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Article
Publication date: 24 November 2020

Hyoung Seog Chung, Seung Pil Kim and Younseok Choi

The purpose of this paper is to propose a new approach of using additively manufactured parametric models in the wind tunnel test-based aerodynamic shape optimization…

Abstract

Purpose

The purpose of this paper is to propose a new approach of using additively manufactured parametric models in the wind tunnel test-based aerodynamic shape optimization (ASO) framework and to present its applicability test results obtained from a realistic aircraft design problem.

Design/methodology/approach

For aircraft shape optimization, the following three methodologies were used. First, as a validation study, the possibility of using rapid prototyping (RP) model in the wind tunnel test was verified. Second, through the wind tunnel test-based ASO, the application and feasibility of the real fighter aircraft shape optimization were verified. A generic fighter configuration is parameterized to generate various test models using additive manufacturing. Wind tunnel tests are conducted to measure their stability criteria in high angle of attack (AOA). Finally, a computational fluid dynamics (CFD) study was performed and analysis procedures, costs and results compared to the wind tunnel test were compared and reviewed.

Findings

RP technology can significantly reduce the time and cost of generating parametric wind tunnel models and can open up new possibilities for wind tunnel tests to be used in the rigorous aerodynamic design loop. There was a slight difference between the results of the RP model and the metallic model because of rigidity and surface roughness. However, the tendency of the aerodynamic characteristics was very similarly predictable. Although there are limitations to obtaining precise aerodynamic data, it is a suitable method to be applied to comparative studies on various shapes with large geo-metric changes in the early phase of design. The CFD analysis indicates that the wind tunnel-based ASO using the RP model shows the efficiency corresponding to the CFD shape optimization.

Research limitations/implications

The RP parametric models may have various assembly error sources and rigidity problems. The proposed methodology may not be suitable for collecting the accurate aerodynamic database of a final design; rather, the methodology is more suitable to screen out many configurations having fairly large shape variation in the early stage of the design process.

Practical implications

The wind tunnel test-based ASO can replace or supplement CFD-based ASO. In areas where CFD accuracy is low, such as high AOA flight characteristics, RP model wind tunnel-based ASO can be a research method that can secure both efficiency and accuracy advantages, providing ten times more effective in terms of cost and time. The wind tunnel test is used to obtain aerodynamic data at the final stage of shape design. It can be extended to a comparative study of several shapes in the early design phase. This procedure can be applied for both industrial level and educational aircraft design activities.

Originality/value

This study is the application to be applied as a parametric study on the whole aircraft, rather than using the RP model applying a simple partial control surface or configuration change of a part of the wing. The possibility of using the RP model was confirmed by comparing and verifying each other in a medium-sized wind tunnel using a relatively large RP model and a metallic model. It was verified that it can be applied in the shape design process, not the shape verification in the traditional design procedure, and a comparison with the CFD method was also performed. With further development and validation efforts, the new design framework may become an industrial standard for future aircraft development.

Details

Rapid Prototyping Journal, vol. 27 no. 1
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 19 January 2015

Chao Wang, Guofu Yin, Zhengyu Zhang, Shuiliang Wang, Tao Zhao, Yan Sun and Dangguo Yang

– The purpose of this paper is to introduce a novel method for developing static aeroelastic models based on rapid prototyping for wind tunnel testing.

Abstract

Purpose

The purpose of this paper is to introduce a novel method for developing static aeroelastic models based on rapid prototyping for wind tunnel testing.

Design/methodology/approach

A metal frame and resin covers are applied to a static aeroelastic wind tunnel model, which uses the difference of metal and resin to achieve desired stiffness distribution by the stiffness similarity principle. The metal frame is made by traditional machining, and resin covers are formed by stereolithgraphy. As demonstrated by wind tunnel testing and stiffness measurement, the novel method of design and fabrication of the static aeroelastic model based on stereolithgraphy is practical and feasible, and, compared with that of the traditional static elastic model, is prospective due to its lower costs and shorter period for its design and production, as well as avoiding additional stiffness caused by outer filler.

Findings

This method for developing static aeroelastic wind tunnel model with a metal frame and resin covers is feasible, especially for aeroelastic wind tunnel models with complex external aerodynamic shape, which could be accurately constructed based on rapid prototypes in a shorter time with a much lower cost. The developed static aeroelastic aircraft model with a high aspect ratio shows its stiffness distribution in agreement with the design goals, and it is kept in a good condition through the wind tunnel testing at a Mach number ranging from 0.4 to 0.65.

Research limitations/implications

The contact stiffness between the metal frame and resin covers is difficult to calculate accurately even by using finite element analysis; in addition, the manufacturing errors have some effects on the stiffness distribution of aeroelastic models, especially for small-size models.

Originality/value

The design, fabrication and ground testing of aircraft static aeroelastic models presented here provide accurate stiffness and shape stimulation in a cheaper and sooner way compared with that of traditional aeroelastic models. The ground stiffness measurement uses the photogrammetry, which can provide quick, and precise, evaluation of the actual stiffness distribution of a static aeroelastic model. This study, therefore, expands the applications of rapid prototyping on wind tunnel model fabrication, especially for the practical static aeroelastic wind tunnel tests.

Details

Rapid Prototyping Journal, vol. 21 no. 1
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 11 January 2013

Yang Dang‐guo, Sun Yan, Zhang Zheng‐yu, Wang Chao and Zhu Wei‐jun

The purpose of this paper is to present a novel method to design and manufacture rapid prototyping (RP) lightweight photopolymer‐resin models for windtunnel tests. This…

Abstract

Purpose

The purpose of this paper is to present a novel method to design and manufacture rapid prototyping (RP) lightweight photopolymer‐resin models for windtunnel tests. This method can ensure the structural configuration similarity considering model deformation under aerodynamic loads.

Design/methodology/approach

Photopolymer‐resin based on RP technique was used to fabricate DLR‐F4 models. Testing in a subsonic and transonic wind tunnel was carried out and the test results were compared to analyze performance predictions.

Findings

RP photopolymer‐resin windtunnel models fabricated by the design methods yielded satisfactory aerodynamic performance. The methods can decrease the model's weight and prevent resonance occurrence among the models, windtunnel, and support system, shorten the processing period, and lead to decrease in manufacturing period and cost.

Research limitations/implications

Stiffness shortage of the thin components, such as wing tip, often leads to deformation occurrence under aerodynamic loads in transonic windtunnel tests, which has significant influence on aerodynamic characteristics of the test models. Therefore, model deformation should be taken into account in the design process.

Originality/value

This design and manufacture method, aerodynamic and structural combination design and structural optimization, can obtain RP lightweight photopolymer‐resin windtunnel models for satisfactory aerodynamic performance, which makes RP techniques more practical for manufacturing transonic windtunnel test models, considering deformation induced by aerodynamic forces such as lift force. The methods also present an inexpensive way to test and evaluate preliminary aircraft designs, in both academia and industry.

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Article
Publication date: 1 September 1939

F.L. Wattendorf

THE Tsing Hua 15‐ft. wind tunnel, with interchangeable 18‐ft. section for full scale engine and airscrew tests, was recently erected in Central China. It was planned as…

Abstract

THE Tsing Hua 15‐ft. wind tunnel, with interchangeable 18‐ft. section for full scale engine and airscrew tests, was recently erected in Central China. It was planned as the central organ for aerodynamic research in China and, as such, was subject to interesting design conditions. The main features of the tunnel design, as well as the considerations underlying their choice, are described in this article.

Details

Aircraft Engineering and Aerospace Technology, vol. 11 no. 9
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 8 September 2021

Bilal Malik, Jehanzeb Masud and Suhail Akhtar

This paper aims to provide a detailed review of the experimental research on the prediction of aircraft spin and recovery characteristics using dynamically scaled aircraft models.

Abstract

Purpose

This paper aims to provide a detailed review of the experimental research on the prediction of aircraft spin and recovery characteristics using dynamically scaled aircraft models.

Design/methodology/approach

The paper organizes experimental techniques to predict aircraft spin and recovery characteristics into three broad categories: dynamic free-flight tests, dynamic force tests and a relatively novel technique called wind tunnel based virtual flight testing.

Findings

After a thorough review, usefulness, limitations and open problems in the presented techniques are highlighted to provide a useful reference to researchers. The area of application of each technique within the research scope of aircraft spin is also presented.

Originality/value

Previous reviews on the prediction of aircraft spin and recovery characteristics were published many years ago and also have confined scope as they address particular spin technologies. This paper attempts to provide a comprehensive review on the subject and fill the information void regarding the state of the art aircraft spin technologies.

Details

Aircraft Engineering and Aerospace Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 2 August 2011

Ehud Kroll and Dror Artzi

The purpose of this paper is to present the benefits offered by rapid prototyping (RP) models for windtunnel testing as part of fourth‐year aerospace engineering student…

Abstract

Purpose

The purpose of this paper is to present the benefits offered by rapid prototyping (RP) models for windtunnel testing as part of fourth‐year aerospace engineering student projects. Ways of overcoming some of the difficulties associated with the 3D printing technology are also discussed.

Design/methodology/approach

Polymer‐based RP was used to fabricate two‐aircraft models, which included stiffening metallic inserts. Testing in a subsonic‐wind tunnel was carried out and the results compared to analytic performance predictions.

Findings

Low‐cost rapid prototypes of windtunnel models yielded satisfactory aerodynamic performance. The savings in acquisition cost and time allowed incorporating actual testing in the aircraft design process within the framework of a tight academic budget and schedule.

Practical implications

Conducting real‐windtunnel testing contributes significantly to the educational experience of students; however, it had rarely been carried out when metal model fabrication was the only option. In contrast, RP facilitates an enhanced and more realistic learning experience by offering a quick and affordable means of model manufacturing.

Originality/value

Simple methods of reinforcing polymer‐based models were incorporated, thus presenting an inexpensive way to test and evaluate preliminary aircraft designs, in both academia and industry.

Details

Rapid Prototyping Journal, vol. 17 no. 5
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 18 January 2011

Yang Dang‐guo, Zhang Zheng‐yu, Sun Yan and Zhu Wei‐jun

In view of the strength and stiffness deficiencies of current photopolymer resin models under high aerodynamic loads, the purpose of this paper is to introduce a…

Abstract

Purpose

In view of the strength and stiffness deficiencies of current photopolymer resin models under high aerodynamic loads, the purpose of this paper is to introduce a preliminary design and manufacturing technique for hybrid lightweight high‐speed windtunnel models with internal metal frame and surface photopolymer resin based on rapid prototyping (RP).

Design/methodology/approach

Internal metal frame structure was designed to be of regular configurations that can be conveniently fabricated by conventionally mechanical manufacturing methods. Outer resin components were designed to meet configuration fidelity and surface quality, which were fabricated by RP apparatus. Combination of aerodynamics and structure was utilized to accomplish structural design, strength and stiffness calibration and vibration analysis. Structural design optimization and manufacturing method of the validated hybrid AGARD‐B models were studied by analysis of manufacturing precision, surface quality processing and mechanical capability.

Findings

The method with internal metal frame and outer resin has dramatically improved the overall strength and stiffness of RP parts of the hybrid AGARD‐B model, and it is suitable to construct the high‐speed windtunnel models with complex internal structure. The method could decrease the model's weight and prevent resonance occurrence among the models, windtunnel and support system, and shorten processing period, and also it leads to decrease in manufacturing period and cost.

Research limitations/implications

Stiffness of thin components for outer resin configuration is somewhat poor under high aerodynamic loads in a high‐speed windtunnel test, and the effect of deformation of the components on the experimental results should be taken into account.

Originality/value

This method can enhance the versatility of using RP technique in the fabrication of high‐speed windtunnel models, especially for experimental models with complex structure. Aerodynamic and structural combination design and structural optimization for hybrid models make RP techniques more practical for manufacturing high‐speed windtunnel models.

Details

Rapid Prototyping Journal, vol. 17 no. 1
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 1 February 1932

Carl J. Wenzinger and Thomas A. Harris

SOME of the major problems under investigation by the National Advisory Committee for Aeronautics may be placed under the general heading of safety in flight. One of the…

Abstract

SOME of the major problems under investigation by the National Advisory Committee for Aeronautics may be placed under the general heading of safety in flight. One of the most important of these problems is the study of spinning, both in the wind tunnel and in free flight. In the usual horizontal type of wind tunnel, however, considerable difficulty is encountered in making spinning tests of aeroplane models, owing to the force of gravity acting with the rotation for part of a revolution and against the rotation for the remainder. This condition tends to give oscillating readings on the measuring apparatus and can be avoided only by very careful counterbalancing of the spinning model and balance parts. This undesirable feature can be overcome by locating the spin axis in the vertical rather than in the horizontal position, because the effect of gravity on the spin apparatus is then constant. In addition, a vertical type of tunnel requires much less floor space than the horizontal type of the same jet diameter.

Details

Aircraft Engineering and Aerospace Technology, vol. 4 no. 2
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 30 August 2018

Z.W. Teo, T.H. New, Shiya Li, T. Pfeiffer, B. Nagel and V. Gollnick

This paper aims to report on the physical distortions associated with the use of additive manufactured components for wind tunnel testing and procedures adopted to correct…

Abstract

Purpose

This paper aims to report on the physical distortions associated with the use of additive manufactured components for wind tunnel testing and procedures adopted to correct for them.

Design/methodology/approach

Wings of a joined-wing test aircraft configuration were fabricated with additive manufacturing and tested in a subsonic closed-loop wind tunnel. Wing deflections were observed during testing and quantified using image-processing procedures. These quantified deflections were then incorporated into numerical simulations and results had agreed with wind tunnel measurement results.

Findings

Additive manufacturing provides cost-effective wing components for wind tunnel test components with fast turn-around time. They can be used with confidence if the wing deflections could be accounted for systematically and accurately, especially at the region of aerodynamic stall.

Research limitations/implications

Significant wing flutter and unsteady deflections were encountered at higher test velocities and pitch angles. This reduced the accuracy in which the wing deflections could be corrected. Additionally, wing twists could not be quantified as effectively because of camera perspectives.

Originality/value

This paper shows that additive manufacturing can be used to fabricate aircraft test components with satisfactory strength and quantifiable deflections for wind tunnel testing, especially when the designs are significantly complex and thin.

Details

Rapid Prototyping Journal, vol. 24 no. 5
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 1 February 2006

Hu weibing and Zhu Kuisheng

Wind tunnel tests of wing/store system flutter semi‐active suppression are shown in this paper. A wind tunnel test model for semi‐active suppression with an…

Abstract

Wind tunnel tests of wing/store system flutter semi‐active suppression are shown in this paper. A wind tunnel test model for semi‐active suppression with an Electro‐Magnetic damper and circuit control system are designed and worked out .The results of these wind tunnel tests show that the flutter response of wing/store system can be suppressed and the method of the tests is reasonable.

Details

Multidiscipline Modeling in Materials and Structures, vol. 2 no. 2
Type: Research Article
ISSN: 1573-6105

Keywords

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