To see the other types of publications on this topic, follow the link: SINK (Computer system).
Journal articles on the topic 'SINK (Computer system)'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'SINK (Computer system).'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Singh, Preeti, Sourav Khanna, Sanjeev Newar, et al. "Solar Photovoltaic Panels with Finned Phase Change Material Heat Sinks." Energies 13, no. 10 (2020): 2558. http://dx.doi.org/10.3390/en13102558.
Full textAbstract:
Phase change material (PCM) based passive cooling of photovoltaics (PV) can be highly productive due to high latent heat capacity. However, the low rate of heat transfer limits its usefulness. Thus, the presented work aims at the improvement in PV cooling by using finned PCM (FPCM) heat sinks. In the present study, PCM heat sink and FPCM heat sinks were investigated numerically for PV cooling and the extracted heat is used for space heating. 4 kWp PV, PV-PCM and PV-FPCM systems were studied under the weather conditions of Southeast of England. It was observed that the PCM heat sinks can drop the peak PV temperature by 13 K, whereas FPCM heat sinks can enhance the PV cooling by 19 K. The PCM heat sinks can increase the PV electrical efficiency from 13% to 14%. Moreover, the daily electricity generation can be boosted by 7% using PCM and 8% by using FPCM heat sinks. In addition, 7 kWh of thermal output was achieved using the FPCM heat sink, and the overall efficiency of system increased from 13% to 19%.
2
Manevitch, L. I., E. Gourdon, and C. H. Lamarque. "Towards the Design of an Optimal Energetic Sink in a Strongly Inhomogeneous Two-Degree-of-Freedom System." Journal of Applied Mechanics 74, no. 6 (2006): 1078–86. http://dx.doi.org/10.1115/1.2711221.
Full textAbstract:
Analytical, numerical, and experimental results of energy pumping in a strongly inhomogeneous two-degree-of-freedom system are to be presented in this study. The latter is based both on efficient analytical solution and comparative analysis for various types of energetic sinks. Considering the efficient pumping process as damped beating with strong energy transfer, it is shown that we can design the sinks with amplitude-phase variables which provide the most efficient result. In this study, the main types of energetic sinks are to be compared. Computer simulation has confirmed the analytical predictions which had been obtained. Experimental verification of the analytical prediction is considered for a particular type of sink.
3
Xu, Shanglong, Weijie Wang, Zongkun Guo, Xinglong Hu, and Wei Guo. "A multi-channel cooling system for multiple heat source." Thermal Science 20, no. 6 (2016): 1991–2000. http://dx.doi.org/10.2298/tsci140313123x.
Full textAbstract:
High-power electronic devices with multiple heating elements often require temperature uniformity and operating within their functional temperature range for optimal performance. A multi-channel cooling experiment apparatus is developed for studying heat removal inside an electronic device with multiple heat sources. It mainly consists of a computer-controlled pump, a multi-channel heat sink for multi-zone cooling and the apparatus for measuring the temperature and pressure drop. The experimental results show the system and the designed multi-channel heat sink structure can control temperature distribution of electronic device with multiple heat sources by altering coolant flow rate.
4
Xu, Qing Hua, and Chang Wan Liu. "Design of Wireless Sensor Network System Based on Computer Control Technology." Applied Mechanics and Materials 608-609 (October 2014): 517–20. http://dx.doi.org/10.4028/www.scientific.net/amm.608-609.517.
Full textAbstract:
In this paper we design a wireless sensor network of Zigbee technology, which consists of sensor nodes, sink nodes and monitoring software design. Through laboratory test, the design of the system is stable and reliable. Although the system can meet the requirements of Zigbee wireless communication hardware, but part of system hardware is relatively simple. If it is applied to the more complex place, we must add the corresponding module in the hardware and software. Adding node function module and the monitoring function in the Zigbee wireless network, it will meet the actual needs.
5
Al Siyabi, Idris, Sourav Khanna, Senthilarasu Sundaram, and Tapas Mallick. "Experimental and Numerical Thermal Analysis of Multi-Layered Microchannel Heat Sink for Concentrating Photovoltaic Application." Energies 12, no. 1 (2018): 122. http://dx.doi.org/10.3390/en12010122.
Full textAbstract:
Concentrating photovoltaic has a major challenge due to the high temperature raised during the process which reduces the efficiency of the solar cell. A multi-layered microchannel heat sink technique is considered more efficient in terms of heat removal and pumping power among many other cooling techniques. Thus, in the current work, multi-layered microchannel heat sink is used for concentrating photovoltaic cooling. The thermal behavior of the system is experimentally and numerically investigated. The results show that in extreme heating load of 30 W/cm2 with heat transfer fluid flow rate of 30 mL/min, increasing the number of layers from one to four reduces the heat source temperature from 88.55 to 73.57 °C. In addition, the single layered MLM heat sink suffers from the highest non-uniformity in the heat source temperature compared to the heat sinks with the higher number of layers. Additionally, the results show that increasing the number of layers from one to four reduces the pressure drop from 162.79 to 32.75 Pa.
6
Jiang, Wei, Jieyun Wang, Qianlong Wang, Song Xu, Seiji Hashimoto, and Zhong Liu. "Design and Implementation of a Low-Power Low-Cost Digital Current-Sink Electronic Load ‡." Energies 12, no. 13 (2019): 2611. http://dx.doi.org/10.3390/en12132611.
Full textAbstract:
Electronic load (e-load) is essential equipment for power converter performance test, where a designated load profile is executed. Electronic load is usually implemented with the analog controller for fast tracking of the load profile reference. In this paper, a low-power low-cost electronic load is proposed. MOSFETs (metal-oxide-semiconductor field-effect transistors) are used as the power consumption devices, which are regulated to the active region as controlled current-sink. In order to achieve fast transient response using the low-cost digital signal controller (DSC) PWM peripherals, the interleaving PWM method is proposed to achieve active current ripple mitigation. To obtain the system open-loop gain for current-sink operation, an offline digital system identification method, followed by model reduction, is proposed by applying Pseudo-Random Binary Sequence (PRBS) excitation. Pole-zero cancelation method is used in the control system design and later implemented in a DSC. The prototype is built and tested, in which meaningful testing scenarios under constant current-sink mode, pulse current sink mode, and double line-frequency current mode are verified. The experimental results indicate that the proposed e-load can sink pre-programmed current profile with well-attenuated ripple for static and dynamic load testing, and is applicable to fully digitalized power testing equipment.
7
Hongliang, YAO, CAO Yanbo, ZHANG Qin, and WEN Bangchun. "Application of Nonlinear Energy Sink for Rotor System Vibration Suppression." Journal of Mechanical Engineering 56, no. 15 (2020): 191. http://dx.doi.org/10.3901/jme.2020.15.191.
Full text
8
Sun, Hai Gang, and Yong Zhou. "Structure Design for Heat Sink Based on Thermal Analysis." Applied Mechanics and Materials 80-81 (July 2011): 767–73. http://dx.doi.org/10.4028/www.scientific.net/amm.80-81.767.
Full textAbstract:
Thermal design and the working temperature control have been a key factor in the design of electronic devices and system. In this paper, a sort of heat sink collocated with high-power IGBT module, which is commonly used in car-carrying motor control system, is designed based on thermal analysis by means of CFD simulation and computer-aided analyzing, also the influence relations of structure parameters with thermal performance are studied. With thermal control as the overall design objective, structure parameters of heat sink are determined according to the obtained relations. Further, thermal performance of the designed heat sink is simulated and analyzed in CFD software to examine the validity of the design result. In this way, a method of thermal analyzing and structure parameter design for heat sink, which is proved as an efficacious approach, is introduced and can be used to thermal design and analysis for similar products.
9
Bhopte, Siddharth, Musa S. Alshuqairi, Dereje Agonafer, and Gamal Refai-Ahmed. "Mixed Convection of Impinging Air Cooling Over Heat Sink in Telecom System Application." Journal of Electronic Packaging 126, no. 4 (2004): 519–23. http://dx.doi.org/10.1115/1.1827267.
Full textAbstract:
The current numerical investigation will examine the effect of an impinging mixed convection air jet on the heat transfer rate of a parallel flat plate heat sink. A three-dimensional numerical model was developed to evaluate the effects of the nozzle diameter d, nozzle-to-target vertical placement H/d, Rayleigh number, and the jet Reynolds number on the heat transfer rates from a discrete heat source. Simulations were performed for a Prandtl number of 0.7 and for Reynolds numbers ranging from 100 to 5000. The governing equations were solved in the dimensionless form using a commercial finite-volume package. Average Nusselt numbers were obtained, at H/d=3 and two jet diameters, for the bare heat source, for the heat source with a base heat sink, and for the heat source with the finned heat sink. The heat transfer rates from the bare heat source surface have been compared with the ones obtained with the heat sink in order to determine the overall performance of the heat sink in an impingement configuration.
10
Bangalee, Zavid Iqbal, Md Mizanur Rahman, Khairy Zaimi, and Mohammad Ferdows. "Numerical Optimization of a CPU Heat Sink Geometry." CFD Letters 13, no. 3 (2021): 1–15. http://dx.doi.org/10.37934/cfdl.13.3.115.
Full textAbstract:
During its operation CPU dissipates undesirable heat. Therefore, heat sink is very essential in modern computing system to absorb extra heat dissipated by the CPU. Forced convection air cooling is common approach. In the present work, a steady-state convective heat transfer process is analyzed for CPU cooling. A rectangular fin heat sink equipped in a computer chassis is numerically investigated and simulated using the software ANSYS CFX. A two-equation based turbulence model is chosen to capture the turbulence of the flow inside the domain. The overall dimension of the heat sink is optimized for three different parameters of the heat sink such as fin quantity, fin height and baseplate thickness. An optimum fin quantity, fin height and baseplate thickness are found, and, respectively. Two different orientations of fins are also compared. Better thermal performance is achieved when the fin channel is perpendicular to the surface parallel to the outlet. The average temperature of the heat sink is found. It is also predicted that the heat sink studied here is capable to keep the CPU temperature underthat is reasonably acceptable.
11
Spicer, J. W. M., M. G. Bevan, W. D. Kerns, and H. S. Feldmesser. "Thermal Characterization of Heat Sink Adhesive Systems for Spacecraft Electronics by Time-Resolved Infrared Radiometry." Journal of Electronic Packaging 115, no. 1 (1993): 101–5. http://dx.doi.org/10.1115/1.2909287.
Full textAbstract:
A new thermal characterization technique, time-resolved infrared radiometry (TRIR), is used to investigate three different heat sink adhesive systems used in spacecraft electronics - a filled epoxy, a filled silicone and a tape adhesive. Measurements of heat sink efficiency are presented as a function of thermal cycling and the TRIR results are compared with ultrasonic and X-ray imaging techniques and with destructive analysis. The TRIR technique is shown to provide a measure of the relative heat sink capabilities of the different systems and can detect subsurface delamination in the filled epoxy system resulting from the development of cracks due to thermal cycling.
12
LIN, YI-KUEI, and PING-CHEN CHANG. "ESTIMATED AND ACCURATE SYSTEM RELIABILITIES OF A MAINTAINABLE COMPUTER NETWORK SUBJECT TO MAINTENANCE BUDGET." Asia-Pacific Journal of Operational Research 29, no. 03 (2012): 1240021. http://dx.doi.org/10.1142/s0217595912400210.
Full textAbstract:
This paper proposes a performance index to evaluate the capability of a maintainable computer network (MCN) that is required to send d units of data from the source to the sink through two paths within time T. The proposed system reliability performance index quantifies the probability that a MCN delivers a sufficient capacity with a maintenance budget no greater than B. Two procedures are integrated in the algorithm — an estimation procedure for estimated system reliability and an adjusting procedure utilizing the branch-and-bound approach for accurate system reliability. Subsequently, the estimated system reliability with lower bound and upper bound, and accurate system reliability can be derived by applying the recursive sum of disjoint products (RSDP) algorithm.
13
Lehmann, G. L., and S. J. Kosteva. "A Study of Forced Convection Direct Air Cooling in the Downstream Vicinity of Heat Sinks." Journal of Electronic Packaging 112, no. 3 (1990): 234–40. http://dx.doi.org/10.1115/1.2904372.
Full textAbstract:
An experimental study of forced convection heat transfer is reported. Direct air cooling of an electronics packaging system is modeled by a channel flow, with an array of uniformly sized and spaced elements attached to one channel wall. The presence of a single or complete row of longitudinally finned heat sinks creates a modified flow pattern. Convective heat transfer rates at downstream positions are measured and compared to that of a plain array (no heat sinks). Heat transfer rates are described in terms of adiabatic heat transfer coefficients and thermal wake functions. Empirical correlations are presented for both variations in Reynolds number (5000 < Re < 20,000) and heat sink geometry. It is found that the presence of a heat sink can both enhance and degrade the heat transfer coefficient at downstream locations, depending on the relative position.
14
DeJong, Ted M., Romeo Favreau, Mitch Allen, and Przemyslaw Prusinkiewicz. "Modeling Fruit Tree Architectural Growth, Source–Sink Interactions, and Physiology with L-PEACH." HortScience 41, no. 4 (2006): 1010D—1010. http://dx.doi.org/10.21273/hortsci.41.4.1010d.
Full textAbstract:
Modeling source–sink interactions and carbohydrate partitioning in plants requires a detailed model of plant architectural development, in which growth and function of each organ is modeled individually and carbohydrate transport among organs is modeled dynamically. L-PEACH is an L-system-based graphical simulation model that combines supply/demand concepts of carbon partitioning with an L-system model of tree architecture to create a distributed supply/demand system of carbon allocation within a growing tree. The whole plant is modeled as a branching network of sources and sinks, connected by conductive elements. An analogy to an electric network is used to calculate the flow and partitioning of carbohydrates between the individual components. The model can simulate multiple years of tree growth and be used to demonstrate effects of irrigation, crop load, and pruning on architectural development, tree growth, and carbon partitioning. Qualitative model outputs are viewed graphically as the tree “grows” on the computer screen while quantitative output data can be evaluated individually for each organ or collectively for an organ type using the MatLab software.
15
Ganescu, V., and A. Pascu. "Imminent Needs in Future Development of Air Cooled Microprocessors Heat Sinks." International Symposium on Microelectronics 2010, no. 1 (2010): 000434–39. http://dx.doi.org/10.4071/isom-2010-wa3-paper1.
Full textAbstract:
This study reiterates the fact that revolutionary heat sink geometries, materials and overall exponentially higher performing alternatives are continuously and highly needed as applied to the air cooling of a typical computer system microprocessor. Attention was focused on forced convection regimes of operation and from a system level approach. Minor improvements in the performance of air cooled microprocessor heat sinks via typical small design improvements are discussed. Laminar convection and constant heat dissipation were looked at. The CFD simulations exemplified were completed for several power levels and ambient air characterized by a Pr = 0.71. The numerical results presented coincided in large with the experimentally derived documented data. In conclusion, the authors stress the fact that leading-edge alternatives in air-cooled heat removal of such applications are imperiously necessary.
16
Yao, Hongliang, Yuwei Wang, Linqing Xie, and Bangchun Wen. "Bi-stable buckled beam nonlinear energy sink applied to rotor system." Mechanical Systems and Signal Processing 138 (April 2020): 106546. http://dx.doi.org/10.1016/j.ymssp.2019.106546.
Full text
17
Denegri, Livio, Sandro Zappatore, and Franco Davoli. "Sensor Network-Based Localization for Continuous Tracking Applications: Implementation and Performance Evaluation." Advances in Multimedia 2008 (2008): 1–11. http://dx.doi.org/10.1155/2008/569848.
Full textAbstract:
The increasing interest in systems able to provide users with immersive services (e.g., domotics, context-aware applications, and immersive distance learning tools) has encouraged the development of cheap and effective platforms aimed at tracking objects and people within a certain space. In this context, wireless sensor networks (WSNs) can play a very important role, since specialized sensors can be fruitfully exploited in order to generate/receive signals by means of which the WSN can derive the position of nodes joined to the objects to be tracked. The paper presents an original localization platform that exploits a single-hop WSN, based on a Microchip MCU and a Cypress RF device, to track its moving nodes. Specifically, the nodes of the network are divided into three sets: the first set consists of anchor nodes that, according to the commands from the sink (the central node of the WSN), generate ultrasonic pulses. These pulses are received by the second set of (moving) nodes, which estimate the pulse time trip and communicate it to the sink. Finally, the last set is constituted by general purpose nodes that collect any kind of data from the surrounding field. The sink gathers all the data, computes the position of moving nodes, and transfers information to external users on the Internet. The algorithms adopted to manage the network and to localize moving nodes are discussed. A working prototype based upon the hardware platform, software, and protocol described in this paper has been deployed and tested, and some results are shown. Simulation results of the localization system are presented to show system scalability.
18
Astanina, Marina, Mikhail Sheremet, U. S. Mahabaleshwar, and Jitender Singh. "Effect of Porous Medium and Copper Heat Sink on Cooling of Heat-Generating Element." Energies 13, no. 10 (2020): 2538. http://dx.doi.org/10.3390/en13102538.
Full textAbstract:
Cooling of heat-generating elements is a challenging problem in engineering. In this article, the transient free convection of a temperature-dependent viscosity liquid inside the porous cavity with copper radiator and the heat-generating element is studied using mathematical modeling techniques. The vertical and top walls of the chamber are kept at low constant temperature, while the bottom wall is kept adiabatic. The working fluid is a heat-conducting liquid with temperature-dependent viscosity. A mathematical model is developed based on dimensionless stream function, vorticity, and temperature variables. The governing properties are the variable viscosity, geometric parameters of the radiator, and size of thermally insulated strip on vertical surfaces of the cavity. The effect of these parameters on the energy transport and circulation patterns are analyzed numerically. Based on the numerical results obtained, recommendations are given on the optimal values of the governing parameters for the effective operation of the cooling system. It is shown that the optimal number of radiator fins for the cooling system configuration under consideration is 3. In addition, the thermal insulation of the vertical walls and the increased thickness of the radiator fins have a negative effect on the operation of the cooling system.
19
McVicker, Gerard, Vijay Khanna, and M. Sri-Jayantha. "Heat Sink Induced Thermomechanical Joint Strain in QFN Devices." Journal of Microelectronics and Electronic Packaging 11, no. 2 (2014): 80–86. http://dx.doi.org/10.4071/imaps.402.
Full textAbstract:
A blade server system (BSS) utilizes voltage regulator modules (VRMs), in the form of quad flat no-lead (QFN) devices, to provide power distribution to various components on the system board. Depending on the power requirements of the circuit, these VRMs can be mounted as single devices or banked together. In addition, the power density of the VRM can be high enough to warrant heat dissipation through the use of a heat sink. Typically, at field conditions (FCs), the BSS are powered on and off up to four times per day, with their ambient temperature cycling between 25°C and 80°C. This cyclical temperature gradient drives inelastic strain in the solder joints due to the coefficient of thermal expansion (CTE) mismatch between the QFN and the circuit card. In addition, the heat sink, coupled with the QFN and the circuit card, can induce additional inelastic solder joint strain, resulting in early solder joint fatigue failure. To understand the effect of the heat sink mounting, a FEM (finite element model) of four QFNs mounted to a BSS circuit card was developed. The model was exercised to calculate the maximum strain energy in a critical joint due to cyclic strain, and the results were compared for a QFN with and without a heat sink. It was determined that the presence of the heat sink did contribute to higher strain energy and therefore could lead to earlier joint failure. Although the presence of the heat sink is required, careful design of the mounting should be employed to provide lateral slip, essentially decoupling the heat sink from the QFN joint strain. Details of the modeling and results, along with DIC (digital image correlation) measurements of heat sink lateral slip, are presented.
20
Roja, A., and B. J. Gireesha. "Second law analysis on Hall effect of natural convection flow through vertical channel in the presence of uniform heat source/sink." International Journal of Numerical Methods for Heat & Fluid Flow 30, no. 10 (2020): 4403–23. http://dx.doi.org/10.1108/hff-10-2019-0767.
Full textAbstract:
Purpose Microfluidics is one of the extensive elaborated technologies in thermal and engineering fields due to its wide range of applications, such as micro heat exchangers, micro mixture and microchannel heat sinks, which is used to develop a large number of microscopic devices and systems. Enhancement of thermal energy using verity of nanoliquids is one of the challenges in these applications of microfluidics. Therefore, using single wall carbon nanotubes for enhancement of thermal energy in microchannel is the main purpose of this study. Hall effect of natural convection flow in a vertical channel with slip and temperature jump condition is considered. The impacts of radiative heat flux, uniform heat source/sink, viscous dissipation and joule heating are also taken into account. Design/methodology/approach Suitable non-dimension variables are applied to the governing equations to reduce the system into ordinary differential equations. The reduced nonlinear system is then solved numerically using Runge–Kutta–Fehlberg fourth–fifth-order method along with shooting technique. The impact of different pertinent parameters on numerical solutions of primary velocity, secondary velocity, temperature, entropy generation and Bejan number is comprehensively discussed in detail. Also, the obtained numerical results are compared with existing one which perfectly found to be in good agreement. Findings It is established that, with the aspects of Joule heating, viscous dissipation, radiative heat flux and uniform heat source/sink, the production in the entropy can be improved. Further, it is found that the increasing ratio of wall ambient temperature difference and nanoparticle volume fraction leads to enhance the entropy generation. The same effect reverses with increasing values of fluid wall interaction parameter (FWIP) and rare faction. The irreversibility ratio enhances with larger values of nanoparticle volume fraction and decelerates with increment values of FWIP. Originality/value The impact of single wall carbon nanoliquid in a vertical channel flow by using radiative heat flux, heat source/sink, joule heating and viscous dissipation is first time investigated. Further, the influence of Hall current is explored in detail.
21
Mahalingam, Raghav, and Ari Glezer. "Design and Thermal Characteristics of a Synthetic Jet Ejector Heat Sink." Journal of Electronic Packaging 127, no. 2 (2004): 172–77. http://dx.doi.org/10.1115/1.1869509.
Full textAbstract:
The design and thermal performance of a synthetic-air-jet-based heat sink for high-power dissipation electronics is discussed. Each fin of a plate-fin heat sink is straddled by a pair of two-dimensional synthetic jets, thereby creating a jet ejector system that entrains cool ambient air upstream of the heat sink and discharges it into the channels between the fins. The jets are created by periodic pressure variations induced in a plenum by electromagnetic actuators. The performance of the heat sink is assessed using a thermal test die encased in a heat spreader that is instrumented with a thermocouple. The case-to-ambient thermal resistance under natural convection with the heat sink is 3.15°C∕W. Forced convection with the synthetic jets enables a power dissipation of 59.2W at a case temperature of 70°C, resulting in a case-to-ambient thermal resistance of 0.76°C∕W. The synthetic-jet heat sink dissipates ∼40% more heat compared to steady flow from a ducted fan blowing air through the heat sink. The synthetic jets generate a flow rate of 4.48 CFM through the heat sink, resulting in 27.8 W/CFM and thermal effectiveness of 0.62. The effect of fin length on the thermal resistance of the heat sink is discussed. Detailed measurements on an instrumented heat sink estimate that the average heat transfer coefficients in the channel flow between the fins is 2.5 times that of a steady flow in the ducts at the same Reynolds Number.
22
Real-Fernández, Navarro-Esbrí, Mota-Babiloni, et al. "Modeling of a PCM TES Tank Used as an Alternative Heat Sink for a Water Chiller. Analysis of Performance and Energy Savings." Energies 12, no. 19 (2019): 3652. http://dx.doi.org/10.3390/en12193652.
Full textAbstract:
Phase change materials (PCMs) can be used in refrigeration systems to redistribute the thermal load. The main advantages of the overall system are a more stable energy performance, energy savings, and the use of the off-peak electric tariff. This paper proposes, models, tests, and analyzes an experimental water vapor compression chiller connected to a PCM thermal energy storage (TES) tank that acts as an alternative heat sink. First, the transient model of the chiller-PCM system is proposed and validated through experimental data directly measured from a test bench where the PCM TES tank is connected to a vapor compression-based chiller. A maximum deviation of 1.2 °C has been obtained between the numerical and experimental values of the PCM tank water outlet temperature. Then, the validated chiller-PCM system model is used to quantify (using the coefficient of performance, COP) and to analyze its energy performance and its dependence on the ambient temperature. Moreover, electrical energy saving curves are calculated for different ambient temperature profiles, reaching values between 5% and 15% taking the experimental system without PCM as a baseline. Finally, the COP of the chiller-PCM system is calculated for different temperatures and use scenarios, and it is compared with the COP of a conventional aerothermal chiller to determine the switch ambient temperature values for which the former provides energy savings over the latter.
23
Faraji, Mustapha. "Cooling Management of Highly Powered Chips Packed in an Insulated Cavity Filled with a Phase Change Material." Journal of Microelectronics and Electronic Packaging 7, no. 2 (2010): 79–89. http://dx.doi.org/10.4071/1551-4897-7.2.79.
Full textAbstract:
This work describes and analyses a novel computer's thermal management system based on a phase change material (PCM) heat storage reservoir. The proposed heat sink consists of a PCM filled enclosure heated by substrate-mounted protruding heat sources (micro processors). PCMs, characterized by high energy storage density and small transition temperature interval, are able to store a high amount of generated heat; which provides a passive cooling of microprocessors. The advantage of this cooling strategy is that the phase change materials are able to absorb a high amount of generated heat without energizing the fan. The proposed strategy is suitable and efficient for situations where the cooling by air convection is not practical (thermal control of recent multiprocessors computers, for example). The problem is modelled as, two dimensional, time dependent and convection–dominated phenomena. A finite volume numerical approach is developed and used to simulate the physical details of the problem. This approach is based on the enthalpy method which is traditionally used to track the motion of the liquid/solid front and obtain the temperature and velocity profiles in the liquid phase. The study gives an instruction on the presentation of PCM heat sink used for cooling management of recent computers. Numerical investigations have been conducted in order to examine the impact of several parameters on the thermal behaviour and efficiency of the proposed PCM-based heat sink. Correlation for the secured operating time (time required by the heat sink before reaching the critical temperature, Tcr) is developed.
24
Gerber, J. D., M. A. Benecke, F. J. Vorster, and E. E. Van Dyk. "Thermal modelling of low concentrator photovoltaic systems." Journal of Energy in Southern Africa 24, no. 1 (2013): 51–55. http://dx.doi.org/10.17159/2413-3051/2013/v24i1a3007.
Full textAbstract:
Efficient thermal management of low concentrator photovoltaic (LCPV) systems will allow maximizing of the power output and may also substantially prolong operating lifetime. For this reason, it is necessary to develop a thorough understanding of the thermal transfer and dissipation mechanisms associated with an LCPV system. The LCPV system under consideration uses a 7-facet reflector optical design, providing a geometric concentration ratio of approximately 4.85. The LCPV system succeeded in increasing the short circuit current from 1A to 5.6A, demonstrating an effective concentration ratio of approximately 4.75. LCPV system temperatures in excess of 80°C were recorded without a thermal management system. A basic thermal model was developed and assessed under various environmental conditions. The effectiveness of a heat-sink, which reduced the temperature difference between the LCPV receiver temperature and the ambient temperature by 37.5%, was also evaluated. The results discussed in this paper will assist the future development of techniques aimed at reducing the high temperatures associated with LCPV systems.
25
Chen, Hui, and Wuyin Jin. "Dynamic Response of a Semiactive Suspension System with Hysteretic Nonlinear Energy Sink Based on Random Excitation by means of Computer Simulation." Complexity 2020 (September 17, 2020): 1–13. http://dx.doi.org/10.1155/2020/3181423.
Full textAbstract:
This paper aims to investigate the property and behavior of the hysteretic nonlinear energy sink (HNES) coupled to a half vehicle system which is a nine-degree-of-freedom, nonlinear, and semiactive suspension system in order to improve the ride comfort and increase the stability in shock mitigation by using the computer simulation method. The HNES model is a semiactive suspension device, which comprises the famous Bouc–Wen (B-W) model employed to describe the force produced by both the purely hysteretic spring and linear elastic spring of potentially negative stiffness connected in parallel, for the half vehicle system. Nine nonlinear motion equations of the half vehicle system are derived in terms of the seven displacements and the two dimensionless hysteretic variables, which are integrated numerically by employing the direct time integration method for studying both the variables of vertical displacements, velocities, accelerations, chassis pitch angle, and the ride comfort and driver safety, respectively, based on the bump and random road inputs of the pseudoexcitation method as excitation signal. Simulation results show that, compared with the HNES model and the magnetorheological (MR) model coupled to the half vehicle system, the ride comfort and stability have been evidently improved. A successful validation process has been performed, which indicated that both the ride comfort and driver safety properties of the HNES model coupled to half vehicle significantly improved.
26
Felsberger, Richard, Armin Buchroithner, Bernhard Gerl, and Hannes Wegleiter. "Conversion and Testing of a Solar Thermal Parabolic Trough Collector for CPV-T Application." Energies 13, no. 22 (2020): 6142. http://dx.doi.org/10.3390/en13226142.
Full textAbstract:
In the field of solar power generation, concentrator systems, such as concentrator photovoltaics (CPV) or concentrated solar power (CSP), are subject of intensive research activity, due to high efficiencies in electrical power generation compared to conventional photovoltaics (PV) and low-cost energy storage on the thermal side. Even though the idea of combining the thermal and electrical part in one absorber is obvious, very few hybrid systems (i.e., concentrator photovoltaics-thermal systems (CPV-T)) are either described in literature or commercially available. This paper features the conversion of a commercial thermal parabolic trough collector to a CPV-T hybrid system using multi-junction PV cells. The design process is described in detail starting with the selection of suitable PV cells, elaborating optical and mechanical system requirements, heat sink design and final assembly. Feasibility is proven by practical tests involving maximum power point tracking as well as empirical determination of heat generation and measurement results are presented.
27
Chen, Zhi Chao, Fu Yang Chen, and Bin Jiang. "A Study on Indoor Environment Monitoring System via WSN." Advanced Materials Research 898 (February 2014): 598–601. http://dx.doi.org/10.4028/www.scientific.net/amr.898.598.
Full textAbstract:
The quality of indoor environment has close relationship with peoples health, while people spend most time indoor during their life time. The development of relative technologies gives us a chance to monitor and change the indoor environment conveniently, such as sensor technology, computer technology and wireless communication technology. WSN (Wireless Sensor Network) has been widely used in many areas and especially in environment monitoring applications. This paper proposes a monitoring system applied in indoor environment which can provide an access to four kinds of parameters, including temperature, humidity, formaldehyde concentration and light intensity. The system is an application of WSN based on TinyOS. The system presented in this thesis is comprised of an upper PC, a sink node and a few sensor nodes. In addition, a monitoring platform with friendly human-machine interface is designed on the upper PC. The result of system test shows that this system can monitor the environmental parameters indoor sequentially and reliably.
28
Jain, Sweta, and Anurag Singh. "Temperature-Aware Routing Using Secondary Sink in Wireless Body Area Sensor Network." International Journal of E-Health and Medical Communications 9, no. 2 (2018): 38–58. http://dx.doi.org/10.4018/ijehmc.2018040103.
Full textAbstract:
Wireless Body Area Sensor Network (WBASN) is a developing application of Wireless Sensor Network (WSN) which is very useful in diagnosis of human health remotely. Tiny and smart sensors are placed inside or outside of human body which collects useful data time to time from various parts of body and send it to the corresponding medical staff or doctor. In the future, WBASN will surely make a huge change in traditional health monitoring system and will be helpful for elderly people and patients who suffer from difficult physical mobility. WBASN have many challenges while its design and one of main challenge is controlling temperature rise of sensor node during routing when placed inside human body because temperature rise beyond certain limit will be harmful for human body. The study of controlling temperature rise of sensor nodes during data routing comes under the category of Temperature Aware Routing Protocols. In this article the authors have raised a problem called “Energy Hole Problem” under Temperature Aware Routing Protocols which affects the performance of a network.
29
Luo, Run, Shripad T. Revankar, and Fuyu Zhao. "Comparative Safety Analysis of Accelerator Driven Subcritical Systems and Critical Nuclear Energy Systems." Applied Sciences 11, no. 17 (2021): 8179. http://dx.doi.org/10.3390/app11178179.
Full textAbstract:
The accelerator driven subcritical system (ADS) has been chosen as one of the best candidates for Generation IV nuclear energy systems which could not only produce clean energy but also incinerate nuclear waste. The transient characteristics and operation principles of ADS are significantly different from those of the critical nuclear energy system (CNES). In this work, the safety characteristics of ADS are analyzed and compared with CNES by a developed neutronics and thermal-hydraulics coupled code named ARTAP. Three typical accidents are carried out in both ADS and CNES, including reactivity insertion, loss of flow, and loss of heat sink. The comparison results show that the power and the temperatures of fuel, cladding, and coolant of the CNES reactor are much higher than those of the ADS reactor during the reactivity insertion accident, which means ADS has a better safety advantage than CNES. However, due to the subcriticality of the ADS core and its low sensitivity to negative reactivity feedback, the simulation results indicate that the inherent safety characteristics of CNES are better than those of ADS under loss of flow accident, and the protection system of ADS would be quickly activated to achieve an emergency shutdown after the accident occurs. For the loss of heat sink, it is found that the peak temperatures of the cladding in the ADS and CNES reactors are lower than the safety limit, which imply these two reactors have good safety performance against loss of heat sink accidents.
30
Mehra, Pawan Singh, Mohammad Najmud Doja, and Bashir Alam. "Enhanced Clustering Algorithm based on Fuzzy Logic (E-CAFL) for WSN." Scalable Computing: Practice and Experience 20, no. 1 (2019): 41–54. http://dx.doi.org/10.12694/scpe.v20i1.1443.
Full textAbstract:
Since longer lifetime of the network is utmost requirement of WSN, cluster formation can serve this purpose efficiently. In clustering, a node takes charge of the cluster to coordinate and receive information from the member nodes and transfer it to sink. With imbalance of energy dissipation by the sensor node, it may lead to premature failure of the network. Therefore, a robust balanced clustering algorithm can solve this issue in which a worthy candidate will play the cluster head role. In this paper, an enhanced clustering algorithm based on fuzzy logic E-CAFL is propound which is an improvement over CAFL protocol. E-CAFL takes account of the residual energy, node density in its locality and distance from sink and feed into fuzzy inference system. A rank of each node is computed for candidature of cluster coordinator. Experiments are performed for the designed protocol to validate its performance in adverse scenarios along with LEACH and CAFL protocol. The results illustrate better performance in stability period and protracted lifetime.
31
Zarrella, Angelo, Roberto Zecchin, Philippe Pasquier, et al. "Analysis of Retrofit Solutions of a Ground Source Heat Pump System: An Italian Case Study." Energies 13, no. 21 (2020): 5680. http://dx.doi.org/10.3390/en13215680.
Full textAbstract:
Ground coupled heat pumps are a notoriously efficient system for heating and cooling buildings. Sometimes the characteristics of the building and the user’s needs are such that the amount of heat extracted from the ground during the winter season can be considerably different from the amount injected in summer. This situation can cause a progressive cooling or heating of the ground with a negative effect on the energy efficiency and correct operation of the system. In these cases, an accurate sizing has to be done. In systems already built, it could be necessary to intervene a posteriori to remedy an excessive ground thermal drift due to the energy unbalance. In this work, such a situation relating to a real office building in Italy is investigated and several solutions are examined, one of which has been then implemented. In particular, a hybrid heat pump using as heat sink both the ground and external air is compared with common solutions through computer simulations using a dedicated numerical model, which has also been compared with monitoring data. As a result, the hybrid heat pump shows better performance and limits the thermal drift of the ground temperature.
32
KENNY, THOMAS W., KENNETH E. GOODSON, JUAN G. SANTIAGO, et al. "ADVANCED COOLING TECHNOLOGIES FOR MICROPROCESSORS." International Journal of High Speed Electronics and Systems 16, no. 01 (2006): 301–13. http://dx.doi.org/10.1142/s0129156406003655.
Full textAbstract:
Recent trends in processor power for the next generation devices point clearly to significant increase in processor heat dissipation over the coming years. In the desktop system design space, the tendency has been to minimize system enclosure size while maximizing performance, which in turn leads to high power densities in future generation systems. The current thermal solutions used today consist of advanced heat sink designs and heat pipe designs with forced air cooling to cool high power processors. However, these techniques are already reaching their limits to handle high heat flux, and there is a strong need for development of more efficient cooling systems which are scalable to handle the high heat flux generated by the future products. To meet this challenge, there has been research in academia and in industry to explore alternative methods for extracting heat from high-density power sources in electronic systems. This talk will discuss the issues surrounding device cooling, from the transistor level to the system level, and describe system-level solutions being developed for desktop computer applications developed in our group at Stanford University.
33
Maguire, Luke, Masud Behnia, and Graham Morrison. "Heat Spreading Enhancement in High Power Amplifier Heat Sinks – Comparison of Measurements with Numerical Predictions." Journal of Microelectronics and Electronic Packaging 1, no. 3 (2004): 117–26. http://dx.doi.org/10.4071/1551-4897-1.3.117.
Full textAbstract:
A comprehensive study has been undertaken to better understand the thermal conditions within high power, radio frequency (r.f.) signal amplifiers. The majority of the heat generated is dissipated from four high power transistors, mounted directly to a large extruded aluminum heat sink measuring 300mm long × 220mm wide × 72mm high. The transistors each dissipate up to 130W across a footprint of only 1.96cm2 and as such, act as high flux, point heat sources across the heat sink base. At maximum power levels the transistor junction temperatures have been shown to approach the manufacturers rated limit of 200°C [1] when ambient temperatures reach 60°C. The prohibitively high cost of replacing the electronic circuits and cooling air delivery system across the entire transmitter network means that design changes to the heat sink that will reduce device temperatures and can be implemented on a retrofit basis are extremely attractive. Numerical and experimental methods have been used to assess the incorporation of high thermal conductivity materials into the heat sink design to improve cooling performance. Numerical simulation of a copper heat spreader embedded into the base of the existing aluminum heat sink predicted a reduction of transistor junction temperatures of up to 11°C. However, in experiments, a maximum temperature drop of only 5°C was achieved due to the introduction of an additional thermal resistance at the copper/aluminum interface.
34
Cho, Young Hoo, Jaehyun Park, Naehyuck Chang, and Jaemin Kim. "Comparison of Cooling Methods for a Thermoelectric Generator with Forced Convection." Energies 13, no. 12 (2020): 3185. http://dx.doi.org/10.3390/en13123185.
Full textAbstract:
A thermoelectric generator (TEG) is a clean electricity generator from a heat source, usually waste heat. However, it is not as widely utilized as other electricity generators due to low conversion efficiency from heat to electricity. One approach is a system-level net power optimization for a TEG system composed of TEGs, heat sink, and fans. In this paper, we propose airflow reuse after cooling preceding TEGs to maximize system net power. For the accurate system net power, we model the TEG system, air, and heat source with proper dimension and material characteristics, and simulate with a computational fluid dynamics program. Next, the TEG power generation and the fan power consumption are calculated in consideration of the Seebeck coefficient and internal electrical resistance varying with hot and cold side temperatures. Finally, we find the optimal number of TEGs and fan speed generating the most efficient system net power in various TEG systems. The results show that the system with a side fan with a specific number of TEGs provides a system net power up to 58.6% higher than when with a top fan. The most efficient system net power with the side fan increases up to four TEGs generating 1.907 W at 13,000 RPM.
35
Frazzica, Andrea, Vincenza Brancato, and Belal Dawoud. "Unified Methodology to Identify the Potential Application of Seasonal Sorption Storage Technology." Energies 13, no. 5 (2020): 1037. http://dx.doi.org/10.3390/en13051037.
Full textAbstract:
In this study, the definition of a new methodology for a preliminary evaluation of the working boundary conditions under which a seasonal thermal energy storage (STES) system operates is described. The approach starts by considering the building features as well as the reference heating system in terms of solar thermal collectors’ technology, ambient heat sinks/source, and space heating distribution systems employed. Furthermore, it is based on a deep climatic analysis of the place where the STES needs to be installed, to identify both winter and summer operating conditions. In particular, the STES energy density is evaluated considering different space heating demands covered by the STES (ranging from 10% up to 60%). The obtained results demonstrate that this approach allows for the careful estimation of the achievable STES density, which is varies significantly both with the space heating coverage guaranteed by the STES as well as with the ambient heat source/sink that is employed in the system. This confirms the need for careful preliminary analysis to avoid the overestimation of the STES material volume. The proposed approach was then applied for different climatic conditions (e.g., Germany and Sweden) and the volume of one of the most attractive composite sorbent materials reported in the literature, i.e., multi-wall carbon nanotubes (MWCNT)-LiCl, using water as the working fluid, needed for covering the variable space heating demand in a Nearly Zero Energy Building (NZEB) was calculated. In the case of Swedish buildings, it ranges from about 3.5 m3 when 10% of the space heating demand is provided by the STES, up to 11.1 m3 when 30% of the space heating demand is provided by the STES.
36
Zhang, Jinhuan, Anfeng Liu, Peng Hu, and Jun Long. "A fuzzy-rule-based packet reproduction routing for sensor networks." International Journal of Distributed Sensor Networks 14, no. 4 (2018): 155014771877401. http://dx.doi.org/10.1177/1550147718774016.
Full textAbstract:
It is a major challenge to transfer target sensing data efficiently to sink in Internet of things. The low-efficiency data transmission can cause low quality of service. To realize the emergent detection and periodic data gathering, the sensed data should be transferred to the sink efficiently and quickly. Recently, there are many related studies. However, there are few researches taking energy efficiency, transport delay, and network reliability into comprehensive consideration. In this article, a novel adaptive green and reliable routing scheme based on a fuzzy logic system is proposed in consideration of energy efficiency, end-to-end transport delay, and network transmission reliability. The key idea of the proposed scheme is to generate different number of renewed packet copies after certain steps according to the fuzzy inference. The fuzzy inference reflects the knowledge that the nodes in the region far to the sink and with more remaining energy initiate and transmit more packet copies concurrently by multiple routing paths to ensure the success rate of data transmission, whereas less. Thus, the high energy efficiency and low latency are obtained for data collection. Our analysis and simulation results show that adaptive green and reliable routing is more superior than the existing scheme.
37
Ahmed, Ghufran, Danish Mehmood, Khurram Shahzad, and Rauf Ahmed Shams Malick. "An efficient routing protocol for internet of medical things focusing hot spot node problem." International Journal of Distributed Sensor Networks 17, no. 2 (2021): 155014772199170. http://dx.doi.org/10.1177/1550147721991706.
Full textAbstract:
The healthcare budget is increasing day-by-day as the population of the world increases. The same is the case regarding the workload of health care workers, that is, doctors and other practitioners. Under such a scenario where workload and cost are increasing drastically, there is a dire need of integrating recent technological enhancements with the said domain. Since the last decade, a lot of work is in the process considering the said integration bringing revolutionary changes. For remote monitoring, existing systems use different types of Internet of things devices that measure different health parameters. One of the major problems in such a system is to find an optimum routing approach that can resolve energy and thermal issues that are taking the limelight in the research arena. In this article, a dynamic routing technique is proposed which is keen to connect multiple in vivo/ex vivo Internet of things devices and a sink (focusing thermal and energy problem) and then forwarding data from sink to remote location for monitoring. Performance parameters are kept energy efficiency and thermal awareness and analytical results show that the proposed protocol supersedes existing approaches in said metrics.
38
Umair, Siddique Mohd, and Nitin Parashram Gulhane. "On numerical investigation of nonuniformity in cooling characteristic for different materials of target surfaces being exposed to impingement of air jet." International Journal of Modeling, Simulation, and Scientific Computing 08, no. 03 (2017): 1750024. http://dx.doi.org/10.1142/s1793962317500246.
Full textAbstract:
Heat transfer using air jet impingement technique is one of the conspicuous tasks in the looming world of electronic packaging system. Here, the material selection of heat sink becomes one of the prior and important assignments to construct a heat sink with desired characteristic cooling rate. In order to study the material effect of heat sink over the cooling characteristic, the present work takes an initiative in plotting the Nusselt magnitude over the radial distance for different material of heat sink. This is done by computing the flow regime and heat transfer characteristic of a 2D axis symmetric geometry in commercial simulating software, ANSYS CFX. The computation of cooling characteristic in form of Nusselt profile is done using SST + Gamma–theta turbulence model. Since the prediction of heat interaction due to the intermediacy and transition in the flow regime is a unique issue of this problem. The results for Nusselt curve signifies a tangible elevation in local Nusselt value (nonuniformity) with decrease in thermal diffusivity of target surface. Also the nonuniformity is observed to vanish above a critical range (66.76[Formula: see text]mm2/s) of thermal diffusivity. This happens due to presences of abnormal turbulence of heat flow which occurs inside the target surface. Since the variation in thermal diffusivity causes some imbalance competition between the heat storage and dissipation capabilities. Above all the target surface carrying thermal diffusivity less than 66.76[Formula: see text]mm2/s possesses a dominating heat storage capability, on behalf of which some heat transfer occurring in near jet and far jet regions are being restricted. These are transferred towards stagnation region in radial direction.
39
C, Jothi Kumar, and Revathi Venkataraman. "EODC: An Energy Optimized Dynamic Clustering Protocol for Wireless Sensor Network using PSO approach." International Journal of Computers Communications & Control 14, no. 2 (2019): 183–98. http://dx.doi.org/10.15837/ijccc.2019.2.3379.
Full textAbstract:
Wireless Sensor Network comprises of a number of small wireless nodes whose role is to sense, gather, process and communicate. One of the primary concerns of the network is to optimize the energy consumption and extend the network lifespan. Sensor nodes can be clustered to increase the network lifespan. This is done by selecting the cluster head for every cluster and by performing data fusion on the cluster head. The proposed system is using an energy efficient hierarchical routing protocol named Energy Optimized Dynamic Clustering (EODC) for clustering large ad-hoc WSN and route the data towards the sink. The sink receives the data collected from the set of cluster heads after every round. The cluster head was selected using Particle Swarm Optimization (PSO) approach and the cluster members are allocated based on Manhattan distance. The metrics used to find the fitness function are location, link quality, energy of active node and energy of inactive node. The system employs shortest path approach to communicate between the cluster heads till it reaches the base station. By this, we have increased the energy efficiency and lifetime of the network. The analysis and outcomes show that the EODC was found to outperform the existing protocol which compares with this algorithm.
40
Im, Piljae, Xiaobing Liu, and Hugh Henderson. "Operational Performance Characterization of a Heat Pump System Utilizing Recycled Water as Heat Sink and Heat Source in a Cool and Dry Climate." Energies 11, no. 1 (2018): 211. http://dx.doi.org/10.3390/en11010211.
Full textAbstract:
The wastewater leaving from homes and businesses contains abundant low-grade energy, which can be utilized through heat pump technology to heat and cool buildings. Although the energy in the wastewater has been successfully utilized to condition buildings in other countries, it is barely utilized in the United States, until recently. In 2013, the Denver Museum of Nature & Science at Denver, the United States implemented a unique heat pump system that utilizes recycled wastewater from a municipal water system to cool and heat its 13,000 m2 new addition. This recycled water heat pump (RWHP) system uses seven 105 kW (cooling capacity) modular water-to-water heat pumps (WWHPs). Each WWHP uses R-410A refrigerant, has two compressors, and can independently provide either 52 °C hot water (HW) or 7 °C chilled water (CHW) to the building. This paper presents performance characterization results of this RWHP system based on the measured data from December 2014 through August 2015. The annual energy consumption of the RWHP system was also calculated and compared with that of a baseline Heating, Ventilation, and Air Conditioning (HVAC) system which meets the minimum energy efficiencies that are allowed by American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 90.1-2013. The performance analysis results indicate that recycled water temperatures were favorable for effective operation of heat pumps. As a result, on an annual basis, the RWHP system avoided 50% of source energy consumption (resulting from reduction in natural gas consumption although electricity consumption was increased slightly), reduced CO2 emissions by 41%, and saved 34% in energy costs as compared with the baseline system.
41
Sivaraja, Subramania Pillai, P. K. Balakumar, G. Sudha, and R. Parthiban. "Heat Transfer Analysis of Extruded Rectangular Fin over Conventional Rectangular Fins by Numerical Simulation." Applied Mechanics and Materials 812 (November 2015): 130–35. http://dx.doi.org/10.4028/www.scientific.net/amm.812.130.
Full textAbstract:
Improving the performance of the computers and maintaining the operating temperature is an important task for the computer hardware manufacturers. The junction temperature of the electronic components is a critical problem which needs to be addressed in a competent way. Due to the improvement in the technology, the size and weight of the electronic components reduced to a greater extent and which in turn increases the operating power and speed. This increases the heat generated by the electronic component. Electronic components normally use conventional rectangular fin as heat sink for the step up in heat transfer. The need is to make a heat sink design that should overcome the problem related to transfer of heat by the electronic components. The heat transfer depends on parameters like heat sink’s surface area, pitch, design and material used. Optimization of the fin design by number of experiments is more expensive and laborious as well. CFD (Computational Fluid Dynamics) simulation validated with experimentation can be a good alternative for performing series of experiments. CFD modeling and simulation for the best fin design has been carried out for the current study. An alternative design for conventional rectangular fin has been proposed for this study called as Extruded Rectangular Fin (ERF). The proposed ERF shows good heat transfer when compared to conventional and interrupted rectangular fin with holes. Optimum cooling achieved for the system with the fin aspect ratio of 3.5.
42
Yu, A. Long, Wei Wei Yang, and Jing Qiao Dai. "Large-Scale Structural Health Monitoring Based on Wireless Sensor Networks." Applied Mechanics and Materials 644-650 (September 2014): 1317–23. http://dx.doi.org/10.4028/www.scientific.net/amm.644-650.1317.
Full textAbstract:
For large-scale structural damage in various forms, a single regional monitoring is difficult to finish. The paper introduces a design method of a large-scale structural health monitoring system based on wireless sensor networks. ZigBee wireless communication technology is used for the system. The ZigBee-based double wireless sensor network architecture is designed. The wireless sensor node, sink node, a gateway node of this system is designed by using the CC2530 chip as core of data processing and wireless transceiver. In the IAR development platform, the lower position machine software is designed by using C language and the LabVIEW is used to finish the remote display in the host computer. The results show that the monitoring system meets the design requirements, has the advantage of good on-line and real-time monitoring etc.
43
Abdu, Abdullahi Ibrahim, Oguz Bayat, and Osman Nur Ucan. "Designing insistence-aware medium access control protocol and energy conscious routing in quality-of-service-guaranteed wireless body area network." International Journal of Distributed Sensor Networks 15, no. 1 (2019): 155014771881584. http://dx.doi.org/10.1177/1550147718815843.
Full textAbstract:
Wireless body area network is a type of wireless sensor network that enables efficient healthcare system. To minimize frequent sensor replacement due to resource restrictions, it is necessary to improve energy efficiency in wireless body area network. This article deals with energy efficiency and quality-of-service improvement together in novel wireless body area network architecture. A novel wireless body area network architecture is designed with dual sink nodes in order to minimize delay and energy consumption. A novel insistence-aware medium access control protocol which is aware of criticality of sensed data is presented in the proposed wireless body area network. Prior knowledge-based weighted routing algorithm is responsible to select optimal route for data transmission. In prior knowledge-based weighted routing, weight value is computed by considering significant metrics such as residual energy, link stability, distance, and delay in order to improve energy efficiency and quality of service in the network. Energy consumption is further minimized by incorporating graph-based sleep scheduling algorithm. In graph-based sleep scheduling, criticality of sensor node is also considered as major metric. In coordinator, split and map–based neural network classifier is involved to perform packet classification. After classification, packets are assigned to corresponding sink node according to packet type. Then, throughput and delay metrics are improved by frame aggregation process which is involved in sink node. Extensive simulation in OMNeT++ shows better performance in network lifetime, throughput, residual energy, dropped packets, and delay.
44
Septiadi, Wayan Nata, Fazlur Rahman, Made Ricki Murti, et al. "Thermal Resistance of Cascade Heat Pipe as CPU Cooling System to Maintain Safe Temperature for Computer." Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 81, no. 1 (2021): 165–73. http://dx.doi.org/10.37934/arfmts.81.1.165173.
Full textAbstract:
Computer will overheat quickly if used in a state of full load continuously. One component on a computer that generates heat is the central processing unit (CPU) which is a key component on a computer where program instructions are processed. One of the right solutions to cool the CPU is the use of heat pipes as cooling system, using several size container, loaded with a special liquid liquid to deliver the heat from the evaporator zone to the other end called condenser zone, but because the heat pipe condenser output temperature is still high therefore a cascade heat pipe was created to lower the output temperature. In this study there are four CPU cooling systems used namely single condenser cascade heat pipe and a double condenser cascade heat pipe, while others two cooling systems as a comparison namely non-cascade heat pipe and non-cascade heat pipe with fan. This study aims to find out the cooling performance of cascade heat pipe as CPU cooling system in a small form factor desktop PC by testing variations in workload, the workload given is idle load (12W) where the processor only runs the operating system without the software load so the processor utilization is only 1% -10%. Next is the medium load (30W) that uses 2 threads with processor utilization of 50% -90%. The last workload is full load (35W) with the number of threads used being 4 with processor utilization of 90% -100%. This research found that the thermal resistance of the cascade heat pipe tended to be higher than that of the non-cascade heat pipe, however the increase that occurred was not too large compared to the resulting performance of 60.2°C in the processor and 40.4°C in the heat sink for the cascade double condenser, the operating temperature of the CPU does not increase significantly as the thermal resistance increases on the cascade heat pipe.
45
Dai, SC, and HT Chen. "Optical design and thermal analysis of high-power light-emitting diode array modules." SIMULATION 88, no. 12 (2012): 1475–83. http://dx.doi.org/10.1177/0037549712457424.
Full textAbstract:
In this paper, the optical-thermal characteristics for single-power light-emitting diodes (LEDs) are firstly studied based on experiment and theory, with both results in good agreement. Based on the results of single-power LED, an optical system is proposed with thermal-optical LED array modules, which are assembled upon a spherical base plate with heat sink. By simulation, the optical system is proved to provide uniform illumination. The luminance uniformity of the illuminated target is up to 0.9. The thermal effects under different heat convection coefficient and power consumption on the LED array modules are discussed in detail. Based on the heat transfer characteristics for the LED system, the approximate allowable power consumption for modules can be found.
46
Hassan, M. R. "System Reliability Optimization of Multi-Source Multi-Sink Stochastic Flow Networks With Budget Constraint." International Journal of Reliability, Quality and Safety Engineering 28, no. 04 (2021): 2150025. http://dx.doi.org/10.1142/s021853932150025x.
Full textAbstract:
In this paper, we investigate system reliability optimization of multi-source multi-sink flow networks subject to transmission budget constraints. More specifically, we present a mathematical model of the optimization problem and a genetic algorithm (GA) to solve it. The GA is based on determining the optimal set of lower boundary points that maximize system reliability such that transmission cost does not exceed a specified upper bound. Finally, to ensure the efficiency of our approach, we apply our proposed algorithm to various network examples.
47
Wu, Shang-Chen, Jong-Chyuan Tzou, and Cheng-Yu Ding. "A Low-Cost System for Measuring Wind Speed and Direction Using Thermopile Array and Artificial Neural Network." Applied Sciences 11, no. 9 (2021): 4024. http://dx.doi.org/10.3390/app11094024.
Full textAbstract:
Recent developments in wind speed sensors have mainly focused on reducing the size and moving parts to increase reliability and stability. In this study, the development of a low-cost wind speed and direction measurement system is presented. A heat sink mounted on a self-regulating heater is used as means to interact with the wind changes and a thermopile array mounted atop of the heat sink is used to collect temperature data. The temperature data collected from the thermopile array are used to estimate corresponding wind speed and direction data using an artificial neural network. The multilayer artificial neural network is trained using 96 h data and tested on 72 h data collected in an outdoor setting. The performance of the proposed model is compared with linear regression and support vector machine. The test results verify that the proposed system can estimate wind speed and direction measurements with a high accuracy at different sampling intervals, and the artificial neural network can provide significantly a higher coefficient of determination than two other methods.
48
Patowari, Promod Kumar, Ambarish Maji, and Dipankar Bhanja. "Computational investigation and optimisation study on system performance of heat sink using perforated pin fins mounted at different angles." Progress in Computational Fluid Dynamics, An International Journal 19, no. 6 (2019): 381. http://dx.doi.org/10.1504/pcfd.2019.10024493.
Full text
49
Maji, Ambarish, Dipankar Bhanja, and Promod Kumar Patowari. "Computational investigation and optimisation study on system performance of heat sink using perforated pin fins mounted at different angles." Progress in Computational Fluid Dynamics, An International Journal 19, no. 6 (2019): 381. http://dx.doi.org/10.1504/pcfd.2019.103262.
Full text
50
Bylykbashi, Kevin, Evjola Spaho, Ryoichiro Obukata, Kosuke Ozera, Yi Liu, and Leonard Barolli. "Implementation and evaluation of an ambient intelligence testbed." International Journal of Web Information Systems 14, no. 1 (2018): 123–35. http://dx.doi.org/10.1108/ijwis-12-2017-0082.
Full textAbstract:
Purpose The purpose of this work is to implement an ambient intelligence (AmI) testbed to improve human sleeping conditions. Design/methodology/approach The implemented testbed is composed of the sensor node, sink node and actor node. As sensor node, the authors use a microwave sensor module (MSM) called DC6M4JN3000, which emits microwaves in the direction of a human or animal subject. These microwaves reflect back off the surface of the subject and change slightly in accordance with movements of the subject’s heart and lungs. As sink node, the authors use Raspberry Pi 3 Model B computers. In the sink node, the data are processed and then clustered by the k-means clustering algorithm. Then, the result is sent to the actor node (Reidan Shiki PAD module), which can be used for cooling and heating the bed. Findings The authors carried out simulations and experiments. Based on the simulation results, it was found that the room lighting, humidity and temperature have different effects on humans during sleeping. The best performance is shown when LIG parameter is 10 units, HUM parameter is 50 and TEM parameter is 25. Based on experimental results, it was found that the implemented AmI testbed has a good effect on humans during sleeping. Research limitations/implications For simulations, three input parameters were considered. However, new parameters that affect human sleeping conditions also need to be investigated. Further, the experiments were carried out for one person. More extensive experiments with multiple people are needed to have a better evaluation. Originality/value In this research work, a new fuzzy-based system was implemented to improve human sleeping conditions. The authors presented three new input parameters to evaluate the output (sleeping condition). The authors implemented and evaluated a testbed and showed that the implemented AmI testbed has a good effect on humans during sleeping, thus improving their quality of life (QoL).