Numerical modeling of the flow section of shaftless combined pump-electric motor

Одним из значимых принципов для обеспечения гидравлической эффективности проточной части безвального совмещенного насоса-электродвигателя, а также технологичности производства рабочих колес с подобной проточной частью является применение при ее проектировании линейчатых поверхностей. С использованием линейчатых поверхностей построена цифровая модель проточной части, для нее определен эффективный диапазон основных геометрических параметров. На основе принципов построения линейчатых поверхностей и задания критериев гидравлической эффективности разработаны граничные условия, позволяющие проводить натурные испытания на более поздних этапах создания безвального насосного агрегата. С учетом вариативности отдельных геометрических параметров проточной части проведена оценка их влияния на гидравлические характеристики проточной части. Комбинации гидравлических параметров цифровой модели, обеспечивающие максимальную эффективность безвального насосного агрегата, позволяют наиболее точно создавать опытные образцы для натурных испытаний. One of the significant principles for ensuring the hydraulic efficiency of the flow section of a shaftless combined pump-electric motor, as well as the manufacturability of impellers with such flow section is the use of linear surfaces in its design. A digital model of the flow section was developed using linear surfaces, and the effective range of the main geometrical parameters was determined for it. Based on the principles of building linear surfaces and setting hydraulic efficiency criteria, boundary conditions have been developed to allow full-scale tests at later stages of creating a shaftless pumping unit. Taking into account the variability of some geometrical parameters of the flow section, their influence on the hydraulic characteristics of the flow section was evaluated. Combinations of hydraulic parameters of the digital model that ensure maximum efficiency of the shaftless pumping unit allow the most accurate creation of prototypes for subsequent full-scale tests.

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ANALYSIS OF THE OPERATION OF PUMPING UNIT UNDER A RANGE OF DIFFERENT LOADS

International Conference on Technics Technologies and Education ◽

10.15547/ictte.2019.04.091 ◽

2019 ◽

pp. 263-267

Author(s):

Antoaneta Dimitrova

Keyword(s):

Electric Motor ◽

Energy Efficient ◽

Frequency Converter ◽

Hot Water ◽

Maximum Efficiency ◽

Pump Unit ◽

Start Up ◽

Different Types ◽

Pumping Unit ◽

Pumping Units

The report analyzes the work of a pumping unit from the hot water installation of the Faculty of Technics and Technologies - Yambol, Bulgaria, under different load conditions. Simulation stands have been adapted that are suitable for analyzing the performance of motors of different types and depending on how they are put into the pump unit. It was found that when the energy inefficient electric motor is directly started, the maximum efficiency is 79,63% and is achieved at 100% of its load. When using a frequency converter, at 100% of its load, the efficiency is 86,83%. The proposed energy-efficient electric motor, with direct start-up, has the highest efficiency of 86,7%. The obtained results can be used in the modernization of the hot water installation of the Faculty of technics and Technologies - Yambol, in the part “pumping units”.

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Full Scale Tests of Water Mist Fire Suppression Systems for Navy Shipboard Machinery Spaces. Part 2. Obstructed Spaces.

10.21236/ada306668 ◽

1996 ◽

Cited By ~ 9

Author(s):

G. G. Back ◽

P. J. DiNenno ◽

Joseph T. Leonard ◽

R. L. Darwin

Keyword(s):

Fire Suppression ◽

Water Mist ◽

Full Scale ◽

Full Scale Tests ◽

Suppression Systems

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Genetic algorithm application for optimization of geometry of synchronous electric motor with permanent magnets by criterion of electromagnetic torque

Issues of radio electronics ◽

10.21778/2218-5453-2019-10-56-62 ◽

2019 ◽

pp. 56-62

Author(s):

I. N. Belezyakov ◽

K. G. Arakancev

Keyword(s):

Genetic Algorithm ◽

Electric Motor ◽

Permanent Magnets ◽

Evolutionary Optimization ◽

Electric Machines ◽

Geometric Parameters ◽

Geometrical Parameters ◽

Electromagnetic Torque ◽

Automatic Control Systems ◽

Optimization Of Geometry

At present time there is a need to develop a methodology for electric motors design which will ensure the optimality of their geometrical parameters according to one or a set of criterias. With the growth of computer calculating power it becomes possible to develop methods based on numerical methods for electric machines computing. The article describes method of a singlecriterion evolutionary optimization of synchronous electric machines with permanent magnets taking into account the given restrictions on the overall dimensions and characteristics of structural materials. The described approach is based on applying of a genetic algorithm for carrying out evolutionary optimization of geometric parameters of a given configuration of electric motor. Optimization criteria may be different, but in automatic control systems high requirements are imposed to electromagnetic torque electric machine produces. During genetic algorithm work it optimizes given geometric parameters of the electric motor according to the criterion of its torque value, which is being calculated using finite element method.

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Full-scale tests on smoke temperature distribution in long-large subway tunnels with longitudinal mechanical ventilation

Tunnelling and Underground Space Technology ◽

10.1016/j.tust.2020.103784 ◽

2021 ◽

Vol 109 ◽

pp. 103784

Author(s):

Congling Shi ◽

Jian Li ◽

Xuan Xu

Keyword(s):

Mechanical Ventilation ◽

Temperature Distribution ◽

Full Scale ◽

Full Scale Tests ◽

Subway Tunnels

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Investigation of planing craft maneuverability using full-scale tests

Proceedings of the Institution of Mechanical Engineers Part M Journal of Engineering for the Maritime Environment ◽

10.1177/14750902211030386 ◽

2021 ◽

pp. 147509022110303

Author(s):

Kazem Sadati ◽

Hamid Zeraatgar ◽

Aliasghar Moghaddas

Keyword(s):

Full Scale ◽

Performance Characteristics ◽

Forward Speed ◽

Speed Reduction ◽

Planing Craft ◽

Full Scale Tests ◽

Turning Maneuver

Maneuverability of planing craft is a complicated hydrodynamic subject that needs more studies to comprehend its characteristics. Planing craft drivers follow a common practice for maneuver of the craft that is fundamentally different from ship’s standards. In situ full-scale tests are normally necessary to understand the maneuverability characteristics of planing craft. In this paper, a study has been conducted to illustrate maneuverability characteristics of planing craft by full-scale tests. Accelerating and turning maneuver tests are conducted on two cases at different forward speeds and rudder angles. In each test, dynamic trim, trajectory, speed, roll of the craft are recorded. The tests are performed in planing mode, semi-planing mode, and transition between planing mode to semi-planing mode to study the effects of the craft forward speed and consequently running attitude on the maneuverability. Analysis of the data reveals that the Steady Turning Diameter (STD) of the planing craft may be as large as 40 L, while it rarely goes beyond 5 L for ships. Results also show that a turning maneuver starting at planing mode might end in semi-planing mode. This transition can remarkably improve the performance characteristics of the planing craft’s maneuverability. Therefore, an alternative practice is proposed instead of the classic turning maneuver. In this practice, the craft traveling in the planing mode is transitioned to the semi-planing mode by forward speed reduction first, and then the turning maneuver is executed.

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