scholarly journals The Study of Hydrodynamic Processes Occurring on Transition of Sudden Expanding of Hydraulic Section of Plane – Parallel Full Pipe Flow

TEM Journal ◽  
2020 ◽  
pp. 1494-1501
Author(s):  
Arestak Sarukhanyan ◽  
Arevshad Vartanyan ◽  
Garnik Vermishyan ◽  
Vache Tokmajyan
Keyword(s):  
Pipe Flow ◽  
Inlet Section ◽  
Transition Section ◽  
Hydrodynamic Parameters ◽  
Plane Parallel ◽  
Parabolic Law ◽  
Parabolic Distribution ◽  
Fluid Velocities ◽  
Calculation Results ◽  
Hydrodynamic Processes

The study regarding the regularity of changes in the hydrodynamic processes in the area of a sudden expanding in hydraulic section of the planeparallel full pipe flow of the liquid is carried out on the basis of the equations on the boundary layer. A method has been developed for determining the changes in the hydrodynamic parameters of the flow in the transition section which makes it possible to obtain the profile of the distribution of fluid velocities in any cross section of the channel based on the results of deformation of the areas of velocity under common initial and boundary conditions. The hydrodynamic processes occurring on transition of sudden expanding on hydraulic section of plane-parallel full pipe flow are studied in cases when: a) the velocity at any point of the inlet section of the channel is constant; b) the velocity at the inlet section is distributed according to the parabolic law. The calculation results for various values of the coefficient of expansion are given: Based on the results of computer simulation, the course of deformation of the velocity diagram along the length of the transition section was obtained for a constant and parabolic distribution of the velocities of the fluid flowing into the expanded section of the channel. The regularities of pressure distribution along the length of the studied section were also determined.

scholarly journals A STUDY ON SUDDEN EXPANSION HYDRODYNAMIC PHENOMENA OCCURRING IN CYLINDRICAL PIPES

2021 ◽  
Vol 6 (4) ◽  
pp. 63-71
Author(s):  
Arestak Sarukhanyan ◽  
◽  
Garnik Vermishyan ◽  
Keyword(s):  
Cross Section ◽  
Sudden Expansion ◽  
Expansion Factor ◽  
Transitional Area ◽  
Boundary Layer Equations ◽  
Hydrodynamic Parameters ◽  
Parabolic Law ◽  
Computer Aided ◽  
Hydrodynamic Processes ◽  
Relevant Section

Introduction: This paper studies the frequency with which hydrodynamic parameters change in the sudden expansion section of axisymmetric pressure flow, based on the boundary layer equations. Methods: The suggested method reveals the regularity of changes in the hydrodynamic parameters of the flow in the transitional area, making it possible to obtain a velocity profile in any cross-section under common initial and boundary conditions. Based on the general solutions, we studied the hydrodynamic processes occurring in the transitional area of the effective sudden cross-section expansion within the axisymmetric pressure movement, in the following cases: a) when the velocity is constant at any point of the inlet face; b) when the velocity is distributed along the inlet face according to the parabolic law. Our calculations were carried out for different values of the expansion factor. Results: Based on the results of the computer-aided experimental study, we obtained velocity diagrams along the length of the transitional area with constant and parabolic velocity distributions for fluid inflowing into the expanded section. We also determined the patterns of pressure distribution along the length of the relevant section.

scholarly journals Multi-mode adaptive-pitch propeller and its application prospects for ships with variable running conditions

2021 ◽  
Vol 4 (398) ◽  
pp. 53-60
Author(s):  
Leonid Vishnevsky ◽  
Keyword(s):  
Experimental Data ◽  
Ship Design ◽  
Design Calculation ◽  
Hydrodynamic Parameters ◽  
Calculation Data ◽  
Propulsion Performance ◽  
Calculation Results ◽  
Selection For ◽  
Multi Mode ◽  
Application Prospects

Object and purpose of research. This paper describes multi-mode adaptive-pitch propeller and its hydrodynamics. Based on the calculation data, the study demonstrates that this kind of propeller might be quite promising in terms of propulsion performance for the ships with variable running conditions, like patrol vessels that switch between patrol and chase running mode. More-over, multi-mode adaptive pitch propellers may work as two-positional CPPs commonly regarded as general-use propellers. These results might be useful in design of ships for various applications. Materials and methods. Experimental data on hydrodynamic parameters of multi-mode adaptive pitch propeller and design calculation results for a virtual triple-shaft patrol vessel. Main results. The results of this study could be useful in propeller selection for given ship design. Conclusion. It is shown that, as compared to FPPs, multi-mode adaptive pitch propellers are more efficient in terms of propulsion performance.

Numerical Analysis of Soil Temperature Distribution around Buried Tube for Ground-Source Heat Pump

2012 ◽  
Vol 170-173 ◽  
pp. 2525-2528 ◽  
Author(s):  
Fa Hui Wang ◽  
Jun Yong Sang ◽  
Dan Zhang
Keyword(s):  
Fluid Flow ◽  
Temperature Distribution ◽  
Soil Temperature ◽  
Heat Pump ◽  
Pipe Flow ◽  
Ground Source Heat Pump ◽  
Ground Source ◽  
Calculation Results ◽  
Ground Coupled Heat Pump ◽  
The Finite Difference Method

The main objective of this work is to introduces the finite difference method based on calculation ground-coupled heat pump implanted tube temperature distribution in the soil around the calculation method of the buried depth, and calculated the 1-m, different quality bury pipe flow around the change rule of soil temperature. The calculation results show that: buried tube weeks with the temperature distribution in soil of fluid flow pipe changes, the change rule is, the greater the fluid quality. Discharge inside around burying tube soil temperature is lower.

Tax maneuver in the oil industry: Provisional results and risks for further implementation

2020 ◽  
pp. 28-43
Author(s):  
A. S. Kaukin ◽  
E. М. Miller
Keyword(s):  
Oil Industry ◽  
Oil Products ◽  
Oil Refining ◽  
State Budget ◽  
Tax Rate ◽  
Oil Companies ◽  
Reform Plan ◽  
Alternative Variant ◽  
Calculation Results ◽  
The Cost

The paper analyzes the consequences of the abolition of the export duty on oil and oil products as a necessary step to stimulate energy efficiency of Russia’s economy and eliminate underdevelopment provoked by a long-term subsidizing of inefficient oil refining sector in Russia. The calculation results have shown that even taking into account several deviations from the planned scenarios of changing the parameters of tax regulation of the oil industry in 2014— 2019, the tax maneuver brought over 3.5 trillion rubles (in 2019 — 148 billion rubles) to the state budget in 2014—2017, mainly due to an increase in the base mineral extraction tax rate, and contributed to an increase in the depth of oil refining from 72% to 85%. In addition, the article analyzes possible risks associated with the current plan for reforming the taxation of the industry until 2024 and proposes an alternative that could level some of them. A comparative analysis of the effects of the tax maneuver under the current reform plan and the alternative variant suggests that the latter will allow to achieve a greater total budgetary effect in four years, reduce the cost of subsidizing domestic oil refining, increase the efficiency of Russian vertically integrated oil companies, and reduce the growth rate of oil products prices in the retail market.

Pengaruh konsep diri, self efficacy dan motivasi terhadap Learning outcome mata pelajaran Aqidah Akhlak di kelas XI MA Pacet Mojokerto

2017 ◽  
Vol 1 (1) ◽  
pp. 37
Author(s):  
Happy Ikmal
Keyword(s):  
Learning Outcomes ◽  
Significant Relationship ◽  
Self Efficacy ◽  
Teaching And Learning ◽  
Regression Coefficient ◽  
T Test ◽  
Self Concept ◽  
Working Hypothesis ◽  
Calculation Results ◽  
The Right

Teaching and learning activities is a conscious activity and aims. Therefore, for these activities can be run well and achieve the expected goals, it must be done with the strategy or the right learning approach .. The purpose of this study were: 1) to describe the influence of Self-Concept on the results of studying chemistry at Class XI MA Pacet Mojokerto. 2) Describe the effect of self-efficacy on Learning outcomes chemistry in Class XI MA Pacet Mojokerto 3) Describe the effect of motivation on Learning outcomes chemistry in Class XI MA Pacet Mojokerto 4) Describe the relationship Self-concept, self-efficacy and motivation to Results studied chemistry at Class XI MA Pacet Mojokerto. From the results of the analysis can be summarized as follows: 1) There is a significant relationship between self-concept of the Learning outcomes chemistry inquiry model. T test against self-concept variables (X1) obtained regression coefficient (B) 0.440 (44.0%), coefficient (Beta) 0.091, tcount of 0.378 with significance 0.006 t. Because of the significance of t less than 5% (0.007 <0.05), the Nil Hypothesis (H0) is rejected and working hypothesis (Hi) is received. 2) There is a significant relationship between self-efficacy toward chemistry Learning outcomes inquiry model. T test for Self-efficacy variable (X2) obtained regression coefficient (B) 0.329 (32.9%), coefficient (Beta) 0.124, tcount of 0.436 with a significance of 0.009 t. Because of the significance of t less than 5% (0.008 <0.05), the Nil Hypothesis (H0) is rejected and working hypothesis (Hi) is received. 3) There is a significant relationship between motivation to learn chemistry results inquiry model. T test for motivation variable (X3) obtained regression coefficient (B) 0.130 (13.0%), coefficient (Beta) 0.065, tcount of 0.230 with a significance of 0.001 t. Because of the significance of t less than 5% (0.001 <0.05), the Nil Hypothesis (H0) is rejected and working hypothesis (Hi) received 4) From the calculation results obtained Fhitung value 2,249 (significance F = 0.001). So Fhitung> F table (2,249> 2:03) or Sig F <5% (0.001 <0.05). It means that together independent variables consisting of variable self-concept (X1), Self-efficacy (X2), motivation (X3) simultaneously to variable results of studying chemistry (Y).

Penentuan Metode Intensitas Hujan Berdasarkan Karakteristik Hujan dari Stasiun Pengamat Hujan Disekitar Kecamatan Karawang Timur

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Melisa Permatasari ◽  
M. Candra Nugraha ◽  
Etih Hartati
Keyword(s):  
Drainage System ◽  
Daily Rainfall ◽  
Intensity Analysis ◽  
Rain Intensity ◽  
Rainy Period ◽  
Discharge Plan ◽  
Calculation Results ◽  
Value Determination ◽  
Maximum Daily Rainfall ◽  
Method Approach

<p>The rain intensity is the high rainfall in unit of time. The length of rain will be reversed by the amount rain intensity. The shorter time the rain lasts, the greater of the intensity and re-period of its rain. The value of rain intensity is required to calculate the flood discharge plan on the drainage system planning area in East Karawang district. Determining the value rain intensity is required the maximum daily rainfall data obtained from the main observer stations in the Plawad station planning area. The method of determination rain intensity analysis can be done with three methods: Van Breen, Bell Tanimoto and Hasper der Weduwen. Selected method is based on the smallest deviation value. Determination deviation value is determined by comparing rain intensity value of Van Breen method, Bell Tanimoto, Hasper der Weduwen. By comparing rain intensity value of the Van Breen method, Bell Tanimoto, Hasper der Weduwen with the results of calculating three methods through the method approach Talbot, Sherman and Ishiguro. Calculation results show that the method of rain has smallest deviation standard is method Van Breen with Talbot approach for rainy period (PUH) 2, 5, 10, 25, 50 and 100 years.</p>

Analysis of Characteristics of Halogen and LED Automobile Lamps

2020 ◽  
pp. 57-62
Author(s):  
Olga Yu. Kovalenko ◽  
Yulia A. Zhuravlyova
Keyword(s):  
Power Consumption ◽  
Flip Chip ◽  
Weather Conditions ◽  
Luminous Flux ◽  
Luminous Efficacy ◽  
Colour Temperature ◽  
Study Results ◽  
Calculation Results ◽  
Mandatory Rules ◽  
Halogen Lamps

This work contains analysis of characteristics of automobile lamps by Philips, KOITO, ETI flip chip LEDs, Osram, General Electric (GE), Gtinthebox, OSLAMPledbulbs with H1, H4, H7, H11 caps: luminous flux, luminous efficacy, correlated colour temperature. Characteristics of the studied samples are analysed before the operation of the lamps. The analysis of the calculation results allows us to make a conclusion that the values of correlated colour temperature of halogen lamps are close to the parameters declared by manufacturers. The analysis of the study results has shown that, based on actual values of correlated colour temperature, it is not advisable to use LED lamps in unfavourable weather conditions (such as rain, fog, snow). The results of the study demonstrate that there is a slight dispersion of actual values of luminous flux of halogen lamps by different manufacturers. Maximum variation between values of luminous flux of different lamps does not exceed 14 %. The analysis of the measurement results has shown that actual values of luminous flux of all halogen lamps comply with the mandatory rules specified in the UN/ECE Regulation No. 37 and luminous flux of LED lamps exceeds maximum allowable value by more than 8 %. Luminous efficacy of LED lamps is higher than that of halogen lamps: more than 82 lm/W and lower power consumption. The results of the measurements have shown that power consumption of a LED automobile lamp is lower than that of similar halogen lamps by 3 times and their luminous efficacy is higher by 5 times.

Pengaruh Pengembangan Karir dan Penempatan Kerja Terhadap Prestasi Kerja Karyawan pada PDAM Tirtanadi Provinsi Sumatera Utara

MBIA ◽  
2019 ◽  
Vol 17 (3) ◽  
pp. 17-24
Author(s):  
Cut Ermiati ◽  
Dita Amanah ◽  
Dedy Ansari Harahap ◽  
Fitriani Tanjung
Keyword(s):  
Data Analysis ◽  
Career Development ◽  
Linear Regression ◽  
Work Performance ◽  
Total Population ◽  
Employee Performance ◽  
Work Placement ◽  
Analysis Technique ◽  
Calculation Results ◽  
North Sumatra

This study aims to determine the effect of career development and work placement on employee work performance at PDAM Tirtanadi, North Sumatra Province. The population in this study were all employees per division, amounting to 182 employees. From the total population can be determined the number of samples in this study amounted to 65 people. The data analysis technique used is the t-test, f-test, multiple linear regression and determinant coefficient test using SPSS 22. From the calculation results using SPSS shows that there is an influence of career development on employee work performance, there is the influence of work placement on employee performance and there is the influence of career development and work placement on employee performance.

MODELING THE HYDRAULIC CHARACTERISTICS OF DRAIN VALVE AND BURST FITTING OF AN AIRCRAFT ACCIDENT-RESISTANT FUEL SYSTEM

2020 ◽  
Vol 7 (3) ◽  
pp. 37-44
Author(s):  
KONSTANTIN NAPREENKO ◽  
◽  
ROMAN SAVELEV ◽  
ALEKSEY TROFIMOV ◽  
ANNA LAMTYUGINA ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Hydraulic Resistance ◽  
Hydraulic Calculation ◽  
Fuel System ◽  
Hydraulic Characteristics ◽  
System A ◽  
Ansys Cfx ◽  
Calculation Results ◽  
Scale Experiment ◽  
Aircraft Accident

The article discusses methods for determining the hydraulic resistance of units of an accident-resistant fuel system. A detailed description of the need to create such fuel systems for modern helicopters is given. The development of such systems today is impossible without the use of the method of mathematical modeling, which allows to qualitatively solve problems arising in the design process. To obtain accurate research results, it is necessary to have a complete description of all elements and assemblies of the system. Methods for determining the hydraulic characteristics of AFS elements using the drag coefficient, reference literature and CFD codes are considered. As the investigated AFS units, a drain valve and burst fitting were studied in the article. A hydraulic calculation of these AFS elements ware performed, the simulation results are presented in the ANSYS CFX software package. Also as the calculation results of bursting fitting, the pressure distribution fields of full and static pressure, velocity and streamlines are also shown. An experimental setup for validating the results obtained using the mathematical modeling method is considered, as well as a methodology for conducting a full-scale experiment to determine the hydraulic resistance of the unit. Materials have been prepared for inclusion in a one-dimensional mathematical model of an accident-resistant fuel system.

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