scholarly journals Laboratory Modeling of an Axial Flow Micro Hydraulic Turbine

2022 ◽  
Vol 12 (2) ◽  
pp. 573
Author(s):  
Daniil Suslov ◽  
Ivan Litvinov ◽  
Evgeny Gorelikov ◽  
Sergey Shtork ◽  
David Wood
Keyword(s):  
High Efficiency ◽  
Experimental Studies ◽  
Axial Flow ◽  
Operating Mode ◽  
Hydraulic Turbine ◽  
Hydraulic Unit ◽  
Impeller Outlet ◽  
Wide Range ◽  
Operation Control ◽  
Swirled Flow

This article is devoted to detailed experimental studies of the flow behind the impeller of an air model of a propeller-type microhydroturbine in a wide range of operating parameters. The measurements of two component distributions of averaged velocities and pulsations for conditions from part load to strong overload are conducted. It is shown that the flow at the impeller outlet becomes swirled when the hydraulic turbine operating mode shifts from the optimum one. The character of the behavior of the integral swirl number, which determines the state of the swirled flow, is revealed. Information about the flow peculiarities can be used when adjusting the hydraulic unit mode to optimal conditions and developing recommendations to expand the hydraulic turbine operation control range with preservation of high efficiency. This stage will significantly save time at the stage of equipment design for specific field conditions of water resource.

Study on Combine Harvester Speed Control Based on Optimum Threshing Power Consumption Model

2011 ◽  
Vol 130-134 ◽  
pp. 1911-1914 ◽  
Author(s):  
Du Chen ◽  
Feng Kang ◽  
Qing Yuan Zhu ◽  
Shu Mao Wang
Keyword(s):  
Power Consumption ◽  
Feeding Rate ◽  
High Efficiency ◽  
Speed Control ◽  
Forward Speed ◽  
Rate Condition ◽  
Hydraulic Unit ◽  
Wide Range ◽  
Combine Harvester ◽  
Consumption Model

Combine harvester have to be operated in a wide range of field condition which may induce varying feeding rate. Forward speed is a main variable to control the feeding rate of combine harvester for high efficiency. In this study a control strategy based on optimum threshing power consumption model was developed and integrated into a speed control system for combine harvester automation. A conventional self-propelled combine harvester (Xinjiang-II) was equipped with multiple sensors to collect online information, including forward speed, threshing drum torque and speed. Forward speed was then adjusted by an electric-hydraulic unit based on designed PID controller to achieve an optimum range of threshing power consumption. Field test was conducted to evaluate the performance of the controller under variable feeding rate condition. From obtained results, the controller can improve the efficiency of tested machine during field operation.

Efficiency Improvement of Industrial Fans if Operating at Off-Design Modes

2019 ◽  
Vol 7 (3) ◽  
pp. 43-51
Author(s):  
Глеб Замолодчиков ◽  
Gleb Zamolodchikov ◽  
Р. Тумашев ◽  
R. Tumashev ◽  
Н. Щеголев ◽  
...  
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
High Efficiency ◽  
Operating Mode ◽  
Rotor Blades ◽  
Aerodynamic Load ◽  
Axial Fan ◽  
Performance Factor ◽  
Wide Range

This paper’s aim is enhancement of efficiency for fans adjusting by turn of rotor blades. A high load axial fan and a fan with decreased rotor’s pitch chord ratio by reduction of blades number were investigated. Have been performed tests of the fan with design characteristics as follows: theoretical head coefficient Ht = 0,3, mass flow rate Ca = 0,4, hub’s relative diameter ν = 0.6, and with blades, graded on the law of permanent circulation. The area of effective adjustment was estimated by the performance factor value η* ≥ 0,8. When changing the stagger angles in a wide range from 26° to 70°, the area of highly economical work was in variation ranges 0,26–0,78 for the mass flow rate Ca , and 0,24–0,5 for the theoretical head coefficient Ht accordingly. Tests of fans with a reduced blades number in the rotor (12 instead of 16 for the original fan) has showed that under the same stagger angles the fan’s high-efficiency operating mode is approximately in the same range of Ca variation at slightly reduced values of theoretical head coefficient. Maximal performance factor has increased on 2.5%. Decreasing the number of rotary blades, simplifying the turning mechanism and reducing the weight are possible in the design of fans with increased values of aerodynamic load coefficients.

Comparative Study on Performance of Very Low Head Axial Hydraulic Turbine Using a Single Rotor and a Contra-Rotating Rotor

2015 ◽  
Vol 758 ◽  
pp. 165-172 ◽  
Author(s):  
Abdul Muis ◽  
Priyono Sutikno ◽  
Aryadi Suwono ◽  
Firman Hartono
Keyword(s):  
Comparative Study ◽  
Rotor Blade ◽  
High Efficiency ◽  
Guide Vane ◽  
Axial Flow ◽  
Hydraulic Turbine ◽  
Operating Conditions ◽  
Total Power ◽  
Numerical Studies ◽  
Low Head

Studies conducted on axial flow hydraulic turbine by comparing the performance of turbines which use a single rotor and two rotors that rotate in opposite (contra-rotating). Both turbines are designed to generate energy utilizing a very low head water flow. Single rotor turbine consists of one row of guide vane and one row of rotor blade. Contra-rotating rotor turbine consists of one row of guide vane and two rows of rotor blade, which is the front rotor blade also serves as a guide vane for the rear rotor. Both of turbines are designed for the same flow and operating conditions. The results of numerical studies show that both of turbines can be applied with a fairly high efficiency, however the single rotor turbine is significantly higher. Especially for contra-rotating turbine, the total power that generated at the same operating conditions will increase because powers are resulted from both of rotors, but the effective head required will be significantly increase compare to the single-rotor turbine. These results may be used as a reference in the development of axial flow hydraulic turbine for very low head sites to expand the applications. Keywords: Single rotor, contra-rotating rotor, axial flow, very low head, hydraulic turbine.

scholarly journals The swirl number as a method for determining the optimal operating mode of the micro hydro turbine

2021 ◽  
Vol 2119 (1) ◽  
pp. 012160
Author(s):  
D A Suslov ◽  
I V Litvinov ◽  
E U Gorelikov ◽  
S I Shtork
Keyword(s):  
High Efficiency ◽  
Flow Characteristics ◽  
Operating Mode ◽  
Automated System ◽  
Swirl Number ◽  
Hydro Turbine ◽  
Operating Modes ◽  
Partial Load ◽  
Operating Regimes ◽  
Swirled Flow

Abstract The paper presents the data of a detailed study of the flow characteristics behind the runner of an air model of a propeller-type micro hydro turbine with varying operating modes from partial load to severe overload. Detailed measurements of the flow field distributions were carried out using an automated system for contactless optical diagnostics (LDA). The obtained data made it possible to link the identified features of the development of the flow structure when changing the operating mode of the installation with the nature of the evolution of the integral swirl number that determines the state of the swirled flow. Eventually, the work results can be used in the elaboration of recommendations for extending the regulation range of the operating regimes of hydraulic microturbines and providing their high efficiency.

scholarly journals Experimental justification of laser therapy efficiency of men's infertility

2017 ◽  
Vol 7 (4) ◽  
pp. 44-53 ◽  
Author(s):  
Sergej V Moskvin ◽  
Sergej Ju Borovets ◽  
Viktor A Toropov
Keyword(s):  
Laser Therapy ◽  
High Efficiency ◽  
Experimental Studies ◽  
Low Level Laser Therapy ◽  
Low Level ◽  
Low Level Laser ◽  
Level Laser ◽  
Wide Range ◽  
Experimental Justification ◽  
The Impact

Male infertility is a multifactorial syndrome, which includes a wide range of disorders. It is a symptom of many different pathological conditions affecting both the reproductive and other body systems: endocrine, nervous, blood-vascular, and immune systems. Low level laser therapy is a method of modern physiotherapy, in which the impact is carried out by low-intensity laser irradiation (LILI). It is widely used in all areas of modern medicine, due to its high efficiency, simplicity of use, the absence of contraindications and side effects. The results of russian and foreign experimental studies on the article subject were analyzed. A definite conclusion is drawn that low level laser therapy should be used as much as possible in the complex treatment of men with infertility, since the effectiveness of the method is not just high, but often has no alternatives. At the same time, the available low level laser therapy techniques should be widely used: locally, rectally, laser acupuncture, ILBI (intravenous laser blood irradiation), on the projection of various organs, paravertebrally, etc. All parameters of laser action should be set (wavelength; mode of operation; frequency for pulsed lasers; power; power density, determined by the method of exposure; exposure, localization), which are specified by the relevant regulatory documents and clinical recommendations. (For citation: Moskvin SV, Borovets SJu, Toropov VA. Experimental justification of laser therapy efficiency of men's infertility. Urologicheskie vedomosti. 2017;7(4):44-53. doi: 10.17816/uroved7444-53).

Deterministic and Stochastic Optimization of a Variable Axial Flow Compressor

1993 ◽  
Author(s):  
I. N. Egorov
Keyword(s):  
High Efficiency ◽  
Axial Flow ◽  
Geometrical Parameters ◽  
Control Laws ◽  
Robust Solution ◽  
Axial Flow Compressor ◽  
Operating Modes ◽  
Wide Range ◽  
Stochastic Case ◽  
Flow Compressor

A procedure is proposed to determine geometrical parameters and control laws of rows of a variable multistage axial flow compressor (VMAC) which are optimum by a criterion of ensuring turbomachine high efficiency within a wide range of operating modes under the row control. It is demonstrated that in shaping a layout of a variable compressor, it is expedient to determine its row geometry on the basis of control efficiency assessment. The paper illustrates a possibility to increase turbomachine efficiency (up to 8%) through optimum monitoring of its rows when studying a compressor as a separate unit and, also, through a decrease of specific fuel consumption (SFC) by 6% when studying a compressor as included in an engine. The paper also presents the results of optimum profiling of 7 rows in a 4-stage variable compressor for a stochastic case, which enables to obtain optimum stable (robust) solution, permitting to increase a possibility to ensure design indices in its practical realization by 2 and more times.

Windage and Axial Friction Losses of High Speed Generator

2003 ◽  
Author(s):  
Wei-Min Ren
Keyword(s):  
High Speed ◽  
High Performance ◽  
High Efficiency ◽  
Transfer Functions ◽  
Early Stage ◽  
Flow Characteristics ◽  
Axial Flow ◽  
Symmetric Model ◽  
Strong Impact ◽  
Wide Range

Air-cooled generators have been fulfilling a wide range of applications recently. Concurrent with a low cost target, the market demands high efficiency and high performance designs. Windage and friction losses, caused by rotor rotation and cooling gas flowing through the ventilation circuits, represents one of the largest loss components in air-cooled generators. Carefully managing the windage and friction loss is critical to ensure the success of air-cooled generators. This work is motivated by development of air-cooled high-speed generators. In such applications, the flow inside the annular gap between the rotor and stator is highly turbulent. The flow characteristics are not fully understood. Physics-based correlations, which calculate the windage and friction losses, don’t exist in the literature. The purpose of this work is to develop such transfer functions for machine design. Numerical simulations, using commercial CFD code FLUENT 6.0 and Design of Experiment (DOE) method, have been carried out to study the flow characteristics in the annular space between the cylindrical rotor and stator. All simulations were performed using an axial-symmetric model, along with RNG k-ε turbulence model and enhanced wall treatment. In the study, the generator rated speed ranged from 5000 to 20000 rpm; the Taylor number ranged from 1750 to 78000; and the Mach number ranged from 0.25 to 1.0. The effect of axial flow on windage loss was carefully studied. Axial flow exhibited a strong impact on windage loss. The CFD results are rationalized. Transfer functions for windage and axial friction losses are created. They provide a better basis to explore the design space at the early stage of the product development.

Synthesis of Elaborate Benzofuran-2-Carboxamide Derivatives Through a Combination of 8-Aminoquinoline Directed C–H Arylations and Transamidations

2019 ◽  
Author(s):  
Michael Oschmann ◽  
Linus Johansson Holm ◽  
Oscar Verho
Keyword(s):  
Small Molecule ◽  
High Efficiency ◽  
Synthetic Strategy ◽  
Small Molecule Screening ◽  
Physiological Properties ◽  
Wide Range ◽  
Directing Group ◽  
Synthetic Sequence

Benzofurans are everywhere in nature and they have been extensively studied by medicinal chemists over the years because of their chemotherapeutic and physiological properties. Herein, we describe a strategy that can be used to access elaborate benzo-2-carboxamide derivatives, which involves a synthetic sequence of 8-aminoquinoline directed C–H arylations followed by transamidations. For the directed C–H arylations, Pd catalysis was used to install a wide range of aryl and heteroaryl substituents at the C3 position of the benzofuran scaffold in high efficiency. Directing group cleavage and further diversification of the C3-arylated benzofuran products were then achieved in a single synthetic operation through the utilization of a two-step transamidation protocol. By bocylating the 8-aminoquinoline amide moiety of these products, it proved possible to activate them towards aminolysis with different amine nucleophiles. Interestingly, this aminolysis reaction was found to proceed efficiently without the need of any additional catalyst or additive. Given the high efficiency and modularity of this synthetic strategy, it constitute a very attractive approach for generating structurally-diverse collections of benzofuran derivatives for small molecule screening.

To the 70th anniversary of World Meteorological Organization. Scientific and technical cooperation of Hydrometeorological Center of the USSR/Russia in the Programs of World Meteorological Organization

2020 ◽  
pp. 117-138
Author(s):  
S.V. Borshch ◽  
◽  
R.M. Vil’fand ◽  
D.B. Kiktev ◽  
V.M. Khan ◽  
...  
Keyword(s):  
Environmental Monitoring ◽  
High Efficiency ◽  
World Meteorological Organization ◽  
70Th Anniversary ◽  
Technical Level ◽  
Technical Cooperation ◽  
Wide Range

The paper presents the summary and results of long-term and multi-faceted experience of international scientific and technical cooperation of Hydrometeorological Center of Russia in the field of hydrometeorology and environmental monitoring within the framework of WMO programs, which indicates its high efficiency in performing a wide range of works at a high scientific and technical level. Keywords: World Meteorological Organization, major WMO programs, representatives of Hydrometeorological Center of Russia in WMO

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