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Journal articles on the topic 'Heat Flux Meter'

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Author: Grafiati
Published: 14 March 2023

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1

Brajuskovic, Branislav, and Naim Afgan. "A heat flux-meter for ash deposit monitoring systems—II. ‘Clean’ heat flux-meter characteristics." International Journal of Heat and Mass Transfer 34, no. 9 (September 1991): 2303–15. http://dx.doi.org/10.1016/0017-9310(91)90056-k.

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2

Martins, N., H. Calisto, N. Afgan, and A. I. Leontiev. "The transient transpiration heat flux meter." Applied Thermal Engineering 26, no. 14-15 (October 2006): 1552–55. http://dx.doi.org/10.1016/j.applthermaleng.2005.11.027.

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3

Watts, D. B., E. T. Kanemasu, and C. B. Tanner. "Modified heat-meter method for determining soil heat flux." Agricultural and Forest Meteorology 49, no. 4 (March 1990): 311–30. http://dx.doi.org/10.1016/0168-1923(90)90004-p.

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4

Karabekova, D. Zh. "MAIN CHARACTERISTICS OF THE HEAT FLOW METER." Eurasian Physical Technical Journal 19, no. 2 (40) (June 15, 2022): 71–74. http://dx.doi.org/10.31489/2022no2/71-74.

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The problems and prospects of application of non-destructive testing methods for technical diagnostics of the thermal networks state and various technological objects are discussed. The recording of the temperature state of thermal processes by using a flow meter is due to its sensitivity to the change of thermophysical characteristics and the ability to control without the use of an external energy source, etc. The description of the developed device to measuring of the heat flow using of a thermoelectric heat flow converter of a special design is shown. A distinctive feature of the device is the heating element that installed on an insulating layer serving as a support surface. Calibration of the device is proposed to be carried out by replacing the heat flow from the investigated object with the heat flow released in the heating element when an electric current passes through it. The developed device can register the changes in the heat flux density in the range of (25-100) W/m2, which allows it possible to detect the smallest thermal insulation defects.
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5

Taler, Jan, Dawid Taler, Tomasz Sobota, and Piotr Dzierwa. "New technique of the local heat flux measurement in combustion chambers of steam boilers." Archives of Thermodynamics 32, no. 3 (December 1, 2011): 103–16. http://dx.doi.org/10.2478/v10173-011-0016-2.

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New technique of the local heat flux measurement in combustion chambers of steam boilers A new method for measurement of local heat flux to water-walls of steam boilers was developed. A flux meter tube was made from an eccentric tube of short length to which two longitudinal fins were attached. These two fins prevent the boiler setting from heating by a thermal radiation from the combustion chamber. The fins are not welded to the adjacent water-wall tubes, so that the temperature distribution in the heat flux meter is not influenced by neighbouring water-wall tubes. The thickness of the heat flux tube wall is larger on the fireside to obtain a greater distance between the thermocouples located inside the wall which increases the accuracy of heat flux determination. Based on the temperature measurements at selected points inside the heat flux meter, the heat flux absorbed by the water-wall, heat transfer coefficient on the inner tube surface and temperature of the water-steam mixture was determined.
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6

Xizhong, Zhang, Dai Zizhu, and Zhou Genhong. "Application of the heat flux meter in physiological studies." Journal of Thermal Biology 18, no. 5-6 (December 1993): 473–76. http://dx.doi.org/10.1016/0306-4565(93)90079-9.

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7

Filtz, J. R., T. Valin, J. Hameury, and J. Dubard. "New Vacuum Blackbody Cavity for Heat Flux Meter Calibration." International Journal of Thermophysics 30, no. 1 (June 18, 2008): 236–48. http://dx.doi.org/10.1007/s10765-008-0452-7.

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8

Gabriel Poloniecki, José, Antoine Vianou, and Emmanouil Mathioulakis. "Steady-state analysis of the zero-balance heat-flux meter." Sensors and Actuators A: Physical 49, no. 1-2 (June 1995): 29–35. http://dx.doi.org/10.1016/0924-4247(95)01009-p.

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9

Ren, Miaomiao, Jianjun Zhi, Zhengjie Fan, Ruizhi Wang, Yanli Chen, and Jian Yang. "Influence of Ladle Exchange on Inclusions in Transition Slabs of Continuous Casting for Automotive Exposed Panel Steel." Metals 13, no. 2 (February 15, 2023): 404. http://dx.doi.org/10.3390/met13020404.

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In the present work, inclusion analyses were carried out for inclusions in the tundish samples and in the 28 m transition slabs produced during the ladle exchange of heats A and B. At the beginning of heat B steel casting, the 12th meter of the casting slabs was in the position of the mold meniscus. The number of densities of the inclusions containing TiN and the inclusions containing Al2O3+TiN increased significantly from the 12th meter to the 22nd meter, while the number densities of the inclusions containing Al2O3 markedly increased from the 13th meter to the 20th meter. Therefore, the length of the transition slabs whose cleanliness was seriously reduced was about 10 m starting from the beginning of heat B steel casting. It was deduced that the contamination of the transition slabs could be caused by the liquid steel exposure in the tundish, the inflow of ladle filling sand of the next heat, or the entrainment of the tundish flux due to the fluctuation of the tundish liquid level at the beginning of heat B steel casting.
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10

Gumbarević, Sanjin, Bojan Milovanović, Mergim Gaši, and Marina Bagarić. "Application of Multilayer Perceptron Method on Heat Flow Meter Results for Reducing the Measurement Time." Engineering Proceedings 2, no. 1 (November 14, 2020): 29. http://dx.doi.org/10.3390/ecsa-7-08272.

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To reduce the impact on climate change, many countries have developed strategies for the building sector with a goal to reduce the energy demands and carbon emission of buildings. As most buildings that exist today will very likely exist in foreseeable future, many buildings will need to undergo major renovations. One of the most important parameters in determining the transmission heat losses through the building envelope is the U-value, i.e., thermal transmittance, and it is simply the rate of heat transfer per unit temperature. Since the U-value is one of the most important parameters regarding building energy performance, envelope elements that do not perform well in terms of transmission heat losses must undergo a renovation processes. The in-situ U-value of building elements is usually determined by the Heat Flux Method (HFM). One of the issues of current application of the HFM is the measurement duration. This paper explores the possibilities of reducing the measurement time by predicting the heat flux rate using a multilayer perceptron (MLP), a class of artificial neural network. The MLP uses two input layers that are the interior and exterior air temperatures, and the output layer that is the predicted heat flux rate. The predicted value is trained by comparing the predicted heat flux rates with the measured values, and by rearranging the neural network parameters (weights and biases) in corresponding neurons by minimizing the mean squared error defined for trained values (measured versus predicted heat flux rates). The use of MLP shows promising results for predicting the heat flux rates for the analyzed cases (4 days HFM results) when the training is performed on 2/3 or 1/2 of the overall measurement time. The application of the MLP could be in reducing the in-situ measurement time when determining heat losses through building elements in shorter time periods.
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11

Crossley, Jacob, A. N. M. Taufiq Elahi, Mohammad Ghashami, and Keunhan Park. "Characterization of commercial thermoelectric modules for precision heat flux measurement." Review of Scientific Instruments 93, no. 11 (November 1, 2022): 114903. http://dx.doi.org/10.1063/5.0115915.

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In this article, we present a cost-effective approach to the precision measurement of heat flux using commercial thermoelectric modules (TEMs). Two different methods of measuring heat flux with TEMs are investigated, namely, passive mode based on the Seebeck effect and active mode based on the Peltier effect. For both modes, a TEM as a heat flux meter is calibrated to show a linear relation between the voltage across the TEM and the heat flux from 0 to ∼450 W m−2. While both modes exhibit sufficiently high sensitivities suitable for low heat flux measurement, active mode is shown to be ∼7 times more sensitive than passive mode. From the speculation on the origin of the measurement uncertainty, we propose a dual TEM scheme by operating the top TEM in passive mode while its bottom temperature maintains constant by the feedback-controlled bottom TEM. The dual TEM scheme can suppress the sensitivity uncertainty up to 3 times when compared to the single-TEM passive mode by stabilizing the bottom temperature. The response time of a 15 × 15 mm2 TEM is measured to be 8.9 ± 1.0 s for heating and 10.8 ± 0.7 s for cooling, which is slower than commercial heat flux meters but still fast enough to measure heat flux with a time resolution on the order of 10 s. We believe that the obtained results can facilitate the use of a commercial TEM for heat flux measurement in various thermal experiments.
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12

Taler, Jan, Dawid Taler, and Andrzej Kowal. "Measurements of absorbed heat flux and water-side heat transfer coefficient in water wall tubes." Archives of Thermodynamics 32, no. 1 (April 1, 2011): 77–88. http://dx.doi.org/10.2478/v10173-011-0004-6.

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Measurements of absorbed heat flux and water-side heat transfer coefficient in water wall tubes The tubular type instrument (flux tube) was developed to identify boundary conditions in water wall tubes of steam boilers. The meter is constructed from a short length of eccentric tube containing four thermocouples on the fire side below the inner and outer surfaces of the tube. The fifth thermocouple is located at the rear of the tube on the casing side of the water-wall tube. The boundary conditions on the outer and inner surfaces of the water flux-tube are determined based on temperature measurements at the interior locations. Four K-type sheathed thermocouples of 1 mm in diameter, are inserted into holes, which are parallel to the tube axis. The non-linear least squares problem is solved numerically using the Levenberg-Marquardt method. The heat transfer conditions in adjacent boiler tubes have no impact on the temperature distribution in the flux tubes.
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13

Xiang-yuan, ZHENG, YE Xin, LUO Zhi-tao, WANG Kuo-chuan, and SONG Bao-qi. "Uncertainty analysis and evaluation of a high-precision radiative heat-flux meter." Chinese Optics 15 (2022): 1–9. http://dx.doi.org/10.37188/co.2022-0023.

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14

Green, A. E., K. J. McAneney, and J. P. Lagouarde. "Sensible heat and momentum flux measurement with an optical inner scale meter." Agricultural and Forest Meteorology 85, no. 3-4 (July 1997): 259–67. http://dx.doi.org/10.1016/s0168-1923(96)02388-x.

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15

Liao, Bin. "The Research of the Ultrasonic Heat Meter Adopting the Two Reflection Structure." Advanced Materials Research 328-330 (September 2011): 2010–13. http://dx.doi.org/10.4028/www.scientific.net/amr.328-330.2010.

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The pattern of using the household billing to promote heating energy savings has become a focus discussion in the current national energy conservation. The key factor for following such way is to find a reasonable heat meter. To the national standard CJ128-2007, the length of the heat meter body is limited to 130/190 mm, compared with the actual diameter of the tube is 18 mm(standard20), the measuring of the small flux by ultrasonic is to some extend difficult. In this paper, we report a research of a two reflection structure flow meter. By a procedure of twice reflection, the effective distance of the spreading of the ultrasonic signal is longer than some other usual structures. So it can work in above conditions. The flow meter has been carried on the online testing in a district of Beijing since 2009.
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16

Zhang, Kexin, Ying Su, Haiyu Wang, Qian Wang, Kai Wang, Yisen Niu, and Jifeng Song. "Highly Concentrated Solar Flux of Large Fresnel Lens Using CCD Camera-Based Method." Sustainability 14, no. 17 (September 5, 2022): 11062. http://dx.doi.org/10.3390/su141711062.

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Fresnel lens is a kind of lens that can concentrate sunlight up to a level of thousands of suns with small space occupation which is widely used in the research of sunlight concentration and transmission systems via optical fiber. Most studies on the concentrated flux of lenses use experimental methods to measure the flux distribution on the receiver of parabolic trough solar concentrators, solar power towers, and parabolic dish concentrators, while for Fresnel lenses, especially large-aperture Fresnel lenses such as the one in this manuscript, the simulation approach was mostly used. In response to this problem, this study has developed an experimental system for measuring the concentrated flux density of Fresnel lenses. A charge-coupled device (CCD) camera was used to capture the image of spot of large-aperture (968 mm) Fresnel lenses in the CCD camera-based method, and a heat flow meter was used to calibrate the spot brightness image obtained by the CCD camera. Experimental data show that the peak flux of concentrated spot can reach 4.06 MW/m2. This method confirms the simulation results of previous studies that using the rays tracing method, that is, the flux level of the Fresnel lenses can reach 5000 suns. The experimental results demonstrated the CCD camera-based method combined with a heat flow meter is competent in measuring the intensity of flux with a level of 5000 suns.
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17

Brajuskovic, Branislav, Miodrag Matovic, and Naim Afgan. "A heat flux-meter for ash deposit monitoring systems—I. Ash deposit prevention." International Journal of Heat and Mass Transfer 34, no. 9 (September 1991): 2291–301. http://dx.doi.org/10.1016/0017-9310(91)90055-j.

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18

Sekma, H., Y. H. Park, and F. Vivier. "Time-Mean Flow as the Prevailing Contribution to the Poleward Heat Flux across the Southern Flank of the Antarctic Circumpolar Current: A Case Study in the Fawn Trough, Kerguelen Plateau." Journal of Physical Oceanography 43, no. 3 (March 1, 2013): 583–601. http://dx.doi.org/10.1175/jpo-d-12-0125.1.

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Abstract The major mechanisms of the oceanic poleward heat flux in the Southern Ocean are still in debate. The long-standing belief stipulates that the poleward heat flux across the Antarctic Circumpolar Current (ACC) is mainly due to mesoscale transient eddies and the cross-stream heat flux by time-mean flow is insignificant. This belief has recently been challenged by several numerical modeling studies, which stress the importance of mean flow for the meridional heat flux in the Southern Ocean. Here, this study analyzes moored current meter data obtained recently in the Fawn Trough, Kerguelen Plateau, to estimate the cross-stream heat flux caused by the time-mean flow and transient eddies. It is shown that the poleward eddy heat flux in this southern part of the ACC is negligible, while that from the mean flow is overwhelming by two orders of magnitude. This is due to the unusual anticlockwise turning of currents with decreasing depth, which is associated with significant bottom upwelling engendered by strong bottom currents flowing over the sloping topography of the trough. The circumpolar implications of these local observations are discussed in terms of the depth-integrated linear vorticity budget, which suggests that the six topographic features along the southern flank of the ACC equivalent to the Fawn Trough case would yield sufficient poleward heat flux to balance the oceanic heat loss in the subpolar region. As eddy activity on the southern flank of the ACC is too weak to transport sufficient heat poleward, the nonequivalent barotropic structure of the mean flow in several topographically constricted passages should accomplish the required task.
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19

Taler, Jan, and Dawid Taler. "Tubular Type Heat Flux Meter for Monitoring Internal Scale Deposits in Large Steam Boilers." Heat Transfer Engineering 28, no. 3 (March 2007): 230–39. http://dx.doi.org/10.1080/01457630601066889.

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20

Wei, Xianggeng, Zhongxu Yang, Shaohua Zhu, Zhixin Zhao, Jinying Ye, and Oskar J. Haidn. "The Confirmation of Thermal Boundary Parameters in an Oxygen Kerosene Fuel-Rich Rocket Engine." Aerospace 9, no. 7 (June 26, 2022): 343. http://dx.doi.org/10.3390/aerospace9070343.

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The thermal environment is an important factor in the design of liquid rockets. In this paper, theoretical analysis, numerical simulation and experimental testing are conducted to study the boundary thermal characteristics of a GOX/kerosene liquid rocket motor with a total flow rate of 120 g/s and an oxygen-fuel ratio of 1:1. We measured the axial temperature in different positions in the combustor using thermocouples and the heat flux using a flux meter. We found that the heat flux at 182 mm increases by 6.8% when a carbon deposit exists. For the theoretical results, after correcting the thermal conductivity by the volume fraction of carbon deposition, the theoretical heat flux (1.11 MW/m2, using the corrected thermal conductivity) and the numerical result (0.89 MW/m2, considering the injectors) are similar to the experimental value (0.937 MW/m2). This study validates the accuracy of theoretical and simulation calculation in this case, and provides verification data for future numerical calculation, as well as data for setting gas temperature at the wall in the simulation of the gas phase.
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21

Guo, Wei, Anqi Chen, You Lv, Yuan Zhu, and Jinda Wu. "Microscale heat-flux meter for low-dimensional thermal measurement and its application in heat-loss modified Angstrom method." International Journal of Heat and Mass Transfer 169 (April 2021): 120938. http://dx.doi.org/10.1016/j.ijheatmasstransfer.2021.120938.

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22

Tahsini, Amir Mahdi, and Samaneh Tadayon Mousavi. "Ablative Heat Shield Design for Reentry Vehicle Using Numerical Analysis." Applied Mechanics and Materials 598 (July 2014): 298–303. http://dx.doi.org/10.4028/www.scientific.net/amm.598.298.

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At this paper, the thermal behavior of ablative materials as heat shields for reentry vehicles is investigated numerically. A one-dimensional finite difference solver is developed to simulate governing mass and energy equations. Four ablative materials; AVCO 5026-HCG, Carbon-Phenolic, Nylon-Phenolic, and Silica-Phenolic; are considered as a heat shield material for a reentry capsule with the diameter 2.8 meter. A heat flux profile from a simulated trajectory of a reentry capsule is used for investigation the performance and essential thickness of these four ablative materials. The only restriction for this simulation is the ultimate temperature of the backup structure which is beneath the ablative heat shield. At all simulations, the final thickness is defined by reaching the interface temperature, the temperature of the border between the ablative heat shield and solid shell, to 80±0.5 degrees Celsius. In addition, the sensitivity analysis is carried out to investigate the effect of properties variations on Carbon-Phenolic’s thickness for this specific heat flux profile.
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23

Parken, W. H., L. S. Fletcher, V. Sernas, and J. C. Han. "Heat Transfer Through Falling Film Evaporation and Boiling on Horizontal Tubes." Journal of Heat Transfer 112, no. 3 (August 1, 1990): 744–50. http://dx.doi.org/10.1115/1.2910449.

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Evaporation and boiling heat transfer coefficients are presented for thin, distilled water films flowing over the outside of horizontal, electrically heated brass tubes. Tests were conducted with a thin-slot water distribution system for 2.54- and 5.08-cm-dia smooth tubes. Both local and average heat transfer data were obtained for nonboiling and boiling conditions corresponding to feedwater temperatures ranging from 49 to 127°C and heat-flux values ranging from 30 to 80 kW/m2. Feed-water flow rates ranged from 0.135 to 0.366 kg/s per meter length per side of the tube. Both nonboiling and boiling correlations of the average heat transfer coefficients were developed and compared.
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24

Uusikivi, Jari, Jens Ehn, and Mats A. Granskog. "Direct measurements of turbulent momentum, heat and salt fluxes under landfast ice in the Baltic Sea." Annals of Glaciology 44 (2006): 42–46. http://dx.doi.org/10.3189/172756406781811150.

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AbstractMeasurements of under-ice turbulence were performed using an acoustic three-dimensional current meter with an attached fast-repetition temperature–conductivity sensor at two coastal areas in the Baltic Sea during two winters. Observations covered both the ice-growth and spring-melt periods. The objective of these measurements was to obtain knowledge of under-ice turbulence and oceanic heat and salt fluxes to and from the ice in the coastal fast-ice region using eddy correlation techniques. The maximum observed daily average heat flux was 1 Wm–2, and the maximum for 10 min periods was an order of magnitude larger. Under-ice turbulence was much smaller than that recorded in the oceans and in coastal regions with tide. These results provide better knowledge of under-ice turbulence and heat-flux variations and are useful for the future development of a Baltic Sea ice salinity model.
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25

Pereselkov, A., and O. Kruglyakova. "EXPERIMENTAL STUDY OF ELEMENTARY ACTS OF HYDRODYNAMICS AND HEAT TRANSFER DURING THE INTERACTION BETWEEN WATER DROPS AND FILM AND CASTING ROLLER SURFACE." Integrated Technologies and Energy Saving, no. 4 (December 12, 2022): 3–12. http://dx.doi.org/10.20998/2078-5364.2022.4.01.

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Experimental studies of the boundary conditions of heat transfer for the thermally stressed state of casting rollers while are spraying with flat-jet nozzles in a thermal preconditioning unit have been carried out. It is shown that the hydrodynamic conditions on the sprinkling surface are formed as a result of both the influx of "primary" dispersed water from the flat jet nozzle, and the "secondary" liquid coming from neighboring areas in the form of reflected drops and films. The heat transfer effecting individual factors that form the hydrodynamic conditions on the sprinkling surface was studied separately. The heat transfer intensity was studied depending on the spraying density, the injection-pressure drop and the temperature of the cooled surface when the "primary" drop flow runs in the heat exchange surface. The local sprinkling density of droplets on the surface under the flat-jet nozzle spray were measured using a sampling tube moved by a coordinator. At the same time, the ingress of “secondary” liquid into it was excluded. The specific heat flux and heat transfer coefficient were determined using a heat meter made of a nichrome tape heated by direct current. In this case, the isothermality of the surface of the measuring section was ensured. Thermocouples measured the temperature of the lower surface of the tape, and then the stationary temperature of the upper surface of the heat meter sprinkled with drops is calculated. As a result of the multivariate analysis of the experimental data, the correlation dependence of the heat transfer coefficient in dependance on the local spraying conditions of the heat meter surface was obtained. Also, studies of the heat transfer during water film flow over the heat meter surface were carried out. A similar situation takes place when water spreads between the adjacent nozzles sprinkling zones of the roller surface. The correlation dependence between the heat transfer coefficient, the water film speed and the cooled surface temperature was obtained. Studies of heat transfer during combined influence of moving water film and a flat-jet nozzle drop flow on the heat exchange surface showed that the heat transfer rate is approximately 80–90 % of the arithmetic sum of the coefficients obtained by separate cooling the heat meter with drops and a water film.
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26

Gohil, Kanishk, and Menglin S. Jin. "Validation and Improvement of the WRF Building Environment Parametrization (BEP) Urban Scheme." Climate 7, no. 9 (September 10, 2019): 109. http://dx.doi.org/10.3390/cli7090109.

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The building environment parameterization scheme (BEP) is a built-in “urban physics” scheme in the weather research and forecasting (WRF) model. The urbanized College Park (CP) in Maryland state (MD) in the United States (US) covers an approximate land area of 14.8 km2 and has a population of 32,000 (reported by The United States Census Bureau, as of 2017). This study was an effort to validate and improve the BEP urban physics scheme for a small urban setting, College Park, MD. Comparing the WRF/BEP-simulated two-meter air temperatures with the local rooftop WeatherBug® observations and with the airport observations, systemic deficiencies in BEP for urban heat island effect simulation are evident. Specifically, WRF/BEP overestimates the two-meter air temperature by about 10 °F during clear summer nights and slightly underestimates it during noon of the same days by about 1–3 °F. Similar deficiencies in skin temperature simulations are also evident in WRF/BEP. Modification by adding an anthropogenic heat flux term resulted in better estimates for both skin and two-meter air temperatures on diurnal and seasonal scales.
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27

Vasilev, Aleksandr, Tommy Lorenz, Vikram G. Kamble, Sven Wießner, and Cornelia Breitkopf. "Thermal Conductivity of Polybutadiene Rubber from Molecular Dynamics Simulations and Measurements by the Heat Flow Meter Method." Materials 14, no. 24 (December 15, 2021): 7737. http://dx.doi.org/10.3390/ma14247737.

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Thermal conductivities of polybutadiene rubbers crosslinked by 2.4 and 2.8 phr of sulfur have been found to be functions of temperature via molecular dynamics (MD) simulations using the Green–Kubo method. From an analysis of the heat flux autocorrelation functions, it has been revealed that the dominant means of heat transport in rubbers is governed by deformations of polymeric chains. Thermal conductivities of rubber samples vulcanized by 2.4 and 2.8 phr of sulfur have been measured by the heat flow meter method between 0 ∘C and 60 ∘C at atmospheric pressure. The temperature dependencies of the thermal conductivities of rubbers and their glass transition temperatures derived from MD simulations are in good agreement with the literature and experimental data. Details are discussed in the paper.
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28

Hotra, Oleksandra, Svitlana Kovtun, Oleg Dekusha, Żaklin Grądz, Vitalii Babak, and Joanna Styczeń. "Analysis of Low-Density Heat Flux Data by the Wavelet Method." Energies 16, no. 1 (December 30, 2022): 430. http://dx.doi.org/10.3390/en16010430.

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When evaluating the energy efficiency of buildings and implementing the necessary measures to increase energy efficiency levels, thermal technical characteristics are determined. For this purpose, in situ measurements of the thermal resistance of external enclosing structures were carried out. One of the methods most often used by researchers is the non-destructive method—the heat flow meter (HFM) method regulated by ISO 9869. In the case of surveying a building with a high level of thermal resistance, researchers are faced with low-density heat flux measurements, which is always a difficult task due to significant fluctuations and the influence of external factors on the measurement results. This is due to the fact that it is difficult to determine what is a useful signal and what is a consequence of the effects of non-stationarity and heat transfer conditions. The article provides an example of low-density heat flux measurements when determining the thermal resistance of a building and proposes a data pre-processing procedure that allows for the reduction of heat flux fluctuations, which has a significant impact on the final result at low density. The proposed use of wavelet analysis in the pre-processing of low-density heat flux measurement data makes it possible to reconstruct them or reduce disturbances that occur during research. A comparison of the obtained results with the results of the calculation according to ISO 9869-1 showed a decrease in the standard deviation of the measurements from 5.74 to 2.81%. The results of this study can be used to reduce the noise of low-density heat flux and, as a result, reduce the standard deviation of the measurement when applying the HFM method of determining the thermal resistance of external enclosing structures.
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29

Ilchenko, Andriy. "The influence of some design parameters on the heat transfer in thermal fuel flowmeter." Journal of Mechanical Engineering and Transport 13, no. 1 (2021): 54–59. http://dx.doi.org/10.31649/2413-4503-2021-13-1-54-59.

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The article analyzes the influence, relationship and value of design parameters of the heat flow meter on its radial and axial heat fluxes in the tube (tube diameter, heater diameter and their ratio, thermal conductivity of the tube material, etc.). It is shown that at the stage of choosing the design parameters of the flowmeter it is necessary to take into account the influence of its radial heat flux on the axial one. The influence of radial heat flux in the flowmeter tube on the error of fuel loss measurement is substantiated. Analytical dependences which allow to define an axial heat stream are resulted, their analysis concerning influence of flowmeter tube constructive parameters on heat transfer is carried out. Measures are planned and recommendations are developed for the choice of design flowmeter parameters, development or use, provided that the influence of radial heat flow on the axial is reduced, which will reduce the total error of fuel consumption measurement. Regarding the choice of design parameters of heat meters while reducing the error of measuring fuel consumption, it is shown that the maximum possible decrease in the diameter of the heater and increase the diameter of the flow tube reduce the impact of radial heat flow on the axial and thus reduce the total fuel consumption error. Numerical ratios of tube diameter to flowmeter heater diameter for different thermal conductivities of tube materials are given under the condition of minimal influence on fuel consumption measurement error. For tube materials with a thermal conductivity 0.16… 0.25 W / (m ∙ K) (ebonite, fluoroplastic F-5, etc.) the tube diameters ratio and the heater should be within 1.51… 1.62, and for materials with more high thermal conductivity (thermal conductivity greater than 14.9 W / (m ∙ K)), this ratio should be equal to 1.99.
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30

Rasooli, Arash, and Laure Itard. "Quicker Measurement of Walls’ Thermal Resistance Following an Extension to ISO 9869 Average Method." E3S Web of Conferences 111 (2019): 04019. http://dx.doi.org/10.1051/e3sconf/201911104019.

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Determination of the thermo-physical characteristics of the buildings’ components is crucial to illustrate their thermal behavior and therefore their energy consumption. Along the same line, accurate determination of the thermal resistance of the building walls falls into one the most important targets. Following the difference between in-lab, and on site thermal performance of walls, in-situ measurements have been highly recommended. The most well-known practice for in-situ measurement of walls’ thermal resistance is the Average Method of ISO 9869, using one heat flux meter and two thermocouples. The method, in comparison with other existing methods is quite straight-forward and therefore, is applied widely in large scale. Despite its simplicity, this method usually needs a relatively long time to reach an acceptable result. The current paper deals with a modification to the ISO 9869 method, making it in many situations much quicker than its original state. Through simulation of walls of different typologies, it is shown in which cases the measurement period becomes longer than expected. It is demonstrated how the addition of a heat flux meter to the aforementioned equipment can lead to a much quicker achievement of the thermal resistance, following the rest of the instructions of the standard method.
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31

Sheng, Chunchen, Peng Hu, and Xiaofang Cheng. "Design and calibration of a novel transient radiative heat flux meter for a spacecraft thermal test." Review of Scientific Instruments 87, no. 6 (June 2016): 064902. http://dx.doi.org/10.1063/1.4953339.

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32

Kamseu, E., B. Ceron, H. Tobias, E. Leonelli, M. C. Bignozzi, A. Muscio, and A. Libbra. "Insulating behavior of metakaolin-based geopolymer materials assess with heat flux meter and laser flash techniques." Journal of Thermal Analysis and Calorimetry 108, no. 3 (August 5, 2011): 1189–99. http://dx.doi.org/10.1007/s10973-011-1798-9.

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33

de Rubeis, Tullio, Luca Evangelisti, Claudia Guattari, Domenica Paoletti, Francesco Asdrubali, and Dario Ambrosini. "How Do Temperature Differences and Stable Thermal Conditions Affect the Heat Flux Meter (HFM) Measurements of Walls? Laboratory Experimental Analysis." Energies 15, no. 13 (June 28, 2022): 4746. http://dx.doi.org/10.3390/en15134746.

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In recent years, experimental tests related to building components through laboratory facilities have relatively matured. The techniques are based on one-dimensional heat transfer by creating a permanent temperature difference over a specimen to control heat fluxes. The three main methods are the Guarded Hot Box (GHB) method, the Calibrated Hot Box (CHB) method, and the Heat-Flow Meter method (HFM). The HFM method is the most widely applied technique for measuring on-site U-values of building components and several scientific works stressed the need for high temperature differences between the environments, suggesting 10 °C or 15 °C. However, temperature stability and high temperature gradients are difficult to obtain, especially for Mediterranean climatic conditions. Starting from this, an experimental study was conducted through a GHB apparatus, setting temperature differences from 2 °C to 20 °C between the hot and cold chambers. Heat flow measurements were performed to compute the thermal conductance of a specimen characterized by a known stratigraphy, thus highlighting the effect of the low thermal gradient on data acquired by the heat flow sensor. It was found that, even for low temperature differences (2 °C) maintained by ensuring stable thermal conditions, the experimental results are comparable with those obtained for higher and usual temperature differences (20 °C).
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34

Usoltseva, Liliya O., Dmitry S. Volkov, Evgeny A. Karpushkin, Mikhail V. Korobov, and Mikhail A. Proskurnin. "Thermal Conductivity of Detonation Nanodiamond Hydrogels and Hydrosols by Direct Heat Flux Measurements." Gels 7, no. 4 (December 3, 2021): 248. http://dx.doi.org/10.3390/gels7040248.

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The methodology and results of thermal conductivity measurements by the heat-flow technique for the detonation nanodiamond suspension gels, sols, and powders of several brands in the range of nanoparticle concentrations of 2–100% w/w are discussed. The conditions of assessing the thermal conductivity of the fluids and gels (a FOX 50 heat-flow meter) with the reproducibility (relative standard deviation) of 1% are proposed. The maximum increase of 13% was recorded for the nanodiamond gels (140 mg mL−1 or 4% v/v) of the RDDM brand, at 0.687 ± 0.005 W m−1 K−1. The thermal conductivity of the nanodiamond powders is estimated as 0.26 ± 0.03 and 0.35 ± 0.04 W m−1 K−1 for the RUDDM and RDDM brands, respectively. The thermal conductivity for the aqueous pastes containing 26% v/v RUDDM is 0.85 ± 0.04 W m−1 K−1. The dignities, shortcomings, and limitations of this approach are discussed and compared with the determining of the thermal conductivity with photothermal-lens spectrometry.
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35

Wu, Guangdong, Xiao Zhang, and Jijun Xu. "Spatial Variability Pattern of Hyporheic Exchange in a braided River." MATEC Web of Conferences 246 (2018): 01098. http://dx.doi.org/10.1051/matecconf/201824601098.

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The streambed flux is variable in space; the spatial variability results in part from bedforms, but few works on streambed fluxes in channels with strongly abrupt varying bedforms are carried out. Heat as a tracer to delineate the streambed flux pattern has been widely adopted in numerous fields. In this paper, a braided channel with complicated topography was selected as study site, where the temperature was monitored. One-dimensional (1-D) analytical method based on the amplitude attenuation (Ar) and 1-D numerical method were used to interpret the temperature. As a result, streambed fluxes of a total of 50 sites in the braided channel are obtained. From the results we can know the magnitude and direction of streamed flow velocity are spatially variable, even within a 1-m distance. Then, this study summarizes five bedform-driven flux patterns: ① downward flow driven by the head difference between groundwater and stream, ② downward flow related to a meter-scale pool, ③ a transition from upward to downward flow associated with a centimeter-scale riffle, ④ horizontal flow in braided bars and ⑤ upward flow driven by vegetation roots. Overall, multiple physical mechanisms together contributed to the complex streambed flow system, which reflected great challenges for the scaling up of point-in-space seepage flux.
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36

Lee, Ruda, Eunho Kang, Hyomun Lee, and Jongho Yoon. "Heat Flux and Thermal Characteristics of Electrically Heated Windows: A Case Study." Sustainability 14, no. 1 (January 3, 2022): 481. http://dx.doi.org/10.3390/su14010481.

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Energy loss through windows can be high relatively compared to other opaque surfaces because insulation performance of fenestration parts is lower in the building envelope. Electrically heated window systems are used to improve the indoor environment, prevent condensation, and increase building energy efficiency. The purpose of this study is to analyze the thermal behaviors of a heated window under a field experiment condition. Experiments were conducted during the winter season (i.e., January and February) with the energy-efficient house that residents occupy. To collect measured data from the experimental house, temperature and heat flux meter sensors were used for the analysis of heat flow patterns. Such measured data were used to calculate heat gain ratios and compare temperature and dew point distribution profiles of heated windows with input power values under the changed condition in the operating temperature of the heated glazing. Results from this study indicated that the input average heat gain ratio was analyzed to be 75.2% in the south-facing and 83.8% in the north-facing at nighttime. Additionally, compared to January, reducing the operating temperature of the heated glazing by 3 °C decreased the input energy in February by 44% and 41% for the south-facing and north-facing windows, respectively. Through such field measurement study, various interesting results that could not be found in controlled laboratory chamber conditions were captured, indicating that the necessity of establishing various control strategies should be considered for the development and commercialization of heated windows.
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37

Kivisalu, M. T., P. Gorgitrattanagul, and A. Narain. "Results for high heat-flux flow realizations in innovative operations of milli-meter scale condensers and boilers." International Journal of Heat and Mass Transfer 75 (August 2014): 381–98. http://dx.doi.org/10.1016/j.ijheatmasstransfer.2014.03.056.

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38

Chen, Lin, and Hui Hui Zeng. "Influence of Preparing Conditions on the Property of a New White-Light Long Afterglow Phosphor Sr2SiO4: Pr3+." Advanced Materials Research 418-420 (December 2011): 274–77. http://dx.doi.org/10.4028/www.scientific.net/amr.418-420.274.

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A new white-light long afterglow phosphor Sr2SiO4: Pr3+was synthesized by solid-state reaction, the influence of preparing conditions on the luminous property of Sr2SiO4: Pr3+were studied, and characterized by X-ray diffractometer, fluorescence spectrophotometer and thermo luminescence(TL) meter. The results indicated that the emission spectra of phosphor is composed of bluish purple (390nm), green(535nm)and red(604nm)light emission, and the sample prepared at 1473K, heat treatment time for 4h, 0.5mol% Pr3+and 1mol% flux H3BO3 conditions shows the best property.
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39

Tsvetkov, N. A., A. N. Kozlobrodov, S. Boldyryev, S. V. Romanenko, T. N. Nemova, and D. N. Tsvetkov. "Thermophysical analysis of heat-insulated glued laminated profiled timber for wooden houses." IOP Conference Series: Earth and Environmental Science 866, no. 1 (October 1, 2021): 012037. http://dx.doi.org/10.1088/1755-1315/866/1/012037.

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Abstract The paper presents the thermophysical analysis of two types of the wall system made of heat-insulated glued laminated timbers with connectors comprised of water-resisting multilayer plywood. The paper describes a novel timber configuration, which reduces the weight of one square meter area by 55% compared with an ordinary timber having a cross-section of 0.21 m × 0.21 m and saves not less than 60% of wood. The latter is highly relevant because forests remove carbon dioxide emissions from the atmosphere; reducing the use of wood in construction is of great importance for ecology. The ANSYS finite element program is used for calculating temperature fields and heat fluxes. It is found that one connector affects not more than 0.2 m of the exterior wall length in relation to the temperature and heat flux fields, whereas the heat loss increase is not over 0.44%.
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40

Shan, Qifeng, Keting Tong, Xiaocun Zhang, and Yushun Li. "Field Test and Simulation Analysis of Thermal Performance of Bamboo Steel Composite Wall in Different Climate Regions." Advances in Civil Engineering 2020 (October 14, 2020): 1–10. http://dx.doi.org/10.1155/2020/8854156.

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In this paper, a bamboo steel composite testing building was designed and built to study the thermal performance of a new proposed bamboo steel composite wall. The heat flux meter method was adopted in the field test to measure the heat transfer coefficient of the composite wall. The energy consumption of testing building was measured to verify the validity of the simulation model. Then, the simulation analysis was conducted to study the energy performance of the composite walls compared with reinforced concrete wall in different climate regions. The result showed that the measurement value of heat transfer coefficient matched well with the theoretical calculation value, and both values meet the requirement of the standard. The simulation result showed that the composite walls had better energy performance and had great potential utilization in residential buildings in different climate regions.
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41

Kolås, Eivind, and Ilker Fer. "Hydrography, transport and mixing of the West Spitsbergen Current: the Svalbard Branch in summer 2015." Ocean Science 14, no. 6 (December 21, 2018): 1603–18. http://dx.doi.org/10.5194/os-14-1603-2018.

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Abstract. Measurements of ocean currents, stratification and microstructure were made in August 2015, northwest of Svalbard, downstream of the Atlantic inflow in Fram Strait in the Arctic Ocean. Observations in three sections are used to characterize the evolution of the West Spitsbergen Current (WSC) along a 170 km downstream distance. Two alternative calculations imply 1.5 to 2 Sv (1 Sv = 106 m3 s−1) is routed to recirculation and Yermak branch in Fram Strait, whereas 0.6 to 1.3 Sv is carried by the Svalbard branch. The WSC cools at a rate of 0.20 ∘C per 100 km, with associated bulk heat loss per along-path meter of (1.1-1.4)×107 W m−1, corresponding to a surface heat loss of 380–550 W m−2. The measured turbulent heat flux is too small to account for this cooling rate. Estimates using a plausible range of parameters suggest that the contribution of diffusion by eddies could be limited to one half of the observed heat loss. In addition to shear-driven mixing beneath the WSC core, we observe energetic convective mixing of an unstable bottom boundary layer on the slope, driven by Ekman advection of buoyant water across the slope. The estimated lateral buoyancy flux is O(10−8) W kg−1, sufficient to maintain a large fraction of the observed dissipation rates, and corresponds to a heat flux of approximately 40 W m−2. We conclude that – at least in summer – convectively driven bottom mixing followed by the detachment of the mixed fluid and its transfer into the ocean interior can lead to substantial cooling and freshening of the WSC.
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42

Ha, Ji Soo. "A Study on the Heat Flux Meter Location for the Performance Test of a Refrigerator Vacuum Insulation Panel." Korean Journal of Air-Conditioning and Refrigeration Engineering 25, no. 8 (August 10, 2013): 471–76. http://dx.doi.org/10.6110/kjacr.2013.25.8.471.

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43

Coquard, R., and D. Baillis. "Modeling of Heat Transfer in Low-Density EPS Foams." Journal of Heat Transfer 128, no. 6 (November 4, 2005): 538–49. http://dx.doi.org/10.1115/1.2188464.

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Expanded polystyrene (EPS) foams are one of the most widely used thermal insulators in the building industry. Owing to their very low density, both conductive and radiative heat transfers are significant. However, only few studies have already been conducted in the modeling of heat transfer in this kind of medium. This is due to their complex porous structure characterized by a double-scale porosity which has always been ignored by the previous works. In this study, we present a model of one-dimensional steady state heat transfer in these foams based on a numerical resolution of the radiation-conduction coupling. The modeling of the conductive and radiative properties of the foams takes into account their structural characteristics such as foam density or cell diameter and permits us to study the evolution of their equivalent thermal conductivity with these characteristics. The theoretical results have been compared to equivalent thermal conductivity measurements made on several EPS foams using a flux-meter apparatus and show a good agreement.
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44

Makaveckas, Tomas, Raimondas Bliūdžius, and Arūnas Burlingis. "The Influence of Different Facings of Polyisocyanurate Boards on Heat Transfer through the Wall Corners of Insulated Buildings." Energies 13, no. 8 (April 17, 2020): 1991. http://dx.doi.org/10.3390/en13081991.

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Polyisocyanurate (PIR) thermal insulation boards faced with carboard, plastic, aluminum, or multilayer facings are used for thermal insulation of buildings. Facing materials are selected according to the conditions of use of PIR products. At the corners of the building where these products are joined, facings can be in the direction of the heat flux movement and significantly increase heat transfer through the linear thermal bridge formed in the connection of PIR boards with facing of both walls. Analyzing the installation of PIR thermal insulation products on the walls of a building, the structural schemes of linear thermal bridges were created, numerical calculations of the heat transfer coefficients of the linear thermal bridges were performed, and the influence of various facings on the heat transfer through the thermal bridge was evaluated. Furthermore, an experimental measurement using a heat flow meter apparatus was performed in order to confirm the results obtained by numerical calculation. This study provides more understanding concerning the necessity to evaluate the impact of different thermal conductivity facings on the heat transfer through corners of buildings insulated with PIR boards.
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45

Baniata, Hamza, Sami Mahmood, and Attila Kertesz. "Assessing anthropogenic heat flux of public cloud data centers: current and future trends." PeerJ Computer Science 7 (May 5, 2021): e478. http://dx.doi.org/10.7717/peerj-cs.478.

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Global average temperature had been significantly increasing during the past century, mainly due to the growing rates of greenhouse gas (GHG) emissions, leading to a global warming problem. Many research works indicated other causes of this problem, such as the anthropogenic heat flux (AHF). Cloud computing (CC) data centers (DCs), for example, perform massive computational tasks for end users, leading to emit huge amounts of waste heat towards the surrounding (local) atmosphere in the form of AHF. Out of the total power consumption of a public cloud DC, nearly 10% is wasted in the form of heat. In this paper, we quantitatively and qualitatively analyze the current state of AHF emissions of the top three cloud service providers (i.e., Google, Azure and Amazon) according to their average energy consumption and the global distribution of their DCs. In this study, we found that Microsoft Azure DCs emit the highest amounts of AHF, followed by Amazon and Google, respectively. We also found that Europe is the most negatively affected by AHF of public DCs, due to its small area relative to other continents and the large number of cloud DCs within. Accordingly, we present mean estimations of continental AHF density per square meter. Following our results, we found that the top three clouds (with waste heat at a rate of 1,720.512 MW) contribute an average of more than 2.8% out of averaged continental AHF emissions. Using this percentage, we provide future trends estimations of AHF densities in the period [2020–2100]. In one of the presented scenarios, our estimations predict that by 2100, AHF of public clouds DCs will reach 0.01 Wm−2.
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46

Ignatyuk, Aleksandr, S. Nikolenko, and Svetlana Sazonova. "THE PROCESS OF THERMAL IMAGING INSPECTION OF BUILDING ENVELOPES." Modeling of systems and processes 12, no. 4 (January 23, 2020): 66–72. http://dx.doi.org/10.12737/2219-0767-2020-12-4-66-72.

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The paper analyzes and develops proposals to improve the energy efficiency of the building of MBOU «Lyceum No. 65» in Voronezh. The energy survey was carried out in order to comply with the requirements of Article 13 of Federal Law of November 23, 2010 No. 261-ФЗ «On Energy Saving and on Improving Energy Efficiency and on Amending Certain Legislative Acts of the Russian Federation». The survey was carried out using a Testo 881-2 thermal imager, a digital thermometer Testo 905-T2, a meter of heat flux density and ITP temperature - MG4.03 / 5 (I) «Potok».
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47

Li, Yinsheng, Jing Yang, Jinxiang Chen, and Jian Yin. "Study of the Heat Transfer Performance of Laminated Paper Honeycomb Panels." Biomimetics 8, no. 1 (January 19, 2023): 46. http://dx.doi.org/10.3390/biomimetics8010046.

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To apply functional honeycomb panels (FHPs) in actual engineering projects, the heat transfer performance and intrinsic heat transfer mechanism of laminated honeycomb panels (LHPs, total thickness of 60 mm) with different structural parameters were investigated in this study by a heat flow meter. The results showed that (1) the equivalent thermal conductivity λequ of the LHP was almost independent of the cell size, when it consisted of a small single-layer thickness. Thus, LHP panels with a single-layer thickness of 15–20 mm are recommended. (2) A heat transfer model of LHPs was developed, and it was concluded that the heat transfer performance of LHPs depends greatly on the performance of their honeycomb core. Then, an equation was derived for the steady state temperature distribution of the honeycomb core. (3) The contribution of each heat transfer method to the total heat flux of the LHP was calculated using the theoretical equation. According to the theoretical results, the intrinsic heat transfer mechanism affecting the heat transfer performance of LHPs was revealed. The results of this study laid the foundation for the application of LHPs in building envelopes.
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48

Sagia, Zoi, Athina Stegou, and Constantinos Rakopoulos. "Borehole Resistance and Heat Conduction Around Vertical Ground Heat Exchangers." Open Chemical Engineering Journal 6, no. 1 (May 4, 2012): 32–40. http://dx.doi.org/10.2174/1874123101206010032.

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Borehole thermal resistance in Ground Heat Exchanger (GHE) installations is affected by several parameters such as geometrical attributes of heat exchanger in the borehole, pipes' characteristics and grout’s thermal conductivity. A study is carried out to compare the values computed by Ground Loop Design (GLD) Software, GLD 2009, with three ana-lytical solutions for U-shaped tubes. The analysis is focused on dimensionless ratios of borehole geometrical parameters (borehole diameter to outside pipe diameter and shank spacing to borehole diameter) and pipes according to Standard Di-mension Ratio (SDR) and on eight common grouts. Finally, the effect of heat conduction in the borehole is examined by means of finite element analysis by Heat Transfer Module of COMSOL Multiphysics. A two-dimensional (2-D) steady-state simulation is done assuming working fluid temperatures for winter and summer conditions and typical Greek undis-turbed ground temperature in a field of four ground vertical U-tube heat exchangers surrounded by infinite ground. The temperature profile is presented and the total conductive heat flux from the pipe to the borehole wall per meter of length of ground heat exchanger is computed for pipes SDR11 (the outside diameter of the pipe is 11 times the thickness of its wall), SDR9 and SDR17 for summer working conditions and three different configurations. It is attempted to reach to comparative results for borehole thermal resistance value through different types of analysis, having considered the major factors that affect it and giving trends for the influence of each factor to the magnitude of its value.
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49

Archer, D. E., and B. A. Buffett. "A two-dimensional model of the methane cycle in a sedimentary accretionary wedge." Biogeosciences 9, no. 8 (August 24, 2012): 3323–36. http://dx.doi.org/10.5194/bg-9-3323-2012.

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Abstract. A two-dimensional model of sediment column geophysics and geochemistry has been adapted to the problem of an accretionary wedge formation, patterned after the margin of the Juan de Fuca plate as it subducts under the North American plate. Much of the model description is given in a companion paper about the application of the model to an idealized passive margin setting; here we build on that formulation to simulate the impact of the sediment deformation, as it approaches the subduction zone, on the methane cycle. The active margin configuration of the model shares sensitivities with the passive margin configuration, in that sensitivities to organic carbon deposition and respiration kinetics, and to vertical bubble transport and redissolution in the sediment, are stronger than the sensitivity to ocean temperature. The active margin simulation shows a complex sensitivity of hydrate inventory to plate subduction velocity, with results depending strongly on the geothermal heat flux. In low heat-flux conditions, the model produces a larger inventory of hydrate per meter of coastline in the passive margin than active margin configurations. However, the local hydrate concentrations, as pore volume saturation, are higher in the active setting than in the passive, as generally observed in the field.
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50

Demetrescu, C., D. Nitoiu, C. Boroneant, A. Marica, and B. Lucaschi. "Thermal signal propagation in soils in Romania: conductive and non-conductive processes." Climate of the Past 3, no. 4 (November 2, 2007): 637–45. http://dx.doi.org/10.5194/cp-3-637-2007.

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Abstract. Temperature data recorded in 2002 and 2003 at 10 stations out of the 70 available in the Romanian automatic weather stations network are presented and analyzed in terms of the heat transfer from air to underground. The air temperature at 2 m, the soil temperatures at 0, 5, 10, 20, 50 and 100 cm below the surface as well as rain fall and snow cover thickness have been monitored. The selected locations sample various climate environments in Romania. Preliminary analytical modelling shows that soil temperatures track air temperature variations at certain locations and, consequently, the heat transfer is by conduction, while at other stations processes such as soil freezing and/or solar radiation heating play an important part in the heat flux balance at the air/soil interface. However, the propagation of the annual thermal signal in the uppermost one meter of soil is mainly by conduction; the inferred thermal diffusivity for 8 stations with continuous time series at all depth levels ranges from 3 to 10×10−7 m2 s−1.
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