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Article
Publication date: 15 July 2021

Svetoslav Zabunov, Garo Mardirossian and Katia Strelnitski

The current manuscript aims to propose a novel multirotor design.

Abstract

Purpose

The current manuscript aims to propose a novel multirotor design.

Design/methodology/approach

This paper presents a novel 16-rotor multicopter design named Emerald. The novel design innovations and benefits are disclosed. Comparison to existing 16-rotor designs is carried out. Implementation areas where the novel idea shall yield benefit are discussed. A prototype of the presented design is described.

Findings

The herein proposed 16-rotor design has a number of benefits over existing 16-rotor multicopters. The paper elaborates on those advantages.

Research limitations/implications

The research was limited to prototype testing, as the presented design is a novel concept.

Practical implications

The motivation to research and develop this novel design is implementing the vehicle for stereoscopic photography and reconnaissance. The design is also applicable to carrying payloads while flying indoors.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 6
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 1 December 2002

Yuan Su and Yihua Cao

As compared with the maneuvering flight studies for single main rotor helicopters, the corresponding studies for coaxial rotor helicopters are relatively poor. In this…

1450

Abstract

As compared with the maneuvering flight studies for single main rotor helicopters, the corresponding studies for coaxial rotor helicopters are relatively poor. In this paper, the maneuvering flight governing equations for coaxial rotor helicopters is established. By introducing induced velocity interference factor analysis, the coaxial rotor aerodynamic interference can be taken into account. With the combination of coaxial rotor helicopter control features and nonlinear inverse simulation technique, the governing equations for maneuvering flight can be solved so as to determine helicopter control input, control force and moment, and helicopter body attitudes which are needed for performing a specified maneuver. Good results of the sample calculations of level turn and lateral jink maneuvers are obtained and simply analyzed.

Details

Aircraft Engineering and Aerospace Technology, vol. 74 no. 6
Type: Research Article
ISSN: 0002-2667

Keywords

Article
Publication date: 2 March 2015

Maria Dems, Krzysztof Komeza, Slawomir Wiak and Sara Fernández Coya

– The purpose of this paper is to present the distribution of the magnetic field and additional losses analysis of the induction motors (IM) with opened and closed rotor slots.

Abstract

Purpose

The purpose of this paper is to present the distribution of the magnetic field and additional losses analysis of the induction motors (IM) with opened and closed rotor slots.

Design/methodology/approach

In the field-circuit approach the distribution and changes of magnetic flux density in the motor are computed using a time-stepping finite element method. The additional losses in each element are evaluated at different frequencies.

Findings

An approximate analytical formulation is derived for rapid losses computation confirmed by the results of field-circuit method. For high-voltage motors due to the size ratios of the core and relatively deep stator and rotor slots major role in causing loss of higher harmonics play a fundamental slot harmonics. Higher harmonics order bigger than 100 cause only small part of total higher harmonics core losses. Closed rotor slots construction influenced significantly on no-load losses mainly due to reduction of losses at slot upper part. For nominal load condition that influence is not so strong according to the saturation of slot tips by rotor leakage flux. Nevertheless, core losses at load are several times higher as at no-load.

Research limitations/implications

In future research authors will take into account motors feed from PWM inverter, working in the frequency range up to 400 Hz.

Practical implications

The results of investigation will be used in more detailed design of IMs especially for motors with closed rotor slots.

Originality/value

The methods presented in the paper was not used before. Also results of additional losses in the motor core calculation, especially according motors with closed slots at no load and load conditions are new.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 34 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 3 May 2013

Michael G. Pantelyat, Oszkár Bíró and Andrej Stermecki

The paper seeks to present a methodology of computer simulation of 3D transient electromagnetic fields, losses and forces due to negative sequence currents in fragments of…

Abstract

Purpose

The paper seeks to present a methodology of computer simulation of 3D transient electromagnetic fields, losses and forces due to negative sequence currents in fragments of large synchronous turbogenerator rotors. The methodology allows for the preparation of initial data for further computations of thermal and mechanical behaviour of rotors.

Design/methodology/approach

The governing equations for 3D negative sequence transient electromagnetic fields with the Coulomb gauge using magnetic vector potential and scalar electric potential A, VA are solved by the nodal finite element method in a Cartesian coordinate system moving synchronously with the rotor.

Findings

The presented methodology of 3D transient electromagnetic phenomena computation seems to be effective because the electromagnetic field in the rotor of a synchronous generator is generally three dimensional, and therefore 2D field‐computation approaches and software are not able to simulate intrinsically 3D electromagnetic processes in turbogenerator rotors.

Research limitations/implications

Currently it is difficult to carry out accurate numerical simulation of 3D transient electromagnetic fields and therefore losses and forces within the whole structure of the rotor because of the resulting huge computational expenses. This paper is devoted to the finite element analysis of electromagnetic fields, losses and forces in separate structural parts of the rotor. As an example of practical utilization of the developed technique, the computer simulation of electromagnetic phenomena in junctions of nonmagnetic rotor slot wedges of a 300 MVA class synchronous turbogenerator is carried out.

Practical implications

The methodology can successfully be used during the design process of modern large synchronous turbogenerators.

Originality/value

This paper presents numerical analysis of intrinsically 3D transient electromagnetic phenomena in large turbogenerator rotors.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 32 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 4 September 2017

Marcin Figat

This paper aims to present the results of aerodynamic calculation of impact the main rotor on the fuselage and the tail of a light gyroplane. This kind of vehicle is a…

Abstract

Purpose

This paper aims to present the results of aerodynamic calculation of impact the main rotor on the fuselage and the tail of a light gyroplane. This kind of vehicle is a type of rotorcraft which uses a non-powered rotor in autorotation to develop lift and engine-powered propeller to provide the thrust. Both of them disturb the flow around the gyroplane body (gyroplane fuselage and tail) and influence on its static stability. The main goal of the presented research was to find the magnitude of this influence. To measure this effect, the main stability derivatives changes of gyroplane body were investigated.

Design/methodology/approach

The CFD analysis of the complete gyroplane was made. Computation was performed for the model of gyroplane which was equipped with the two sub-models of the main rotor and the engine-powered propeller. Both of them were modelled as the actuator discs. This method allows to compute the aerodynamic impact of rotating components on the gyroplane body. All aerodynamic analysis was made by the MGAERO software. The numerical code of the software bases on the Euler flow model. Next, the resulting aerodynamic coefficients were used to calculate the most important stability derivatives of the gyroplane body.

Findings

The result obtained by computation presents the change in the most important aerodynamic coefficients and stability derivatives of the gyroplane body caused by the impact of its main rotor. Moreover, the result includes the change of the aerodynamic coefficients and stability derivatives caused by change of the main rotor configuration (change of rotation rate and angle of incidence) and change of the flight condition (gyroplane angle of attack sideslip angle and flight speed).

Practical implications

Analysis of the main rotor impact will be very useful for evaluation of dynamic stability of the light gyroplane. Moreover, the results will be helpful to design the horizontal and vertical tail for the light gyroplane.

Originality/value

This paper presents the method of the numerical analysis of the static stability of the light gyroplane’s body. The results of analysis present the impact of disturbance generated by the rotating main rotor on the static stability of the gyroplane body. Moreover, the impact of the main rotor configuration change and the flight condition change on the static stability were investigated too. The evaluation of the gyroplane’s body static stability was made by the stability derivatives. The methodology and obtained result will be very useful for analysis of the dynamic stability of the light gyroplanes. Moreover, the results will be helpful during design the main components of the gyroplane like vertical and horizontal tail.

Details

Aircraft Engineering and Aerospace Technology, vol. 89 no. 5
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 1 October 1997

Simon Newman

Explains the origins of rotor aerodynamic limits for helicopters including retreating and advancing blade limits. Examines the compounding of a helicopter for higher…

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Abstract

Explains the origins of rotor aerodynamic limits for helicopters including retreating and advancing blade limits. Examines the compounding of a helicopter for higher forward speed and reports the conclusions of a student project to design a rotorcraft capable of 300 knots and carrying a payload of 30 passengers.

Details

Aircraft Engineering and Aerospace Technology, vol. 69 no. 5
Type: Research Article
ISSN: 0002-2667

Keywords

Article
Publication date: 1 July 1978

Tommy H. Thomason

Tilt rotor aircraft will add new dimensions to corporate and charter air transportation beginning in the 1980s or 1990s. The tilt rotor combines the VTOL capability of the…

Abstract

Tilt rotor aircraft will add new dimensions to corporate and charter air transportation beginning in the 1980s or 1990s. The tilt rotor combines the VTOL capability of the helicopter with the speed, range, and fuel economy of the turboprop aircraft. The civil use of he helicopter has expanded enormously in the last 25 years because of its effectiveness in point‐to‐point transportation and its capability to operate from confined or limited areas. The tilt rotor dramatically increases that effectiveness because it hovers like a helicopter but cruises at twice the speed for twice the range on the same amount of fuel.

Details

Aircraft Engineering and Aerospace Technology, vol. 50 no. 7
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 11 February 2021

Ghassem Faezian, Ahmad Darabi and Nader Sargolzaei

This study aims to design the rotor geometry of switched reluctance motor (SRM) in a completely flexible way. In the proposed method, there is no default geometry for the…

Abstract

Purpose

This study aims to design the rotor geometry of switched reluctance motor (SRM) in a completely flexible way. In the proposed method, there is no default geometry for the rotor. The initial geometry of the rotor can start from a circle or any other shape and depending on the required performance takes the final shape during the optimal design. In this way, the best performance, possible with geometric design, can be achieved.

Design/methodology/approach

The rotor boundary of a 4/2 SRM is defined by a few B-splines. Some control points are located around the rotor and changing their locations causes customized changes in the rotor boundary. Locations of these points are defined as design variables. A 2-D finite element analysis using MATLAB/PDE is applied to the SRM model and sensitivity analysis is used to optimization design by means of minimizing of objective function.

Findings

The proposed method has many more capabilities for matching different objective functions. For the suggested objective function, while the conventional rotor torque profile difference with the desired torque profile reaches 40%, this difference for B-spline rotor is about 17%. Experimental results from a prototype motor have a close agreement with analysis results.

Originality/value

The B-splines have been used to design machines and electromagnetic devices. However, this method is used for the first time in design of the whole rotor of a SRM.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 40 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 January 2012

Piotr Kołodziejek and Elżbieta Bogalecka

The purpose of this paper is to investigate the need for a universal method for sensorless controlled induction motor drive diagnosis. The increasing number of sensorless…

Abstract

Purpose

The purpose of this paper is to investigate the need for a universal method for sensorless controlled induction motor drive diagnosis. The increasing number of sensorless control systems in industrial applications require a universal method for the drive diagnosis, which provides reliable diagnostic reasoning independent of control system structure and state variables measurement or estimation method.

Design/methodology/approach

Simulations and experimental investigation has been done with assumptions of multiscalar control system as a generalized vector control method, voltage source inverter application, sensorless control system based on selected speed observer structure and squirrel cage induction motor. Broken rotor symptoms are analyzed in the state variables and control system variables using DSP processing without outside measurement devices.

Findings

Symptoms of rotor asymmetry caused by broken rotor in the state and control variables was identified and symptoms amplitudes were compared. Based on the simulation and experimental results a new diagnosis method was proposed.

Practical implications

For early broken rotor detection there is a need to identify variables most sensitive to rotor asymmetry. In closed‐loop operation broken rotor symptom signals amplitudes are changed due to control system influence and in sensorless control due to used estimator frequency characteristics. The proposed method assumption is to aggregate symptoms in variables that altogether give results for broken rotor range regardless of applied control system structure or state variable estimator.

Originality/value

This paper shows control system influence to rotor fault symptom amplitudes in the state and control system variables. Identified phenomena is used for a new diagnosis method development.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 31 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 January 2006

Simon Newman

This paper reflects the design characteristics of helicopters and how each addresses the requirements of efficiency in operation and the ability to perform these…

1223

Abstract

Purpose

This paper reflects the design characteristics of helicopters and how each addresses the requirements of efficiency in operation and the ability to perform these operations effectively.

Design/methodology/approach

The basic requirements of a helicopter are discussed. A survey of the various rotorcraft configurations follows. A brief perusal of possibilities for the future concludes the paper.

Findings

The helicopter appears in various guises. Each version is designed to a particular brief and fulfils its own particular purpose.

Originality/value

The paper content is generally available from the various rotary wing texts both in print and within libraries. The originality comes from the assembly of these items within one paper which attempts to highlight the particular difficulties faced when designing rotary wing aircraft.

Details

Aircraft Engineering and Aerospace Technology, vol. 78 no. 1
Type: Research Article
ISSN: 0002-2667

Keywords

1 – 10 of over 4000