1.5 m trisonic wind tunnel

Contact us

To discuss your project or find out more about how we can support your business, contact:

Matthew Tobin
Telephone: 613-990-0765
Email: Matthew.Tobin@nrc-cnrc.gc.ca

Targeted industries

Aerospace, Civil Engineering, Wind Energy.

Location

CF-18 on roof-mounted sting during stores release test

CF-18 on roof-mounted sting during stores release test.

Measurements of model deformation on a business jet half-model

Measurements of model deformation on a business jet half-model.

The 1.5 m trisonic wind tunnel has played an instrumental part of Canadian and international research and development into the aerodynamics of aircraft and defence systems. This facility has a demonstrated track record in performing aerodynamic assessment through a wide range of operational envelopes over subsonic through to high supersonic flow conditions. These test capabilities have been developed in a secure environment to deliver high-quality aerodynamic data of complete test articles and their sub components.

The 1.5 m trisonic wind tunnel is a pressurized, intermittent flow wind tunnel capable of providing subsonic, transonic, and supersonic flows, Mach 0.1 to 4.25. Independent control of the stagnation pressure over the full operational envelope permits a range of Reynolds numbers to be simulated while maintaining a constant Mach number.

A high mass flow compressor plant maintains high test productivity. Time to recharge between runs is less than 30 minutes.

The facility offers three main test configurations to meet a number of test requirements.

3D test configuration

This standard test configuration permits the model to be mounted from a downstream strut with a roll drive, sting and internal balance. Automated Pitch-Roll combinations within the limits of -14 to +28°, and ±360° respectively permit a wide range of model angle of attack and sideslip to be obtained.

For the subsonic and transonic regimes, the model is tested in the transonic test section. This test section makes use of perforated wall boundaries enclosed in a pressure tight plenum and is easily installed in the circuit downstream of the supersonic nozzle using automated systems. Control of the Mach number is achieved using a servo controlled diffuser throat area or plenum outflow flaps with fixed nozzle geometries. The Mach number is infinitely variable up to Mach 1.2.

For supersonic testing (typically Mach 1.4 and above)the transonic test section is taken out of line and the test region is at the end of the supersonic nozzle. The supersonic nozzle is of the 2D flexible wall type with 16 nozzle geometries providing 16 fixed Mach numbers covering Mach 1 to Mach 4.25.

A single blow-down can provide between 30 to 40 seconds of runtime for all Mach numbers below Mach 4 with unit Reynolds numbers in the range of 15 to 20+ million/m. Higher Reynolds numbers (up to 80+ million/m) will result in lower available run time.

A production mode system is also available to perform “store release” studies. This setup is shown in the accompanying figure. The parent model is mounted from a separate sting off of the ceiling of the transonic test section. The store under study is supported on its own balance and is traversed over an array of prescribed vectors from its carriage position. This data provides the aerodynamic coefficients of the store within the flow field of the releasing aircraft.

A blade/plate mount is also available for subsonic-transonic conditions.

Half-model configuration

For these tests, a solid reflection plane is mounted off of a wall of the standard 3D transonic test section. The starboard (or inverted Port) half of the flight vehicle is built as a model and mounted to an external six component balance. The model is typically pitched at a rate of 2 to 3° per second during the run. The pitch range is primarily determined by the model length. This mode of testing permits a model of approximately double the scale of the standard 3D configuration, providing higher Reynolds number, improved access for surface pressure tap instrumentation, and an ability to accurately represent flaps, slats, and other component features.

Subsonic and transonic conditions are available for this configuration. With a typically sized aircraft model, Reynolds numbers based on the mean aerodynamic chord of over 7 million can be achieved from Mach 0.2 to Mach 1, with 12 or more seconds of usable run time.

2D test configuration

Through the use of the Roll-in Roll-out interchangeable transonic test section system the 3D transonic test section can be replaced with a 1.5 m high by 0.38 m wide transonic channel. This test section is suitable for testing airfoil profiles or other section shapes over the Mach range of 0.1 to 1.0. Chord Reynolds numbers of 40 to 50 million, can be achieved with typical model chord lengths at Mach numbers above o.6.

Typical current uses of this test capability are: rotary wing rotor airfoil development and verification, evaluation of active flow control concepts, civil engineering studies of bluff body sections at high Reynolds number and wind turbine blade designs.

Measurement techniques

  • Internal and external strain gauge balances for force and moment measurements
  • Digitally scanned pressure transducers for extensive discrete surface pressure measurements
  • Surface flow visualization using fluorescent mini tufts is a production standard option. The surface is imaged at approximately 5 frames per second and each image is annotated with synchronized model measurements.
  • Multi-focused Schlieren off surface flow visualization in the
    3-D supersonic and transonic modes only
  • Pressure Sensitive Paint (PSP) to optically measure pressures over entire model surfaces
  • Non-intrusive optical Model Deformation Measurement capability to assess the wind-on deflected twist and displacement of wings or other highly loaded flexible components
  • Optical tracking of models while being moved with load deflected supports (a standard technique for stores release testing)

Test Support

  • Wind tunnel test project planning and coordination
  • Wind tunnel test optimization
  • Model design and manufacture
  • Advanced wind tunnel test technique development
  • Data analysis
  • Computational fluid dynamics (CFD)