10x5 Tunnel

The newly refurbished 10x5 Wind Tunnel is a highly reconfigurable temperature controlled facility with two test sections offering a wide range of features covering just about any study involving airflow. It provides an excellent facility for aerodynamic development and safety evaluation studies of road and race cars, aircraft, buildings and structures. The lower test section is a full 20m long (one of the longest test sections in Europe) and a 3m x 1.5m cross sectional area. It is equipped with a rolling road, traverse and full boundary layer control. The upper test section is in effect a large wind testing arena 18m in length and a massive 5.7m x 2.8m cross sectional area. Both test sections are outfitted with an intellegent fully computerised control system and tunnel local area network for the distribution of data. Brand new National Instruments hardware and state-of-the-art LabVIEW based data-processing software enable the user to make maximum use of the facility.

The lower section continues the tradition of the previous tunnel with very high quality flow and the facility is complemented by a comprehensive range of instrumentation which enable measurements of force, pressure and flow velocity to be made accurately and efficiently.

As well as offering an all round aerodynamic testing solution, the lowertest section is highly optimized for race car testing. Capable of speeds of up to 40m/s, it has an automated support strut and integral 6-component force balance. This greatly simplifies the testing of road vehicles. The rolling road can be yawed to simulate the effects of crosswind and the tunnel uses a novel high-precision wheel drag cell system supplied by Flow Dynamics. A smaller 4.5 x 4 working section tunnel is also available when large scale testing is not required.

Tunnel information

Specification

Type Closed return, closed twin test sections. Twin axial flow fans with pre-rotation and straightening vanes. Fully computerised National Instruments control and LabVIEW based data acquisition.
 Lower Test section 3.05m wide x 1.524m high x 20m long.
 Upper Test section 5.7m wide x 2.8m high x 18m long
 Air speed Empty tunnel speed range is 0-40 m/s lower section, 0-13m/s upper section. Infinitely variable with precision air speed control.
 Flow quality Flow uniformity (lower section)  ± 1.0%; Turbulence <0.25%; Boundary layer
Deficit <0.5% 
 Moving floor Dimensions: 1.84m (6') wide x 2.4m (7.87') long.
Speeds up to 40 m/s; infinitely variable.
Full boundary layer control applied at two points ahead of the moving floor.
Automatic adjustment of under-floor suction to prevent belt lift.
Water cooled platen.
Yaw adjustment from -5° to +20°.
 Balance and strut

The wind tunnel is equipped with an automated strut and balance:-
Six component load cell balance and automated strut. The balance is designed to be installed within a 33% or 40% scale racing car or other road vehicle. It is supported by a streamlined strut which can move the car vertically and in pitch. Automatic ride height and pitch control is by means of pre-programmed computer control. Manual yaw and roll adjustment. Four complementary wheel drag balances are available. Data acquisition and processing is fully automatic. 

Typical Ranges:-
Lift 1000N, Drag 250N, Pitching Moment ±150Nm,
Side Force ±250N, Yawing Moment ±75Nm,
Rolling Moment ±40Nm, Wheel Drag 50N.

 Pressure 128 Channel PSI Initium pressure scanning system allowing instantaneous collection of pressure information at any time.
 Traverse Precision 3 axis probe supporting traverse.
Computer controlled ranges of movement are:-
Stream wise 4m, Across flow 3m, Vertically 1.5m (positionalble anywhere in the lower section)

A range of pressure sensing, hot-wire and hot-film probes are available.
Other Instrmentation Powerful Class-4 high and low speed laser systems for PIV, LDA and other flow visualisation techniques.
 Model assembly There is a lockable workshop suite for the hirer's use while renting the wind tunnel.
 Access The tunnel is situated close to a vehicle unloading area. Unloading is therefore quick and convenient.

Race car testing

The design and manufacture of racing cars is a highly successful sector of the UK’s engineering industry and the Department of Aeronautics at Imperial College has been working with the industry for more than 30 years. This collaboration has been primarily in the area of aerodynamic design involving model cars in wind tunnels and the development of wind tunnel techniques.

One of the first investigations carried out was for Donald Campbell on his Bluebird record breaking car. At about the same time the importance of aerodynamics in Formula 1 racing was becoming more widely appreciated and the department became involved in much of the pioneering work in this field.

A major advance was the introduction of a moving floor beneath the model to simulate correctly the airflow around and under a racing car fixed in a wind tunnel. This led to some spectacular improvements in aerodynamic performance, including the development at Imperial College by Peter Wright of the highly successful Lotus 78 ground effect car.

Since then the wind tunnels at Imperial College have been used by many major Formula 1 teams including McLaren, Williams and Ferrari. The governing body of Formula 1, the FIA, commissioned a program of testing at the Imperial wind tunnel to determine how downforce and drag are affected during an overtaking manoeuvre. 

Work in Formula 1 has led to projects in other areas of motorsport and passenger car design. Sports cars have been tested including the successful Jaguar Le Mans car of a few years ago. A contract from Honda in the 1980’s enabled the department to build a substantially larger wind tunnel, the Honda 10x5 Tunnel, for road vehicle aerodynamics and considerable research has been carried out into the aerodynamics of passenger cars.

This year as a result of a large EPSRC grant, the tunnel has been completely refurbished and the design took into account the need to maintain all the outstanding features of the original tunnel, but also to add many more features, such as the extended lower test section, large upper test section and tunnel cooler. The tunnel is one of the National Wind Tunnel Facility tunnels.

It is possible to test racing car or road vehicle models up to 40% of full scale. The Imperial College 10x5 wind tunnel has been used extensively by industry for research and development into road vehicle aerodynamics. A highly satisfactory spin-off from this activity has been the placing of a significant number of graduates, at first degree and PhD level, in the racing car industry. In almost every Formula 1 team there is at least one alumnus from the Department of Aeronautics.