Log in

Relevant bibliographies by topics / Helical rotor / Journal articles

To see the other types of publications on this topic, follow the link: Helical rotor.

Journal articles on the topic 'Helical rotor'

Author: Grafiati

Published: 4 June 2021

Last updated: 2 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Helical rotor.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Chen, Guang Zhong, Bing Zhang, Yue Yang, Jin Han, and Lin Jun Tong. "3D Visualization Automatic Modeling of Helical Rotors." Applied Mechanics and Materials 321-324 (June 2013): 1721–24. http://dx.doi.org/10.4028/www.scientific.net/amm.321-324.1721.

Full text

Abstract:

Structure of Helical rotor is complicated.3D visualization automatic modeling of Helical Rotors with CAD could make the design of product more efficient. Scheme of 3D visualization automatic modeling of Helical Rotors is described in detail and Generation Principle of end surface curve of rotor and Scanning helix is analyzed deeply in the paper. With the further development of SolidWorks by Visual C#, 3D Visualization Automatic Modeling of Helical Rotors is accomplished .

APA, Harvard, Vancouver, ISO, and other styles

2

Stošić, N. "On gearing of helical screw compressor rotors." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 212, no. 7 (1998): 587–94. http://dx.doi.org/10.1243/0954406981521556.

Full text

Abstract:

Twin-screw compressor rotors are effectively helical gears. When these are formed from a hobbing cutter, the hobbing tool and the rotor together constitute a pair of crossed helical gears. In the present paper, the envelope gearing method is used to derive a meshing condition for crossed helical gears which is then used to create the profile of a hobbing tool. A reverse transformation enables the rotor profile thereby manufactured to be calculated. Simplification of the main gearing condition leads to the meshing expression for helical gears which may be used for the design of screw compressor

APA, Harvard, Vancouver, ISO, and other styles

3

Chen, Feng, Liang Yao Gu, Yue Yang, and Chun Yang Jia. "Design and Realization of Helical Rotor NC Automatic Programming System." Advanced Materials Research 605-607 (December 2012): 1469–73. http://dx.doi.org/10.4028/www.scientific.net/amr.605-607.1469.

Full text

Abstract:

Helical rotor is a core component of helical-lobe compressor. Analysis was made on the geometrical properties of tooth curves. Using standard spherical milling cutter on 4-axis NC machine, normal migration method was used to rotor surface processing. Based on the generation characteristics of helical rotor surface, object-oriented design method is used to achieve automatic programming system of helical rotor. The calculation of helical rotor end face profile lines and cutter location point are realized, and over cutting analysis is carried out to generate high efficient numerical control proce

APA, Harvard, Vancouver, ISO, and other styles

4

Gupta, Rajat, Bachu Deb, and R. D. Misra. "Performance Analysis of a Helical Savonius Rotor with Shaft at 45° Twist Angle Using CFD." Mechanical Engineering Research 3, no. 1 (2013): 118. http://dx.doi.org/10.5539/mer.v3n1p118.

Full text

Abstract:

Helical Savonius rotor is considered to be superior to conventional Savonius rotor in terms of higher power coefficient (Cp) and better starting characteristic. However studies related to helical Savonius rotors is few. In view of this, in this paper, the performance of a helical Savonius rotor with shaft at 45° bucket twist angle for one complete cycle of rotation was analyzed using Computational Fluid Dynamics. A two-bucket helical Savonius rotor with shaft was designed using GAMBIT, having a height of 60 cm and diameter of 17 cm with 45° bucket twist angle. A three dimensional Computational

APA, Harvard, Vancouver, ISO, and other styles

5

Popa, Camelia, Virgil Gabriel Teodor, Nicuşor Baroiu, and Nicolae Oancea. "Side Mill Tool Profiling for Generation of Helical Surfaces Determined by Reverse Engineering." Applied Mechanics and Materials 657 (October 2014): 28–32. http://dx.doi.org/10.4028/www.scientific.net/amm.657.28.

Full text

Abstract:

The compressor rotors usually are helical surfaces with constant pitch and are composed crossing profiles. Frequently, for repair operations occurs the reconstruction necessity for one or both of the worms, drive and driven, from the helical compressors gear. The helical composed surface of rotor flank is generated usually with side mill. The knowledge of worm shape can not be made from geometrical conditions. In these conditions it is necessary to determine the flank form by actual measuring the crossing profiles of these parts. So, the theoretical helical surface of the worm is being substit

APA, Harvard, Vancouver, ISO, and other styles

6

Stefan, Vasilica, Ladislau David, Radu Ciuperca, Ana Zaica, Ancuta Nedelcu, and Albert Suvac. "Experimental testing of a helical rotor for compost distribution." E3S Web of Conferences 180 (2020): 03027. http://dx.doi.org/10.1051/e3sconf/202018003027.

Full text

Abstract:

It is well known that a manure spreader must be able to apply manure consistently, effectively and uniformly over the time. An overapplying doze will cause serios environmental problems (pollution) and a sub-applying doze will not contribute to plants growth and the applying of the fertilizer will be a loss. Corroborate with others problems such as maintaining a constant tractor speed, a constant rotational speed of the rotor, a constant and continuous flow of the material make the manure spreading machines an important subject for study and continuously improving . The propose of this study i

APA, Harvard, Vancouver, ISO, and other styles

7

Adams, G. P., and W. Soedel. "Computation of Compression Loads in Twin Screw Compressors." Journal of Mechanical Design 117, no. 4 (1995): 512–19. http://dx.doi.org/10.1115/1.2826712.

Full text

Abstract:

The compression mechanism in a twin screw compressor consists of two helical rotors. In this work, a method is presented for computing the forces and moments induced on each rotor due to gas compression. These are defined as the compression loads. The helical rotor surfaces are defined by the end profiles, wrap angle and rotor length. The 3D surface of each rotor is mapped to 2D integration regions. These regions correspond to the surfaces associated with individual compression chambers. The compression loads are computed by integrating the chamber pressure over the rotor surfaces. The integra

APA, Harvard, Vancouver, ISO, and other styles

8

Ilie, K., and A. Subic. "Parametric modelling of helical rotors for efficient design of twin-screw superchargers." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 221, no. 2 (2007): 267–72. http://dx.doi.org/10.1243/0954406jmes421ft.

Full text

Abstract:

The parametric three-dimensional geometric model of twin-screw supercharger rotors of any aspect ratio was developed. For model validation through visualization, computer-aided design (CAD) rotor models with scalable data were generated in commercial CAD software and calibrated experimentally by laser Doppler velocimetry (LDV) tests. Calibrated rotor profile data can be transferred into CAD-CFD interface for flow simulation for performance optimization.

APA, Harvard, Vancouver, ISO, and other styles

9

Chen, Ying-Chung, Tsung-Hsien Yang, and Siu-Tong Choi. "Dynamic analysis of a double-helical geared rotor system with oil-film bearing." Aircraft Engineering and Aerospace Technology 92, no. 4 (2020): 653–62. http://dx.doi.org/10.1108/aeat-05-2019-0094.

Full text

Abstract:

Purpose This paper aims to study a dynamic analysis of a double-helical geared rotor system with oil-film bearing. Design/methodology/approach A finite element model of a double-helical geared rotor system with oil-film bearing is developed, in which a rigid mass is used to represent the gear and the Timoshenko beam finite element represents the shaft; the equations of motion are obtained by applying Lagrange’s equation. Natural frequencies, Campbell diagram, lateral responses, axial responses, bearing stiffness coefficients, bearing damping coefficients and bearing force are investigated. Fin

APA, Harvard, Vancouver, ISO, and other styles

10

Chen, Guang Zhong, Bing Zhang, Yue Yang, Jin Han, and Lin Jun Tong. "Optimization of Helical Rotors in 3D Modeling Design and Processing." Applied Mechanics and Materials 321-324 (June 2013): 1775–78. http://dx.doi.org/10.4028/www.scientific.net/amm.321-324.1775.

Full text

Abstract:

3D modeling process and shaped conductor of head face of helical rotor is described, and the constructing method of critical curves of head face is explained in detail. The processing principle of helical rotor is discoursed in paper and the four-axis tool path of the helical rotor based on ball cutter is deduced in UG environment. The Dynamic Process Simulation of tool path is finished, which Verify the feasibility of tool paths

APA, Harvard, Vancouver, ISO, and other styles

11

Лебедев, Валерий, Valeriy Lebedev, Георгий Серга, et al. "Arrangement circuits of small-size of rotor-helical vibration technological systems for parts finish-strengthening." Science intensive technologies in mechanical engineering 2, no. 10 (2017): 24–27. http://dx.doi.org/10.12737/article_59d496ec40df54.66288140.

Full text

Abstract:

Advantages and a field of the actual application of rotor-helical vibration technological systems are presented. Arrange-ment circuits of small-size rotor-helical vibration machines for parts finish-strengthening obtained through the methods of engineering geometry and computer graphic are shown.

APA, Harvard, Vancouver, ISO, and other styles

12

Lebedev, Valeriy A., Georgy V. Serga, Irina V. Davydova, Tatiana V. Atoyan, Irina G. Koshlyakova, and Alexander V. Gordienko. "Main trends in intensification of rotor-screw processing of parts." MATEC Web of Conferences 226 (2018): 01008. http://dx.doi.org/10.1051/matecconf/201822601008.

Full text

Abstract:

The ways of productivity increase in details finishing-strengthening processing executed in rotor-screw technological systems are presented. It is shown that the use of rotor-screw machines makes it possible to combine the parts machining using a vibrating field with a large amplitude of oscillations and their transportation in a streamlined form of production organization. Two main directions of rotor-helical processing stimulation are identified: on the basis of structural changes in the screw rotor, as the main working element of the rotor-screw machine and by equipping the screw rotor with

APA, Harvard, Vancouver, ISO, and other styles

13

Yao, L., Z. Ye, H. Cai, and J. S. Dai. "Design of a milling cutter for a novel three-lobe arc-cycloidal helical rotor." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 218, no. 10 (2004): 1233–41. http://dx.doi.org/10.1243/0954406042369071.

Full text

Abstract:

This paper focuses on the design of a milling cutter for machining the arc-cycloidal helical rotor of a Roots blower. The milling cutter is developed on the basis of a novel rotor of a Roots blower which consists of both concave and convex arcs and a cycloidal curve in the transversal section. The geometric analysis of the transverse section and the helical tooth profile for the proposed rotor are presented. The paper reveals the contact characteristics between the cutter and the rotor blank being machined and derives the normal vectors of three different tooth sections. The paper further deve

APA, Harvard, Vancouver, ISO, and other styles

14

Baroiu, Nicuşor, Georgiana-Alexandra Moroşanu, Virgil-Gabriel Teodor, and Nicolae Oancea. "Roller Profiling for Generating the Screw of a Pump with Progressive Cavities." Inventions 6, no. 2 (2021): 34. http://dx.doi.org/10.3390/inventions6020034.

Full text

Abstract:

Progressive cavity pumps are used in industry for the circulation of high viscosity fluids, such as crude oil and petroleum products, sewage sludge, oils, salt water, and wastewater. Also known as single screw pumps, these pumps are composed of a single rotor which has the shape of a rounded screw, which moves inside a rubber stator. The stator has an double helical internal surface which, together with the helical surface of the rotor, creates a cavity that moves along the rotor. The movement effect of the cavity inside the stator is the movement of the fluid with a constant flow and high pre

APA, Harvard, Vancouver, ISO, and other styles

15

Zhao, Qian Cheng, Chang You Lu, Qiao Xu, and Geng Huang. "Analysing by Simulation to Evaluate the Method of Measuring Screw Rotors with CMM." Applied Mechanics and Materials 36 (October 2010): 63–67. http://dx.doi.org/10.4028/www.scientific.net/amm.36.63.

Full text

Abstract:

The important parts of a screw compressor are the two rotors. At present, generally use a CMM to check the form and other parameters of the rotors to ensure its function. Among the all geometrical parameters of a rotor, the form of traverse section profile is the most important one. In the process of measurement, the key technology problem is the probe radius correction because of the complexity of 3D helical surface. When the nominal values of the rotors are unknown, the radius correction is more difficult than that is known. This paper presents a method to evaluate the precision of measuring

APA, Harvard, Vancouver, ISO, and other styles

16

Yang, Jian, Fang-Hong Sun, and Zheng Lu. "Solving the screw compressor rotor-forming grinding wheel using the edge detection method based on the graphic method." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 233, no. 5 (2019): 967–79. http://dx.doi.org/10.1177/0954408918818281.

Full text

Abstract:

As a complex grinding wheel for special use, the screw compressor rotor-forming grinding wheel needs to be designed according to the specific profile of the workpiece. The design process is complicated and difficult to grasp, and various design issues are likely to occur. This study is based on the design theory of helical rotor-forming grinding wheels. Here, disc-shaped forming grinding wheels for machining a helical surface were studied, with discrete point workpiece cross-sections as examples. MATLAB was used as the development tool, and the Unigraphics motion simulation function was applie

APA, Harvard, Vancouver, ISO, and other styles

17

Chen, Ying-Chung. "Time-Varying Dynamic Analysis of a Helical-Geared Rotor-Bearing System with Three-Dimensional Motion Due to Shaft Deformation." Applied Sciences 10, no. 4 (2020): 1542. http://dx.doi.org/10.3390/app10041542.

Full text

Abstract:

The rotordynamics of a helical-geared rotor-bearing system were investigated. A new dynamic model for a helical-geared rotor-bearing system, which takes into account three-dimensional (3-D) motion due to rotating shaft deformation, was proposed. The proposed model considers the time-varying effect, which in other models, is considered constant. The system equations of motion were obtained by applying Lagrange’s equation, and the dynamic responses were computed by the fourth-order Runge–Kutta method. The time-varying dynamic responses of the helix angle, transverse pressure angle, gear pair cen

APA, Harvard, Vancouver, ISO, and other styles

18

OKULOV, V. L., and J. N. SØRENSEN. "Stability of helical tip vortices in a rotor far wake." Journal of Fluid Mechanics 576 (March 28, 2007): 1–25. http://dx.doi.org/10.1017/s0022112006004228.

Full text

Abstract:

As a means of analysing the stability of the wake behind a multi-bladed rotor the stability of a multiplicity of helical vortices embedded in an assigned flow field is addressed. In the model the tip vortices in the far wake are approximated by infinitely long helical vortices with constant pitch and radius. The work is a further development of a model developed in Okulov (J. Fluid Mech., vol. 521, p. 319) in which the linear stability of N equally azimuthally spaced helical vortices was considered. In the present work the analysis is extended to include an assigned vorticity field due to root

APA, Harvard, Vancouver, ISO, and other styles

19

Popa, Camelia Lacramioara, and Viorel Popa. "Graphic Method Profiling of the End Mill Cutter Generating the Screw Compressor Rotor." Applied Mechanics and Materials 658 (October 2014): 123–28. http://dx.doi.org/10.4028/www.scientific.net/amm.658.123.

Full text

Abstract:

Helical rotors, components of screw compressors have different structural shapes: rotors circular front section, rotors elliptic front section or asymmetric rotors. Manufacturing rotors involves profiling a tool bordered by a revolution surface, enveloping of each helical channel. This paper proposes a method developed in AutoCAD, in order to determine the profile of end mill cutter which generates the helical channel. Graphic method is based on the principle of complementary theorems' "Substitute Circles Family Method" component of envelope surfaces theory.

APA, Harvard, Vancouver, ISO, and other styles

20

Белокур, Кирилл, Kirill Belokur, Георгий Серга, et al. "ROTARY-HELICAL TECHNOLOGICAL SYSTEMS FOR PARTS MACHINING." Bulletin of Bryansk state technical university 2016, no. 2 (2016): 132–37. http://dx.doi.org/10.12737/20266.

Full text

Abstract:

The technical solutions for efficiency increase of technological systems for parts finishing and strengthening based on the use of screw containers are offered. The essence is revealed, design peculiarities and technological possibilities of a rotor-helical technological system with a vibrocontainer and an adjusting spring and a rotor-helical technological system with a rotating container are described. The results of experi-mental researches of granular material motion in a screw container with the use of three-factor experiment planning are shown. The assessment of the screw containers effic

APA, Harvard, Vancouver, ISO, and other styles

21

Shayak, B. "A new self-propelled magnetic bearing with helical windings." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 472, no. 2196 (2016): 20160579. http://dx.doi.org/10.1098/rspa.2016.0579.

Full text

Abstract:

In this work, a design is proposed for an active, permanent magnet based, self-propelled magnetic bearing, i.e. levitating motor having the following features: (i) simple winding structure, (ii) high load supporting capacity, (iii) no eccentricity sensors, (iv) stable confinement in all translational dimensions, (v) stable confinement in all rotational dimensions, and (vi) high efficiency. This design uses an architecture consisting of a helically wound three-phase stator, and a rotor with the magnets also arranged in a helical manner. Active control is used to excite the rotor at a torque ang

APA, Harvard, Vancouver, ISO, and other styles

22

SØRENSEN, J. N. "Instability of helical tip vortices in rotor wakes." Journal of Fluid Mechanics 682 (August 11, 2011): 1–4. http://dx.doi.org/10.1017/jfm.2011.277.

Full text

Abstract:

The conditions for the appearance of instabilities in systems of helical vortices constitute an intriguing problem that still remains partly unsolved. The experimental study of Felli, Camussi & Di Felice (J. Fluid Mech., this issue, vol. 682, 2011, pp. 5–53) has shed new light on some of the basic mechanisms governing the instability mechanisms.

APA, Harvard, Vancouver, ISO, and other styles

23

Lajnef, Mariem, Mabrouk Mosbahi, Youssef Chouaibi, and Zied Driss. "Performance Improvement in a Helical Savonius Wind Rotor." Arabian Journal for Science and Engineering 45, no. 11 (2020): 9305–23. http://dx.doi.org/10.1007/s13369-020-04770-6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Li, Chao Feng, Shi Hua Zhou, and Jie Liu. "Numerical Simulation of a Bending-Torsion Coupling Gear Transmission System." Applied Mechanics and Materials 448-453 (October 2013): 3403–7. http://dx.doi.org/10.4028/www.scientific.net/amm.448-453.3403.

Full text

Abstract:

Based on the establishment of angular contact ball bearing mechanical model, a nonlinear coupled lateral, torsional and axial dynamic model of helical gear-rotor-bearing system is established, and the dynamic differential equations of the coupled lateral-torsional-axial nonlinear vibration are deduced for imbalance rotors. The investigations are systematically carried out by oscillograms and spectrograms with rotating speed, taking into account eccentricity and nonlinear supporting by rolling bearing. The results show that the rotation frequency of the driven shaft appears in the driving shaft

APA, Harvard, Vancouver, ISO, and other styles

25

Durán Venegas, E., and S. Le Dizès. "Generalized helical vortex pairs." Journal of Fluid Mechanics 865 (February 20, 2019): 523–45. http://dx.doi.org/10.1017/jfm.2019.65.

Full text

Abstract:

New solutions describing the interaction of helical pairs of counter-rotating vortices are obtained using a vortex filament approach. The vortices are assumed to have a small core size allowing the calculation of the self-induced velocities from the Biot–Savart law using the cutoff theory. These new vortex structures do not possess any helical symmetry but they exhibit a spatial periodicity and are stationary in a rotating and translating frame. Their properties, such as radial deformation, frame velocity and induced flow, are provided as a function of the four geometric parameters characteriz

APA, Harvard, Vancouver, ISO, and other styles

26

Nemes, András, David Lo Jacono, Hugh M. Blackburn, and John Sheridan. "Mutual inductance of two helical vortices." Journal of Fluid Mechanics 774 (June 8, 2015): 298–310. http://dx.doi.org/10.1017/jfm.2015.288.

Full text

Abstract:

The pairing of helical tip vortices in the wake of a two-bladed rotor is investigated experimentally. Time-resolved particle image velocimetry measurements provide a clear temporal and spatial evolution of the vortical structures, highlighting the transition to instability and the effect of tip speed ratio and helical spacing. The temporal growth rate of the vortex system instabilities were measured and are shown to be dependent on helical spacing. The evolution of filaments and their growth rates support the argument that the mutual inductance mode is the driving mechanism behind the transiti

APA, Harvard, Vancouver, ISO, and other styles

27

Kuang, Yuchun, Wei Lin, Zongzheng Dong, Longmei Wu, and Qin Wang. "A cutter path generation strategy for helical surface machining of screw rotor." Science Progress 103, no. 1 (2019): 003685041988218. http://dx.doi.org/10.1177/0036850419882180.

Full text

Abstract:

In this article, the disk mill cutter path generation strategy for the machining of complex helical surface via a currently developed minimal orientation-distance algorithm based on spatial discretization method is studied. The strategy proposed here is, first, to establish the helical surface and cutting surface in the unique coordinate system. Then, the two surfaces are divided into a series of parts by n equidistant planes, and the minimal orientation-distance algorithm is used to determine all the cutter locations. Finally, on the basis of Archimedes helical interpolation, cutter path is g

APA, Harvard, Vancouver, ISO, and other styles

28

Fleming, J. S., Y. Tang, and G. Cook. "The twin helical screw compressor Part 1: Development, applications and competitive position." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 212, no. 5 (1998): 355–67. http://dx.doi.org/10.1243/0954406981521286.

Full text

Abstract:

Part 1 of this paper describes the origins, principal developments, characteristics, applications and current competitive position of the twin helical screw compressor. It is now the preferred type in a large range of gas and refrigeration applications previously serviced by the larger piston and smaller centrifugal compressors. Its success has been made possible by two crucial developments: (a) a lubricated variant in which one rotor drives the other without timing gears and (b) the introduction of advanced machine tools capable of mass producing reliably a rotor pair of high efficiency and l

APA, Harvard, Vancouver, ISO, and other styles

29

Mimmi, Giovanni, and Paolo Pennacchi. "Compression Load Dynamics in a Special Helical Blower: A Modeling Improvement." Journal of Mechanical Design 123, no. 3 (1999): 402–7. http://dx.doi.org/10.1115/1.1377016.

Full text

Abstract:

The instantaneous variation of pressure loads acting on the rotors of positive displacement rotary blowers may produce vibrations and noise that in some case produce the failure of the machine and of the piping. In a previous paper the authors determined the pressure loads acting on the rotors, starting from the geometry of the chambers that are formed during the rotor meshing and the thermodynamic transformation of the working fluid. The calculation of the loads has been made in a quasi-static manner. In this paper the model has been improved by taking into account the effects due to a closed

APA, Harvard, Vancouver, ISO, and other styles

30

Mimmi, G., and P. Pennacchi. "Analytical model of a particular type of positive displacement blower." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 213, no. 5 (1999): 517–26. http://dx.doi.org/10.1243/0954406991522743.

Full text

Abstract:

Many papers exist in the literature that deal with the twin-screw compressor. This usually has two different rotors, a male and a female, and is commonly used to produce compressed gas for industrial uses. However, a different type of positive displacement rotary compressor with two screws is sometimes used, one of its typical applications being in car engine supercharging. The present paper deals with the latter type, which is defined as a two-screw blower. This blower has two identical helical rotors, each with three lobes. The kinematics and the geometry of the rotors are analysed here, and

APA, Harvard, Vancouver, ISO, and other styles

31

Zhang, Zhen, Hua Yan, Yu Mei Ding, Chang Feng Guan, and Wei Min Yang. "Numerical Study on Heat Transfer Enhancement Performence of the Helical Blade Rotors." Key Engineering Materials 561 (July 2013): 101–6. http://dx.doi.org/10.4028/www.scientific.net/kem.561.101.

Full text

Abstract:

Based on the advantages of polymer materials over other materials, rotors which are made of the polymer material, are the functional elements of the rotor-assembled strand, and rotate under certain mass flow rate to obtain heat transfer enhancement and online automatic cleaning. The paper carried out numerical studies on heat transfer and friction loss characteristics of the tube fitted with rotors of different spaces. The comparison of the field synergy angle between plain tube and the tube fitted with rotors was also presented in the paper. The numerical data had good agreement with the expe

APA, Harvard, Vancouver, ISO, and other styles

32

Yang, Yi, Xurong Wang, Mingkun Wang, Hang Li, and Yiping Dai. "Dynamic behaviors of helical geared multishaft rotor systems by modal synthesis." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 231, no. 8 (2016): 1410–26. http://dx.doi.org/10.1177/0954406216681596.

Full text

Abstract:

A theoretical investigation of dynamic behaviors of helical geared multishaft rotor systems is performed in this paper. A modal synthesis is developed to calculate free and forced vibrations for geared rotor systems including more than two shafts and gears. Degrees of freedom can be reduced to save the computing time in this method. Results of reduced model are compared with those of full degrees of freedom model, to obtain the acceptable reduction of degrees of freedom without significant loss of accuracy in predicting free and forced vibrations. Then, with the help of this method, dynamic be

APA, Harvard, Vancouver, ISO, and other styles

33

Kim, Lock-Song, Zhao-Quan Tian, Xi-Ning Li, Ying Zhang, and Jin Wang. "Centrifugal couner-current partition chromatography with helical coil rotor." Journal of Chromatography A 483 (January 1989): 359–68. http://dx.doi.org/10.1016/s0021-9673(01)93135-8.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Deb, Bachu, Rajat Gupta, and R. D. Misra. "Experimental Analysis of a 20° Twist Helical Savonius Rotor at Different Overlap Conditions." Applied Mechanics and Materials 592-594 (July 2014): 1060–64. http://dx.doi.org/10.4028/www.scientific.net/amm.592-594.1060.

Full text

Abstract:

Wind power is a major source of sustainable energy and can be harvested using both horizontal and vertical axis wind turbines. Vertical axis wind turbines (VAWTs) accrue more popularity due to its self-starting characteristics and Omni directional in nature. Out of which Savonius rotor is the most popular drag-based VAWT which is having lower efficiencies but having good self-starting characteristics. In order to improve the performance, helix in the tip of the blade is targeted which reduces the negative torque coefficient of the rotor thereby could improve the performance of the rotor. There

APA, Harvard, Vancouver, ISO, and other styles

35

Lian, Li Ming, and Gui Min Liu. "The Natural Frequency Analysis of Wind Turbine Gear Rotor System." Advanced Materials Research 580 (October 2012): 227–30. http://dx.doi.org/10.4028/www.scientific.net/amr.580.227.

Full text

Abstract:

The Natural frequency of wind turbine gear rotor system was analyzed by the Ansys11.0 software. It was found that the deformation of three-order was larger than others in low-order mode, through that a helical gear’s mode of weak links of the gear transmission system was analyzed. The result is an important theoretical support to prevent the resonance of gear rotor system.

APA, Harvard, Vancouver, ISO, and other styles

36

Damak, A., Z. Driss, and M. S. Abid. "Optimization of the helical Savonius rotor through wind tunnel experiments." Journal of Wind Engineering and Industrial Aerodynamics 174 (March 2018): 80–93. http://dx.doi.org/10.1016/j.jweia.2017.12.022.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Ohanian, Christopher V., Gregory J. McCauley, and Ömer Savaş. "A Visual Study of Vortex Instabilities in the Wake of a Rotor in Hover." Journal of the American Helicopter Society 57, no. 4 (2012): 1–8. http://dx.doi.org/10.4050/jahs.57.042005.

Full text

Abstract:

A visual study of the instability characteristics of the helical vortex filaments trailing from the tips of a three-bladed lifting rotor in a water tank is presented. The rotor diameter was 25.4 cm, and its rotation rate ranged from 4 to 12 revolutions per second. Soon after their formation, the vortex filaments developed long- and short-wave instabilities. In the long-wave instability mode, two of the three vortices coming off the rotor orbited around each other and merged in about 0.4 of the theoretical orbit time of equistrength two-dimensional vortices, after which the third vortex joined

APA, Harvard, Vancouver, ISO, and other styles

38

Popa, Camelia Lǎcrǎmioara. "Graphical Method in CAD Environment for Profiling End Mill Tool." Applied Mechanics and Materials 809-810 (November 2015): 787–92. http://dx.doi.org/10.4028/www.scientific.net/amm.809-810.787.

Full text

Abstract:

The actives surfaces of screw compressors are helical surfaces, cylindrical and uniform pitch. The generation of helical surfaces can be done using tools bordered by revolution surfaces (as end mill cutter, or disk cutter). The shaping of generating tools is based on fundamentals theorem of the enveloping surfaces. This paper consists to propose a graphic solution, using specific tools of the design environment AUTOCAD, to problem concerning the shaping end mill tool which generates the helical flute of male rotor component of screw compressor. The algorithm has been developed based on a compl

APA, Harvard, Vancouver, ISO, and other styles

39

WOOD, D. H., and J. BOERSMA. "On the motion of multiple helical vortices." Journal of Fluid Mechanics 447 (October 30, 2001): 149–71. http://dx.doi.org/10.1017/s002211200100578x.

Full text

Abstract:

The analysis of the self-induced velocity of a single helical vortex (Boersma & Wood 1999) is extended to include equally spaced multiple vortices. This arrangement approximates the tip vortices in the far wake of multi-bladed wind turbines, propellers, or rotors in ascending, descending, or hovering flight. The problem is reduced to finding, from the Biot–Savart law, the additional velocity of a helix due to an identical helix displaced azimuthally. The resulting Biot–Savart integral is further reduced to a Mellin–Barnes integral representation which allows the asymptotic expansions to be

APA, Harvard, Vancouver, ISO, and other styles

40

Okulov, Valery L., Igor V. Naumov, Robert F. Mikkelsen, Ivan K. Kabardin, and Jens N. Sørensen. "A regular Strouhal number for large-scale instability in the far wake of a rotor." Journal of Fluid Mechanics 747 (April 17, 2014): 369–80. http://dx.doi.org/10.1017/jfm.2014.174.

Full text

Abstract:

AbstractThe flow behind a model of a wind turbine rotor is investigated experimentally in a water flume using particle image velocimetry (PIV) and laser Doppler anemometry (LDA). The study performed involves a three-bladed wind turbine rotor designed using the optimization technique of Glauert (Aerodynamic Theory, vol. IV, 1935, pp. 169–360). The wake properties are studied for different tip speed ratios and free stream speeds. The data for the various rotor regimes show the existence of a regular Strouhal number associated with the development of an instability in the far wake of the rotor. F

APA, Harvard, Vancouver, ISO, and other styles

41

White, G. "Design study of a split-torque helicopter transmission." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 212, no. 2 (1998): 117–23. http://dx.doi.org/10.1243/0954410981532180.

Full text

Abstract:

A helicopter transmission with split-torque drive trains to the main rotor and tail rotor drive shaft is described. A design based on two 1200 kW engines supplying torque to a 350 r/min main shaft demonstrates a weight reduction of 40 per cent, extreme low height and reduced losses. Four double-helical pinions drive a combining gear and provide a 10:1 reduction ratio to the main shaft; flexible torque tubes, set by fine-difference splines, control the division of torque between pairs of pinions. Rotor loads bypass the transmission housings and pass to the fuselage through a large-diameter mast

APA, Harvard, Vancouver, ISO, and other styles

42

Quaranta, Hugo Umberto, Hadrien Bolnot, and Thomas Leweke. "Long-wave instability of a helical vortex." Journal of Fluid Mechanics 780 (September 9, 2015): 687–716. http://dx.doi.org/10.1017/jfm.2015.479.

Full text

Abstract:

We investigate the instability of a single helical vortex filament of small pitch with respect to displacement perturbations whose wavelength is large compared to the vortex core size. We first revisit previous theoretical analyses concerning infinite Rankine vortices, and consider in addition the more realistic case of vortices with Gausssian vorticity distributions and axial core flow. We show that the various instability modes are related to the local pairing of successive helix turns through mutual induction, and that the growth rate curve can be qualitatively and quantitatively predicted

APA, Harvard, Vancouver, ISO, and other styles

43

Quaranta, Hugo Umberto, Mattias Brynjell-Rahkola, Thomas Leweke, and Dan S. Henningson. "Local and global pairing instabilities of two interlaced helical vortices." Journal of Fluid Mechanics 863 (January 31, 2019): 927–55. http://dx.doi.org/10.1017/jfm.2018.904.

Full text

Abstract:

We investigate theoretically and experimentally the stability of two interlaced helical vortices with respect to displacement perturbations having wavelengths that are large compared to the size of the vortex cores. First, existing theoretical results are recalled and applied to the present configuration. Various modes of unstable perturbations, involving different phase relationships between the two vortices, are identified and their growth rates are calculated. They lead to a local pairing of neighbouring helix loops, or to a global pairing with one helix expanding and the other one contract

APA, Harvard, Vancouver, ISO, and other styles

44

Ye, Zhonghe. "Design and cutting of three-lobe helical rotor in roots blower." Chinese Journal of Mechanical Engineering (English Edition) 17, supp (2004): 102. http://dx.doi.org/10.3901/cjme.2004.supp.102.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Damak, A., Z. Driss, and M. S. Abid. "Experimental investigation of helical Savonius rotor with a twist of 180°." Renewable Energy 52 (April 2013): 136–42. http://dx.doi.org/10.1016/j.renene.2012.10.043.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Chen, Zi-Jian, Hsiu-Feng Lu, Chun-Wei Chiu, et al. "A Molecular Rotor That Probes the Helical Inversion of Stiff-Stilbene." Organic Letters 22, no. 23 (2020): 9158–62. http://dx.doi.org/10.1021/acs.orglett.0c02993.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Saad, Ahmed, Ali AbdelSalam, I. Sakr, and W. El-Askary. "Performance Analysis of a Helical Savonius Wind Turbine with Modified Rotor." International Conference on Aerospace Sciences and Aviation Technology 17, AEROSPACE SCIENCES (2017): 1–14. http://dx.doi.org/10.21608/asat.2017.22459.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Okulov, Valery L., Ivan K. Kabardin, Robert F. Mikkelsen, Igor V. Naumov, and Jens N. Sørensen. "Helical self-similarity of tip vortex cores." Journal of Fluid Mechanics 859 (November 28, 2018): 1084–97. http://dx.doi.org/10.1017/jfm.2018.850.

Full text

Abstract:

The present work investigates local flow structures and the downstream evolution of the core of helical tip vortices generated by a three-bladed rotor. Earlier experimental studies have shown that the core of a helical tip vortex exhibits a local helical symmetry with a simple relation between the axial and azimuthal velocities. In the present study, a self-similarity scaling argument further describes the downstream development of the vortex core. Self-similarity has up to now only been investigated for longitudinal vortices and it is the first time that helical vortices have become the subje

APA, Harvard, Vancouver, ISO, and other styles

49

Mula, Swathi M., and Charles E. Tinney. "A study of the turbulence within a spiralling vortex filament using proper orthogonal decomposition." Journal of Fluid Mechanics 769 (March 25, 2015): 570–89. http://dx.doi.org/10.1017/jfm.2015.104.

Full text

Abstract:

The stability and turbulence characteristics of a vortex filament emanating from a single-bladed rotor in hover are investigated using proper orthogonal decomposition (POD). The rotor is operated at a tip chord Reynolds number and tip Mach number of 218 000 and 0.23, respectively, and with a blade loading of $C_{T}/{\it\sigma}=0.066$. In-plane components of the velocity field (normal to the axis of the vortex filament) are captured by way of two-dimensional particle image velocimetry with corrections for vortex wander being performed using the ${\it\Gamma}_{1}$ method. The first POD mode alone

APA, Harvard, Vancouver, ISO, and other styles

50

Mohamed Iyad Al, Naboulsi, Niculae Napoleon Antonescu, Alin Dinita, and Marius Morosanu. "Tribological Characterization of Some Elastomers Used at Progressive Cavity and Piston Pumps." MATEC Web of Conferences 318 (2020): 01016. http://dx.doi.org/10.1051/matecconf/202031801016.

Full text

Abstract:

The progressive cavity pump (PCP) is a positive displacement pump, consisting of a polished helical-shaped rod (rotor) turning inside a helical elastomer (stator). PCP has many advantages, but the pump durability is manly limited by elastomer behavior. At piston pumps (PP) used for drilling mud piston has an elastomer sleeve that also limit the durability. Standards like ISO 15136.1 & 2 for pumps developed by manufactures and users’ committees provides requirements for design, quality design verification etc., but do not define specifically the elastomer for the stator or the metal used fo

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!