The hydrodynamic resistance of the coagulating bath for spinning viscose cord

1971 ◽  
Vol 2 (3) ◽  
pp. 237-240
Author(s):  
A. V. Ryabushkin ◽  
A. T. Serkov ◽  
E. V. Korchagina
Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 268
Author(s):  
Olga V. Soloveva ◽  
Sergei A. Solovev ◽  
Ruzil R. Yafizov

In this work, a study was carried out to compare the filtering and hydrodynamic properties of granular filters with solid spherical granules and spherical granules with modifications in the form of micropores. We used the discrete element method (DEM) to construct the geometry of the filters. Models of granular filters with spherical granules with diameters of 3, 4, and 5 mm, and with porosity values of 0.439, 0.466, and 0.477, respectively, were created. The results of the numerical simulation are in good agreement with the experimental data of other authors. We created models of granular filters containing micropores with different porosity values (0.158–0.366) in order to study the micropores’ effect on the aerosol motion. The study showed that micropores contribute to a decrease in hydrodynamic resistance and an increase in particle deposition efficiency. There is also a maximum limiting value of the granule microporosity for a given aerosol particle diameter when a further increase in microporosity leads to a decrease in the deposition efficiency.


2019 ◽  
Vol 1300 ◽  
pp. 012107
Author(s):  
Lili Wang ◽  
Kangning Sun ◽  
Yufeng Cai ◽  
Jun Jiao ◽  
Jiaxu Zhang ◽  
...  

2010 ◽  
Vol 42 (11) ◽  
pp. 985-1000 ◽  
Author(s):  
George Tzabiras ◽  
Konstantinos Kontogiannis

1972 ◽  
Vol 2 (6) ◽  
pp. 538-539
Author(s):  
V. I. Khrulev ◽  
G. A. Maksimova ◽  
A. G. Arseenko ◽  
R. G. Ermolaeva ◽  
V. P. Abramenko
Keyword(s):  

2015 ◽  
Vol 74 (5) ◽  
Author(s):  
M. Nakisa ◽  
A. Maimun ◽  
Yasser M. Ahmed ◽  
F. Behrouzi ◽  
Jaswar Jaswar ◽  
...  

The presentarticle focuses on the hydrodynamic resistance reduction of Multipurpose Amphibious Vehicles (MAV) usingthe air lubrication layer effect. The use of air cushions to support marine vehicles, heavy floating structures and in other operation is well known. The main problem in Multi-purpose Amphibious Vehicles (MAV) is the amount of power needed in order to overcome the hydrodynamic resistance acting on the hull which is included the frictional and pressure resistances. Therefore, more power is needed to move the MAV forward. In this respect, more fuel will be required to operate the amphibious vehicles. This problem could be effectively reduced by the introduction of the air cushion concept. With the air being drawn from top of craft to the cavity below the hull will produce some cushioning effect and also help to reduce skin friction drag. In this paper, air cushion effect will be studied in rigid surface cavity instead of using flexible skirts. This would avoid the problem of high maintenance due to replacement of damaged skirts. Finally, the MAV will be supported using air cavity and bubbles generated by an air pump (compressor and air pressure vessel) to pushes the hull of multi-purpose amphibious vehicle up and reduce the frictional resistance due to draft and wetted surface reduction and layer of air between hull surface and water. This research would be done via CFD (ANSYS-CFX 14.0) and analyzed the hydrodynamic resistance.


2020 ◽  
Vol 14 (1) ◽  
pp. 55-60
Author(s):  
O. N. Didmanidze ◽  
R. T. Khakimov ◽  
E. P. Parlyuk ◽  
N. A. Bol’shakov

Global car manufacturers wish to increase the number of manufactured products, reduce their cost and labor input. The choice of research areas, design and technological developments in radiator construction is an extremely important and urgent task, due to the mass production of radiators for tractors and automobiles on the one hand, and the favorable development prospects of these interrelated industries, on the other. (Research purpose) To substantiate theoretically and experimentally the use of a combined cooling system containing both aluminum and polymeric water radiators and similarly liquid-oil heat exchangers based on the four principles listed above on automobiles and tractors. (Materials and methods) The authors performed bench tests using a special wind tunnel to study the thermal and aerodynamic characteristics of a prototype tractor radiator with a polyurethane core. After reaching the steady-state operating mode of the installation, the experimental values were determined for the control and measuring instruments. (Results and discussion) The authors carried out measurements of all parameters of both coolants in series at each steady-state operating mode of the bench. They obtained the main indicators dependences (reduced heat transfer, aerodynamic and hydraulic drag) of the heat exchanger, close to the operating conditions of the vehicles. (Conclusions) A prototype MTZ-80 radiator with a polyurethane core has great prospects as a future alternative radiator. An increase by 10-15 percent in the radiator heat transfer is possible by using aluminum fi ns on the surface of the polyurethane plate. A 15-20 percent reduction in hydrodynamic resistance is achieved by increasing the diameter of the capillary throughput in a polyurethane plate and the number of plates themselves in the radiator cell.


2020 ◽  
Vol 6 (2) ◽  
pp. 146-151
Author(s):  
Ihor Holovach ◽  
◽  
Lidiia Kasha ◽  
Ivan Hudzii

The article analyses the modern lubrication systems for internal combustion engines. Systems with mechanical drive components that contain mechanical and electronic components have been found to have a number of disadvantages. In particular, when the internal combustion engine is started cold, when the viscosity of the oil is high, the hydrodynamic resistance characteristic rises sharply, which leads to high pressure at low speeds and the drive requires low pump speeds. Again, the increase in oil temperature causes a decrease in viscosity, the hydrodynamic resistance characteristic becomes flatter. This, in turn, reduces the pressure in the lubrication system and requires an increase in pump speed in order to keep the pressure constant. Based on the analysis, the requirements for lubrication systems are formulated and a separate lubrication system with forced oil supply is proposed in this paper. For the drive of pump lubrication system of the internal combustion engine, a switched reluctance motor is proposed and calculated. Such motor by its qualities is one of the most useful in this type of systems.


2019 ◽  
pp. 307-314
Author(s):  
Iuriy Davydovich Alashkevich ◽  
Mikhail Semenovich Lur’e ◽  
Ol'ga Mikhaylovna Lur’e ◽  
Aleksandr Sergeyevich Frolov

The question of the features of operation of submersible vortex flowmeters of water and water suspensions of low concentrations in pulp and paper production, which are installed in process pipelines with local hydraulic resistance, is considered. It is shown that with an insufficient straight section after local resistance, an additional error appears, which appears due to the influence of local resistance (transition or retraction) on the symmetry of the velocity diagram in front of the device. This error arises due to a change in the Strouhal number (Sh) and is related to the measurement method. The Strouhal number begins to depend on both the distance to the local resistance and the fluid flow rate. Identify this relationship and is dedicated to this work. Recommendations on the length of straight pipeline sections in front of the flow meter have been developed, which can be significantly reduced by limiting the range of operating flow rates. The studies were carried out by the method of numerical simulation of hydrodynamic processes with subsequent processing of the results by the method of experiment planning. The dependence of the number Sh on the length of the relative diameter of the pipeline L/ for hydrodynamic resistance in the form of a transition is presented. This error shows that the measurement error is within 2% already with a straight section in front of the flowmeter equal to 5–7 diameters. The response surface for pipe bends (rotations) is considered at 90º from which it follows that while maintaining the length of the straight section within 5–7 pipe diameters, it is necessary to narrow the measurement range of the instruments 2.5 times.


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