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Article
Publication date: 5 May 2015

Witold Mazgaj and Adam Warzecha

The purpose of this paper is to present the differences in results of numerical calculations arising from different simplifications of the rotational magnetization model…

Abstract

Purpose

The purpose of this paper is to present the differences in results of numerical calculations arising from different simplifications of the rotational magnetization model in typical dynamo sheets.

Design/methodology/approach

A comprehensive model of rotational magnetization processes in typical dynamo sheets should take into consideration the magnetic hysteresis and eddy current phenomena and also certain anisotropic properties. The chosen model of the rotational magnetization is briefly presented in this paper. A method of the inclusion of the rotational magnetization model into equations of the magnetic field distribution is described. The correctness of these equations has been verified experimentally. Numerical calculations of the rotational magnetization in two types of dynamo sheets were carried out for several simplifications of the described model.

Findings

Results of numerical calculations of the rotational magnetization with the omission of the hysteresis phenomenon or with the omission of eddy currents were compared with results obtained with the use of the comprehensive model of the rotational magnetization.

Practical implications

The paper presents comments and recommendations concerning the omission of both the hysteresis phenomenon and eddy currents in the analysis of the rotational magnetization in dynamo sheets and the impact of these simplifications on numerical calculation results.

Originality/value

The content of the paper refers to very important issues of modeling and calculations of the rotational magnetization in typical dynamo steel sheets.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 34 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 February 1936

W.E. Crook

IN the previous section chemical methods of producing or storing electrical energy were considered. There is also the possibility of deriving the required electrical…

Abstract

IN the previous section chemical methods of producing or storing electrical energy were considered. There is also the possibility of deriving the required electrical energy from some machine which converts mechanical energy into the electrical form. The ground engineer must appreciate that in no case can we get something for nothing, and that the output from the dynamo, plus the losses, does actually come from the engine of the aeroplane. Where the dynamo is wind‐driven, this is still true, the observable connexion being the reduction in the speed of the aeroplane when the dynamo is fitted. In fact, the speed of the aeroplane will vary with the electrical load on the dynamo, other conditions remaining constant, but this variation is too small or too obscured by other factors to be noticeable. In this section, the principles and general properties of the D.C. dynamo will be described.

Details

Aircraft Engineering and Aerospace Technology, vol. 8 no. 2
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 4 January 2016

Caroline Nore, Houda Zaidi, Frederic Bouillault, Alain Bossavit and Jean-Luc Guermond

The purpose of this paper is to present a new formulation for taking into account the convective term due to an imposed velocity field in the induction equation in a code…

Abstract

Purpose

The purpose of this paper is to present a new formulation for taking into account the convective term due to an imposed velocity field in the induction equation in a code based on Whitney elements called DOLMEN. Different Whitney forms are used to approximate the dependent variables. The authors study the kinematic dynamo action in a von Kármán configuration and obtain results in good agreement with those provided by another well validated code called SFEMaNS. DOLMEN is developed to investigate the dynamo action in non-axisymmetric domains like the impeller driven flow of the von Kármán Sodium (VKS) experiment. The authors show that a 3D magnetic field dominated by an axisymmetric vertical dipole can grow in a kinematic dynamo configuration using an analytical velocity field.

Design/methodology/approach

Different Whitney forms are used to approximate the dependent variables. The vector potential is discretized using first-order edge elements of the first family. The velocity is approximated by using the first-order Raviart-Thomas elements. The time stepping is done by using the Crank-Nicolson scheme.

Findings

The authors study the kinematic dynamo action in a von Kármán configuration and obtain results in good agreement with those provided by another well validated code called SFEMaNS. The authors show that a 3D magnetic field dominated by an axisymmetric vertical dipole can grow in a kinematic dynamo configuration using an analytical velocity field.

Originality/value

The findings offer a basis to a scenario for the VKS dynamo.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 35 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 8 April 2020

Xingrong Chen, Li Xiao, Sifeu Takougang Kingni, Irene Moroz, Zhouchao Wei and Hadi Jahanshahi

The purpose of this paper is to investigate coexisting attractors, chaos control and synchronization in a self-exciting homopolar dynamo system in this paper.

Abstract

Purpose

The purpose of this paper is to investigate coexisting attractors, chaos control and synchronization in a self-exciting homopolar dynamo system in this paper.

Design/methodology/approach

Two single controllers are designed and added to the proposed 3D autonomous chaotic system, and its stability at zero equilibrium point is guaranteed by applying an appropriate control signal based on the Lyapunov stability theory.

Findings

Numerical simulations reveal that the proposed 3D dynamo system exhibits periodic oscillations, double-scroll chaotic attractors and coexisting attractors. Finally, a single controller is designed for the global asymptotic synchronization of a unidirectionally coupled identical 3D autonomous chaotic system.

Originality/value

The derived results of this paper are new and complement some earlier works. The innovation concludes two points in this paper; coexisting attractors are foundthe and an appropriate control signal based on the Lyapunov stability theory is established. The ideas of this paper can be applied to investigate some other homopolar dynamo systems.

Details

International Journal of Intelligent Computing and Cybernetics, vol. 13 no. 2
Type: Research Article
ISSN: 1756-378X

Keywords

Article
Publication date: 1 March 1998

Brian Rooks

Digital prototyping is becoming a major tool in the fight to shorten product lead times. A further development is digital mock‐up that allows designers to investigate the…

Abstract

Digital prototyping is becoming a major tool in the fight to shorten product lead times. A further development is digital mock‐up that allows designers to investigate the “assemblability” of a product and the constraints imposed by manufacturing processes. The leading software system for digital mock‐up is DYNAMO, developed by Tecnomatix Technologies. The attributes and benefits of this computer‐aided production engineering (CAPE) tool are discussed and its link to other CAPE products highlighted. Many of the major automotive companies are now adopting DYNAMO and the experience of Rover in particular is related.

Details

Assembly Automation, vol. 18 no. 1
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 17 May 2022

Vinoth Kumar K., Loganathan T.G. and Jagadeesh G.

The Purpose of this study is to prove the possibility of developing low cost mechanical anti – lock braking system (ABS) for the passenger’s safety.

Abstract

Purpose

The Purpose of this study is to prove the possibility of developing low cost mechanical anti – lock braking system (ABS) for the passenger’s safety.

Design/methodology/approach

The design methodology of the proposed newer mechanical ABS comprises of two units, namely, the braking unit and wheel lock prevention unit. The braking unit actuates the wheel stopping as and when the driver applies the brake, whereas the wheel lock prevention unit initiates wheel release to prevent locking and subsequent slip/skidding. The brake pedal with master cylinder assembly and double-arm cylinder forms the braking unit, brake pad cylinder, movable brake pad, solenoid valve and dynamo forms the wheel lock prevention unit. The dynamo coupled with the rotor energises/de-energises the solenoid values to direct airflow for applying brake and release it, which makes the system less energy-dependent.

Findings

The braking unit aids in vehicle stops, by locking the disc with the brake pad actuated by a double-arm cylinder. The dynamo energises the solenoid valve to activate the brake pad cylinder piston for applying the brake on the disc. Instantaneously, on applying the brake the dynamo de-energises the solenoid to divert the pneumatic flow for retracting the brake pad thereby minimizing the braking torque. The baking torque reduction revives the wheel rotating and prevents slip/skidding.

Originality/value

Mechanical ABS preventing wheel lock by torque reduction principle is a novel method that has not been evolved so far. The system was designed with repair/replacement of the parts and subcomponents to support higher affordability on safety grounds.

Details

World Journal of Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 1 March 1936

W.E. Crook

IN the previous section it was explained how the terminal P.D. of a shunt dynamo can be adjusted manually by means of a field regulator. Although such a device may find a…

Abstract

IN the previous section it was explained how the terminal P.D. of a shunt dynamo can be adjusted manually by means of a field regulator. Although such a device may find a place where large dynamos are concerned, conditions involving a fluctuating load necessitate some form of automatic voltage control. Where a floating battery is used with the dynamo it is further desirable that the dynamo output should be suited to the state of charge of the battery, and again that it should change with every variation of load. While it would be quite possible to make all these adjustments by manual controls, such a scheme is obviously ruled out on motor vehicles and aeroplanes. The basic aim of the automatic voltage controller must, therefore, be to keep the battery fully charged, but the actual achievement of this aim turns out to involve much greater complexity than would be anticipated.

Details

Aircraft Engineering and Aerospace Technology, vol. 8 no. 3
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 1 January 1980

H. KRALLMANN

The integration of System Dynamics with LP‐ and Input‐Output models is realized by means of simple examples. Aspects of programming techniques as well as the conceptual…

Abstract

The integration of System Dynamics with LP‐ and Input‐Output models is realized by means of simple examples. Aspects of programming techniques as well as the conceptual meaning of this model‐method integration are discussed. By the combination of the stated methods with System Dynamics models an improved flexibility of the System Dynamics method is obtained. The optimization of a Simulation model is represented by the integration of a System Dynamics model into a higher level feedback loop structure. The optimization algorithm, the Razor Search procedure, modifies the parameters of the control vector in order to generate the optimal behaviour of the state vector of the model in relation to an objective function.

Details

Kybernetes, vol. 9 no. 1
Type: Research Article
ISSN: 0368-492X

Article
Publication date: 15 October 2008

Maurits Butter and Joost Hoogendoorn

The EU Framework Programme and the foresight community are both focusing on future developments in innovation. This paper seeks to answer the questions: How much can they

Abstract

Purpose

The EU Framework Programme and the foresight community are both focusing on future developments in innovation. This paper seeks to answer the questions: How much can they learn from one another to enhance their visions on the future? Are both perspectives aligned?

Design/methodology/approach

This research used the Dynamo approach, which analyses the match and mismatch of innovation entities by characterising both by a codified taxonomy on innovation. This taxonomy is based on the experience of TNO in innovation. In total, 140 flagship foresight activities from the EFMN database are analysed, as well as the Working Programmes 2007‐2008 from FP7 Cooperation.

Findings

The findings show that the perspectives of FP7 and the foresight community on innovations in health are highly aligned. Some interesting mismatches are identified that can be taken up by FP8 and the foresight community. Only a limited number of innovation themes are not addressed by both perspectives.

Practical implications

These results can help the foresight community to focus on important innovation themes in health not generally addressed and give input to the new FP7 working for 2009‐2013.

Originality/value

The results of the study show a more detailed insight into what innovation topics foresight and FP7 are mentioning/addressing.

Details

Foresight, vol. 10 no. 6
Type: Research Article
ISSN: 1463-6689

Keywords

Article
Publication date: 1 August 1938

ALTHOUGH the Ground Engineer may take every precaution to eliminate all possible causes o{ trouble in electrical equipment, failure may occasionally develop through causes…

Abstract

ALTHOUGH the Ground Engineer may take every precaution to eliminate all possible causes o{ trouble in electrical equipment, failure may occasionally develop through causes outside his control. The most probable faults have been tabulated, according to the symptoms which are displayed, in the “fault‐finding” tables here published.

Details

Aircraft Engineering and Aerospace Technology, vol. 10 no. 8
Type: Research Article
ISSN: 0002-2667

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