scholarly journals Numerical–Experimental Analysis of Polyethylene Pipe Deformation at Different Load Values

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 160
Author(s):  
Adam Gnatowski ◽  
Agnieszka Kijo-Kleczkowska ◽  
Mateusz Chyra ◽  
Dariusz Kwiatkowski
Keyword(s):  
Computer Simulation ◽  
Numerical Analysis ◽  
Experimental Analysis ◽  
External Load ◽  
Experimental Studies ◽  
Strain Gauges ◽  
Experimental Investigations ◽  
Polyethylene Pipe ◽  
External Forces ◽  
The Impact

Polymer pipes are used in the construction of underground gas, water, and sewage networks. During exploitation, various external forces work on the pipeline, which cause its deformation. In the paper, numerical analysis and experimental investigations of polyethylene pipe deformation at different external load values (500, 1000, 1500, and 2000 N) were performed. The authors measured strains of the lower and upper surface of the pipe during its loading moment using resistance strain gauges, which were located on the pipe at equal intervals. The results obtained from computer simulation and experimental studies were comparable. An innovative element of the research presented in the article is recognition of the impact of the proposed values of the load of polyethylene pipe on the change in its deformation.

scholarly journals Analysis of Energy Exchange with the Ground in a Two-Chamber Vegetable Cold Store, Assuming Different Lengths of Technological Break, with the Use of a Numerical Calculation Method—A Case Study

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4970
Author(s):  
Paweł Sokołowski ◽  
Grzegorz Nawalany
Keyword(s):  
Numerical Analysis ◽  
Air Temperature ◽  
Energy Demand ◽  
Experimental Studies ◽  
Calculation Model ◽  
Energy Losses ◽  
Cold Store ◽  
Numerical Calculation Method ◽  
The Impact ◽  
Floor Temperature

The paper deals with the impact of the technological break duration during the cold storage cycle on the energy demand of the cold store for vegetables and fruit and the temperature distribution in the ground under the cold store. The studied facility was a two-chamber vegetable cold store located in southern Poland used to store carrots (Daucus carota) for nine months a year. The experiments were conducted for 12 months (01.05.2017–30.04.2018). The technological break during this period lasted three months (from 1 July 2018 to 30 September 2018). Continuous measurements (with 1-h frequency) were made in order to determine the boundary conditions for numerical analysis. The measured parameters included indoor air temperature, outdoor air temperature, ground temperature under the building and in its vicinity. There were 22 measuring points andPT100 sensors were used. The numerical analysis was based on the elementary balances method. WUFIplus® software was used as a calculation supporting tool. The numerical analysis was conducted for 14 calculation variants, with different duration of technological break. The calculation model validation was performed and the results showed a good correlation with the experimental data. The results of experimental studies and of calculations showed a significant impact of the technological break duration on the soil distribution in the ground and the building energy demand. A technological break of less than 4 weeks is the most optimal in the summer. The technological break longer than 4 weeks significantly affects the cooling energy demand in the first days of the cooling cycle and significantly extends the time necessary for the ground and the floor to reach the optimum temperature. The analysis of the floor temperature results (points A1–C1) showed that the technological break longer than four weeks causes the average floor temperature to exceed 4.0 °C. Therefore, the optimum solution is technological break lasting 7–35 days. Absence of technological break results in a decrease of energy gains from the ground by 20% relative to a three-month technological break. The impact of technological break duration was clearly seen in terms of energy losses from the cold store to the ground. In case of a 91-day technological break, the energy losses to the ground were 1289.5 kWh/a, while in case of absence of technological break this value was ninefold lower (147.5 kWh/a).

Hollywood in China: How American Popular Culture Shapes Chinese Views of the “Beautiful Imperialist” – An Experimental Analysis

2015 ◽  
Vol 224 ◽  
pp. 1070-1082 ◽  
Author(s):  
Peter Gries ◽  
Matthew A. Sanders ◽  
David R. Stroup ◽  
Huajian Cai
Keyword(s):  
Popular Culture ◽  
Experimental Analysis ◽  
Experimental Studies ◽  
Specific Nature ◽  
Mainland Chinese ◽  
Personality Differences ◽  
American Popular Culture ◽  
Popular Magazine ◽  
Magazine Covers ◽  
The Impact

AbstractWhile most mainland Chinese today have extremely few direct contacts with either America or Americans, their indirect contacts with both, via globalized American popular culture, are increasing rapidly. Do daily parasocial contacts with American celebrities shape Chinese views of America? Based on two experimental studies, this paper argues that even indirect, subconscious exposure to American celebrities via popular magazine covers shapes Chinese views of America. However, the impact of that exposure depends upon both the specific nature of the bicultural exposure and the psychological predispositions of the Chinese involved. Not all Chinese are alike, and their personality differences shape whether they experience American popular culture as enriching or threatening, leading to integrative and exclusionary reactions, respectively.

Experimental Studies of the Effect of Vortex Disturbances on the Flow Around the Wing Model at Low Reynolds Numbers

2014 ◽  
Vol 9 (3) ◽  
pp. 32-38
Author(s):  
Boris Zanin ◽  
Mikhail Katasonov ◽  
Mikhail Mikhaelis ◽  
Alexandr Pavlenko
Keyword(s):  
Experimental Studies ◽  
Reynolds Numbers ◽  
Wind Tunnels ◽  
Experimental Investigations ◽  
Low Reynolds Numbers ◽  
Free Stream Turbulence ◽  
Vortex Control ◽  
Wing Model ◽  
Thin Thread ◽  
The Impact

Results of experimental investigations in subsonic wind tunnels, which studied the impact of artificial forcing on the flow in the boundary layer of straight wing model were described. The feature of this work is the use of such locally impact that can change the general flow pattern. The influences of the angle of attack, free stream turbulence level, and wake behind thin thread on the flow near the wing profile were studied at this paper. The method of oil-film based on titanium dioxide was applied for flow visualization, also hot-wire measurements were used. The obtained results were analyzed with the aim of finding the most efficient ways of vortex control to the flow

Effects of the Steady Wake-Tip Clearance Vortex Interaction in a Compressor Cascade: Part I — Experimental Investigations

2014 ◽  
Author(s):  
Andreas Krug ◽  
Peter Busse ◽  
Konrad Vogeler
Keyword(s):  
Flow Field ◽  
Experimental Studies ◽  
Axial Compressor ◽  
Field Measurements ◽  
Tip Clearance ◽  
Experimental Investigations ◽  
Compressor Cascade ◽  
Linear Compressor Cascade ◽  
Tip Clearance Vortex ◽  
The Impact

An important aspect of the aerodynamic flow field in the tip region of axial compressor rotors is the unsteady interaction between the tip clearance vortex and the incoming stator wakes. In order to gain an improved understanding of the mechanics involved, systematic studies need to be performed. As a first step towards the characterisation of the dynamic effects caused by the relative movement of the blade rows, the impact of a stationary wake-induced inlet disturbance on a linear compressor cascade with tip clearance will be analysed. The wakes were generated by a fixed grid of cylindrical bars with variable pitch being placed at discrete pitchwise positions. Part I of this two-part paper focuses on experimental studies conducted at the newly designed low-speed cascade wind tunnel in Dresden. The general tunnel configuration and details on the specific cascade setup will be presented. Steady state flow field measurements were carried out using five-hole probe traverses up- and downstream of the cascade and accompanied by static wall pressure readings. 2D-PIV measurements complemented these results by visualizing the blade-to-blade flow field. Hence, the structure of the evolving secondary flow system is evaluated and compared for all tested configurations.

Experimental and Computer Researches of Ferroconcrete Beams at High-Temperature Influences

2019 ◽  
Vol 968 ◽  
pp. 355-360 ◽  
Author(s):  
Yuriy Otrosh ◽  
Mykola Surianinov ◽  
Alexander Golodnov ◽  
Olena Starova
Keyword(s):  
Computer Simulation ◽  
High Temperature ◽  
Numerical Analysis ◽  
Experimental Research ◽  
Experimental Studies ◽  
Research Data ◽  
Fire Tests ◽  
Practical Application ◽  
Software Complex

The paper presents experimental and computer researches of ferroconcrete beams at high-temperature influences. There were conducted the experimental fire tests of ferroconcrete beams. The most promising way of verifying these experimental research data is computer simulation of structures, also during a fire. In order to evaluate the quality of the experiment and the reliability of the received temperature distribution, there was conducted a computer simulation of the ferroconcrete beam in the ANSYS R.17.1 software complex. There were conducted a comparative analysis of the results of experimental studies and numerical analysis. The results confirm that the method of conducted experimental research and computer simulation with further numerical analysis can be recommended for practical application.

On Experimental Studies of Longitudinal and Flexural Wave Propagations: An Annotated Bibliography

1986 ◽  
Vol 39 (6) ◽  
pp. 853-865 ◽  
Author(s):  
M. M. Al-Mousawi
Keyword(s):  
Wave Propagation ◽  
Cross Section ◽  
Material Properties ◽  
Experimental Studies ◽  
Flexural Wave ◽  
Experimental Investigations ◽  
Velocity Impact ◽  
Flexural Wave Propagation ◽  
The Impact

Experimental investigations in the field of longitudinal wave propagation in beams are plentiful; however, experimental studies of flexural wave propagation problems are scarce and are restricted mainly to uniform and infinite structures where the effects of reflected waves are not generally included. This review is mostly restricted to low velocity impact and does not cover the so-called high velocity impact such as those of bullets and explosives. In addition to a brief survey of classical work related to impact, this article covers publications related to experimental studies of longitudinal and flexural elastic waves due to impact. This includes the longitudinal, central as well as eccentric impact and transverse impact of two bars and the impact achieved by sphere impinging on a beam. Many workers used experimental findings to study the adequacy of various theoretical solutions of the wave propagation problem such as those by Pochhammer and Chree, Euler–Bernoulli, and the Timoshenko beam theory. The revival of interest in the recent years is due to, among other things, the advancement of experimental equipment and measurement techniques for data acquisition of stress waves and associated signals. An important application of transient waves is their use for the determination of material properties under various loading conditions and strain rates that can be studied by the split Hopkinson pressure bar techniques. The problem of longitudinal and flexural waves in bars with discontinuities of cross section are covered, and some publications on fracture of materials due to bending waves are also included. Experimental investigations demonstrate the effect of abrupt change of cross section and/or material properties on reflected and transmitted waves where reflections are to be taken into consideration when estimating the level of stresses and strains in finite beam with discontinuities. In the field of flexural wave propagation, comparison of theoretical predictions with experimental results verified and validated the adequacy of the Timoshenko theory for the determination of bending strain in finite structures, a one-dimensional theory that takes into account the effect of shear deformation and rotatory inertia.

Воздействиеультразвуковогополянадинамическуювязкостьводы

2019 ◽  
pp. 27-29
Author(s):  
P. Vikulin ◽  
K. Khlopov ◽  
M. Cherkashin
Keyword(s):  
Dynamic Viscosity ◽  
Experimental Studies ◽  
Ultrasonic Field ◽  
Maximum Effect ◽  
Ultrasonic Frequency ◽  
Ultrasonic Vibrations ◽  
Wastewater Disposal ◽  
Laboratory Setup ◽  
Sonic Treatment ◽  
The Impact

Enhancing water purification processes is provided by various methods including physical ones, in particular, exposure to ultrasonic vibrations. The change in the dynamic viscosity of water affects the rate of deposition of particles in the aquatic environment which can be used in natural and wastewater treatment. At the Department Water Supply and Wastewater Disposal of the National Research Moscow State University of Civil Engineering experimental studies were conducted under laboratory conditions to study the effect of ultrasound on the change in the dynamic viscosity of water. A laboratory setup has been designed consisting of an ultrasonic frequency generator of the relative intensity, a transducer (concentrator) that transmits ultrasonic vibrations to the source water, and sonic treatment tanks. Experimental studies on the impact of the ultrasonic field in the cavitation mode on the dynamic viscosity of the aqueous medium were carried out the exposure time was obtained to achieve the maximum effect.Интенсификация процессов очистки воды осуществляется с помощью различных методов, в том числе и физических, в частности воздействием ультразвуковых колебаний. Изменение динамической вязкости воды влияет на скорость осаждения частиц в водной среде, что может быть использовано в процессах очистки природных и сточных вод. На кафедре Водоснабжение и водоотведение Национального исследовательского Московского государственного строительного университета в лабораторных условиях проведены экспериментальные исследования по изучению влияния ультразвука на изменение динамической вязкости воды. Разработана схема лабораторной установки, состоящая из генератора ультразвуковых частот с соответствующей интенсивностью, преобразователя (концентратора), передающего ультразвуковые колебания в исходную воду, и емкости для озвучивания. Выполнены экспериментальные исследования по влиянию ультразвукового поля в режиме кавитации на динамическую вязкость водной среды, получено время экспозиции для достижения максимального эффекта.

Family Influences on Youth Offending

2018 ◽  
pp. 377-403
Author(s):  
Abigail A. Fagan ◽  
Kristen M. Benedini
Keyword(s):  
Life Course ◽  
Family Environment ◽  
Parenting Practices ◽  
Experimental Studies ◽  
The United States ◽  
Parental Violence ◽  
Youth Delinquency ◽  
The Impact ◽  
Children’S Exposure

This chapter reviews the degree to which empirical evidence demonstrates that families influence youth delinquency. Because they are most likely to be emphasized in life-course theories, this chapter focuses on parenting practices such as parental warmth and involvement, supervision and discipline of children, and child maltreatment. It also summarizes literature examining the role of children's exposure to parental violence, family criminality, and young (teenage) parents in affecting delinquency. Because life-course theories are ideally tested using longitudinal data, which allow examination of, in this case, the impact of parenting practices on children's subsequent behaviors, this chapter focuses on evidence generated from prospective studies conducted in the United States and other countries. It also discusses findings from experimental studies designed to reduce youth substance use and delinquency by improving the family environment.

scholarly journals Improvement Dependability of Offshore Horizontal-Axis Wind Turbines by Applying New Mathematical Methods for Calculation the Excess Speed in Case of Wind Gusts

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3085
Author(s):  
Konstantin Osintsev ◽  
Seregei Aliukov ◽  
Alexander Shishkov
Keyword(s):  
Computer Simulation ◽  
Wind Turbines ◽  
Experimental Studies ◽  
Offshore Wind ◽  
Approximation Schemes ◽  
Calculation Error ◽  
Strong Wind ◽  
Mathematical Methods ◽  
Wind Gusts ◽  
Gas Dynamic

The problem of increasing the reliability of wind turbines exists in the development of new offshore oil and natural gas fields. Reducing emergency situations is necessary due to the autonomous operation of drilling rigs and bulk seaports in the subarctic and Arctic climate. The relevance of the topic is linked with the development of a methodology for theoretical and practical studies of gas dynamics when gas flows in a pipe, based on a mathematical model using new mathematical methods for calculation of excess speeds in case of wind gusts. Problems in the operation of offshore wind turbines arise with storm gusts of wind, which is comparable to the wave movement of the gas flow. Thus, the scientific problem of increasing the reliability of wind turbines in conditions of strong wind gusts is solved. The authors indicate a gross error in the calculations when approximating through the use of the Fourier series. The obtained results will allow us to solve one of the essential problems of modeling at this stage of its development, namely: to reduce the calculation time and the adequacy of the model built for similar installations and devices. Experimental studies of gas-dynamic flows are carried out on the example of a physical model of a wind turbine. In addition, a computer simulation of the gas-dynamic flow process was carried out. The use of new approximation schemes in processing the results of experiments and computer simulation can reduce the calculation error by 1.2 percent.

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