Established and officially launched in 2003, the Red Bull Air Race is globally renowned. By taking the existing model of Formula One Racing, and combining it with extreme aerial challenges, the sport has grown into one of the most exhilarating and fastest motorsport races on the planet. The ability to fly at speeds in excess of 250mph at low altitude, and to deal with extreme and punishing race conditions, has seen some of the best pilots from all over the world involved in flying some of the most aerodynamically modified racing machines known to man. Changes to the World Series aircraft specifications for the 2014 season has seen individual planes changed drastically, due to standardisation in the area of aircraft propulsion. This change to the sport has levelled the playing field, as well as improved the safety conditions during races.
This has led each individual team to analyse their current plane’s performance in considerably more engineering detail than was previously done in the past. When the main propulsion of every plane is standardised, the only areas left to adjust are the aerodynamics of the plane body itself. This specifically relates to how the airflow affects the plane and also the surplus drag coefficient that is applied to parts that aren’t aerodynamically enhanced. The same engineering strategy can also be directly applied to the angle of attack on the race track; adjusting the entry speeds and pulls between pylons during a race can result in times that are in some cases milliseconds apart. All of these factors, along with the natural ability of each pilot, make for an extremely challenging environment.
The result of all of this testing and modifications saw the Breitling Racing Team, with British pilot Nigel Lamb, clinch the World Championship with a dramatic victory on the last day of racing in October 2014. Nigel has been working on his MXS aircraft since 2010 and has invested in a multitude of technologies to assist the design and air flow developments across the surface of the plane. Some of these changes are clearly identifiable in the construction of the wing tips, which were specifically designed to reduce the aircraft’s induced drag without detriment to other performance criteria. Apart from the exterior modifications, advanced analytical software has also been used in an attempt to correctly calculate the right approach for every single gate, and gain as many split seconds as the Breitling Racing Team can find.
Measurement Solutions : So Why 3D Scanning ?
As with most high performance manufacturers, the complete CAD assembly of the aircraft structure is strictly confidential and kept under lock and key. So how does this affect modifications to a plane ?
In terms of a high speed sport, the surface profiles and shape are generally designed to deal with optimal air flow across the body, and as such the direct replication of the machine can be difficult to comprehend when the critical information isn’t available. In the Aerospace industry, these complex shapes can’t be measured with traditional methods and would conventionally take several weeks to capture in a standard working environment, and then more time would be required to digitally create the model in a CAD package. This all assumes that the measurements were correct in the 1st place !
With this in mind, and due to the need to make some radical changes to his existing MXS, Nigel Lamb approached Measurement Solutions for this year’s race season for assistance in digitising his current plane as accurately as possible. One of the UK’s leading companies in the fields of 3D measurement and scanning, many prominent organisations have put their faith in Measurement Solutions to deliver class leading services and products, including BMW Group, Jaguar Land Rover, BAE Systems, Honda, EasyJet and many more !
The requirement from the Breitling Racing Team was to provide Nigel with a full and accurate 3D scan of the complete aerodynamic shape of the aircraft, such that the shape of the aircraft could be truly represented in flow analysis testing. As is often the case with motorsport, the data required needed to be of sub-millimetre accuracy, yet it must be acquired and completed with minimal interference in the run up to the season start. With the variety of surface changes, air intake upgrades and optimum race course approach calculations to be researched, this was the most efficient course to take - as with most motorsports, time is precious!
When considering the need for scanning, users usually need to contemplate 3 main factors – accuracy, resolution and the ideal scanning technology for the application. In the case of portable scanning systems, there is no better alternative than the World’s foremost developers of laser scanning solutions, Creaform3D. As a UK partner for multiple inspection technologies, Measurement Solutions has access to a multitude of systems - for the application at hand, accuracy over a large volume was the most critical aspect to consider. This could not be achieved with traditional scanning systems such as portable arms, as the accuracy over large areas is simply not possible. Similarly, laser tracking was not an option as line of sight is extremely limited around the aircraft, requiring dozens of station moves (which all adds up to time and inaccuracy). As the time constraints were extremely tight considering the measurement demands, the Measurement Solutions team needed a solution that was quick and easy, yet 100% reliable.
As a result, the MetraSCAN3D was used to scan the whole aircraft, as this was seen to be the most suitable tool for the job due to its high accuracy and ability to measure over large areas. With the patented TRUaccuracy technology built into the system, full system accuracy is assured in all measurement conditions, unlike conventional measuring equipment that requires stable environments and experienced users. This proved invaluable while scanning an aircraft in a cold hangar late into the evening!
The MetraSCAN3D is a hand-held laser scanner, capable of acquiring large surfaces extremely quickly to an accuracy of less than 0.1mm. The scanner is tracked by a dual-camera system, which uses conventional photogrammetry techniques to continuously locate the position of the scanner relative to the aircraft at all times. A high accuracy dynamic referencing system also means the measured part can move during measurement, making the system ideal for applications such as press-shops and areas where vibration will affect traditional measuring systems. This same system provides the ability to quickly and easily extend the measuring volume or to re-position the tracking device without the need for complicated and time-consuming leap-frog or bundle adjustment manoeuvres, as with portable arms and laser trackers. This all adds up to a complete guarantee of accuracy, irrespective of the environmental conditions.
To further enhance this accuracy, the system was used in conjunction with a Creaform MaxSHOT photogrammetry system to provide an accurate reference map across the whole surface of the plane. This ultimately minimised the time that would normally be required to manually register the scan data sets together. This also enabled areas to be re-scanned as required, or for parts to be removed such that 'hidden surfaces” could also be scanned in great detail.
Within 24 hours, Application Engineers from Measurement Solutions had managed to 3D scan the entire aircraft to within 1mm accuracy. This acquisition was completed and post processed, before leaving site, into an industry standard STL mesh, ready for direct import into airflow analysis and CAD software. Of course, the speed of scanning does not quite match up to the final speed of Nigel’s World Championship winning aircraft, but Measurement Solutions are extremely proud to know that the accurate scan data produced many months ago may well have contributed to Britain’s Nigel Lamb enjoying World Championship glory for the first time.