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Article
Publication date: 1 March 1945

A.R. Weyl

IN a series of articles entitled “Tailless Aircraft and Flying Wings”, concluded last month, the evolution of the tailless aeroplane and the flying wing was treated. The…

Abstract

IN a series of articles entitled “Tailless Aircraft and Flying Wings”, concluded last month, the evolution of the tailless aeroplane and the flying wing was treated. The different trends of the development were classified, and a short discussion of the difficulties which had been experienced during experimental work given.

Details

Aircraft Engineering and Aerospace Technology, vol. 17 no. 3
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 March 1937

J.H. Crowe

THE basic theory of stability has undergone no important modification since the publication of Professor G. H. Bryan's book on Stability in Aviation in 1911. The stability

Abstract

THE basic theory of stability has undergone no important modification since the publication of Professor G. H. Bryan's book on Stability in Aviation in 1911. The stability equations derived therein serve to‐day with the difference that axes and symbols have now been standardised and with the additional refinement of a non‐dimensional form of the stability equation introduced by H. Glauert. Due to the vastly increased knowledge of aerodrynamic characteristics, however, the stability derivatives are more readily assessable in any particular design case. This applies more particularly to longitudinal stability calculations which may, and indeed often arc, carried through with no wind tunnel tests available apart from a lift and drag curve for the aerofoil section used. There has also been some extension of the use of stability charts for deriving an approximate knowledge of the behaviour of the aeroplane when it receives a disturbance. These charts are exceedingly useful for obtaining periodic time and damping factor, but the assumptions on which they are based should be clearly realized.

Details

Aircraft Engineering and Aerospace Technology, vol. 9 no. 3
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 26 August 2020

Anil Kumar Gulivindala, M.V.A. Raju Bahubalendruni, S.S. Vara Prasad Varupala and Sankaranarayanasamy K.

Parallel assembly sequence planning (PASP) reduces the overall assembly effort and time at the product development stage. Methodological difficulties at framework…

Abstract

Purpose

Parallel assembly sequence planning (PASP) reduces the overall assembly effort and time at the product development stage. Methodological difficulties at framework development and computational issues at their implementation made the PASP complex to achieve. This paper aims to propose a novel stability concept for subassembly detection to minimize the complexities in PASP.

Design/methodology/approach

In this research, a heuristic method is developed to identify, represent and implement the stability predicate to perform subassembly detection and assembly sequence planning (ASP) at the further stages. Stability is organized into static, dynamic, enriched and no stability between the mating assembly parts. The combination of parts that possesses higher fitness is promoted to formulate the final solution about PASP.

Findings

The results obtained by applying the proposed concept on complex configurations revealed that stability predicate plays a dominant role in valid subassembly detection and final sequence generation further.

Originality/value

The value of the presented study lies in the three types of stability conditions and effective integration to existed ASP method. Unlike the existed heuristics in subassembly detection, the proposed concept identifies the parallel subassemblies during ASP.

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Article
Publication date: 1 April 1945

A.R. Weyl

THE complexity of the problems which are associated with the lateral stability and directional control of tailless aeroplanes was not realized until rather late.

Abstract

THE complexity of the problems which are associated with the lateral stability and directional control of tailless aeroplanes was not realized until rather late.

Details

Aircraft Engineering and Aerospace Technology, vol. 17 no. 4
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 June 1992

P. WRIGGERS and C. CARSTENSEN

Many engineering structures exhibit loss of stability under static and dynamic loading. Due to the significance of these phenomena in engineering design this topic has…

Abstract

Many engineering structures exhibit loss of stability under static and dynamic loading. Due to the significance of these phenomena in engineering design this topic has attracted considerable attention during the last decades. In recent years much effort has been made to devise algorithms within finite element analysis to investigate the static stability behaviour of structures. With these methods stable and unstable paths can be traced, and limit or bifurcation points can be computed efficiently. The associated arc‐length or branch‐switching procedures are today standard tools in existing finite element codes.

Details

Engineering Computations, vol. 9 no. 6
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 4 January 2019

Katarzyna Pobikrowska and Tomasz Goetzendorf-Grabowski

This paper aims to present stability analysis of a small pulsejet-powered airplane. This analysis is a part of a student project dedicated to designing an airplane to test…

Abstract

Purpose

This paper aims to present stability analysis of a small pulsejet-powered airplane. This analysis is a part of a student project dedicated to designing an airplane to test valved pulsejet engine in flight conditions.

Design/methodology/approach

The panel method was chosen to compute the airplane’s aerodynamic coefficients and derivatives for various geometry configurations, as it provides accurate results in a short computational time. Also, the program (PANUKL) that was used allows frequent and easy changes of the geometry. The evaluation of dynamic stability was done using another program (SDSA) equipped with means to formulate and solve eigenvalue problem for various flight speeds.

Findings

As a result of calculations, some geometry corrections were established, such as an increase of the vertical stabilizer’s size and a new wing position. Resulting geometry provides satisfactory dynamic and static stability characteristics for all flight speeds. This conclusion was based on criteria given by MIL-F-8785C specifications. This paper presents the results of the first and the final configuration.

Practical implications

The results shown in this paper are necessary for the continuation of the project. The aircraft’s structure was being designed in the same time as the calculations described in this paper proceeded. With a few modifications to make up for the changes of external geometry, the structure will be ready to be built.

Originality/value

The idea to design an airplane specifically to test a pulsejet in flight is a unique one. Most RC pulsejet-powered constructions that can be heard of are modified versions of already existing models. What adds more to the value of the project is that it is being developed only by students. This allows them to learn various aspects of aircraft design and construction on a soon-to-be real object.

Details

Aircraft Engineering and Aerospace Technology, vol. 91 no. 6
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 3 January 2017

Mojtaba Tahani, Mehran Masdari and Ali Bargestan

This paper aims to investigate the aerodynamic characteristics as well as static stability of wing-in-ground effect aircraft. The effect of geometrical characteristics…

Abstract

Purpose

This paper aims to investigate the aerodynamic characteristics as well as static stability of wing-in-ground effect aircraft. The effect of geometrical characteristics, namely, twist angle, dihedral angle, sweep angle and taper ratio are examined.

Design/methodology/approach

A three-dimensional computational fluid dynamic code is developed to investigate the aerodynamic characteristics of the effect. The turbulent model is utilized for characterization of flow over wing surface.

Findings

The numerical results show that the maximum change of the drag coefficient depends on the angle of attack, twist angle and ground clearance, in a decreasing order. Also, it is found that the lift coefficient increases as the ground clearance, twist angle and dihedral angle decrease. On the other hand, the sweep angle does not have a significant effect on the lift coefficient for the considered wing section and Reynolds number. Also, as the aerodynamic characteristics increase, the taper ratio befits in trailing state.

Practical implications

To design an aircraft, the effect of each design parameter needs to be estimated. For this purpose, the sensitivity analysis is used. In this paper, the influence of all parameter against each other including ground clearance, angle of attack, twist angle, dihedral angle and sweep angle for the NACA 6409 are investigated.

Originality/value

As a summary, the contribution of this paper is to predict the aerodynamic performance for the cruise condition. In this study, the sensitivity of the design parameter on aerodynamic performance can be estimated and the effect of geometrical characteristics has been investigated in detail. Also, the best lift to drag coefficient for the NACA 6409 wing section specifies and two types of taper ratios in ground effect are compared.

Details

Aircraft Engineering and Aerospace Technology, vol. 89 no. 1
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 1 August 1945

G.W. Drury

CASTORING stability requires automatic return, after displacement, of the castoring wheel to the central position. A hinged wheel may be automatically stable under static

Abstract

CASTORING stability requires automatic return, after displacement, of the castoring wheel to the central position. A hinged wheel may be automatically stable under static conditions, but dynamically unstable, or vice versa. Dynamic stability may be defined as the condition in which the forces on the wheel in motion secure its return to the path of direction of motion.

Details

Aircraft Engineering and Aerospace Technology, vol. 17 no. 8
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 10 June 2021

Khurrum Mahmood and Norilmi Amilia Ismail

This paper aims to optimize the mass of a tethered aerostat to achieve optimum hull volume, and fins to generate aerodynamic lift to reduce the blow-by.

Abstract

Purpose

This paper aims to optimize the mass of a tethered aerostat to achieve optimum hull volume, and fins to generate aerodynamic lift to reduce the blow-by.

Design/methodology/approach

The design code of aerostat involving structure, aerostatics, aerodynamics and stability has been developed using MATLAB®. The design code is used to obtain the baseline configuration for a tactical aerostat mission by using the statistical values of the hull fineness ratio and the fin parameters of in-service aerostats. The effect of the design variables that include the hull fineness ratio, fin area and fin position on the aerostat mass and blow-by is determined through sensitivity analysis. The aerostat is optimized with an objective function of minimization of mass for the bounded values of design variables and taking blow-by limit as a constraint.

Findings

This study reveals that the simultaneous optimization of the aerostat hull fineness ratio, fin area and fin position results in an improvement in the design. The aerostat design with optimum values of these parameters helps in a reduction in its size and mass without compromising the blow-by limits.

Research limitations/implications

This study has been conducted by keeping the hull shape constant by selecting standard National Physics Laboratory envelope shape. The aerodynamic model used in the design code is based on empirical relationships that can be improved in future studies that can use high fidelity aerodynamic models using CFD based surrogate models.

Originality/value

The previous studies on optimization of aerostats are limited to hull envelope shape only, whereas this paper presents the optimization of the hull and fin together. The optimized configuration obtained has a reduced mass and can operate within the specified blow-by limits.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 4
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 5 April 2019

Agnieszka Kwiek

The purpose of this paper is to present the results of a conceptual design of Martian aircraft. This study focuses on the aerodynamic and longitudinal dynamic stability

Abstract

Purpose

The purpose of this paper is to present the results of a conceptual design of Martian aircraft. This study focuses on the aerodynamic and longitudinal dynamic stability analysis. The main research questions are as follows: Does a tailless aircraft configuration can be used for Martian aircraft? How to the short period characteristic can be improved by side plates modification?

Design/methodology/approach

Because of a conceptual design stage of this Martian aircraft, aerodynamic characterises were computed by the Panukl package by using the potential flow model. The longitudinal dynamic stability was computed by MATLAB code, and the derivatives computed by the SDSA software were used as the input data. Different aircraft configurations have been studied, including different wing’s aerofoils and configurations of the side plate.

Findings

This paper presents results of aerodynamic characteristics computations and longitudinal dynamic stability analysis. This paper shows that tailless aircraft configuration has potential to be used as Martian aircraft. Moreover, the study of the impact of side plates’ configurations on the longitudinal dynamic stability is presented. This investigation reveals that the most effective method to improve the short period damping ratio is to change the height of the bottom plate.

Practical implications

The presented result might be useful in case of further design of the aircrafts for the Mars mission and designing the aircrafts in a tailless configuration.

Social implications

It is considered by the human expedition that Mars is the most probable planet to explore. This paper presents the conceptual study of aircraft which can be used to take the high-resolution pictures of the surface of Mars, which can be crucial to find the right place to establish a potential Martian base.

Originality/value

Most of aircrafts proposed for the Mars mission are designed in a configuration with a classic tail; this paper shows a preliminary calculation of the tailless Martian aircraft. Moreover, this paper shows the results of a dynamic stability analysis, where similar papers about aircrafts for the Mars mission do not show such outcomes, especially in the case of the tailless configuration. Moreover, this paper presents the results of the dynamic stability analysis of tailless aircraft with different configurations of the side plates.

Details

Aircraft Engineering and Aerospace Technology, vol. 91 no. 6
Type: Research Article
ISSN: 1748-8842

Keywords

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