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Wind Tunnel Model Design with Active Flow Control, for Low Speed Test

European Union
Complete with results
Geo-spatial type
Total project cost
€219 000
EU Contribution
€164 250
Project Acronym
STRIA Roadmaps
Vehicle design and manufacturing (VDM)
Transport mode
Airborne icon
Transport policies
Environmental/Emissions aspects,
Transport sectors
Passenger transport,
Freight transport


Call for proposal
Link to CORDIS

The original requirement covered by this DEAFCON proposal was for the detailed design of two low speed half models, with a fully pressure plotted low sweep and high sweep wing respectively.

Removable and variable Leading Edge, Trailing Edge and Wing Tip devices were to be included, and the main element of innovation and learning for ARA would have been the integration of some form of Active Flow Control technology, which had not yet been defined.

Also included would be relevant design changes to an unknown, but existing, half fuselage FALCON model to enable appropriate integration of either wing configurations together with their relevant AFC actuators (recognising that these fuselage design modifications would need to be considered fully reversible).

However, prior to commencement of this programme, the scope and work content was changed quite considerably by the Topic Leader to comply with their final Specification document DGT-132940 Iss C Oct 2013.

This document presented the specification of the design of a single large scale half-model for testing in a pressurized low speed wind tunnel. Integration of any Active Flow technology was thus dropped at this stage, and the parts to design within DEAFCON became therefore:-

  • A left-hand side modular wing with high aspect-ratio and low sweep
  • A set of Body fairings to fit with the fuselage
  • A left hand side cross-shaped HTP and its movable attachment fitting compatible with the former Vertical Tail
  • A simplified main landing gear and its cavity

Project Context and Objectives:

The objectives within the framework of this overall project are now therefore:-

  • Design of a pressure plotted left hand wing, with appropriate mounting to the WT test facility (ONERA) and relevant wing / fuselage fairings to mate with an existing fuselage
  • Design of various Leading Edge (Kruger slat) devices
  • Design of various Trailing Edge devices (conventional and Smart flap)
  • Design of a left hand HTP to mate with an existing (modified) VTP
  • Design of a simplified main landing gear
  • Provide as Output Deliverables, the full CAD model and a final Stress Report


Parent Programmes
Institution Type
Public institution
Institution Name
European Commission
Type of funding
Public (EU)
Specific funding programme
Other Programme
JTI-CS-2010-3-SFWA-02-007 Wind Tunnel Model Design for Low Speed Test with Active Flow Control


Final Report Summary - DEAFCON (Wind Tunnel Model Design with Active Flow Control, for Low Speed Test)

Project Results:

WP1 – Technical / Financial Management of the programme.

Technical management and financial administration has been maintained by ARA throughout the duration of this programme, but several issues combined to necessitate a request for extension up to the current 18 months timeframe.

The programme was late in starting not least in part to the significant change of direction with regard to the ultimate design specification provided by the Topic Leader.

However toward the end of the project, there was also an issue with regard to the level of content of Deliverables requested by the Manufacturing Consortium.

Although ARA were not selected for the subsequent manufacturing phase after this design programme, there was still significant discussion and review throughout with the resultant Manufacturing Consortium.

Partly due to budgetary constraints being approached, ARA were advocating that manufacture could be undertaken direct from the CAD model data supplied, as is the norm during our own manufacturing processes.

However, the Manufacturing Consortium suggested that they would need a set of hard copy manufacturing drawings to assist in this process, even though the Deliverables as identified in the Design Specification, did not include provision for drawings (only the CAD data).

After much discussion, it was eventually agreed that this issue would be resolved directly between Dassault Aviation and the Manufacturing Consortium.

WP2 – Design of the wing, HTP, undercarriage and mounting componentry.

The wing was equipped with several lines of pressure probes (over 300 in total), some of which were included on the design of:-

  • Wing-box
  • Aileron

A simple wingtip was included, and the wing was also equipped with one aileron capable of deflections between -35° and +35°. Angle settings allowed for several discrete settings including the clean position. The rotation of deployment angle was performed by two hinges and set by dedicated brackets.

A simplified main landing gear with doors was designed and integrated into the wing in a generic cavity. The cavity was closable with a dedicated part at the lower wing shape for clean and take-off configurations.

The HTP was a simple one-part all movable part (+ tail configuration). There was no movable elevator but a new HTP attachment fitting was needed to enable a trim capacity with several discrete positions, incorporating modifications to an existing VTP and HTP mounting arrangement.

To avoid any leakage between the lower and upper part of the leading edges, it was required to put a sealing system (O-Ring) between leading edge parts and this wingbox.

A new main mounting adaptor for the wing (compatible with the ONERA test facility), together with associated wing / fuselage fairings were also designed.

The final CAD model, together with relevant Stress Reports, has been provided to the customer and as confirmed at CDR / Design Approval stages (see Ref 6), the Work Package was therefore successfully achieved in line with the agreed re-schedule.

WP3 – Design of Leading Edge and Trailing Edge components

A removable leading edge has been designed as follows:-

  • 4 different parts in span
  • These parts would be interchangeable with alternate leading edge design (except for the tip one

A total of 11 different leading edge parts with an expected chord extension of 25% were therefore required.

Additionally a set of Kruger slats with capacity of gap and overlap settings were designed The Kruger slat would be dedicated to only one set of leading-edge. This specific set of leading edge would therefore also present a removable lower panel to mimic the open cavity when the slat is deployed. The Krueger slat was also divided in 4 parts in span and for each part, 3 different set of brackets were designed to enable different slat deflection.

The different set of brackets would permit:-

  • 40° deflection
  • 55° deflection
  • Airfoil tangential position for 40° deflection

Setting capacity for the slats is:-

  • ± 5 mm in X location and evolutive in span
  • ± 5 mm in Z location

All setting capacity is included in the Krueger slat cavity to avoid disturbances on the slat itself.

The trailing edge was to be capable of 2 different trailing edge concepts:-

One conventional single slotted flap with normal extension (50% to 60% of flap chord)

  • Clean configuration: the flaps are at 0° deflection
  • Take-off configuration: 20° deflection. The brackets will permit a slight capacity of overlap and gap settings (roughly a X and Z setting capacity)
  • Landing configuration: 40° deflection. The brackets will permit a slight capacity of overlap and gap settings (roughly a X and Z setting capacity)

One “Smart Flap” system that presents a high extension capacity (≈80% of flap chord) and a two degree-of-freedom flap (extension and camber). It is therefore capable of both lift increment and lift-dumping:

  • Clean configuration: the flaps are at 0° of deflection

The following deflections were also required:-

  • -30° (lift dumping)
  •  0° (extended but no camber)
  •  10° (performance Take-off)
  •  20° (normal Take-off)
  •  30° (sensibility for Landing configuration)
  •  40° (Landing configuration)

Therefore all the brackets will permit a slight capacity of overlap and gap settings (roughly a X and Z setting capacity)

In terms of moving parts, there are:-

  • 2 different inner flaps
  • 2 different outer flaps
  • 2 sets of flap roof

For the conventional flap roof, 4 spoilers/airbrakes were also required (deflection: 0°, 30°, 50°, 70°), but for the “Smart Flap” roof, only a clean flap roof was needed

The final CAD model , together with relevant Stress Reports, has been provided to the customer and as confirmed at CDR / Design Approval stages (see Ref 6), the Work Package was therefore successfully achieved in line with the agreed re-schedule

Potential Impact:

The overall aim of this programme of work is to provide a wind tunnel model which facilitates an efficient, productive wind tunnel test campaign and the acquisition of valuable data to permit the innovative aircraft design to be evaluated

The wind tunnel model and measurement techniques developed during this programme of work will be available for use in future experimental investigations.

This information will be utilised in the design of future aircraft to enhance performance and reduce fuel consumption

List of Websites:

Project Officer: Helmut Schwarze

Topic Manager: Olivier Colin

Dassault Aviation, Aircraft & Stores Engineering Technical Directorate

92552 Saint-Cloud, France

+33 (0) 147 113894

Project Co-ordinator: Robert Daly

ARA Manton Lane, Bedford

MK41 7PF

+44 (0) 1234 321686

Task Manager: Peter Spiers

ARA Manton Lane, Bedford

MK41 7PF

+44 (0) 1234 321690


Lead Organisation
Aircraft Research Association Limited
Manton Lane, Bedford, MK41 7PF, United Kingdom
Organisation website
EU Contribution
€164 250
Partner Organisations
EU Contribution


Technology Theme
Aircraft design and manufacturing
Aircraft design model
Development phase

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