Search results

1 – 6 of 6
To view the access options for this content please click here
Article
Publication date: 25 January 2021

Mohamed Arif Raj Mohamed, Rajesh Yadav and Ugur Guven

This paper aims to achieve an optimum flow separation control over the airfoil using a passive flow control method by introducing a bio-inspired nose near the leading edge…

Abstract

Purpose

This paper aims to achieve an optimum flow separation control over the airfoil using a passive flow control method by introducing a bio-inspired nose near the leading edge of the National Advisory Committee for Aeronautics (NACA) 4 and 6 series airfoil. In addition, to find the optimised leading edge nose design for NACA 4 and 6 series airfoils for flow separation control.

Design/methodology/approach

Different bio-inspired noses that are inspired by the cetacean species have been analysed for different NACA 4 and 6 series airfoils. Bio-inspired nose with different nose length, nose depth and nose circle diameter have been analysed on airfoils with different thicknesses, camber and camber locations to understand the aerodynamic flow properties such as vortex formation, flow separation, aerodynamic efficiency and moment.

Findings

The porpoise nose design that has a leading edge with depth = 2.25% of chord, length = 0.75% of chord and nose diameter = 2% of chord, delays the flow separation and improves the aerodynamic efficiency. Average increments of 5.5% to 6° in the lift values and decrements in parasitic drag (without affecting the pitching moment) for all the NACA 4 and 6 series airfoils were observed irrespective of airfoil geometry such as different thicknesses, camber and camber location.

Research limitations/implications

The two-dimensional computational analysis is done for different NACA 4 and 6 series airfoils at low subsonic speed.

Practical implications

This design improves aerodynamic performance and increases the structural strength of the aircraft wing compared to other conventional high lift devices and flow control devices. This universal leading edge flow control device can be adapted to aircraft wings incorporated with any NACA 4 and 6 series airfoil.

Social implications

The results would be of significant interest in the fields of aircraft design and wind turbine design, lowering the cost of energy and air travel for social benefits.

Originality/value

Different bio-inspired nose designs that are inspired by the cetacean species have been analysed for NACA 4 and 6 series airfoils and universal optimum nose design (porpoise airfoil) is found for NACA 4 and 6 series airfoils.

To view the access options for this content please click here
Article
Publication date: 20 June 2019

Mohamed Arif Raj Mohamed, Ugur Guven and Rajesh Yadav

The purpose of this paper is to achieve an optimum flow separation control over the airfoil using passive flow control method by introducing bio-inspired nose near the…

Abstract

Purpose

The purpose of this paper is to achieve an optimum flow separation control over the airfoil using passive flow control method by introducing bio-inspired nose near the leading edge of the NACA 2412 airfoil.

Design/methodology/approach

Two distinguished methods have been implemented on the leading edge of the airfoil: forward facing step, which induces multiple accelerations at low angle of attack, and cavity/backward facing step, which creates recirculating region (axial vortices) at high angle of attack.

Findings

The porpoise airfoil (optimum bio-inspired nose airfoil) delays the flow separation and improves the aerodynamic efficiency by increasing the lift and decreasing the parasitic drag. The maximum increase in aerodynamic efficiency is 22.4 per cent, with an average increase of 8.6 per cent at all angles of attack.

Research limitations/implications

The computational analysis has been done for NACA 2412 airfoil at low subsonic speed.

Practical implications

This design improves the aerodynamic performance and increases structural strength of the aircraft wing compared to other conventional high-lift devices and flow-control devices.

Originality/value

Different bio-inspired nose designs which are inspired by the cetacean species have been analysed for NACA 2412 airfoil, and optimum nose design (porpoise airfoil) has been found.

Details

Aircraft Engineering and Aerospace Technology, vol. 91 no. 7
Type: Research Article
ISSN: 1748-8842

Keywords

To view the access options for this content please click here
Article
Publication date: 2 January 2020

Abderahmane Marouf, Yannick Bmegaptche Tekap, Nikolaos Simiriotis, Jean-Baptiste Tô, Jean-François Rouchon, Yannick Hoarau and Marianna Braza

The purpose of this study illustrates the morphing effects around a large-scale high-lift configuration of the Airbus A320 with two elements airfoil-flap in the take-off…

Abstract

Purpose

The purpose of this study illustrates the morphing effects around a large-scale high-lift configuration of the Airbus A320 with two elements airfoil-flap in the take-off position. The flow around the airfoil-flap and the near wake are analysed in the static case and under time-dependent vibration of the flap trailing-edge known as the dynamic morphing.

Design/methodology/approach

Experimental results obtained in the subsonic wind tunnel S1 of Institut de Mécanique des Fluides de Toulouse of a single wing are discussed with high-fidelity numerical results obtained by using the Navier–Stokes multi-block (NSMB) code with advanced turbulent modelling able to capture the predominant instabilities and coherent structure dynamics. An explanation of the dynamic time-dependent grid deformation is provided, which is used in the NSMB code to simulate the flap’s trailing-edge deformation in the morphing configuration. Finally, power spectral density is performed to reveal the coherent wake structures and their modification because of the morphing.

Findings

Frequency of vibration and amplitude of deformation effects are investigated for different morphing cases. Optimal morphing regions at a specific frequency and a slight deformation were able to attenuate the predominant natural shear-layer frequency and to considerably decrease the width of the von Kármán vortices with a simultaneous increase of aerodynamic performances.

Originality/value

The new concept of future morphed wings is proposed for a large scale A320 prototype at the take-off position. The dynamic morphing of the flap’s trailing-edge is simulated for the first time for high-lift two-element configuration. In addition, the wake analysis performed helped to show the turbulent structures according to the organised eddy simulation model.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 31 no. 2
Type: Research Article
ISSN: 0961-5539

Keywords

To view the access options for this content please click here
Article
Publication date: 2 March 2015

Ramy Harik, Alipio Nicolas, Mohamed Dassouki and Alain Bernard

Biomimetic study existing natural biological elements to produce engineering products with similar performance and abilities. The purpose of this paper is to highlight…

Abstract

Purpose

Biomimetic study existing natural biological elements to produce engineering products with similar performance and abilities. The purpose of this paper is to highlight biomimetic studies to produce a new type of airplanes: adding remiges, bending ability and flapping mechanisms.

Design/methodology/approach

The used methodology was to thoroughly investigate the literature, to define the proper endurance and fatigue parameters, to perform a series of numerical studies and report improvement percentages relevant to defined parameters.

Findings

By adding remiges and the bending mechanism, the authors managed to reach – numerically – the preset desired structure goal. Efficiency increased using remiges with less drag force. In addition, with the help of the bending wing technique, the drag force was improved. The flapping mechanism showed high vibration rates. Last but not least, applying multiple winglets gave a better optimization of the endurance parameter.

Research limitations/implications

Research is conducted at a university without any research facilities. No laboratories exist, and acquiring research papers is mostly difficult and costly.

Originality/value

The research study is original in the sense of its numerical investigation. Proposing biomimetic was at the heart of the airplane invention and cannot be stated as an original contribution. Rather the field has been recently abandoned, and performing this major literature review can be considered as original in a sense it summarizes recent to somewhat old advancement.

Details

Engineering Computations, vol. 32 no. 1
Type: Research Article
ISSN: 0264-4401

Keywords

To view the access options for this content please click here
Article
Publication date: 22 October 2020

Rawad Himo, Charbel Bou-Mosleh and Charbel Habchi

Flow separation on wings, blades and vehicles can be delayed or even suppressed by the use of vortex generators (VG). Numerous studies, documented in the literature…

Abstract

Purpose

Flow separation on wings, blades and vehicles can be delayed or even suppressed by the use of vortex generators (VG). Numerous studies, documented in the literature, extensively describe the performance of triangular and rectangular VG winglets. This paper aims to focus on the use of non-conventional VG shapes, more specifically an array of trapezoildal-perforated VG tabs.

Design/methodology/approach

In this study, computational fluid dynamic simulations are performed on an inline array of trapezoidal VG with various dimensions and inclination angles, in addition to considering perforations in the VG centers. The methodology of the present numerical study is validated with experimental data from the literature.

Findings

The performance and the associated flow structures of these tested non-conventional VG are compared to classical triangular winglets. For the proposed non-conventional trapezoidal VG, at the onset of stall, a 21% increase of lift over drag on the airfoil is observed. The trapezoidal VG enhancement is also witnessed during stall where the lift over drag ratio is increased by 120% for the airfoil and by 10% with respect to the triangular winglets documented in the literature.

Originality/value

The originality of this paper is the use of non-conventional vortex generator shape to enhance lift over drag coefficient using three-dimensional numerical simulations.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 1
Type: Research Article
ISSN: 1748-8842

Keywords

To view the access options for this content please click here
Article
Publication date: 17 October 2016

Zhengxing Wu, Junzhi Yu, Jun Yuan and Min Tan

This paper aims to propose a novel design concept for a biomimetic dolphin-like underwater glider, which can offer the advantages of both robotic dolphins and underwater…

Abstract

Purpose

This paper aims to propose a novel design concept for a biomimetic dolphin-like underwater glider, which can offer the advantages of both robotic dolphins and underwater gliders to achieve high-maneuverability, high-speed and long-distance motions.

Design/methodology/approach

To testify the gliding capability of dolphin-like robot without traditional internal movable masses, the authors first developed a skilled and simple dolphin-like prototype with only gliding capability. The hydrodynamic coefficients, including lift, drag and pitching moment, are obtained through computational fluid dynamics method, and the hydrodynamic analysis in the steady gliding motion is also executed.

Findings

Experimental results have shown that the dolphin-like glider could successfully glide depending on the pitching torques only from buoyancy-driven system and controllable fins without traditional internal moveable masses.

Originality/value

A hybrid underwater glider scheme that combines robotic dolphin and glider is firstly proposed, shedding light on the creation of innovation gliders with maneuverability and durability.

Details

Industrial Robot: An International Journal, vol. 43 no. 6
Type: Research Article
ISSN: 0143-991X

Keywords

1 – 6 of 6