1.5 m trisonic wind tunnel

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 an intermittent blowdown type facility with a speed range from low subsonic (M ≈ 0.1) to a maximum Mach number of 4.25 and has the capability to provide independent control of stagnation pressure across the full operating envelope.

The 1.5 m trisonic wind tunnel is an intermittent blowdown type facility with a speed range from low subsonic (M ≈ 0.1) to a maximum Mach number of 4.25 and has the capability to provide independent control of stagnation pressure across the full operating envelope.

The speed range is from 1/10 to more than four times sonic speed. Although an intermittent facility, the air storage system permits run times ranging from 6 seconds to 120 seconds depending on flow parameters, with a 20-second run being typical. Flow Reynolds numbers can reach 120 million/meter. Stream stagnation pressure is closely controlled during the blow-down and, by varying the diffuser throat area or controlling the outflow from the plenum chamber, the test Mach number may be held within very tight tolerance as a model pitches, even at sonic conditions.

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

3D Test configuration

The efficient aerodynamic assessment of civil and defence concepts calls for facilities that can provide a wide range of flow conditions and offer flexibility in adjustment of model configurations and orientation to the oncoming flow. With the 3D testing configuration, the full Mach number range of the wind tunnel (Mach 0.1 to 4.25) is utilized consistent with the operational flight envelopes common to many aircraft and defence systems. In addition, the model support system provides automated attitude control (through the course of wind tunnel run) through a range of -14° to +28° in pitch and ±354° in roll.

A number of internal strain-gauged force balances are available for use with this support system and can be selected to best match expected load ranges and data resolution requirements. The capability to measure loads on individual control surfaces is also provided.

The array of standard data output of a 3D test program enables our clients to perform design assessments through validations and parametric studies and provides aerodynamic data from which trajectory predictions and control strategies can be developed.

Complete three dimensional models are mounted using either a rear sting, or a "plate mount" system which permits correct modeling of the rear fuselage for transport aircraft configurations. By installing a "reflection plane" and five-component sidewall balance, it is possible to test semi-span models of larger scale, for which higher Reynolds numbers can be achieved.

Half-model configuration

Through the use of a reflection plane and a five component force balance, the 1.5 m trisonic test section can accommodate semi span models at larger scale and provide Reynolds numbers greater than 27 million per meter (8.3 million/ft). With a model support system that can provide a wide angle of attack range, testing conditions encompassing standard flight envelop through to the deep stall regimes can be accommodated. The array of aerodynamic data provided by this test capability, combined with the ability to provide over 300 discrete pressure measurements over the wing and fuselage, has a proven track record in providing high quality / high productivity data for the assessment of take-off, landing and cruise condition performance.

Recent developments have enhanced the half-model test capability by enabling simultaneous comparison of aerodynamic characteristics (through balance and pressure data) with visualisation of flow profiles across wing and tail surfaces. This technique, using fluorescent micro tufts, provides considerable information for the assessment and development of aircraft design in both high lift and cruise conditions.

2D Test Configuration

Through the use of interchangeable test sections the 1.5 m trisonic wind tunnel can be easily converted to accommodate the testing of 2D model configurations. When operating in this mode, the test section geometry converts to 1.5m x 0.38m cross section and is capable of testing at Mach numbers ranging from 0.1 to 0.95 at Reynolds Numbers up to 160 million per meter (50 million/ft). Categorized as a Class 2 facility under controlled test conditions of a NACA 0012, this facility has a proven track record in the testing of aerofoil configurations for fixed and rotary wing concepts.

This test capability can also be extended to development and optimization of blade designs for wind turbines and offers an environment suitable for fundamental studies into High Reynolds number effects of flow past bluff bodies such as cables and building sections.

Support provided:

• Wind tunnel testing techniques
• Wind tunnel instrumentation
• Model design, model manufacture
• Model deformation measurement under load
• Data analysis capability
• Computational fluid dynamics

Testing configurations

Model mountings

Data acquisition and analysis

In addition to force and moment data, high-precision surface pressure measurements are routinely made on aircraft or aerofoil section models. These measurements are made using electronic pressure scanning (EPS) techniques. Force and moment measurements can also be made on external stores in the parent aircraft flow field.

The data system used for recording nominal steady state information is a PXI / PC based system controlled through a LabView environment. A high-speed data acquisition system is also available for making measurements involving unsteady phenomena.