scholarly journals Blowdown heat transfer program. Task B-2 skin heater feasibility test results

1972 ◽  
Author(s):  
G. Sozzi
Keyword(s):  
Heat Transfer ◽  
Test Results ◽  
Transfer Program ◽  
Feasibility Test

scholarly journals Pengembangan media pembelajaran AIKO berbasis aplikasi android dari PowerPoint materi pertumbuhan dan pembangunan ekonomi kelas XI

2021 ◽  
Vol 1 (8) ◽  
pp. 735-745
Author(s):  
Nazilatul Muharrami Nasifa ◽  
Ro’ufah Inayati
Keyword(s):  
Research And Development ◽  
Growth And Development ◽  
Test Results ◽  
Economic Growth And Development ◽  
Technological Developments ◽  
Android Applications ◽  
Addie Model ◽  
Feasibility Test ◽  
Alternative Solutions ◽  
Group Trial

Abstract Being in the industrial era 4.0, teachers as educators are required to understand technology more than their students. Teachers need to understand students' needs for technological developments so that classroom learning runs well. The development of learning media is one of the alternative solutions that can be used by teachers to meet the needs of students for technological developments. The purpose of research and development is to produce learning media products based on android applications from Microsoft PowerPoint on material for economic growth and development for class XI. This research and development uses the ADDIE model. The results of the research and development were obtained from the results of the feasibility test through filling out validation questionnaires with validators of material experts (lecturers), media experts (lecturers), learning practitioners (economics teachers), and test results with users (students) through small group trials and large group trial. The average result of the validation and testing as a whole obtained a score of 92.177 percent so that this research and development product is very valid and very feasible to be used as a learning medium. Abstrak Berada pada era industri 4.0 guru sebagai pendidik diharuskan untuk memahami teknologi lebih dari siswanya. Guru perlu memahami kebutuhan siswa atas perkembangan teknologi agar pembelajaran di kelas berjalan dengan baik. Pengembangan media pembelajaran menjadi salah satu solusi alternatif yang bisa digunakan oleh guru untuk memenuhi kebutuhan siswa atas perkembangan teknologi. Tujuan dari penelitian dan pengembangan adalah untuk menghasilkan produk media pembelajaran berbasis aplikasi android dari Microsoft PowerPoint pada materi pertumbuhan dan pembangunan ekonomi kelas XI. Penelitian dan pengembangan ini menggunakan model ADDIE. Hasil dari penelitian dan pengembangan diperoleh dari hasil uji kelayakan melalui pengisian kuisioner validasi bersama validator ahli materi (dosen), ahli media (dosen), praktisi pembelajaran (guru ekonomi), dan hasil uji coba bersama pengguna (siswa) melalui uji coba kelompok kecil dan uji coba kelompok besar. Rata-rata asil validasi dan uji coba secara keseluruhan memperoleh skor sebesar 92,177 persen sehingga produk penelitian dan pengembangan ini sangat valid dan sangat layak untuk digunakan sebagai media pembelajaran.

Natural-Convection Heat Transfer in Liquids Confined by Two Horizontal Plates and Heated From Below

1959 ◽  
Vol 81 (1) ◽  
pp. 24-28 ◽  
Author(s):  
Samuel Globe ◽  
David Dropkin
Keyword(s):  
Heat Transfer ◽  
Silicone Oil ◽  
Convection Heat Transfer ◽  
Test Results ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Silicone Oils ◽  
Prandtl Numbers ◽  
The Relationship ◽  
Rayleigh Numbers

This paper presents results of an experimental investigation of convective heat transfer in liquids placed between two horizontal plates and heated from below. The liquids used were water, silicone oils of 1.5, 50, and 1000 centistoke kinematic viscosities, and mercury. The experiments covered a range of Rayleigh numbers between 1.51(10)5 and 6.76(10)8. and Prandtl numbers between 0.02 and 8750. Tests were made in cylindrical containers having copper tops and bottoms and insulating walls. For water and silicone oils the container was 5 in. in diam and 2 in. high. For mercury, two containers were used, both 5.28 in. in diameter, but one 1.39 in. high and another 2.62 in. high. In all cases the bottom plates were heated by electric heaters. The top plates were air-cooled for the water and silicone-oil experiments and water-cooled for the mercury tests. To prevent amalgamation, the copper plates of the mercury container were chromium plated. Surface temperatures were measured by thermocouples embedded in the plates. The test results indicate that the heat-transfer coefficients for all liquids investigated may be determined from the relationship Nu=0.069Ra13Pr0.074 In this equation the Nusselt and Rayleigh numbers are based on the distance between the copper plates. The results of this experiment are in reasonable agreement with the data reported by others who used larger containers and different fluids.

scholarly journals Condensation of Novec 649 refrigerant in pipe minichannels

2018 ◽  
Vol 70 ◽  
pp. 02002 ◽  
Author(s):  
Tadeusz Bohdal ◽  
Henryk Charun ◽  
Małgorzata Sikora
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Mass Flux ◽  
Flow Structures ◽  
Test Results ◽  
Calculation Results ◽  
Vapour Quality ◽  
Inner Diameter

The paper presents the results of experimental investigation of Novec 649 refrigerant condensation in tube minichannels. This is a low-pressure refrigerant. This investigations are basis for flow structures visualization during condensation in pipe minichannels. The local and the average values of pressure drop (Δp/L) and heat transfer coefficient α in the whole range of the changes of vapour quality (x = 1 ÷ 0) were calculated. On the basis of the obtained test results there was illustrated the influence of the vapour quality x, the mass flux density G and the inner diameter of channel d changes on the studied parameters. These results were compared with the calculation results based on the dependencies of other authors.

scholarly journals Experimental study on heat transfer of concrete at high temperatures under hygrothermal environment

2019 ◽  
Vol 275 ◽  
pp. 02020
Author(s):  
Min Tu ◽  
Jun Deng ◽  
Yi Wang
Keyword(s):  
Heat Transfer ◽  
Temperature Increase ◽  
Concrete Structures ◽  
Fire Damage ◽  
Test Results ◽  
Saturation Degree ◽  
Spalling Failure ◽  
Increase Rate ◽  
Hygrothermal Environment ◽  
Damage Simulation

Safety of concrete structures could be threatened under fire exposure, especially for structures under hygrothermal environment. Existing studies have shown that concrete contains large amount of moisture could induce spalling failure and the temperature is a critical parameter for the damage. However, until now, the study for heat transfer of concrete with different saturation degree remains limited. In this paper, the temperature increase of concrete specimens with different saturation degree is experimentally studied. Results show that the temperature increase rate could be affected by the moisture content significantly, especially for the cases under higher temperatures. The test results could be significant for our future fire damage simulation of concrete structures under hygrothermal environment.

Preliminary Testing of Metal-Based Thermal Barrier Coating in a Spark-Ignition Engine

2009 ◽  
Author(s):  
Michael Marr ◽  
James S. Wallace ◽  
Larry Pershin ◽  
Sanjeev Chandra ◽  
Javad Mostaghimi
Keyword(s):  
Heat Transfer ◽  
Thermal Barrier Coating ◽  
Substrate Surface ◽  
Temperature Fluctuations ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Thermal Barrier ◽  
Cylinder Wall ◽  
Test Results ◽  
Barrier Coating

A novel metal-based thermal barrier coating was tested in a spark-ignition engine. The coating was applied to the surface of aluminum plugs and exposed to in-cylinder conditions through ports in the cylinder wall. Temperatures were measured directly behind the coating and within the plug 3 and 11 mm from the surface. In-cylinder pressures were measured and analyzed to identify and quantify knock. Test results suggest the coating does not significantly reduce overall heat transfer, but it does reduce the magnitude of temperature fluctuations at the substrate surface. It was found that heat transfer can be reduced by reducing the surface roughness of the coating. The presence of the coating did not promote knock.

Hybrid Expansion Revisited

2006 ◽  
Vol 129 (3) ◽  
pp. 482-487 ◽  
Author(s):  
Stanley Yokell
Keyword(s):  
Heat Transfer ◽  
Microscopic Examination ◽  
Load Test ◽  
Shear Load ◽  
Test Results

This paper describes new hitherto unused procedures that combine hydraulic and explosive expanding to produce tube-to-tubesheet joints in tubular heat transfer equipment with thick tubesheets. This paper also interprets shear load test results and microscopic examination of polished and sectioned specimens used to validate the adequacy of the method for producing strong, leak tight joints. It concludes that the method is successful.

The Use of Organic Coatings to Promote Dropwise Condensation of Steam

1987 ◽  
Vol 109 (3) ◽  
pp. 768-774 ◽  
Author(s):  
K. M. Holden ◽  
A. S. Wanniarachchi ◽  
P. J. Marto ◽  
D. H. Boone ◽  
J. W. Rose
Keyword(s):  
Heat Transfer ◽  
Atmospheric Pressure ◽  
Polymer Coatings ◽  
Organic Coatings ◽  
Major Constituent ◽  
Dropwise Condensation ◽  
Test Results ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Sustained Performance

Fourteen polymer coatings were evaluated for their ability to promote and sustain dropwise condensation of steam. Nine of the coatings employed a fluoropolymer as a major constituent; four employed hydrocarbons and one a silicone. Each coating was applied to 25-mm-square by approximately 1-mm-thick metal substrates of brass, copper, copper–nickel, and titanium. While exposed to steam at atmospheric pressure, each coating was visually evaluated for its ability to promote dropwise condensation. Observations were also conducted over a period of 22,000 hr. Hardness and adhesion tests were performed on selected specimens. On the basis of sustained performance, six coatings were selected for application to the outside of 19-mm-dia copper tubes in order to perform a heat transfer evaluation. These tubes were mounted horizontally in a separate apparatus through which steam flowed vertically downward. Steam-side heat transfer coefficients were inferred from overall measurements. Test results indicate that the steam-side heat transfer coefficient can be increased by a factor of five to eight through the use of polymer coatings to promote dropwise condensation.

FEASIBILITY TEST RESULTS OF BILATERAL TELEOPERATION USING THE ENERGY-BOUNDING ALGORITHM

2008 ◽  
Vol 41 (2) ◽  
pp. 14096
Author(s):  
Changhoon Seo ◽  
Jong-Phil Kim ◽  
Yo-An Lim ◽  
Joo Hong Yoon ◽  
Jeha Ryu
Keyword(s):  
Test Results ◽  
Bilateral Teleoperation ◽  
Feasibility Test

Optimizing Laminar Natural Convection for a Heat Generating Cylinder in a Channel

2014 ◽  
Vol 136 (11) ◽  
Author(s):  
Corey E. Clifford ◽  
Mark L. Kimber
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Natural Convection ◽  
Rayleigh Number ◽  
Spent Nuclear Fuel ◽  
Reactor Core ◽  
Horizontal Cylinder ◽  
Cylinder Surface ◽  
Transfer Program ◽  
Wet Storage

Natural convection heat transfer from a horizontal cylinder is of importance in a large number of applications. Although the topic has a rich history for unconfined cylinders, maximizing the free convective cooling through the introduction of sidewalls and creation of a chimney effect is considerably less studied. In this investigation, a numerical model of a heated horizontal cylinder confined between two vertical adiabatic walls is employed to evaluate the natural convective heat transfer. Two different treatments of the cylinder surface are investigated: constant temperature (isothermal) and constant surface heat flux (isoflux). To quantify the effect of wall distance on the effective heat transfer from the cylinder surface, 18 different confinement ratios are selected in varying increments from 1.125 to 18.0. All of these geometrical configurations are evaluated at seven distinct Rayleigh numbers ranging from 102 to 105. Maximum values of the surface-averaged Nusselt number are observed at an optimum confinement ratio for each analyzed Rayleigh number. Relative to the “pseudo-unconfined” cylinder at the largest confinement ratio, a 74.2% improvement in the heat transfer from an isothermal cylinder surface is observed at the optimum wall spacing for the highest analyzed Rayleigh number. An analogous improvement of 60.9% is determined for the same conditions with a constant heat flux surface. Several correlations are proposed to evaluate the optimal confinement ratio and the effective rate of heat transfer at that optimal confinement level for both thermal boundary conditions. One of the main application targets for this work is spent nuclear fuel, which after removal from the reactor core is placed in wet storage and then later transferred to cylindrical dry storage canisters. In light of enhanced safety, many are proposing to decrease the amount of time the fuel spends in wet storage conditions. The current study helps to establish a fundamental understanding of the buoyancy-induced flows around these dry cask storage canisters to address the anticipated needs from an accelerated fuel transfer program.

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