Journal articles on the topic 'COMSOL Thin-Film Flow module'

This work focuses on modeling and simulating the absorption and scattering of radiation in a photocatalytic annular reactor. To achieve so, a model based on four fluxes (FFM) of radiation in cylindrical coordinates to describe the radiant field is assessed. This model allows calculating the local volumetric rate energy absorption (LVREA) profiles when the reaction space of the reactors is not a thin film. The obtained results were compared to radiation experimental data from other authors and with the results obtained by discrete ordinate method (DOM) carried out with the Heat Transfer Module of Comsol Multiphysics® 4.4. The FFM showed a good agreement with the results of Monte Carlo method (MC) and the six-flux model (SFM). Through this model, the LVREA is obtained, which is an important parameter to establish the reaction rate equation. In this study, the photocatalytic oxidation of benzyl alcohol to benzaldehyde was carried out, and the kinetic equation for this process was obtained. To perform the simulation, the commercial software COMSOL Multiphysics v. 4.4 was employed.

A thin-film thermoelectric generator (TEG) applying a novel folded design where both the heat flux and current flow are in the plane of the thin-film is presented. The performance of the first fabricated devices is demonstrated and the results compared with the computational ones. The produced power is analyzed against the power requirements of a wireless sensor node and it is shown that a thermoelectric module of the area of <1 m2 consisting of the novel TEG units is able to power a wireless sensor node of various sensors applicable e.g., to environmental monitoring of a building. The integration of energy-autonomous sensors for multifunctional smart windows providing the required temperature gradient is anticipated.

By using numerical simulation, the operating temperatures of a thin-film solar cell based on CuInSe2 have been determined and the solar radiation density values, at which stabilization of the temperature operating conditions of the thin-film solar cell is not required, have been optimized. The maximum possible efficiency value of ~14.8 % is achieved under actual operating conditions, and is maintained by the incoming thermal energy as both emitted in this cell and infrared radiation of the sun and the environment. A model of the proposed thin-film solar cell was implemented in the COMSOL Multiphysics program environment with the use of the Heat Transfer Module. The operating temperatures of the solar cell without thermal stabilization under conditions of the diurnal and seasonal variations of both the ambient temperature and the power density of the AM1.5 solar spectrum have been determined. The maximum value of this power density was varied from 1.0 to 500 kW/m2 when using concentrators. The obtained values of operating temperatures of the thin-film solar cell were used to determine its main parameters in the SCAPS-1D program. The graphs of the operating temperature, efficiency and fill factor of the thin-film solar cell versus the solar radiation density are provided. It is shown that in order to obtain the highest possible efficiency of a solar cell, it is necessary to use concentrated solar radiation with a power density, the maximum value of which should be 8 kW/m2 in July and 10 kW/m2 in January. In the case of lower and higher values of power density, an appropriate thermal stabilization of the cell under consideration is necessary. The dependencies of efficiency, fill factor and open-circuit voltage versus the stabilization temperature of the solar cell, temperature gradients at the interfaces of the thermoelectric layer were also calculated. It is shown that by choosing optimal values of the thermal stabilization, the efficiency of the proposed solar cell may be about 15 % or more.

CuInSe2 thin-film solar cells are promising materials for photovoltaic devices. One of the main tasks of researchers is to find ways to increase the solar cells efficiency. In this paper we propose an original structure of a thin-film solar cell based on a tandem connection of a photoelectric converter and a thermoelectric layer based on CuInSe2. The photoelectric converter consists of CuInSe2 and CdS layers. A 3D model of the proposed thin-film solar cell was implemented in the COMSOL Multiphysics environment with using the Heat Transfer module. The simulation was carried out taking into account the diurnal and seasonal variations of both the ambient temperature and the power density of the AM1.5 solar spectrum for the geographical coordinates of Minsk. The solar radiation power density of about 500 kW/m2 can be achieved by using concentrators. The temperature pattern and temperature gradients are calculated in each layer of the solar cell without and with the temperature stabilization of the substrate back side as well as without and with the thermal insulation of the substrate ends. Graphs of the temperature gradients of the thermoelectric layer and the temperature variations of the photoelectric converter of the solar cell are given. As a result of the simulation, it is shown how the uneven heating of both the surface of a thin-film solar cell and its layers occur under conditions of diurnal and seasonal variations of both the ambient temperature and the solar radiation power density. Under concentrated solar radiation exposure, the photoelectric converter surface can be heated up to 700 °C without temperature stabilization of the solar cell substrate. The operating temperature of the photoelectric converter was maintained at no more than 2.35 °C in January and at no more than 14.23 °C in July due to the temperature stabilization of the substrate back side of the proposed device. This made it possible to achieve an increase in the output power of the solar cell both by summing the photoand thermoelectric output voltages and by the concentration of solar radiation.

In this paper, an alternative strategy for the design of a bidirectional inductive power transfer (IPT) module, intended for the continuous monitoring of cardiac pressure, is presented. This new integrated implantable medical device (IMD) was designed including a precise ventricular pressure sensor, where the available implanting room is restricted to a 1.8 × 1.8 cm2 area. This work considers a robust magnetic coupling between an external reading coil and the implantable module: a three-dimensional inductor and a touch mode capacitive pressure sensor (TMCPS) set. In this approach, the coupling modules were modelled as RCL circuits tuned at a 13.56 MHz frequency. The analytical design was validated by means of Comsol Multiphysics, CoventorWare, and ANSYS HFSS software tools. A power transmission efficiency (PTE) of 94% was achieved through a 3.5 cm-thick biological tissue, based on high magnitudes for the inductance (L) and quality factor (Q) components. A specific absorption rate (SAR) of less than 1.6 W/Kg was attained, which suggests that this IPT system can be implemented in a safe way, according to IEEE C95.1 safety guidelines. The set of inductor and capacitor integrated arrays were designed over a very thin polyimide film, where the 3D coil was 18 mm in diameter and approximately 50% reduced in size, considering any conventional counterpart. Finally, this new approach for the IMD was under development using low-cost thin film manufacturing technologies for flexible electronics. Meanwhile, as an alternative test, this novel system was fabricated using a discrete printed circuit board (PCB) approach, where preliminary electromagnetic characterization demonstrates the viability of this bidirectional IPT design.

This paper reports a multi-valve module with high chemical inertness and embedded flow heating for microscale gas chromatography (µGC) systems. The multi-valve module incorporates a monolithically microfabricated die stack, polyimide valve membranes, and solenoid actuators. The design incorporates three valves within a single module of volume 30.2 cm3, which is suitable for the small form factor of µGC systems. The die stack uses fused silica wafers and polyimide valve membranes that enhance chemical inertness. The monolithic die stack requires only three lithographic masks to pattern fluidic microchannels, valve seats, and thin-film metal heaters and thermistors. The performance of fabricated multi-valve modules is compared to a commercial valve in tests using multiple volatile organic compounds, including alkanes, alcohols, ketones, aromatic hydrocarbons, and phosphonates. The valves show almost no distortion of chromatographic peaks. The experimentally measured ratio of flow conductance is 3.46 × 103, with 4.15 sccm/kPa in the open state and 0.0012 sccm/kPa in the closed state. The response time is <120 ms.

This study demonstrates a designed pins-module tool and a precise reclamation system using a micro electroremoval process for sensing material of tin-doped indium oxide thin-films dissolved from a surface of polyethylene terephthalate of touch-panel. In the current experiment, a higher dissolution rate of the defective tin-doped indium oxide corresponds to high rotational speed of the cylinders tool with large flow rate of the electrolyte. A small diameter of the anode or a small diameter of the cathode combined with enough electric power, results in fast dissolution. The removal rate of tin-doped indium oxide thin-film is improved by decreasing the cylinders number. Importantly, the performance of a designed pins-module tool was found to be more effective in the micro electroremoval process. It requires only a short period of time to dissolve the nanostructured of tin-doped indium oxide easily and cleanly.

Purpose This study aims to improve the performance of hydrodynamic journal bearings through partial grooving on the bearing surface. Design/methodology/approach Bearing performance analysis is numerically carried out using the thin film flow physics of COMSOL Multiphysics 5.0 software. Initially, the static performance analysis is carried out for hydrodynamic journal bearing system with smooth surface, and the results of the same are validated with results from the literature. In the later part of the paper, the partial rectangular shape micro-textures are modeled on bearing surface. The effects of partial groove pattern on the bearing performance parameters, namely, fluid film pressure, load carrying capacity, frictional power loss and frictional torque, are studied in detail. Findings The numerical results show that the values of maximum fluid film pressure, load carrying capacity, frictional power loss and frictional torque are considerably improved due to deterministic micro-textures. Bearing surface with partial groove along 90°-180° region results in 81.9 per cent improvement in maximum fluid film pressure and 75.9 per cent improvement in load carrying capacity as compared with smooth surface of journal bearing, with no increase in frictional power loss and frictional torque. Maximum decrease in frictional power loss and frictional torque is observed for partially grooving along 90°-360° region. The simulations are supported by proof-of-concept experimentation. Originality/value This study is useful in the appropriate selection of groove parameters on bearing surface to the bearing performance characteristics.

The development of solid oxide fuel cells (SOFCs) and gas separation membranes for fossil (fuel?) power plants has previously suffered from cost issues like the manufacturing of the core components including i) the ceramic fuel cell and ii) the ceramic membrane, and from insufficient power density (current density or flow rate) on the stack, module or system level. Forschungszentrum Jülich has been working on SOFC development for 20 years, and on membrane development for 6 years. Both energy-related applications are based on similar materials systems, similar micro-structural features (porous-dense, coarse-fine), comparable application parameters (e.g. high temperature) and are manufactured with similar technologies. In the past the focus laid mostly on basic materials research and proving the functionality of the membranes or fuel cells. Meanwhile, one key topic has been the application of low-cost thin-film high-throughput manufacturing technologies. This includes the fabrication of the supports (mostly tape-casting), the coating with functional layers by ceramics technologies (screen printing, roll coating) and the reduction of sintering steps and temperatures. Additionally special thin-film technologies like sol-gel technique and electron beam evaporation / sputtering have also been applied for functional layers, depending on the functional necessities. The presentation gives an overview regarding the state-of-the-art in SOFC and gas separation membrane development at Forschungszentrum Jülich with an emphasis on the manufacturing technologies, resulting in optimized layer micro-structures and thickness. Additionally it summarizes the electrochemical and permeation data obtained so far.

Purpose The purpose of this study is to improve the tribological performance of meso scale air journal bearing by adopting texture on the bearing surface. Design/methodology/approach The present study is based on numerical analysis. The detailed numerical investigation is carried out using a fluid flow based thin-film model in COMSOL 5.2 software. Findings The influence of texture design parameters: geometry (shape, orientation and slender ratio), and position on the tribological performance of meso scale air journal bearing is investigated. It is found that texture shape has a strong influence on the tribological characteristics such as load capacity and friction coefficient of the bearing. Slender texture improves the load capacity, but it has a negligible effect on the reduction of friction coefficient. In contrast, texture orientation is found to be insignificant for both increasing load capacity and decreasing friction coefficient. Furthermore, the maximum improvement in load capacity is obtained for partially textured bearing, but the minimum friction coefficient is achieved for full texturing. Originality/value The present study investigates the influence of texture design parameters viz geometry (shape, orientation and slender ratio), and position on the tribological performance of meso scale air journal bearing.

The operating temperature is an essential parameter determining the performance of a photovoltaic (PV) module. Moreover, the estimation of the temperature in the absence of measurements is very complex, especially for outdoor conditions. Fortunately, several models with and without wind speed have been proposed to predict the outdoor operating temperature of a PV module. However, a problem for these models is that their accuracy decreases when the sampling interval is smaller due to the thermal inertia of the PV modules. In this paper, two models, one with wind speed and the other without wind speed, are proposed to improve the precision of estimating the operating temperature of outdoor PV modules. The innovative aspect of this study is two novel thermal models that consider the variation of solar irradiation over time and the thermal inertia of the PV module. The calculation is applied to different types of PV modules, including crystalline silicon, thin film as well as tandem technology at different locations. The models are compared to models that are described in the literature. The results obtained in different time steps show that our proposed models achieve better performance and can be applied to different PV technologies.

This study aimed to develop emulsification assisted with ultrasonic atomization (EUA) to make embolic biodegradable poly(caprolactone) (PCL) spherical-microcarriers with uniform particle size for mass production which was used to cure hepatocellular carcinoma, because this kind of embolic drugs is expensive at the current market due to their complex manufacturing process. The embolic spherical-microcarriers with sustained-releasing therapeutic agents can shrink an unresectable tumor into a respectable size. Through high frequency vibrating surface on the ultrasonic atomizer nozzle, the thin liquid film for PCL oil-phase solution was broken into the uniform PCL microdroplets (particle sizes are from 20 to 55 μm) with less medicine loss. To determine the optimal parameters to make PCL microcarriers, the ultrasonic module parameters including the concentration of PCL solution, vibrating amplitude of atomizer, feeding rate of PCL oil-phase solution and collection distance on the particle size of microdroplets were analyzed. Besides, a vertical circulation flow field of aqueous-phase poly(vinyl alcohol) (PVA) solution was created to enhance the separation of the microdroplets and increase the production of the PCL microcarriers, and about 8~11 wt% of PVA solution with high stable dispersion property was used to effectively improve the yield rate of PCL spherical-microcarriers (89.8~98.2 wt%). The final particle size of PCL microcarriers was ca. 5–18 μm, indicating an about 25–50% volume shrinkage from microdroplets to solid spherical-microcarriers.

New system level IC package integration requires a flexible assembly portfolio. A review of current wafer scale processing and assembly solutions and new development directions is warranted. 2.5D TSV System level IC packaging is not new, but the performance levels that are being attained today with memory stacking, interposers, advanced silicon nodes and advanced packaging are new and are unparalleled. Several key technologies have come together to create this bold shift to higher performance. The Thru-Silicon Via (TSV) technology has been foremost, whether in the interposer, memory or logic devices, the importance of the this electrical pass through connection in silicon cannot be overstated. To commercialize the TSV package constructions, IC packaging technology had to be developed to permit its use. This included TSV reveal on TSV-bearing interposers, new ways of controlling warpage due to the presence of large x-y interposers, new functional IC bumping technologies and attachment methods. This portfolio of advanced technologies are then combined to provide package constructions that are increasingly compelling as a result of the higher electrical performance attained, while at the same time minimizing unwanted die to die interface power requirements. 2.5D TSV bearing products have enabled an array of multi-die products and have a significant role to play in the semiconductor industry going forward. Examples include new economics for SOC-splitting, and especially for combinations of logic and high speed memory (HBM), with performance levels heretofore unachievable. With fine line damascene Cu Back End of Line (BEOL) typical of a 65nm Cu backend, the signal routing resources available for multi-die implementation is unparalleled. Functionally, the TSV is required to provide a suitable power deliver network (PDN), and to enable off-package IO signaling. 3D TSV The COS Chip last is a proven approach for 2.5D TSV packages and is already in early production. This process flow is also being developed for 3D packages applications as well. New technologies being developed for 3D applications include new UF processing technologies that will be used to extend this technology to a 2-die stack with the same die size top and bottom, as well as 50 um large die silicon handling. These will include logic on logic combinations and memory on logic configurations, as well as stacked memory offerings. SLIMTM Amkor's most advanced integrated modular based package development program is for SLIMTM (Silicon-Less Integrated Module). The roots of SLIM innovation were forged during the 2.5D TSV-bearing interposer package development. SLIMTM attempts to retain all the best features of a 2.5D TSV interposer approach, but without bulk silicon for TSVs. The objective of SLIM is to retain the very strong signal routing capability afforded by the damascene BEOL, and provide that benefit without the requirement for a TSV. This can enable a lower total cost than the 2.5D interposers, and some specific electrical performance improvements as well. The primary mechanical feature of the SLIMTM construction is the lack of TSVs. For SLIM, the TSV is not in the electrical path from the top die to the C4, providing electrical benefits. In the case of SLIM the bulk silicon has been removed from the interposer, so that only the thin-film metal and dielectric layers present in the BEOL construction are retained. Connection to the BEOL metal stack is made directly using thin film techniques developed for 2.5D TSV. The end result is a very thin package, with signal routing resources on par with the 2.5D interposer, and without bulk silicon or a TSV. This can have electrical signaling advantage, especially for very high speed IO off package signals which avoid bulk silicon dielectric losses that can be significant above 20 Gigabit/sec. The process flow developed for SLIM is essentially a truncated version of the 2.5D production line. Key steps not required are CVD deposition of inorganic dielectrics and CMP processing. In summary, the final system package construction can be derived with different process approaches as previously discussed, each with their own particular benefits. Amkor continues in its commitment to the development of these critical process modules to enable customers to achieve their ultimate system-in-module product designs.

AbstractDesalination of nitrates from brackish water is prominent in the coastal areas due to excessive disposal of pesticides by agricultural industries. Nowadays, membrane processes are growing tremendously for the desalination of brackish water. In this context, polyurea (PU) could be a useful membrane material for the treatment of brackish water. The present work deals with the removal of nitrates from synthetic water using PU membranes by nanofiltration (NF) process. Polyurea thin film composite (PU-TFC) membranes were prepared by interfacial polymerization followed by thermal crosslinking and characterized using Fourier transformed infrared spectral (FTIR), X-ray diffraction (XRD), scanning electron microscopy– energy dispersion X-ray spectroscopy (SEM–EDS), Atomic force microscopy (AFM), thermogravimetric (TGA), and universal testing machine (UTM) for structural analysis, crystallinity, morphological, compositional, thermal and mechanical properties, respectively. Experimental studies were conducted on an NF pilot plant by varying operating pressure from 2 to 10 bar and feed nitrate concentration from 60 to 200 mg/L for evaluating PU membrane performance. Experimental observations revealed a maximum water flux of 30.6 L/m2 h and nitrate rejection of 97.2% at a pressure of 10 bar for feed containing 140 mg/L of nitrate. A mass transfer model was developed on the basis of solution–diffusion mechanism for a semi-batch NF process by considering cake enhanced concentration polarization model, for laminar flow with feed recycle, using a plate and frame membrane module. A generic semi-batch NF process model was integrated taking into account concentration polarization and fouling layer resistance. The integrated model was successfully compared with existing data in literature and could be used for process scale-up. Due to the merits of hydrophilicity, negative charge, high thermal and mechanical resistance, the PU membrane can be termed as a low cost, commercially viable and ecofriendly barrier for separation of nitrates.