Modelling Optimal Pre-cooling Time for Buildings

2017 ◽  
Author(s):  
Kumar Saurav
Keyword(s):  
Cooling Time

Regression analysis of indicators of a numerical experiment to determine the cooling time of oil

2020 ◽  
pp. 89-97
Author(s):  
A. U. Yakupov ◽  
D. A. Cherentsov ◽  
K. S. Voronin ◽  
Yu. D. Zemenkov
Keyword(s):  
Regression Analysis ◽  
Computer Experiment ◽  
Calculation Model ◽  
Cooling Time ◽  
Regression Coefficients ◽  
Fisher Criterion ◽  
Empirical Relationships ◽  
Factors Affecting ◽  
Oil Pipeline ◽  
Significant Regression

The article performed the processing of the results of a computer experiment to determine the cooling time of oil in a stopped oil pipeline. We proposed a calculation model in previous works that allows you to simulate the process of cooling oil.There was a need to verify the previously obtained results when conducting a laboratory experiment on a stand with soil. To conduct the experiment, it was necessary to conduct the planning of the experiment. The factors affecting the cooling time of oil in the oil pipeline, which will vary in the proposed experiment, are determined, empirical relationships are established. A regression analysis was carried out, and the dispersion homogeneity was checked using the Cochren criterion. The estimates of reproducibility variances are calculated. The adequacy hypothesis was tested using the Fisher criterion. Significant regression coefficients are established.

scholarly journals Improving Cooling Performance of Injection Molding Tool with Conformal Cooling Channel by Adding Hybrid Fillers

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1224
Author(s):  
Chil-Chyuan Kuo ◽  
Wei-Hua Chen
Keyword(s):  
Thermal Conductivity ◽  
Injection Molding ◽  
Cooling Time ◽  
Performance Ratio ◽  
Cooling Efficiency ◽  
Cooling Channel ◽  
Conformal Cooling Channel ◽  
Conformal Cooling ◽  
Fused Deposition ◽  
Silicone Rubber Mold

Silicone rubber mold (SRM) is capable of reducing the cost and time in a new product development phase and has many applications for the pilot runs. Unfortunately, the SRM after injection molding has a poor cooling efficiency due to its low thermal conductivity. To improve the cooling efficiency, the thermal conductivity of the SRM was improved by adding fillers into the SRM. An optimal recipe for fabricating a high cooling efficiency low-pressure injection mold with conformal cooling channel fabricated by fused deposition modeling technology was proposed and implemented. This study proposes a recipe combining 52.6 wt.% aluminum powder, 5.3 wt.% graphite powder, and 42.1 wt.% liquid silicon rubber can be used to make SRM with excellent cooling efficiency. The price–performance ratio of this SRM made by the proposed recipe is around 55. The thermal conductivity of the SRM made by the proposed recipe can be increased by up to 77.6% compared with convention SRM. In addition, the actual cooling time of the injection molded product can be shortened up to 69.1% compared with the conventional SRM. The actual cooling time obtained by the experiment is in good agreement with the simulation results with the relative error rate about 20%.

scholarly journals Growth and structure of multiphase gas in the cloud-crushing problem with cooling

2020 ◽  
Vol 501 (1) ◽  
pp. 1143-1159
Author(s):  
Vijit Kanjilal ◽  
Alankar Dutta ◽  
Prateek Sharma
Keyword(s):  
Mixing Layer ◽  
Cooling Time ◽  
Radiative Cooling ◽  
Late Time ◽  
Dense Gas ◽  
Mixed Gas ◽  
Continuous Growth ◽  
Dense Cloud ◽  
Set Up ◽  
Background Gas

ABSTRACT We revisit the problem of the growth of dense/cold gas in the cloud-crushing set-up with radiative cooling. The relative motion between the dense cloud and the diffuse medium produces a turbulent boundary layer of mixed gas with a short cooling time. This mixed gas may explain the ubiquity of the range of absorption/emission lines observed in various sources such as the circumgalactic medium and galactic/stellar/active galactic nucleus outflows. Recently, Gronke & Oh showed that the efficient radiative cooling of the mixed gas can lead to continuous growth of the dense cloud. They presented a threshold cloud size for the growth of dense gas that was contradicted by the more recent works of Li et al. & Sparre et al. These thresholds are qualitatively different as the former is based on the cooling time of the mixed gas whereas the latter is based on the cooling time of the hot gas. Our simulations agree with the threshold based on the cooling time of the mixed gas. We argue that the radiative cloud-crushing simulations should be run long enough to allow for the late-time growth of the dense gas due to cooling of the mixed gas but not so long that the background gas cools catastrophically. Moreover, the simulation domain should be large enough that the mixed gas is not lost through the boundaries. While the mixing layer is roughly isobaric, the emissivity of the gas at different temperatures is fundamentally different from an isobaric single-phase steady cooling flow.

Analytic method of calculating channel cooling time for a single-phase coolant

1989 ◽  
Vol 25 (6) ◽  
pp. 332-336
Author(s):  
S. P. Gorbachev ◽  
A. A. Krikunov
Keyword(s):  
Single Phase ◽  
Cooling Time ◽  
Analytic Method

Physical Simulation of Weldability of Weldox 1300 Steel

2013 ◽  
Vol 762 ◽  
pp. 551-555 ◽  
Author(s):  
Marek Stanislaw Węglowski ◽  
Marian Zeman ◽  
Miroslaw Lomozik
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Physical Simulation ◽  
High Strength ◽  
Parent Material ◽  
Cooling Time ◽  
Electron Microscopies ◽  
Transmission Electron ◽  
Transformation Diagrams ◽  
The Impact

In the present study, the investigation of weldability of new ultra-high strength - Weldox 1300 steel has been presented. The thermal simulated samples were used to investigate the effect of welding cooling time t8/5 on the microstructure and mechanical properties of the heat affected zone (HAZ). In the frame of these investigation the microstructure was studied by the light (LM) and transmission electron microscopies (TEM). It has been shown that the microstructure of the Weldox 1300 steel is composed of tempered martensite, and inside the laths the minor precipitations mainly V(CN) and molybdenum carbide Mo2C were observed. Mechanical properties of parent material were analysed by the tensile, impact and hardness tests. In details the influence of cooling time in the range of 2,5 - 300 s. on hardness, impact toughness and microstructure of simulated HAZ was studied by using welding thermal simulation test. The results show that the impact toughness and hardness decrease with the increase of t8/5 under the condition of a single thermal cycle in simulated HAZ. The continuous cooling transformation diagrams (CCT-W for welding conditions) of Weldox 1300 steel for welding purposes was also elaborated. The steel Weldox 1300 for cooling time in the range of 2,5 - 4 s showed martensite microstructure, for time from 4 s to 60 s mixture of martensite and bainite, and for longer cooling time mixture of ferrite, bainite and martensite. The results indicated that the weldability of Weldox 1300 steel is limited and to avoid the cold cracking the preheating procedure or medium net linear heat input should be used.

Calculation of the cooling time in quenching bodies of complex shape

1972 ◽  
Vol 14 (4) ◽  
pp. 345-348 ◽  
Author(s):  
V. I. Fedorov ◽  
N. I. Kobasko
Keyword(s):  
Complex Shape ◽  
Cooling Time

Simultaneous Independent Measurement of Splat Diameter and Cooling Time during Impact on a Substrate of Plasma Sprayed Molybdenum Particles

1997 ◽  
Author(s):  
P. Gougeon ◽  
C. Moreau
Keyword(s):  
High Speed ◽  
Thermal Emission ◽  
Particle Temperature ◽  
Cooling Time ◽  
Spray Parameters ◽  
Coating Structure ◽  
Molten Droplets ◽  
Plasma Sprayed ◽  
The Impact ◽  
Molybdenum Particles

Abstract In thermal spray processes, the coating structure is the result of flattening and cooling of molten droplets on the substrate. The study of the cooling time and evolution of the splat size during impact is then of the highest importance to understand the influence of the spray parameters and substrate characteristics on the coating structure. Measurement of particle temperature during impact requires the use of a high-speed 2-color pyrometer to collect the thermal emission of the particle during flattening. Simultaneous measurement of the splat size with this pyrometer is difficult since the size of the particle can change as it cools down. To measure the splat size independently, a new measurement technique has been developed. In this technique the splat size is measured from the attenuation of the radiation of a laser beam illuminating the particle during impact. Results are presented for plasma sprayed molybdenum particles impacting on a glass substrate at room temperature. It is shown that the molybdenum splat reaches its maximum extent about 2 microseconds after the impact. In this work, we show that this increase of the splat surface is followed by a phase during which the splat size decreases significantly during 2 to 3 microseconds.

The Use of Advanced Aluminum Alloys for Enhanced Productivity in Plastic Injection Molding

2000 ◽  
Author(s):  
Jim Nerone ◽  
Karthik Ramani
Keyword(s):  
Aluminum Alloys ◽  
Injection Molding ◽  
Wall Thickness ◽  
Simulation Software ◽  
Cooling Time ◽  
Coolant Temperature ◽  
Steel Mold ◽  
Cooling Channels ◽  
Injection Molding Simulation ◽  
Increased Strength

Abstract New aluminum alloys, QC-7® and QE-7®, have thermal conductivities four times greater than traditional tool steels, and have significantly increased strength and hardness compared to traditional aluminum materials. Molds were constructed of P-20 tool steel and QE-7® aluminum and were used to provide experimental data regarding thermal mold characteristic and confirm injection molding simulation predictions using C-Mold®. The relationships between cooling time reduction (using aluminum alloys) and polymer type, cooling channel depth, part wall thickness, and coolant temperature were explored both experimentally and using simulation software. It was shown that the potential reduction in cooling time varied from 5% to 25%. The most significant percentage improvements were observed in parts with part wall thickness of 0.05″ to 0.10″ and in molds with cooling channels at a depth ratio (D/d) of 2.0. The thermal pulses in the steel mold 0.10″ from the surface were approximately 63% larger than in aluminum mold.

Sign in / Sign up

Export Citation Format

Share Document