Sports Aerodynamics #3 - Aerodynamic backpack ventilation


Sports Aerodynamics #3 - Aerodynamic backpack ventilation

For more on cycling aerodynamics: - Iron man: - Custom aerodynamic clothing: Aerodynamic backpack ventilation – Vaude has your back Why do we sweat when we exercise? Well, we like to keep our body temperature constant and when doing sports, that temperature increases. To counter that, we sweat. The sweat evaporates into the air around your body and the energy needed to do so is drawn from your body, cooling it down. But what if you’re blocking the air? Then the sweat piles up and you’ll need to sweat even more in other places to get enough cooling. It leaves commuters with a soaked T-shirt on the back and athletes with decreased performance. So Vaude turned up the technology level on their newest backpack to come up with a solution for this. In a first step, they ran several airflow simulations on a digital mountain biker without a backpack, simply to understand how the air moves around the body and find sources of cooling. They saw that the airflow around neck & shoulders re-joins at the higher part of the back, to then channel down at relatively high speed before letting go somewhere lower down the back. At some point, the air going around the torso was also considered to help drive air underneath the backpack. But with the air being too turbulent after going around the torso and the backpack hidden in the wake of the rider’s back, this turned out to be less efficient. So together, we figured it would be quite nice to use the central airstream at neck & shoulders to help cool down the rider’s back in the locations where it matters most: the central part of the lower back. Multiple concepts were thought of, all with the aim to capture this airstream and channel it between the rider’s back, and the backpack itself. Aerodynamically optimized channels were carved out of the padding between rider and backpack and after numerous checks via simulation, we ended up with a design that outperforms anything that is currently out there in the market. And that’s not just us talking: Vaude performed multiple wind tunnel tests, with riders going at it in well-controlled conditions, like the temperature, seating position, produced power and so on. They even went to the Sports Tech Research Centre, who operate a specialized wind tunnel, to put their new backpack design to the test. ----------------------------------------------------------------------------------------------------------- The AirShaper videos cover the basics of aerodynamics (aerodynamic drag, drag & lift coefficients, boundary layer theory, flow separation, reynolds number...), simulation aspects (computational fluid dynamics, CFD meshing, ...) and aerodynamic testing (wind tunnel testing, flow visualization, ...). We then use those basics to explain the aerodynamics of (race) cars (aerodynamic efficiency of electric vehicles, aerodynamic drag, downforce, aero maps, formula one aerodynamics, ...), drones and airplanes (propellers, airfoils, electric aviation, eVTOLS, ...), motorcycles (wind buffeting, motogp aerodynamics, ...) and more! For more information, visit

Trusted By

  • General Electric Renewable Energy
  • Deme
  • Aptera
  • Decathlon
  • MV Agusta
  • Vaude
  • Damon Motorcycles
  • Pal-V - World’s First Flying Car
  • Deme
  • A2Mac1
  • SenseFly
  • Sapim

Awards and Support

  • Solar Impulse
  • iMec
  • Voxdale
  • Professional MotorSport World Awards – MotorSport Technology of the Year

Code contributions by

  • KU Leuven
  • Inholland
  • Linkoping University