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Article
Publication date: 15 November 2018

Julius Dahms and Andreas Bardenhagen

This paper deals with the estimation of the necessary masses of propulsion components for multirotor UAS. Originally, within the design process of multirotors, this is an…

Abstract

Purpose

This paper deals with the estimation of the necessary masses of propulsion components for multirotor UAS. Originally, within the design process of multirotors, this is an iterative problem, as the propulsion masses contribute to the total takeoff mass. Hence, they influence themselves and cannot be directly calculated. The paper aims to estimate the needed propulsion masses with respect to the requested thrust because of payload, airframe weight and drag forces and with respect to the requested flight time.

Design/methodology/approach

Analogue to the well-established design synthesis of airplanes, statistical data of existing electrical motors, propellers and rechargeable batteries are evaluated and analyzed. Applying Rankine and Froude’s momentum theory and a generic model for electro motor efficiency factors on the statistical performance data provides correlations between requested performance and, therefore, needed propulsion masses. These correlations are evaluated and analyzed in the scope of buoyant-vertical-thrusted hybrid UAS.

Findings

This paper provides a generic mathematical propulsion model. For given payloads, airframe structure weights and a requested flight time, appropriate motor, propeller and battery masses can be modelled that will provide appropriate thrust to lift payload, airframe and the propulsion unit itself over a requested flight time.

Research limitations/implications

The model takes into account a number of motors of four and is valid for the category of nano and small UAS.

Practical implications

The presented propulsion model enables a full numerical design process for vertical thrusted UAS. Hence, it is the precondition for design optimization and more efficient UAS.

Originality/value

The propulsion model is unique and it is valid for pure multirotor as well as for hybrid UAS too.

Details

Aircraft Engineering and Aerospace Technology, vol. 91 no. 2
Type: Research Article
ISSN: 1748-8842

Keywords

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Article
Publication date: 1 July 1962

J. Fletcher

The stability and control systems adopted by the Bell Aircraft Corporation and for the Short S.C.1 are discussed with reference to efficiency, and the importance of low…

Abstract

The stability and control systems adopted by the Bell Aircraft Corporation and for the Short S.C.1 are discussed with reference to efficiency, and the importance of low loss nozzle systems is emphasized. The form of auto‐stabilization and its application to the aircraft control system are to sonic extent governed by the operating requirements of the V.T.O.L. aircraft. Lift engine intake problems and the interaction effects of the airflow passing through the lift engines on the airframe as a whole are considered at length, along with ground effects and novel model testing techniques. The author concludes that much model and full‐scale research is still needed to investigate further the many problems which remain and which can critically affect the feasibility of projects for operational use.

Details

Aircraft Engineering and Aerospace Technology, vol. 34 no. 7
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 6 March 2017

Harijono Djojodihardjo, Riyadh Ibraheem Ahmed, Abd Rahim Abu Talib and Azmin Shakrine Mohd Rafie

The purpose of this paper is to reformulate the governing equations incorporating major variables and parameters for the design a Micro Air Vehicle (MAV), to meet the…

Abstract

Purpose

The purpose of this paper is to reformulate the governing equations incorporating major variables and parameters for the design a Micro Air Vehicle (MAV), to meet the desired mission and design requirements.

Design/methodology/approach

Mathematical models for various spherical and cylindrical Coandă MAV configurations were rederived from first principles, and the performance measures were defined. To verify the theoretical prediction to a certain extent, a computational fluid dynamic (CFD) simulation for a Coandă MAV generic models was performed.

Findings

The major variables and parameters of Coandă MAV have been formulated into practical guidelines, which relate the lift (or thrust) produced for certain input variables, particularly the Coandă MAV jet momentum coefficient. The influences of the geometrical parameters are elaborated.

Research limitations/implications

The present analysis on Coandă jet-configured MAV is focused on the lift generation due to the Coandă jet effect through a meticulous analysis. The effects of viscosity, the Coandă jet thickness, the radius of curvature of the surface and the stability of Coandă jet are not considered and will be the subject of the following work.

Practical implications

The results obtained can be used for sizing in the preliminary design of Coandă MAVs.

Originality/value

Physical and mathematical models were developed which can describe the physical phenomena of the flow field near the Coandă MAV surfaces influenced by Coandă jet sheets and for obtaining a relationship between relevant variables and parameters to the lift of practical interest.

Details

Aircraft Engineering and Aerospace Technology, vol. 89 no. 2
Type: Research Article
ISSN: 1748-8842

Keywords

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Article
Publication date: 1 December 1962

FEW advances in aircraft design have aroused such intense controversy as that which at present surrounds the philosophy of jet lift vertical take‐off and landing…

Abstract

FEW advances in aircraft design have aroused such intense controversy as that which at present surrounds the philosophy of jet lift vertical take‐off and landing techniques. On the one hand, there are the disciples of the composite power plant system, and on the other, those who adhere to the vectored thrust solution; both factions being equally certain that their particular technique provides the best answer to the jet lift problem.

Details

Aircraft Engineering and Aerospace Technology, vol. 34 no. 12
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 16 November 2018

Vittorio Cipolla, Karim Abu Salem and Filippo Bachi

The present paper aims to assess the reliability and the limitations of analysing flight stability of a box-wing aircraft configuration known as PrandtlPlane by means of…

Abstract

Purpose

The present paper aims to assess the reliability and the limitations of analysing flight stability of a box-wing aircraft configuration known as PrandtlPlane by means of methods conceived for conventional aircraft and well known in the literature.

Design/methodology/approach

Results obtained by applying vortex lattice methods to PrandtlPlane configuration, validated previously with wind tunnel tests, are compared to the output of a “Roskam-like” method, here defined to model the PrandtlPlane features.

Findings

The comparisons have shown that the “Roskam-like” model gives accurate predictions for both the longitudinal stability margin and dihedral effect, whereas the directional stability is always overestimated.

Research limitations/implications

The method here proposed and related achievements are valid only for subsonic conditions. The poor reliability related to lateral-directional derivatives estimations may be improved implementing different models known from the literature.

Practical implications

The possibility of applying a faster method as the “Roskam-like” one here presented has two main implications: it allows to implement faster analyses in the conceptual and preliminary design of PrandtlPlane, providing also a tool for the definition of the design space in case of optimization approaches and it allows to implement a scaling procedure, to study families of PrandtlPlanes or different aircraft categories.

Social implications

This paper is part of the activities carried out during the PARSIFAL project, which aims to demonstrate that the introduction of PrandtlPlane as air transport mean can fuel consumption and noise impact, providing a sustainable answer to the growing air passenger demand envisaged for the next decades.

Originality/value

The originality of this paper lies in the attempt of adopting analysis method conceived for conventional airplanes for the analysis of a novel configuration. The value of the work is represented by the knowledge concerning experimental results and design methods on the PrandtlPlane configuration, here made available to define a new analysis tool.

Details

Aircraft Engineering and Aerospace Technology, vol. 91 no. 3
Type: Research Article
ISSN: 1748-8842

Keywords

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Article
Publication date: 1 November 1990

Terry Ford CEng and MRAeS

THE title of this report comes from the Keynote Address to the recent International Powered Lift Conference organised by the Royal Aeronautical Society. Attention at this…

Abstract

THE title of this report comes from the Keynote Address to the recent International Powered Lift Conference organised by the Royal Aeronautical Society. Attention at this gathering was focussed entirely on short take‐off and vertical landing (STOVL) technologiesf for fast jet combat aircraft. The strong international collaboration particularly between the USA and the UK has been a main feature of the evolution of these types. Seven areas of work have been outlined at the last conference of this nature and these largely remain the central themes. These are: plenum chamber burning; hot gas reingestion during VTOL manoevres; ground erosion; near field jet noise; powerplant controls; aircraft controls and flight/ powerplant controls integration; and airframes. It has been concluded that the most promising configuration for a future aircraft would include the two specific features of remote vertical lift in jet‐borne flight and conventional mixed flow propulsion for wing‐borne flight.

Details

Aircraft Engineering and Aerospace Technology, vol. 62 no. 11
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 March 1969

N.W. Boorer and B.J. Davey

A study of the main parameters to be resolved for civil V/S.T.O.L. aircraft, the necessity for all weather operation, the airport requirements and the competition from…

Abstract

A study of the main parameters to be resolved for civil V/S.T.O.L. aircraft, the necessity for all weather operation, the airport requirements and the competition from other forms of transport. FROM a choice of a wide range of V/S.T.O.L. applications, this paper is concerned with the civil aircraft aspects. It deals with the main parameters to be studied in resolving V.T.O.L. and S.T.O.L. aircraft characteristics, the weighting of these toward favourable performance and to meeting the proposed certification rules for this form of transport. The part to be played by electronics in all weather operations is also discussed. Competition from surface transport, and V/S.T.O.L. airport requirements are referred to, and some general characteristics of the many different aircraft configurations are discussed. Some conclusions are reached suggesting the direction and weighting of future work.

Details

Aircraft Engineering and Aerospace Technology, vol. 41 no. 3
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 April 1968

L.J. Willmer, L.J. Davies and Edmund Davies

November 28, 1967 Factory — Lifting tackle — Hook — Steelworks — Removal of scab — Hook placed under it — Hook suspended from chain of crane — Strain taken up by crane to…

Abstract

November 28, 1967 Factory — Lifting tackle — Hook — Steelworks — Removal of scab — Hook placed under it — Hook suspended from chain of crane — Strain taken up by crane to enable brick to be placed under scab — Whether “raising” operation — Factories Act, 1961 (9 & 10 Eliz. II. c.34), s. 26(1).

Details

Managerial Law, vol. 4 no. 1
Type: Research Article
ISSN: 0309-0558

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Article
Publication date: 29 January 2020

Jian-Ping Wang, Mei-Ru Wang, Jian-Lan Zhou, Qing-Jun Zuo and Xun-Xian Shi

The purpose of this study is to develop optimal evacuation plan to provide valuable theoretical and practical insight in the fire evacuation work of similar structures, by…

Abstract

Purpose

The purpose of this study is to develop optimal evacuation plan to provide valuable theoretical and practical insight in the fire evacuation work of similar structures, by proposing a systematic simulation-based guided-evacuation agent-based model (GAM) and a three-stage mathematical evacuation model to investigate how to simulate, assess and improve the performance efficiency of the evacuation plan.

Design/methodology/approach

The authors first present the self-evacuation and guided-evacuation models to determine the optimal evacuation plan in ship chamber. Three key performance indicators are put forward to quantitatively assess the evacuation performance within the two fire scenarios. The evacuation model in tower is built to obtain the dividing points of the three different fire evacuation plans.

Findings

The study shows that the optimal evacuation plan determined by the GAM considering social relationships effectively relieves the congestion or collision of evacuees and improves the evacuation uniformity. The optimal evacuation plan not only solves the crush caused by congestion or collision of evacuees but also can greatly shorten the evacuation time for passenger ship fire.

Originality/value

This study establishes the GAM considering the interactive evacuee characteristics and the proportion of evacuees guided by the crew members to make the optimal evacuation plan more time-efficient. The self-evacuation process is simulated to assess the performance of the guided-evacuation strategies, which are used to verify the effectiveness and feasibility of the optimal evacuation plan in this research.

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Article
Publication date: 5 September 2016

Meinhard Schwaiger and David Wills

This paper aims to provide the international aeronautical community with details of the development of a new disruptive technology for aircraft propulsion.

Abstract

Purpose

This paper aims to provide the international aeronautical community with details of the development of a new disruptive technology for aircraft propulsion.

Design/methodology/approach

This paper describes the results achieved by a small Austrian aeronautical innovations company in developing a cyclogyro propulsion system capable of vertical launch and efficient forward flight. The research team progressed from concept definition and simulation (2004-2006), through experimental validation and concept demonstration (2006), component optimization (2006-2012), full system demonstration (2012-2014) and examination of ability to scale (both larger and smaller) (2015 onwards). This paper provides details of the results of each of these stages.

Findings

The research team proved that cyclogyro propulsion can be used for the vertical launch, and that, in forward flight, it has the potential to achieve efficiency beyond the range of conventional fixed wing and rotorcraft.

Research limitations/implications

This research indicates that the efficiency increases with forward speed within the range achieved in standard wind tunnels (up to 35 m/s). This efficiency appears to be caused by a unique chamber effect within the cyclogyro rotor assembly. Future research should be conducted to analyse this chamber effect in greater detail and to test the cyclogyro rotor for speeds beyond 35 m/s.

Practical implications

This work indicates that cyclogyro propulsion could have the potential to provide vertical launch, high speed and highly efficient aircraft that have reduced wing span, no external rotors and exceptional agility. This technology could therefore be feasible for vertical take-off and landing aircraft that can safely form densely packed swarms.

Social implications

It could be researched as an efficiency increase in forward flight completely different to existing propulsion systems. This could open a way for a more efficient air traffic in future and faster reduction of CO2 and NOX emission an allow an environment-friendlier air travelling.

Originality/value

This paper provides the details of the first cyclogyro aircraft to have flown and will serve the aeronautical community by stimulating the debate on this new disruptive technology.

Details

Aircraft Engineering and Aerospace Technology, vol. 88 no. 5
Type: Research Article
ISSN: 1748-8842

Keywords

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