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Wind Tunnel 21 Oct 1960 - .PDF file.
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Post Office Research Station - .PDF file.
In October 1960, The Engineer reported on the opening of two new high speed wind tunnels at the Warton Aerodrome, near Preston.
With computing ability advancing rapidly, the 1960s saw some key advances in the application of wind tunnel testing. And in October 1960, The Engineer reported on the opening of two new high speed wind tunnels at the Warton Aerodrome, near Preston.
The facility, which was owned and operated by English Electric, was already home to four other wind tunnels but the two new tunnels introduced a valuable new capability for aircraft and weapons development.
With a speed range from Mach 0·4 to 4·0 and a working section 4ft square, the larger of the two tunnels – M4 – was intended mainly for aircraft development. The smaller tunnel – which had have a speed range of Mach 1·5 to 6·0, and a working section 18in square was described as a guided weapons tunnel.
Because of its wide working speed range, the design of the control system for the larger tunnel proved particularly challenging wrote The Engineer. ’The characteristics of the control valve ….called for a two-stage device in which the first stage opened to an extent inversely proportional to the upstream pressure the constant of proportionality being varied with the desired density and the second stage responded to errors in the selected pressure drop along the tunnel. The article explained that the smaller tunnel had separate shut-off and control valves developed by US firm Compudyne Corporation.
Given the vast computing power available to today’s engineers, the article’s description of how the system’s data was recorded and analysed is perhaps particularly notable. ‘The instrumentation of the larger tunnel is a conventional digital system with all inputs from strain gauges,’ wrote The Engineer. ‘The nine one-second chart recorders include digitisers, and the outputs of the latter are transferred to punched cards up to 100 times per minute.’
The smaller tunnel had a higher speed recording system. ‘Eight quantities, including the balance measurements if being observed, are continuously presented by d.c. amplifiers. At intervals separated by one-eightieth second, sampling amplifiers store these eight values and present them in sequence to a Packard Bell ” Multiverter ” which converts them from analogue to digital form and transfers them in binary code to a high-speed store of magnetic tape. Subsequently the tape record is transferred to punched cards, which, with those from the other tunnel, are processed by a ” Deuce ” computer..’
Amongst other projects, the tunnels, which had been developed and installed at a cost of £750,000 were used in projects as the TSR-2 (Tactical Strike and Reconnaissance aircraft) and the “Blue Water” surface to surface missile.
Today, the facility is owned and operated by BAE Systems, and it continues to play a major role in the development of aircraft and weapons systems. It has been used by engineers working on the Tornado, and the Eurofighter Typhoon as well as host of UAV (Unmanned aerial vehicle) projects. The tunnels were even used by the British Bobsleigh team, who, ahead of the 2014 winter Olympics, used them to simulate full racing conditions and examine how different sled set ups and crew positions affect wind resistance.
Will our Editor please stop doing this: Once again he reminds me how old I am!
I went to St Andrews Uni in October 1960, the date of this wind-tunnel installation! and one of my lecturers (indeed with whom I did my Honours dissertation a few years later on the Ranque-Hilsch Vortex Tube) had worked in the same area of ultra-high speed airflow, albeit at Bristol Aeroplane Co. He regularly used to intersperse his aerodynamics lectures with talk of his linked work in this area. Loved the description of how data was gathered/stored. If I recall, we did take high-speed pictures of the flow: we had a small Tunnel (run by compressed air for a few seconds at a time) and several models of the ‘ English Electric Lightning Wing shape that he had ‘achieved’ from somewhere.
A question I have often heard asked by undergraduates is ‘what relevance does so-and-so have to our likely/future careers as practicing Engineers’.
In the case of aerodynamics (as described above) I did use directly some of the material from a part of the course.
Think ‘laminar flow, boundary layers, sub-layers and choking flow through orifices (and if I recall the directional vanes in gas turbines?0
In synthetic fibre manufacture one of the ways we deal with the natural tendency of filaments (because of the static charge they develop) to ‘balloon’ away from each other is by putting a slight twist in them. Another (quicker) way is to direct jets of compressed air at the ‘bundle’ and literally interlace/entangle/snag them together. [Think ladies hair, first thing in the morning!]
This is expensive (compressed air) and after testing, it was often the case that operatives, recording that the filaments were not sufficiently entangled….would invariably increase the compressed air pressure (believing that such would increase the flow) and hope this did the trick. Unfortunately the orifices through which the flow was passing (think hollow needles) were often so choked that all that was achieved was heat gain (the extra energy has to go somewhere) and waste of air.
I did manage to confound/surprise my seniors with actually offering some equations that defined the point I was making. The new instruction to operatives was to reduce the pressure-and it worked.
Fellow Bloggers may have noticed that occasionally I have had occasion to question the contribution that ‘our learned? friends’ make in technological areas. This whole area became the subject of some patent infringement litigation. I was given the benefit of Counsel’s opinion about ‘our’ patent: that was completely superfluous and irrelevant to what we were doing…what frightened me was that his fee for a single consultation was the same as my then annual salary . Perhaps my questioning of ‘their’ contribution started then!
I had the very great pleasure of being given a tour of the larger recirculating wind tunnel, as shown in the bobsleigh photograph. It was wonderful to see this 60’s engineered facility still being in daily use. The most impressive thing about it was the great fan that drives the air around the circuit and the enormous balance mechanism that is four floors deep below the test section and is extremely accurate.
This facility and the others around it are a testament to the glorious past of British aerospace research and development, sad to say there is little being developed these days that shows such ambition.
Was about to post comments about this: only to find that I did so last year! When one gets older three things happen :First one starts to lose one’s memory and
I can’t remember the other two! Mike B