Farnborough Air Sciences No2 Tunnel

No2 Wind Tunnel

In Brief:

The No.2 low speed tunnel was built in 1942 and given a major refurbishment in 1970. It has a long and distinguished history of testing, culminating in five years of F1 racing car tests before being shut down in 1998 by the MoD.

The tunnel has a reinforced concrete air circuit of rectangular cross-section and a closed working section designed to operate at atmospheric pressure. Three of the sets of corner vanes are hollow so that they can be cooled by refrigerant. The return air circuit contains a box-like structure to remove swirl from the air flow. The arrangement gives fully satisfactory turbulence levels but it could be replaced, for example, with a ring of radial vanes if lower aerodynmic losses were required for operation at high speeds.

No 2 windtunnel - plan view

The mahogany six-bladed fan is powered by two 2000HP direct current motors on a pedestal in the motor room shared with R133. A modern solid-state motor drive unit will be needed to drive the fan motor to ensure that voltage fluctuations to other tenants in the Business Park are kept within acceptable limits. Limitations on the power available to the Business Park are likely to restrict the power consumption of the fan motor to 1.25 MVA, which corresponds to a tunnel speed of approximately 90m/sec. One of the two fan motors would be adequate for this.

The cooling plant for the tunnel is no longer available, but the tunnel was operated at up 50m/sec without cooling. There is sufficient power allocated to the domestic supply to meet the demands of a new cooling plant.

The tunnel could be restored to its design operating speed of 110m/sec given suitable power reinforcement at the Park’s primary substation.

Full Colour Brochure in PDF format (1,220kB)

Working section	11½’ x 8½’ x 20' (3.5m x 2.6m x 6.1m)
Design speed	Up to 360ft/sec (110m/sec)
Maximum speed without cooling	200ft/sec (60m/sec)
Maximum speed @ 1.25MVA	300ft/sec (90m/sec)
Rolling road	Up to 250ft/sec (45m/sec)
Floor balance	Six component with electrical readout
Roof balance	Three component with manual readout
Sting support	-10° to +30° incidence
Cooling	Cooling surfaces, pipes and pumps only - new refrigeration unit would be needed

Tunnel Equipment

The tunnel is currently equipped with a rolling road, owned by McLaren but used by Benetton for testing their F1 racing cars in the 1990s.

McLaren plan to remove the rolling road during 2005, allowing the under-floor balance to be reinstated. This is an extremely accurate, six-component balance that floats on air bearings and provides electrical output of the measured loads. A compressor located in the tunnel building supplies compressed air for the air bearings.
The tunnel has a three-component mechanical roof-balance and a variable-incidence vertical traverse for a sting.

Previous Uses of the No.2 Tunnel

The following list of the tunnel’s past uses gives an indication of its capabilities.

Testing F1 Racing cars
Testing Post Office telegraph wires
V/STOL research, including Harrier predecessors
Aircraft model tests
Oil cooler research for piston engines
Combat aircraft research
Comet 3 wing tank development
Weapon systems research
Vortex flap research
Aircraft wake characteristics research
Swept wing stall behaviour research
Testing bobsleighs for the RAF team
High incidence canard delta tests
Drag test on Olympic skiers

Building Modifications

The external fabric of the building, known as R136, which houses and is integral with the No.2 tunnel is being restored by Slough Estates to the same high standard as R133, the adjoining Grade I listed transonic wind tunnel building . R136, though not listed, comes within the curtilage of R133 and for this reason planning authorities should be notified of any intended changes to the building.

The building has some space for offices and workshops. There will be additional space available close by, in small or large units, as part of the Slough Estates’ development plans for the Park.

Ground Floor	First floor

Uses	square metres
Windtunnel	1027
Offices	105
Facilities: WC’s, kitchens	37
Circulation	247
total	1416

Refurbishment costs of interior and equipment

A full report on the condition of the tunnel and its equipment is available to parties having a serious interest in making use of the tunnel. Additionally, Slough Estates has comissioned FAST to prepare a schedule and cost estimate of the work required to bring the tunnel up to modern standards.

Enquiries

For further information please contact:
Stephen Lord, Senior Development Manager
Slough Estates plc
234 Bath Road
Slough
Berkshire SL1 4EE
Tel: 01753 213472
email: Stephen.Lord@sloughestates.co.uk

Full Colour Brochure in PDF format (1,220kB)

[back]

Copyright © Farnborough Air Sciences Trust: Registered Charity 1040199
Version: 1.03 date: 10 June 2005, URL: http://www.airsciences.org.uk