A vehicle model is craned into the NRC 9 m wind tunnel test section through the open roof. The turntable, which enables testing of the vehicle in yawed wind conditions, and the Ground Effect Simulation System (GESS) belt, are visible below the car.

When was the National Research Council Canada (NRC)’s 9 m wind tunnel built and for what purpose?

The 9 m wind tunnel was built in 1970 to support development of short take-off and landing aircraft. In 1973, the oil crisis stimulated R&D on fuel efficiency and drag reduction efforts on ground vehicles. Much of the original work on drag reduction for transport trucks (including deflectors and air shields) was undertaken at NRC.

Has the wind tunnel been improved over the years, adding to its capabilities?

NRC continues to invest in the facility to support enhanced vehicle aerodynamics capabilities. In the late 1990s a boundary-layer suction system was added to improve flow simulation, and a decade later a moving ground plane for full-scale automobiles was incorporated.

Recently, the capability to simulate large-scale atmospheric turbulence has become more desirable, and so facilities to accommodate this have been commissioned. More general upgrades include regular investments in the data acquisition system, balance upgrades, wake rakes and particle image velocimetry capability. A new 10 tonne crane installation

project is currently underway, and we are in the detailed phases of planning an upgrade to our moving ground plane, which will result in increased test efficiency.

How many wind tunnels exist in North America? How do NRC’s tunnels differ from the others?

There are about eight wind tunnels capable of testing full-scale vehicle aerodynamics in North America. Three are owned by automotive original equipment manufacturers (OEMs – the Detroit Three). Of these, the NRC facility is one of the largest, so it has less blockage and is the only one with a moving ground plane capable of yawing so that wind-averaged drag data can be accurately determined. We believe that our new turbulence-generating capability is unique. Proximity to the NRC Automotive and Surface Transportation climatic chamber, which is less than 1 km away, is an advantage to be explored.

What kind of services does the wind tunnel offer to the transportation industry? How are the needs of this industry met by NRC’s innovative solutions?

In addition to highly accurate aerodynamic drag measurements, NRC has a staff of aerodynamics experts on hand who can

advise on data interpretation and work with clients to improve products. NRC also has expertise in on-road (track) testing and measuring and modelling vehicle response to turbulence – a growing concern as vehicles are becoming lighter. Finally, we are developing a LIDAR-based measurement system to provide on-road drag measurements with a significant reduction in uncertainty.

Could you highlight some of your most high-profile clients, and explain the results and outcomes of these collaborations?

NRC actively works with other government agencies such as Transport Canada (TC) and Environment Canada.

We have long-term partnerships with major OEMs. We support their drag-reduction goals for a large number of vehicles produced for North America, working with stylists at model scale and prototype vehicles at full scale.

Another recent success involved us working with a Canadian Tier 1 supplier on a product development to reduce drag for a foreign OEM. We exceeded their drag reduction target. For TC and Environment Canada (and the US Environmental Protection Agency),

International Innovation discusses the finer points of aerodynamic testing with the National Research Council Canada’s Dr Guy Larose and the 9 m wind tunnel team, who also offer vital details of the organisation’s newest and most advanced wind tunnel facility

Aerodynamic assistance

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NRC

As one of North America’s largest wind tunnels, the NRC 9 m wind tunnel can accommodate all sorts of models, including full-scale transport trucks.

we are providing benchmark data on various active technologies now being introduced in the marketplace for passenger cars. The regulators need to understand how effective such technologies are. Similar studies are also underway with the same organisations to support fuel-burn reduction for Class 8 trucks and trailers. With TC and the other government partners, we are also involved in helping to define the standards for aerodynamic testing.

How does NRC go about using the 9 m wind tunnel to stay ahead of the curve when it comes to trends in the transportation industry?

We continue to listen to our clients and engage with government agencies, and to invest in capabilities and technologies that our clients will need in the next few years. A good example of this is the newly developed turbulence simulation system. Some research and client data are showing that trends observed in smooth flow wind tunnels are not consistent with on-road results, and our turbulence-generation system is designed to address this gap.

What other NRC wind tunnel facilities are available for the surface transportation industry?

The 2 m × 3 m wind tunnel is a high-quality and productive model-scale facility. It has drag repeatability with one automotive count, particle image velocimetry capability, turbulence-generation capability, controlled facility access and wake traverse capability. Using this facility, we have investigated the dynamic response of lightweight vehicles to wake turbulence initiating from large-scale trucks upstream of cars.

THE WIND TUNNEL is one of those ingenious concepts in the applications of science. Testing facilities of this nature have existed since the late 1800s, a time when scientists and engineers were still searching for the solutions that would allow humankind to take to the sky in crafts heavier than air. The study of aerodynamics, however, had existed long before this period, and it was in the early 18th Century that whirling-arm machines were devised – centrifuges that span objects around at high speed in order to determine their airflow characteristics. The problem with this, the proponents of the whirling-arm setup soon realised, was that the object being moved travelled in its own slipstream, and was subject to centrifugal forces that disrupted the results.

The wind tunnel was an idea that had been approached by early experimenters when they sought to use caves to isolate easily measurable airflows for their studies, but it was not until 1871 that the first enclosed wind tunnel was built by the Aeronautical Society of Great Britain. As facilities like this grew more popular, they not only solved the problems associated with powered flight, but were also recognised as invaluable tools for aerodynamic and fluid physics experiments with a variety of applications. All manner of vehicles, from cars and tractor trailers to boats and helicopters, are now routinely tested in wind tunnels as part of

their design process. The same is true for the structural design of ground-based structures such as tall buildings and long-span bridges that rely heavily on wind tunnel test campaigns.

DECADES OF SERVICEMany prominent R&D organisations maintain their own wind tunnel facilities, and this is certainly the case for the National Research Council Canada (NRC). NRC opened its first wind tunnel in a renovated sawmill in Ottawa around 85 years ago, at a time when flight science was still in its infancy. Since then, virtually every aeroplane designed and built in Canada has been tested at the NRC facility – along with many other surface vehicles, buildings and other structures. Although NRC itself is a Canadian Government organisation, its priorities centre on shortening the gap between the initiation of research and commercialisation; it is therefore unsurprising that its wind tunnels have often been used by many prominent stakeholders in North American industry.

The use of wind tunnels has changed since the 1930s, and the NRC facilities have been adjusted accordingly. Such facilities were comparatively expensive to run at first, and so the original wind tunnels of the early 20th Century were very small. Because of this, the testing of aeronautic crafts was mostly carried out using scale models. Today, NRC

Expert researchers and technicians at the National Research Council Canada have been serving industry and academia for 85 years by providing wind tunnel testing facilities and dedicated support and guidance. Today, the opportunities they offer are more wide-ranging than ever

Which way the wind blows

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1.5 M TRISONIC WIND TUNNEL

The 1.5 m trisonic wind tunnel is named for its impressive ability to produce airflow at subsonic, transonic and supersonic speeds, up to Mach 4.25. It exceeds other wind tunnels in this ability because it is not a continuous wind tunnel, but a blowdown test facility. This means that instead of using fans to pass air through the tunnel continuously, the 1.5 m trisonic instead builds up pressure in a large tank and releases more powerful but shorter and fully controlled gusts of air that last between 5 and 100 seconds. This capacity, plus the flexibility to test 2D, 3D or half models, has led to the wind tunnel’s proven track record of success in aerodynamic testing – and made it very attractive for certain forms of testing involving, for example, Reynolds number sweeps at constant Mach number.

maintains eight wind tunnels in a range of sizes, all of which have different and valuable capabilities. These facilities include 0.9 m, 1.5 m trisonic, 2 m × 3 m, 3 m × 6 m icing, 9 m and altitude icing wind tunnels.

THE WHOLE 9 METRESThe 9 m wind tunnel is a particularly key facility within the NRC portfolio, as its large scale and flexibility make it the wind tunnel of choice for a number of important industry sectors, including automotive, aeronautical and construction. Unlike most other wind tunnels, which tend to be smaller, the 9 m tunnel is not constrained by the need to admit only scale models – its high capacity allows it to accept full-size surface vehicles for aerodynamic development. This has an obvious benefit in that it removes the difficulty associated with interpreting data collected at a lower Reynolds number than full-scale conditions, but also offers advantages in terms of the cost and delays of fabricated models.

Equipped with a comprehensive array of sensors as well as devices to simulate turbulence, rain and snow, the 9 m wind tunnel is able to test most vehicles with high accuracy and repeatability at wind velocities reaching 200 km/h. To better meet the needs of the automotive industry, a ground simulation system, or rolling road, has also been added to the wind tunnel, comfortably allowing anything up to a large SUV or a standard pick-up truck to be subjected to realistic road conditions within the facility. Furthermore, these systems and the data acquisition and control system are continually upgraded and improved to meet client needs – in particular, the control and data acquisition components of the wind tunnel have recently undergone a major renovation.

HUMAN RESOURCESWhichever of its many wind tunnels is in use, NRC provides more than a research facility for clients; the organisation also offers expertise and knowledge accrued

in more than 85 years of testing. In addition to wind tunnel operators and test engineers, NRC clients can also utilise the advice of mechanical and instrumentation technical experts who are on hand to provide their valuable inputs.

The NRC itself benefits from a number of superior features that make it an attractive partner for business. Apart from having secure building access and the ability to pursue projects in strict confidentiality, NRC can also offer flexible business arrangements and the advantages of its strong relationship with Transport Canada and Environment Canada. Geographically, its proximity to Ottawa Airport and clients in the Northeastern US make it ideally located to continue the work that it has been performing for decades at the centre of automotive research in North America.

2 M × 3 M WIND TUNNEL

NRC’s 2 m × 3 m wind tunnel is one of the organisation’s most extensively used facilities. Although primarily suited to the scale-model testing of aeroacoustic and aerodynamic responses, the wind tunnel’s dimensions also make it ideal for live testing in the field of sport aerodynamics. Athletes including cyclists can use the wind tunnel, along with its extensive instrumentation, to obtain an accurate picture of how they can better position themselves and design their equipment to reduce drag. The wind tunnel is able to create wind at a considerable speed – up to 500 km/h – and has therefore been used to support industrial demands from aviation, wind energy, ground-based structures and automotive clients.

3 M × 6 M ICING WIND TUNNEL

Unlike the other tunnels, the 3 m × 6 m icing wind tunnel has an open circuit layout which, among other things, allows it to generate very cold test conditions when necessary. It also provides the opportunity to use the facility in much the same way that an engine test stand might be used, since contaminants can be ejected rather than being allowed to recirculate. Spray rigs are also installed in order to simulate an FAA-Appendix C certified icing cloud, completing an overall package that suits testing on aeronautical propulsion, as well as simulate rain for ground-based vehicles.

THE NATIONAL RESEARCH COUNCIL CANADA (NRC) offers wind tunnel testing services in its eight wind tunnels located in Ottawa, Ontario, at competitive rates that include the support of technical experts, research officers and engineers. The Council also offers research and business opportunities that can translate into collaborative agreements or consortia work. To discuss a project or find out more about how NRC can support your automotive business, please contact Craig Ceppetelli.

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Wheel rollers, just visible below this front wheel, improve simulation of the flow around the wheel wells and underbody.

Alain Goulet at the control of the NRC 9 m wind tunnel.

Canadian long track speed skater Ivanie Blondin fine tunes her aerodynamics in the 2 m x 3 m wind tunnel.

The 9 m wind tunnel is a key facility for the Automotive and Surface Transportation portfolio at NRC.

Today, the National Research Council Canada maintains eight wind tunnels in a range of sizes, all of which have different and valuable capabilities

ALTITUDE ICING WIND TUNNEL

At full speed (M=0.65), the altitude icing wind tunnel can generate static air temperatures as low as -35 °C, along with its ability to recreate rain and simulate altitude up to a height of 9,000 m – features making it ideal for testing the ice accretion characteristics of aviation sensors. Recently, NRC even added a controlled hot air supply to the setup so that clients could gauge not only the icing conditions, but also the efficacy of the measures they employ to counteract icing. This wind tunnel is also useful from the viewpoint of the many climate researchers interested in atmospheric conditions, who have used it to validate numerical models of ice formation and gain an insight into the physical processes involved.

0.9 M WIND TUNNEL

Originally created as a 1:10 scale model of the larger 9 m wind tunnel, the 0.9 m wind tunnel has proven an excellent testing ground for prototype development. Its reduced size makes the NRC’s smallest wind tunnel easier to maintain than the other facilities, and it is just as well equipped as its large-scale counterparts. Capable of generating winds with speeds of up to 160 km/h, the wind tunnel allows for particle image velocimetry measurements to be taken, and has been upgraded with acoustically treated turning vanes and acoustic wedges. These features accommodate measurements of the sound generated by a model under wind; a prime concern in the development of quieter cars and planes.

NRC WIND TUNNEL TESTING FACILITIES

OBJECTIVETo support industry, government and university clients in bespoke projects requiring wind tunnel testing facilities, applying innovative approaches to instrumentation, software and operations.

PARTNERSVarious project partners in aerospace, automotive and ground transportation, construction, and marine sectors.

FUNDINGNational Research Council Canada

CONTACTCraig CeppetelliPortfolio Business Advisor

Automotive & Surface TransportationNational Research Council of Canada1200 Montreal Road, OttawaON K1A 0R6Canada

T +1 613 998 9388E craig.ceppetelli@nrc-cnrc.gc.ca

www.nrc-cnrc.gc.ca

http://linkd.in/1DccFDT

@NRC_CNRC

DR GUY LOUIS LAROSE is a specialist of wind engineering and wind-tunnel testing at the Aerodynamics Laboratory of the National Research Council Canada.

Originally from Quebec City, he holds degrees from Laval University, the University of Western Ontario and the Technical University of Denmark. Before joining NRC in 1999, he worked for seven years in Copenhagen as an expert in bridge and bluff-body aerodynamics and has worked on the world’s longest bridges and tallest structures. At present, the focus of his research is on the aerodynamics of surface vehicles, Olympic sports and bridge cables. Dr Larose is Adjunct Professor at the University of Ottawa and Carleton University. He received the Queen Elizabeth II Diamond Jubilee Medal in 2013 for his contributions to engineering.

INTELLIGENCE

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