Academic literature on the topic 'Regular heating mode'
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Journal articles on the topic "Regular heating mode"
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Tkachenko, Stanislav, Olga Vlasenko, and Natalia Rezydent. "Heat Exchange of the Cylindrical Liquid Body of a Limited Height with the Environment." NTU "KhPI" Bulletin: Power and heat engineering processes and equipment, no. 2 (December 30, 2021): 27–30. http://dx.doi.org/10.20998/2078-774x.2021.02.05.
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The experimental investigations of the intensity of the heat exchange between the internal surface of the thin-wall metal cylinder and the studied liquid medium were carried out in conditions of its cooling (heating), i.e. under nonstationary heat exchange conditions. The existence of the regular thermal mode in the liquid medium surrounded by the thin-wall metal cylinder has been established. Local in time heat loss coefficients were derived using appropriate dimensionless equations for the stationary mode conditions of heat-exchange in a large volume. Heat loss coefficients were determined using regular thermal mode methods and computational-&-experimental heat loss coefficients. The changes in the relative values of the heat loss coefficients were analyzed using the method of regular thermal mode and computational-&-experimental heat loss coefficients. The deviations in the values of given coefficients in time are mainly within ± 10 %. Relative values of the heat loss coefficients deviate within ± 40 % using appropriate dimensionless equations for the conditions of the stationary mode of heat exchange in a large volume. This conclusion is natural because the cooling (heating) process is nonstationary.
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DMITRIENKO, I. S. "Resonant absorption and heating in a nonlinear dissipative resonance layer." Journal of Plasma Physics 67, no. 1 (2002): 59–71. http://dx.doi.org/10.1017/s0022377801001465.
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The technique for analytical investigation of the Alfvén resonance, proposed by Dmitrienko [J. Plasma Phys.57, 311 (1997); 62, 145 (1999)] is used to obtain the matching conditions and to calculate the rate of resonant absorption and heating in a nonlinear dissipative resonance layer. It is shown that one matching condition is the invariability condition for the coefficient of the singular part of the solution describing the MHD mode outside the resonance layer, and the other condition is a jump of the coefficient of a regular solution, the value of which depends on the ratio of the dissipative to nonlinear spatial scales. It is established that the ratio of the jump of the imaginary part of the regular solution to the coefficient of the singular solution is exactly equal to the rate of resonant heating, and this heating is calculated as a function of the ratio of the linear dissipative to nonlinear scales. The resonant absorption coefficient is calculated as well. It is shown that the nonlinearity leads to a decrease of the heating rate and the absorption coefficient compared with those predicted by linear theory.
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Zhu, Jiayin, Yingfang Liu, Ruixin Li, Bin Chen, Yu Chen, and Jifu Lu. "Thermal Storage Performance of Underground Cave Dwellings under Kang Intermittent Heating: A Case Study of Northern China." Processes 10, no. 3 (2022): 595. http://dx.doi.org/10.3390/pr10030595.
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The intermittent heating mode of Kang plays an important role in the heat storage and release in cave dwellings. However, research on the effect of Kang heating on the thermal process of traditional buildings is rare. Therefore, based on long-term monitoring of cave dwellings, regular conclusions about the influence of Kang heating on the thermal environment were obtained. Furthermore, an unsteady heat transfer model of the envelope was proposed for the first time. Then, based on this model, the thermal storage performance of cave dwellings during the period of Kang intermittent heating was explored. The results showed that, due to Kang heating, the indoor air temperature of cave dwellings could be increased by an average of 3.1 °C. Furthermore, the inner walls had a large thermal mass and the maximum heat storage in a single day was 487.75 kJ/m2, while the maximum heat release was 419.02 kJ/m2. The heat release at night could reach 87%. In this paper, the law of thermal storage and release characteristics of earthen building envelopes under intermittent heating was firstly obtained. Results can enrich the thermal process theory of earthen buildings and provide a theoretical basis and technical support for building thermal environmental construction.
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Zhu, Lin, and Hai Zhang. "Application of WSN in the Remote Monitoring for Heating Network." Applied Mechanics and Materials 392 (September 2013): 791–95. http://dx.doi.org/10.4028/www.scientific.net/amm.392.791.
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For the characteristics of urban centralized heating system are wide geography coverage and large span of density distribution in the monitoring system but having regular, the paper put forward a remote communication mode combined by WSN and GPRS. As the background of the remote monitoring for the client operating condition in heating network, the paper elaborate the structure of urban remote monitoring system for heating network, and the design idea of its hardware and software. As well as the WSN self-organized protocol is analyzed carefully. The scheme can effectively solve the industrial field problem, which industrial environment is difficult to wire, and the construction and running cost is high in the remote monitoring system. It also has high application value.
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Ziatdinov, Mansur, Zhukov Alexander, Vladimir Promakhov, and Nikita Schulz. "Combustion Synthesis of Chromium Nitrides." Metals 9, no. 1 (2019): 98. http://dx.doi.org/10.3390/met9010098.
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This paper explores different modes of synthesis by combustion of chromium-nitrogen and ferrochromium-nitrogen alloys. The SH-synthesis of chromium nitrides and ferrochromium nitrides was performed. Regular patterns in layer-by-layer and surface modes of Cr combustion in nitrogen were investigated. The mechanism of non-stationary combustion during the synthesis of chromium was investigated. Regular patterns of chromium and ferrochromium combustion in the cocurrent filtration mode were analyzed, and the possibility to intensify the SHS process using the pressure filtration principle was assessed. The process of chromium powder combustion in the cocurrent flow of nitrogen-containing gas in the range of specific flow rates from 20 cm3/s·cm2 was investigated. Pressure filtration intensifies the process of combustion wave propagation in the Cr–N2 system. Here, the combustion rate increases while the degree of nitridation decreases. We discovered superadiabatic heating modes when the reaction zone was blown with pure nitrogen and a nitrogen-argon mixture. The tempering mode that was realized during pressure filtration allows for the uptake of high-temperature single-phase non-stoichiometric phases of Cr2N.
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Tkachenko, Stanislav, Olha Vlasenko, Nataliia Rezydent, Dmytro Stepanov, and Nataliia Stepanova. "Cooling and heating of the fluid in the cylindrical volume." Acta Innovations, no. 42 (March 14, 2022): 15–26. http://dx.doi.org/10.32933/actainnovations.42.2.
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Experimental studies of the non-stationary heat exchange in the system «environment I – body II» have been carried out. It is established that in the body II, which consists of the fluid and thin-walled metal envelope, the characteristic features of the regular thermal mode occur, i.e., cooling (heating) rate of the body II- m = const; heat transfer coefficient between the water (environment I) and body II is practically stable α1 = const; uneven temperatures distribution coefficient in the body II ψ = const. This new notion of the heat transfer regularities in the body II is planned to apply for further development of the experimental-calculation method for the forecasting of the heat exchange intensity in the compound fluid media with limited information regarding thermophysical and rheological properties.
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Baida, Evgen, and Oleksandr Chepeliuk. "Advanced method for determining the steady temperature and constant heating time of electric apparatus." Bulletin of NTU "KhPI". Series: Problems of Electrical Machines and Apparatus Perfection. The Theory and Practice, no. 1 (5) (May 28, 2021): 8–12. http://dx.doi.org/10.20998/2079-3944.2021.1.02.
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The article proposes an improvement in the method for determining the steady-state heating temperature of current-carrying parts of an electrical apparatus and its time constant in the case of real measurements of temperature values made with some error. In accordance with the specified method, at a known ambient temperature, the apparatus is turned on with the measurement of its heating temperature at regular intervals; based on the measurement data, a graph of the temperature derivative is plotted over time; according to the data of the graph, the steady-state temperature and the constant heating time are determined. It is shown that inaccuracies in temperature measurement can significantly distort the dependences obtained for determining the time constant and the steady-state heating temperature, and for a correct estimation of the parameters, the form of the approximating function of the temperature derivative with respect to time must be known a priori - a linear function. This method can significantly reduce the time for testing electrical devices for heating in continuous operation. This method is illustrated by the example of determining the heating of the coil over time by measuring the active resistance. On the basis of the obtained and processed experimental data, the power overload coefficients are also determined in the long-term operation mode, as well as in the short-term and intermittent modes, which makes it possible to correctly operate the electrical apparatus.
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Osipov, V. S., та A. S. Terenchenko. "Evaluation of the internal combustion engine pre-heating methods and their influence on the cold engine start performance at an ambient temperature of –40°C". Trudy NAMI, № 1 (24 березня 2022): 17–25. http://dx.doi.org/10.51187/0135-3152-2022-1-17-25.
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Introduction (statement of the problem and relevance). Starting an internal combustion engine (ICE) at negative ambient temperatures is difficult for a number of reasons. A decrease in the volatility of gasoline leads to the liquid fuel deposition on the cylinder walls, as a result of which the fuel-air mixture ignition is difficult or impossible. Another reason is the geometric dimensions reduction of the gaps in the plain bearings, which is a consequence of the use of materials with different thermal expansion coefficients in the engine design. The high kinematic viscosity of the oil creates a higher hydraulic resistance in the system. These factors complicate the engine oil flow to friction pairs, which can lead to an oil starvation and bearing shell life reduction.The purpose of the research was to determine the optimal pre-heating mode from the point of view of the process energy efficiency and the preservation of the engine resource.Methodology and research methods. To control the thermal state, the internal combustion engine and the cooling circuit were equipped with measuring equipment. The values of temperature, pressure and volume flow sensors were recorded. To implement the pre-heating modes proposed in the article, an engineering engine control unit was used, which allowed making changes in the basic software configuration.Scientific novelty and results. An alternative method of pre-heating has been proposed, including preheating of the engine oil-water heat exchanger to reduce the time for reaching the minimum oil pressure at the main gallery inlet during a cold start. The article provides descriptions of the regular and proposed pre-heating cycles, their assessment in accordance with the represented criteria. Experimental data on pre-heating cycles and cold starts at an ambient temperature of –40°C are presented. The necessity of warming up the engine standard water-oil heat exchanger before a cold start has been experimentally proved, the curves of pressure changes at the main gallery inlet, depending on the pre-heating mode, are given.Practical significance. Reducing the negative influence of cold start on the ICE resource.
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Sabater, Carlos, Carlos Untiedt, and Jan M. van Ruitenbeek. "Evidence for non-conservative current-induced forces in the breaking of Au and Pt atomic chains." Beilstein Journal of Nanotechnology 6 (December 9, 2015): 2338–44. http://dx.doi.org/10.3762/bjnano.6.241.
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This experimental work aims at probing current-induced forces at the atomic scale. Specifically it addresses predictions in recent work regarding the appearance of run-away modes as a result of a combined effect of the non-conservative wind force and a ‘Berry force’. The systems we consider here are atomic chains of Au and Pt atoms, for which we investigate the distribution of break down voltage values. We observe two distinct modes of breaking for Au atomic chains. The breaking at high voltage appears to behave as expected for regular break down by thermal excitation due to Joule heating. However, there is a low-voltage breaking mode that has characteristics expected for the mechanism of current-induced forces. Although a full comparison would require more detailed information on the individual atomic configurations, the systems we consider are very similar to those considered in recent model calculations and the comparison between experiment and theory is very encouraging for the interpretation we propose.
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Shelimanova, O., and V. Tkachenko. "Development of technological line for obtaining flax trust." Energy and automation, no. 6(58) (November 24, 2021): 118–28. http://dx.doi.org/10.31548/energiya2021.06.118.
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One of the most effective ways to intensify heat transfer when blowing surfaces with air is jet blowing. High intensity of transfer processes during jetting, relatively low energy costs for its implementation, simplicity and flexibility of control of this process have led to its widespread use in various fields. Mathematical modeling of heat transfer regularities in systems of impact jets is significantly complicated due to the three-dimensional nature of the flue-channel flow near the surfaces of complex shape. Therefore, it is advisable to use experimental research methods. The purpose of this study is to justify the use of the method of regular thermal regime to determine the average heat transfer coefficient during jet cooling of the surface. Regular mode of cooling (heating) of bodies is characterized by the fact that the relative rate of change of excess temperature for all points of the body remains constant. Since the thermal model was made of a highly thermally conductive duralumin alloy, the condition Bi <0.1 was met, when the average temperatures on the surface and volume will be the same. Therefore, the experiments recorded the readings of only one thermocouple. To compare the results of this experimental study with the results of other authors, cases of blowing a smooth concave surface with single - and three - row jet systems were chosen. The first case was studied in [3,4], the second - in [5]. The results of the performed test experiments agree satisfactorily with the data of these works, which were obtained both by the method of regular mode [5] and other methods of recording heat fluxes ([3] - passive heat flux sensor; [4] - electrocalorimetry). The difference between the average heat transfer coefficients and the known literature data does not exceed ±7..12%, which indicates a sufficient probability of the results obtained in this work, and the possibility of using the method of regular thermal regime in the study of jet cooling of complex bodies. Key words: heat exchange, jet system, cooling, concave surface
Dissertations / Theses on the topic "Regular heating mode"
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Сотник, Ірина Миколаївна, Ирина Николаевна Сотник, Iryna Mykolaivna Sotnyk, Микола Іванович Сотник, Николай Иванович Сотник та Mykola Ivanovych Sotnyk. "Впровадження режимів чергового опалення як організаційний чинник підвищення енергоефективності бюджетних установ". Thesis, ХНЕУ ім. С. Кузнеця, 2016. http://essuir.sumdu.edu.ua/handle/123456789/44585.
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Проаналізовано проблеми забезпечення ефективності теплоспоживання бюджетними установами України. Визначено напрями оптимізації витрат на опалення будівель. Обґрунтовано економічну доцільність впровадження індивідуальних режимів теплоспоживання (чергового опалення) бюджетними закладами.<br>Проанализированы проблемы обеспечения эффективности теплопотребления бюджетными учреждениями Украины. Определены направления оптимизации затрат на отопление зданий. Обоснована экономическая целесообразность внедрения индивидуальных режимов теплопотребления (дежурного отопления) бюджетными учреждениями.<br>There are analyzed problems of ensuring the effectiveness of heat consumption by budget institutions of Ukraine. The ways to optimize costs for heating buildings are determined. There is substantiated the economic expediency of individual heat consumption modes (regular heating) for budgetary institutions.
Book chapters on the topic "Regular heating mode"
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Frolova, Tetyana, Vyacheslav Buts, Gennadiy Churyumov, Eugene Odarenko, and Vladimir Gerasimov. "Microwave Heating of Low-Temperature Plasma and Its Application." In Microwave Heating - Electromagnetic Fields Causing Thermal and Non-Thermal Effects. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.97167.
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In this chapter, the results of theoretical and experimental studies of the interaction of an electromagnetic field with a plasma (fundamental interaction of the wave-particle type) both in the regime of standing waves (in the case of a resonator) and in the case of traveling waves in a waveguide are presented. The results of computer modeling the distribution of a regular electromagnetic field for various designs of electrodynamic structures are considered. The most attractive designs of electrodynamic structures for practical application are determined. A brief review and analysis of some mechanisms of stochastic plasma heating are given as well as the conditions for the formation of dynamic chaos in such structures are determined. Comparison analysis of microwave plasma heating in a regular electromagnetic field (in a regime with dynamical chaos) with plasma heating by random fields is considered. It is shown, that stochastic heating of plasma is much more efficient in comparison with other mechanisms of plasma heating (including fundamental interaction of the wave-wave type). The results obtained in this work can be used to increase the efficiency of plasma heating as well as to develop promising new sources of electromagnetic radiation in the microwave and optical ranges.
Conference papers on the topic "Regular heating mode"
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Liu, Yu-Cheng, Mihai G. Burzo, Scott Sier, and Cassandra Ellis. "Improved Thermal Comfort of Office Occupants Through Better Air Diffuser Designs." In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-52879.
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In this work we are exploring the influence of the design of air diffusers on a number of parameters that influence the thermal comfort of building occupants. In particular we are looking at calculating the Air Diffusion Performance Index (ADPI) and vertical temperature difference as well as the throw and drop parameters for various diffuser designs. The results show that while a complex radial vane diffuser that uses the Coanda effect could offer good performance if the HVAC system is used for cooling, the same design might not give any advantage as compared to a regular multi-cone design while the system is used for heating. This is mostly due to the strong air stratification observed for both diffuser designs, while the HVAC system is in the heating mode. Consequently we propose a better alternative, namely, to use a variable geometry (angle) air diffuser. To prove this concept we performed a CFD analysis of several diffusers, each delivering the air at different angles, for both heating and cooling mode, and we show that indeed using a design that allows changing the angle of the air jets between the heating and cooling season is the optimal way of delivering air to a room.
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Guo, Yifan, Vijay Sarihan, and Tom Lee. "Accelerated Reliability Testing Method for Sensors With a Pulsing Membrane Structure." In ASME 1997 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/imece1997-1223.
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Abstract In chemical sensors, the sensing element is heated to a high temperature (around 450°C) for optimizing sensitivity and selectivity. In order to minimize power dissipation, the power supply for the heating is operated in a pulsed mode. The duration of the high temperature period is set by the required sensor response time for low gas concentrations. In qualification of chemical sensors, it is important to test the reliability of the membrane structures under realistic conditions of pulsed-mode operation. From these data, it is possible to link time-to-failure with changes in material or layout design. Under the operation condition, the cyclic power input generates local heat and thermal gradient in the membrane as well as physical deformation and local stress. The regular reliability test — thermal cycles with isothermal temperature distribution — cannot simulate the membrane stress or induce the failure processes that occur in the membrane, heater or sensor films under real operational conditions. This paper describes a unique testing technique which is suited for reliability tests and field life prediction in a pulsed sensor. The methods of determining the acceleration factor and the procedures to execute the life test are discussed. Using this testing method, the fatigue life of the sensor configurations can be evaluated within a much shortened testing time.
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Nagy, Lukas, and Viera Stopjakova. "Self-heating spectre model of high frequency voltage regulator." In 2013 21st Telecommunications Forum Telfor (TELFOR). IEEE, 2013. http://dx.doi.org/10.1109/telfor.2013.6716286.
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Zhang, Yuzhe, Shan Liang, Yupeng Yuan, and Qingyu Xiong. "Model reference adaptive controller to regulate sample temperature in microwave heating application." In 2015 34th Chinese Control Conference (CCC). IEEE, 2015. http://dx.doi.org/10.1109/chicc.2015.7260133.
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Chamoun, George, Wayne Strasser, Renato Acosta Herrera, and Bob Casper. "Numerical and Experimental Investigations of Non-Newtonian Polymer Heating in a Static Mixer." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-63195.
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A non-Newtonian polymer is heated by co-current hot water in an insulated jacketed pipe. Both the viscosity and density depend on the temperature and shear rate. The polymer passes through two static mixers which are manufactured by KOFLO and are intended to accelerate the heating process. Each static mixer’s length to diameter ratio is approximately 16. An experiment was carried out in which the temperature of the polymer was measured directly downstream of the first static mixer with a thermocouple. The results from a 3D computational model were compared with those from an experiment. It was found that the polymer’s temperature rise with the simulation was within 6.5% of the experiment. The heating performance and residence time were also compared with a regular pipe.
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Cosentino, Sara, Elisa Guelpa, Roberto Melli, et al. "Optimal Operation and Sensitivity Analysis of a Large District Heating Network Through POD Modeling." In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-39509.
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District heating networks (DHNs) are crucial infrastructures for the implementation of energy efficiency and CO2 reduction plans, especially in countries with continental climate. DHNs are often complex systems and their energy performance may be largely affected by the operating conditions. Optimal operation of DHNs involves the optimization of the pumping system. This is particularly important for large networks and for low temperature networks. A common practice to perform optimization consists in using a phyical model. Nevertheless, simulation and optimization of DHNs may involve large computational resources, because of thire possible large extension and the number of scenarios to be examined. A reduced model, obtained from the physical model, can be effectively applied to multiple simulations of a network, with significant reduction of the computational time and resources. In this paper, a large district heating system, which supplies heating to a total volume of buildings of about 50 million of cubic meters, is considered. The use of a reduced model based on proper orthogonal decomposition (POD) is investigated. Various operating conditions corresponding to partial load operation are analyzed using a fluid-dynamic model of the network. Results show that optimal settings are not particularly regular with respect to load variation. This means that any variation in the thermal load generally involves changes in the set points of all groups. For this reason, a sensitivity analysis is performed using the POD model in order to check the opportunities to limit the number of variations in the pumping settings without significant penalization of the total pumping power. The proposed approach is shown to be very effective for the optimal management of complex district heating systems.
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Wu, Yuan Ting, Zhi-feng Huang, Pei-feng Hsu, and Huaichun Zhou. "A Hybrid Partial Coherence and Geometry Optics Model of Thin Film Optics on Coated Rough Surfaces." In ASME 2012 Third International Conference on Micro/Nanoscale Heat and Mass Transfer. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/mnhmt2012-75184.
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Thermal and optical engineering applications of electromagnetic wave reflectance from rough surfaces include temperature measurement, radiation heating process, etc. Most of the surfaces are random roughness and often with coating material different from the substrate. This paper presented a novel hybrid partial coherence and geometry optics (HPCGO) model to improve the generic geometry optics (GO) method by incorporating a previously developed partial coherence reflectance equation. In this way, HPCGO expands the applicable region of GO model, and largely reduces the computation time of integrating different wavelength results in the regular hybrid model that considers coherence effect only. First, the HPCGO model is validated by more rigorous Maxwell equations solvers, for example, the finite-difference time-domain (FDTD) method and integral equation (IE) method. Then, the HPCGO model is applied to study the coherent effect of directional-hemispherical reflectance from coated rough surfaces. It is found the roughness of coated rough surface can cause partial or non-coherent scattered light even if the incident light source is coherent. It also shows the coherence effect reduces with increased incident wave-number bandwidth.
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Karis, T. E., and M. D. Carter. "Oxidation Chemistry of Primary and Secondary Antioxidants." In World Tribology Congress III. ASMEDC, 2005. http://dx.doi.org/10.1115/wtc2005-63592.
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Inhibition of oil oxidation is the key to long life of synthetic lubricants operating in thermal stress and boundary lubrication environments [1]. Bench-scale tests to screen oil formulations provide a rapid means for optimizing formulations prior to longer running verification tests done with the oil in the end-use application [2]. The ultimate goal of accelerated oil life tests is to link the sample combustion temperature, or induction time, at a given heating rate, or temperature, to the estimated lifetime under normal use temperatures. A first order reaction model has recently been employed to derive kinetic parameters from the heating rate dependence of the combustion temperature in the non-isothermal pressure DSC (NIPDSC) test by Adhvaryu et al. [3]. The first order reaction model [4] is also employed here, but we show that a more detailed scheme is needed to fit the heat flow during the combustion exotherm. The detailed kinetic model also provides the link between the NIPDSC test and the isothermal pressure DSC test, as well lifetime estimation at temperatures closer to the end-use conditions. Although isothermal PDSC is useful on grease [5], it does not provide a sharp exotherm for the unthickened base oil [6]. The NIPDSC test provides a reasonably sharp exotherm for formulated base oil in a relatively short amount of time. In the NIPDSC test, 10–12 mg of oil is placed in an open DSC pan. The sample chamber is pressurized with oxygen. The sample temperature is linearly increased with time until the occurrence of the combustion exotherm. The exotherm peak temperature and total heat flow did not exhibit any regular dependence on oxygen pressure between 0.55 and 3.4 MPa. The base oil was an (average) C7 ester of pentaerythritol. Primary antioxidants were hindered phenol and aromatic amines, and Zn-dialkyldithiocarbamate (ZDTC) and Zn-dialkyldithiophosphate (ZDDP) were used as secondary antioxidants. For some of the tests, soluble catalyst [2] was incorporated as iron (III) 2-ethylhexanoate. The reduced heat flow thermograms during the NIPDSC test on the base oil are shown in Fig. 1. The curves are normalized by the peak heat flow rate as Q/Qp, and the symbols denote curves from the first order reaction model, discussed below. The exotherm temperature increases and the exotherm sharpens with increased heating rate. At the 20 °C/min heating rates, the internal heating upon combustion noticeably skews the shape of the exotherm.
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Mohammed, Rahima K., Ridvan A. Sahan, and Ying-Feng Pang. "System Level Thermal Design Challenges in Validation Platforms." In ASME 2009 InterPACK Conference collocated with the ASME 2009 Summer Heat Transfer Conference and the ASME 2009 3rd International Conference on Energy Sustainability. ASMEDC, 2009. http://dx.doi.org/10.1115/interpack2009-89412.
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Unprecedented growth in the semiconductor industry has been enabled by decreasing transistor feature size. As silicon technology continues to scale per Moore’s law, multi-core and many-core are the new trends of the semiconductor industry. While bus speeds, features and functionalities are increasing, shrinking system volume, compact component placements on the board and system noise reduction are the trends. These silicon and system trends make the thermal design challenging. Validation platforms are used to validate processors/chipsets to ensure world-class quality and reliable Intel products. These platforms are usually open chassis to allow ease of accessibility. In this paper, we present an innovative methodology of active air cooling coupled with mechanical retention designs at the component level. Component level thermal testing data are correlated with computational fluid dynamics (CFD) simulations to provide guidance for system simulations. Well-validated and correlated active heatsink thermal model can be used in the system level thermal simulations for studying the mutual pre-heating effect among the components around the heatsink and other thermally critical components. System level thermal design incorporating the effects of memory cooling, voltage regulator module cooling, graphics card preheating, air blockages effect due to probing cables are presented. In addition, system level acoustic measurements methodology is shown. Finally, fan control methodologies to control the noise below safety guidelines while enhancing the validation customer’s experience are presented.
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Wang, Lu, Nobuyuki Oshima, and Sangwon Kim. "Analysis on Heat Transfer and Phase Change for Two-Phase Boiling Flow in Quenching Process." In ASME-JSME-KSME 2019 8th Joint Fluids Engineering Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/ajkfluids2019-4832.
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Abstract A series of numerical simulations using “interThermalPhaseChangeFOAM” solver with improved VOF multiphase flow model in OpenFOAM were conducted to investigate the heat transfer and phase change characteristics for liquid-vapor boiling flow in quenching process. The computational domain is a cuboid with the heating wall at the bottom for both the variable and fixed wall temperature cases. The results for the variable wall temperature case with the heating wall temperature Twall = 150K show that the boiling phenomenon can be divided into the vapor film stage, the boiling stage and the convection stage. Then the fixed wall temperature cases with Twall = 110K, 120K and 140K are analyzed. It is found that 140K case is the most stable one, in which bubble formation is regular such as the bubble at the corner, resulting in the steady variation of heat flux. 120K case is the most unstable one, since the liquid phase and gas phase form the cross-interface shape and maintain this for a long time, leading to the fluctuations in heat flux. Finally, the influence of computational sizes on predicting the properties of boiling phenomenon is investigated. Although the variations of heat flux are not exactly same, the whole tendency is similar.