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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 leading…

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

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 of the…

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.

Article
Publication date: 2 December 2022

Mohamed Arif Raj Mohamed, Ketu Satish Kumar Reddy and Somaraju Sai Sri Vishnu

The high lift devices are effective at high angle of attack to increase the coefficient of lift by increasing the camber. But it affects the low angle of attack aerodynamic…

Abstract

Purpose

The high lift devices are effective at high angle of attack to increase the coefficient of lift by increasing the camber. But it affects the low angle of attack aerodynamic performance by increasing the drag. Hence, they have made as a movable device to deploy only at high angles of attack, which increases the design and installation complexities. This study aims to focus on the comparison of aerodynamic efficiency of different conventional leading edge (LE) slat configurations with simple fixed bioinspired slat design.

Design/methodology/approach

This research analyzes the effect of LE slat on aerodynamic performance of CLARK Y airfoil at low and high angles of attack. Different geometrical parameters such as slat chord, cutoff, gap, width and depth of LE slat have been considered for the analysis.

Findings

It has been found that the LE slat configuration with slat chord 30% of airfoil chord, forward extension 8% of chord, dip 3% of chord and gap 0.75% of chord gives higher aerodynamic efficiency (Cl/Cd) than other LE slat configurations, but it affects the low angles of attack aerodynamic performance with the deployed condition. Hence, this optimum slat configuration is further modified by closing the gap between LE slat and the main airfoil, which is inspired by the marine mammal’s nose. Thus increases the coefficient of lift at high angles of attack due to better acceleration over the airfoil nose and as well enhances the aerodynamic efficiency at low angles of attack.

Research limitations/implications

The two-dimensional computational analysis has been done for different LE slat’s geometrical parameters at low subsonic speed.

Practical implications

This bio-inspired nose design improves aerodynamic performance and increases the structural strength of aircraft wing compared to the conventional LE slat. This fixed design avoids the complex design and installation difficulties of conventional movable slats.

Social implications

The findings will have significant impact on the fields of aircraft wing and wind turbine designs, which reduces the design and manufacturing complexities.

Originality/value

Different conventional slat configurations have been analyzed and compared with a simple fixed bioinspired slat nose design at low subsonic speed.

Details

Aircraft Engineering and Aerospace Technology, vol. 95 no. 5
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 3 July 2017

Leifur Leifsson and Slawomir Koziel

The purpose of this paper is to reduce the overall computational time of aerodynamic shape optimization that involves accurate high-fidelity simulation models.

Abstract

Purpose

The purpose of this paper is to reduce the overall computational time of aerodynamic shape optimization that involves accurate high-fidelity simulation models.

Design/methodology/approach

The proposed approach is based on the surrogate-based optimization paradigm. In particular, multi-fidelity surrogate models are used in the optimization process in place of the computationally expensive high-fidelity model. The multi-fidelity surrogate is constructed using physics-based low-fidelity models and a proper correction. This work introduces a novel correction methodology – referred to as the adaptive response prediction (ARP). The ARP technique corrects the low-fidelity model response, represented by the airfoil pressure distribution, through suitable horizontal and vertical adjustments.

Findings

Numerical investigations show the feasibility of solving real-world problems involving optimization of transonic airfoil shapes and accurate computational fluid dynamics simulation models of such surfaces. The results show that the proposed approach outperforms traditional surrogate-based approaches.

Originality/value

The proposed aerodynamic design optimization algorithm is novel and holistic. In particular, the ARP correction technique is original. The algorithm is useful for fast design of aerodynamic surfaces using high-fidelity simulation data in moderately sized search spaces, which is challenging using conventional methods because of excessive computational costs.

Article
Publication date: 4 July 2008

Parsaoran Hutapea, Jinho Kim, Andrew Guion, Charlie Hanna and Noah Heulitt

The objective of this paper is to develop an actuation system utilizing smart materials such as shape memory alloys (SMA) to control the position of an aircraft's flaps.

1435

Abstract

Purpose

The objective of this paper is to develop an actuation system utilizing smart materials such as shape memory alloys (SMA) to control the position of an aircraft's flaps.

Design/methodology/approach

The proposed smart wing consisted of SMA springs that were fixed at one end to the wing box toward the leading edge of the airfoil. The other end of each spring was attached tangentially to a rotating cylinder fixed to the flap. The springs were arranged in an upper and a lower layer to cause rotation of the flap in both the upward and downward directions. The spring actuators were controlled by the introduction of heat resulting from the applied current. A prototype of the smart wing was developed and tested to demonstrate the design concept.

Findings

A prototype of a smart actuation system for controlling the flaps of an aircraft was successfully developed. Through the experimental and theoretical analyses conducted, the design was validated and showed strong potential for future application.

Practical implications

The proposed concept can be applied to other aircraft systems such as ailerons, slats, rudders and elevators.

Originality/value

The prototype of a smart wing is unique. It utilizes smart materials for aircraft flap actuation. The concept can be applied on ailerons, slats, rudders and elevators.

Details

Aircraft Engineering and Aerospace Technology, vol. 80 no. 4
Type: Research Article
ISSN: 0002-2667

Keywords

Article
Publication date: 1 June 2022

Somashekar V. and Immanuel Selwynraj A.

The heatwave effects over an airfoil have a greater influence in the aerodynamic efficiency. The purpose of this study is to investigate the effects of heatwave upon the low…

Abstract

Purpose

The heatwave effects over an airfoil have a greater influence in the aerodynamic efficiency. The purpose of this study is to investigate the effects of heatwave upon the low Reynolds number airfoil aerodynamic performance.

Design/methodology/approach

In this research, the heatwave effects on micro-aerial vehicles’ wing operation are also demonstrated both numerically and experimentally, at the Chord-based Reynolds number Rec = 2 × 105, and under the influence of various environmental temperatures, i.e. 27ºC (room temperature), 40ºC and 50ºC for various flying conditions. A numerical investigation of the low Reynolds number flows with the thermal effect around the unmanned aerial vehicle is presented using the k–ɛ turbulent model. Besides that, the low Reynolds number-based wind tunnel experimental setup is developed to determine the effects of a heatwave over an airfoil. Then, the numerical simulations and wind tunnel experiments are conducted.

Findings

The numerical and wind tunnel’s experimental investigations have been performed on a 2D airfoil under a heatwave environment, i.e. 27ºC, 40ºC and 50ºC for different flight conditions. The numerical and experimental results revealed that the heatwave effect and aerodynamic performance are validated with experimental results. The lift and drag coefficients for both numerical and experimental results show very good correlation at Reynolds number 2 × 105.

Practical implications

The consequences of the increasing temperatures to varying degrees will also be experienced by all commercial aircraft. That is why some great findings are presented here, which are highly relevant for the current and future airline operations. However, sooner than later, the aviation industry should also begin to consider the rising effects of temperature on aircraft operations to develop the loss-reducing adaptable plans.

Originality/value

From the numerical and wind tunnel experimental results, the recorded maximum lift coefficients are observed to be 2.42, 2.39 and 2.36 for 27ºC (room temperature), 40ºC and 50ºC, respectively, at 16° angle of attack, numerically. Similarly, the recorded maximum lift coefficients are observed to be 2.410, 2.382 and 2.354 for 27ºC (room temperature), 40ºC and 50ºC, respectively, at 16° angle of attack, experimentally. The heatwave effects over an airfoil have a greater influence in the aerodynamic efficiency.

Details

Aircraft Engineering and Aerospace Technology, vol. 95 no. 1
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 1 August 1966

H.D. Ruben

THE B.206 had its origin in the B.206X experimental aircraft which was built in 1961 to obtain aerodynamic and structural data for the production series, and it first flew in…

Abstract

THE B.206 had its origin in the B.206X experimental aircraft which was built in 1961 to obtain aerodynamic and structural data for the production series, and it first flew in August 1961.

Details

Aircraft Engineering and Aerospace Technology, vol. 38 no. 8
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 1 May 1965

Rendering fluid flow visible can be of great help in the teaching of Mechanics of Fluids and Aerodynamics. A smoke tunnel for lecture demonstrations was developed at a leading…

Abstract

Rendering fluid flow visible can be of great help in the teaching of Mechanics of Fluids and Aerodynamics. A smoke tunnel for lecture demonstrations was developed at a leading university and, since others wanted it, the design was passed to Plint and Partners Ltd, who now manufacture it. The unit is simple to operate and is mobile, while the smoke produced is non‐toxic and insufficient in quantity to be objectionable. A general view is shown in FIGURE 1.

Details

Education + Training, vol. 7 no. 5
Type: Research Article
ISSN: 0040-0912

Article
Publication date: 12 August 2014

Odeh Dababneh and Altan Kayran

In modeling an aircraft wing, structural idealizations are often employed in hand calculations to simplify the structural analysis. In real applications of structural design…

Abstract

Purpose

In modeling an aircraft wing, structural idealizations are often employed in hand calculations to simplify the structural analysis. In real applications of structural design, analysis and optimization, finite element methods are used because of the complexity of the geometry, combined and complex loading conditions. The purpose of this paper is to give a comprehensive study on the effect of using different structural idealizations on the design, analysis and optimization of thin walled semi-monocoque wing structures in the preliminary design phase.

Design/methodology/approach

In the design part of the paper, wing structures are designed by employing two different structural idealizations that are typically used in the preliminary design phase. In the structural analysis part, finite element analysis of one of the designed wing configurations is performed using six different one and two dimensional finite element pairs which are typically used to model the sub-elements of semi-monocoque wing structures. Finally in the optimization part, wing structure is optimized for minimum weight by using finite element models which have the same six different finite element pairs used in the analysis phase.

Findings

Based on the results presented in the paper, it is concluded that with the simplified methods, preliminary sizing of the wing configurations can be performed with enough confidence as long as the simplified method based designs are also optimized iteratively, which is what is practiced in the design phase of this study.

Originality/value

This research aims at investigating the effect of using different one and two dimensional element pairs on the final analyzed and optimized configurations of the wing structure, and conclusions are inferred with regard to the sensitivity of the optimized wing configurations with respect to the choice of different element types in the finite element model.

Details

International Journal of Structural Integrity, vol. 5 no. 3
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 11 June 2020

José Francisco Villarreal Valderrama, Luis Takano, Eduardo Liceaga-Castro, Diana Hernandez-Alcantara, Patricia Del Carmen Zambrano-Robledo and Luis Amezquita-Brooks

Aircraft pitch control is fundamental for the performance of micro aerial vehicles (MAVs). The purpose of this paper is to establish a simple experimental procedure to calibrate…

Abstract

Purpose

Aircraft pitch control is fundamental for the performance of micro aerial vehicles (MAVs). The purpose of this paper is to establish a simple experimental procedure to calibrate pitch instrumentation and classical control algorithms. This includes developing an efficient pitch angle observer with optimal estimation and evaluating controllers under uncertainty and external disturbances.

Design/methodology/approach

A wind tunnel test bench is designed to simulate fixed-wing aircraft dynamics. Key elements of the instrumentation commonly found in MAVs are characterized in a gyroscopic test bench. A data fusion algorithm is calibrated to match the gyroscopic test bench measurements and is then integrated into the autopilot platform. The elevator-angle to pitch-angle dynamic model is obtained experimentally. Two different control algorithms, based on model-free and model-based approaches, are designed. These controllers are analyzed in terms of parametric uncertainties due to wind speed variations and external perturbation because of sudden weight distribution changes. A series of experimental tests is performed in wind-tunnel facilities to highlight the main features of each control approach.

Findings

With regard to the instrumentation algorithms, a simple experimental methodology for the design of optimal pitch angle observer is presented and validated experimentally. In the context of the platform design and identification, the similitude among the theoretical and experimental responses shows that the platform is suitable for typical pitch control assessment. The wind tunnel experiments show that a fixed linear controller, designed using classical frequency domain concepts, is able to provide adequate responses in scenarios that approximate the operation of MAVs.

Research limitations/implications

The aircraft orientation observer can be used for both pitch and roll angles. However, for simultaneousyaw angle estimation the proposed design method requires further research. The model analysis considers a wind speed range of 6-18 m/s, with a nominal operation of 12 m/s. The maximum experimentally tested reference for the pitch angle controller was 20°. Further operating conditions may require more complex control approaches (e.g. scheduling, non-linear, etc.). However, this operating range is enough for typical MAV missions.

Originality/value

The study shows the design of an effective pitch angle observer, based on a simple experimental approach, which achieved locally optimum estimates at the test conditions. Additionally, the instrumentation and design of a test bench for typical pitch control assessment in wind tunnel facilities is presented. Finally, the study presents the development of a simple controller that provides adequate responses in scenarios that approximate the operation of MAVs, including perturbations that resemble package delivery and parametric uncertainty due to wind speed variations.

Details

Aircraft Engineering and Aerospace Technology, vol. 92 no. 7
Type: Research Article
ISSN: 1748-8842

Keywords

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