Aerodynamics of bluff bodies: Surface vehicles, ground-based structures and athletes

 
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Photo: NRC performing aerodynamic tests on a 30% scale model of a transport truck.

Technical service highlights

Air flow affects more than just aircraft. Non-aeronautical, bluff and semi-streamlined bodies such as cars and bridges are equally affected by how air moves around or through them.

NRC has the expertise and state-of-the-art facilities to support our clients' aerodynamics testing requirements in a variety of areas specific to bluff bodies: design, stability, fuel efficiency, performance, drag, wind-induced dynamic loads, vibration and noise.

Our clients include original equipment manufacturers (OEMs), after-market part manufacturers, transport operators, government and regulatory authorities, major civil engineering firms, small start-up companies with specific aerodynamic needs, national sports teams, and more.

NRC tailors its testing to improve the product design and performance of:

  • Surface vehicles – trains, buses, passenger cars, motorcycles, race cars, light-duty and transport trucks, and ships
  • Ground-based structures – tall buildings, wind turbines, and long-span bridges
  • Athletes – National team athletes and Olympians as well as sports equipment and clothing

What we offer

NRC is equipped to provide a variety of services related to bluff body aerodynamics.

The measurement, validation and interpretation of aerodynamic data

Our team of experts has decades of experience in delivering cost-effective approaches for acquiring accurate data and interpreting its impacts on your products. Our state-of-the–art testing bays and equipment include six wind tunnels and computational fluid dynamics (CFD) capabilities. Our experts use a wide range of parameters to collect representative data in scaled conditions, taking into account the underlying physics of the test.

Acoustic testing

We have advanced capabilities in the measurement and characterization of flow-induced noise. Our aeroacoustic tests identify areas clients can explore to develop quieter products, including vehicles. When studied together with aerodynamic data, the acoustic data can pinpoint areas of excessive drag, which if addressed can lead to improved fuel efficiency and quieter vehicles.

Full-scale vehicle testing

Our 9 m wind tunnel can accommodate a range of full-size vehicles, from cars to Class 8 transport trucks. This facility is unmatched on the continent when it comes to assessing vehicle drag in yawed winds. The backbone of this capability is our flush-mounted, moving ground plane within a 7  m diameter turntable. Generating spectrally correct turbulence allows us to create even more realistic conditions for aerodynamic measurement. We can also work with you to test and develop after-market spoilers and non-OEM parts to determine flow changes and potential gains in fuel economy.

When it comes to your early concept design work, our 2 x 3 m wind tunnel with its high-precision balance is an ideal model-scale wind tunnel. Tests are accurate and repeatable. Every time.

Ground-based structures

From aeroelastic scale-models of bridges to product prototypes, our team can assess the aerodynamic aspects of your design in our facilities. With a trend toward ever-taller buildings and ever-longer bridge structures, proper assessments of wind loads become paramount. NRC has the expertise and facilities to conduct static and dynamic experiments on proposed structural designs in both smooth and turbulent flows at Reynolds numbers unmatched elsewhere.

Cable vibration studies

Inclined bridge cables are susceptible to wind induced vibrations that can be reproduced in our facilities. Results from our research projects in this area have impacted international regulations, and we continue to enhance our understanding of these complex flow-induced phenomena in both smooth and turbulent flow. Rain and ice add further threats to the cable performance, and ultimately to bridge safety. Our icing wind tunnel, allows us to study the effects of icing and turbulence on the performance and safety of bridge cables.

Non-intrusive flow diagnostics

Using optical measurements, we can perform non-intrusive flow diagnostics to quantify the details of the flow over any product.

Sports aerodynamics

Flow optimization can mean the difference between winning a medal and a good performance. Our specially tuned facilities allow us to create correctly scaled turbulence, and provide real-time feedback, allowing professional and world-class athletes to shave valuable seconds off of their performance targets. See more about our research and testing in sports aerodynamics.

Why work with us

Your benefits

Our aerodynamic tests allow us to gather quality data to guide your decision-making as you move through the product design, development and refinement stages.

Through carefully chosen experiments and modelling, we can identify ways to help you:

  • enhance stability
  • heighten performance
  • improve fuel efficiency
  • improve safety
  • minimize drag coefficients
  • reduce noise

Our value

In anticipation of future certification requirements, our team of experts can modernize our facilities and services to meet our clients' unique needs. For example, we upgraded our 9  m wind tunnel in response to an increasing need for representative flow simulation for the study of drag-reduction of vehicles. We developed a flow treatment system, which recreates the types of turbulence vehicles encounter on North American highways.

When it comes to fuel economy studies, our aerodynamics experts, mechanical engineers, electrical engineers and technicians also work closely with colleagues in the surface transportation field who have complementary and extensive experience overcoming materials and manufacturing challenges. These experts from the NRC's Automotive and Surface Transportation Research Centre apply their expertise and access specialized infrastructure and advanced processes for passenger vehicles, heavy-haul and light rail, heavy-duty trucking fleets, specialized military vehicles, and first-response vehicles.

NRC's experts in Design and Fabrication Services develop prototypes and tailor models and auxiliary systems to support test programs in our wind tunnels. Beyond supporting our internal needs, NRC offers these design and fabrication services to industry clients.

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Photo: Min . of State for Sport, the Honourable Bal Gosal gets advice from Olympic speedskater Ivanie Blondin at an NRC wind tunnel.

In addition to the technical services we provide, our aerodynamics team also actively contributes to broader NRC initiatives and collaborative projects involving national and international partners. Bluff-body aerodynamic clients may be interested in the following initiatives:

  • Advanced Manufacturing and Design Systems (AMDS)
  • Fleet forward 2020
  • Critical Concrete Infrastructure

Our aerodynamics team is recognized internationally for its unparalleled research in bluff bodies, including studies to improve the stability of the world's tallest buildings and longest bridges, to enhance vehicle performance, and to contribute to Canada's medal count during the Olympics.

Contact us

Contact us to discuss how NRC can help fulfill your research and technology needs through our fee-for-service testing, consulting, collaborative research agreements and licensing arrangements.

Dean Flanagan, Business Development Officer
Telephone: 613-990-8319
Email: Dean.Flanagan@nrc-cnrc.gc.ca