problems, which are focused on the commonly partial differential equations. Finally, based on the time-frequency bridge theory, we adopted several examples for verification from the formula derivation to numerical validation in electromagnetic field, acoustic field and heat-transfer field, respectively.
关键词： Acoustic,Heat-transfer,Associated Hermite,Finite difference time domain (FDTD)
更新于2025-09-23 15:22:29
-
[Energy, Environment, and Sustainability] Advances in Solar Energy Research || Techno-Economic Potential of Large-Scale Solar Deployment in the US
摘要： PV system generates electricity with minimum environmental impact reduces than conventional greenhouse gas emission and consequently reduces the effects of global warming. In late of 2014, the Indian government announced an ambitious target of 100 GW installation capacity of solar PV systems by 2022. Since then, India has achieved notable progress towards this goal and has installed 20 GW cumulative solar capacity with 9.6 GW in 2017 alone. Based on the 2015 MIT Energy Initiative, by 2050, a major fraction of the world’s electric power will come from solar sources. However, this poses many technical and economic challenges on the electrical infrastructure. In this chapter, we focus on the US case, by studying the technical and economic potentials of large-scale deployment of the most commonly recognized types of solar; photovoltiac (PV) and concentrated solar power (CSP) at different locations in the US. The technical potential is assessed based on grid interconnection topologies, and solar system performance. The economic potential is evaluated based on several metrics such as the levelized avoided cost of energy (LACE) and levelized cost of electricity (LCOE), and the possibility of integration into the electricity markets. The economic potential also covers the subsidies, taxes, policies, and incentives for large-scale solar deployment. Two simulation case studies are implemented on two large-scale solar PV and CSP projects at different locations in the US to evaluate their techno-economic potentials.
关键词： Concentrated solar power,Heat transfer fluid,NPV,LCOE,Thermal energy storage,Photovoltaic system,LACE,Payback period,Mounting system
更新于2025-09-23 15:21:21
-
A fully coupled numerical simulation of a hybrid concentrated photovoltaic/thermal system that employs a therminol VP-1 based nanofluid as a spectral beam filter
摘要： 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 coupling method (FCM) are extensively analyzed and compared with the other two coupling methods 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.
关键词： Radiative heat transfer,Multiphysics coupling method,Nanofluid,Concentrated photovoltaic/thermal system,Spectral beam filter
更新于2025-09-23 15:21:01
-
Wettability Control of Copper Surface Using Picosecond Laser for Enhancing Condensation Heat Transfer
摘要： One of the most important and widely visualized process taking place in nature is condensation. Superhydrophobic surfaces, which facilitates dropwise condensation has been the principal area of research in the last decade or so. Fabrication of superhydrophobic surface can be achieved by either surface modification using mechanical process, surface treatment like coating or by the combination of both. But, the major drawback of coating is its durability and vulnerability. So, in this work we have fabricated a robust surface by means of picosecond laser machining. Apart from being a simple process, this method has an advantage of cutting down the surface fabrication time by several hours as compared to other methods like one-step immersion, electro-deposition, top-down fabrication method, etc. In our work three different work specimens irradiated with different laser power were studied for its surface morphologies by scanning electron microscope (SEM) images and its wettability was measured using contact angle meter. It is found that the wettability of surface changes with different laser power and hence it is possible to control the wettability by adjusting the laser parameters. Condensation experiment was carried out on these different surfaces and its performance was compared with plain surface.
关键词： Wettability control,micro grooves,Condensation heat transfer,Contact angle,Picosecond laser
更新于2025-09-23 15:21:01
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Direct Fluid Cooling of Concentrator Photovoltaics for Hybrid Photovoltaic-Solar Thermal Energy Conversion
摘要： A spectrum-splitting photovoltaic module is developed for hybrid photovoltaic-solar thermal energy conversion using direct fluid cooling (DFC) of partially transmissive concentrator photovoltaic cells. The waste heat generated in photovoltaic cells can be more efficiently extracted by flowing a heat transfer fluid in direct contact with both sides of the cells. The module also acts as a beam splitter, dividing the incident light into two parts. Photons with higher energy than the bandgap of the cells are absorbed in cells, while photons with lower energy are passed through the infrared-transmissive module to a thermal receiver. Optical modeling (experimental) shows 63.2% (34.3%) out-of-band transmittance through the cell regions and 90.4% (89.0%) full spectrum transmittance through the surrounding bypass region. Thermal modelling verifies the direct cooling fluid method is an effective way to maintain cell temperature < 110℃. Electrical power conversion efficiency in a first prototype module is 79% of the bare cell efficiency. Fluid flow characterization shows laminar flow. The modules are currently undergoing field testing.
关键词： hybrid CPV/T system,active cooling,silicone oil heat transfer fluid,CPV
更新于2025-09-23 15:21:01
-
Fabrication and characterization of graphene quantum dots thin film for reducing cross-sectional heat transfer through smart window
摘要： Graphene and its derivatives have been reported as materials with excellent electrical and thermal conductivity, allowing for various promising applications. In particular, the large-scale surface coating of graphene-based materials can be employed to minimize cross-sectional heat transfer through the glass window. This study introduces a facile and cost-effective method to fabricate graphene quantum dots (GQDs) thin film on Fluorine-doped Tin Oxide (FTO) glass via casting of the GQDs dispersion and stabilizing with poly-vinyl-pyrrolidone (PVP). The thin film possesses excellent optical properties of GQDs and allows more than 80 % of visible transmittance. The presence of the GQDs thin film shows effective reduction in the cross-sectional thermal diffusivity of FTO glass, from 0.55 mm2/s to zero when measured with laser flash over a 4-second period. This low cost and eco-friendly GQDs thin film will be a promising material for heat management in smart window applications.
关键词： Smart window,Cross-Sectional heat transfer,Graphene quantum dots,Poly-Vinyl-Pyrrolidone,Visible transmittance
更新于2025-09-23 15:21:01
-
Thermal and optical properties of high-density GaN micro-LED arrays on flexible substrates
摘要： Flexible GaN-based micron-size light-emitting diodes (μLEDs) with high brightness and low power-consumption are a promising technology for next-generation wearable displays. While, integrating GaN μLEDs onto flex can provide more functionality, the bending-induced strain and potential self-heating of the device are the challenges that degrade the device performance on plastic platforms. Here, a novel “paste-and-cut” approach to selectively transfer GaN μLEDs from sapphire substrates onto flexible platforms demonstrated the effectiveness of various intermediate metallic-bonding layers and LED geometries on the optical properties and performance of the flexible devices. Computational thermal simulation of the flexible μLEDs showed effective heat dissipation for devices mounted on plastic platforms bonded using a 0.5 μm thick Cu metallic pad to create stable optical emission (λ = 450 nm) under current densities of > 1 A/cm2. Through a finite-element analysis (FEA), it was determined that the applied stress-induced strain near the quantum wells of the μLEDs can be negligible for devices with diameters smaller than 20 microns. Experimental verification supported the simulation results; the diodes were found to be electrically and thermally stable when copper electrode layers > 600 nm thick was used to bond the LEDs onto the plastic platforms. The I-V characteristics of the μLEDs showed no measurable degradation after transfer onto the flexible substrate with a turn-on voltage of 2.5 V. Commensurate to the FEA simulations, no measurable optical wavelength shift was observed for LED having a diameter of 20 microns when driven at a current density of 1 A/cm2 under different mechanical strain.
关键词： Flexible Display,Heat Transfer,Invariant Emission,GaN Micro-LED
更新于2025-09-23 15:21:01
-
Near-field radiative heat transfer between black phosphorus and graphene sheet
摘要： Low thermal conductivity of black phosphorus (BP) makes it difficult to cool BP-based electronic or optoelectronic devices. Therefore, developing a cooling strategy for BP-based nano devices is highly required. We theoretically study the near-field radiative heat transfer between BP sheets as well as between BP and graphene. We find that the heat transfer between BP sheets is determined by its electron doping. Plasmons excited by BP in different directions dominate the heat transfer for different electron doping. At optimum electron doping, heat transfer between the BP sheets increases significantly. The heat transfer between BP and graphene is dependent on both the electron doping of BP and chemical potential of graphene. Modulating the chemical potential of graphene can result in a strong coupling between graphene plasmons and BP plasmons, which will lead to a significant enhancement of heat transfer between BP and graphene. Our results are not only meaningful in controlling the heat transfer between BP-based structures but also helpful in developing cooling strategies for BP-based nano devices.
关键词： near-field radiative heat transfer,plasmons,graphene,black phosphorus,chemical potential,electron doping
更新于2025-09-23 15:21:01