Computational Fluid Dynamics and Downhill Skateboarding… really?

Yes, really.

Regular readers of this blog will know that Pete Connolly has the speed bug like no other, and he’s working together with many influential people in European downhill scene to push the boundaries of speed on his skateboard.

If you’ve ever been really fast on a skateboard, you’ll know that aerodynamics are a big part of the game.

Recently Pete’s been working with SimScale – a Computational Fluid Dynamics simulation company – to analyse and learn from his wind tunnel data.

This post originally appeared on Simscale’s blog, and is reproduced here with kind permission.

Downhill skateboarding record being broken as Pete Connolly hits 146.73 km/h

In September 2017, gravity sports enthusiast Pete Connolly became the first person in history to exceed 91 mph on a skateboard, making him a world record holder in downhill skateboarding as well as deeming him the fastest downhill skateboarder on the planet.

This fastest skateboard speed downhill (standing) record was achieved at the L’Ultimate Descente competition in Quebec, Canada. The extreme event invites masters of all things gravity sports from skateboarders to gravity cars to try to achieve the fastest speeds humanly possible, and the chance to make history.

How Was This Possible for Pete?

In order to become the world record holder for downhill skating, a lot of time, effort, and aerodynamic design factors were accounted for and evaluated.

“As you might expect we get fairly into the aerodynamic aspects of our sport when pushing the top speeds. To set the record, I designed and produced an aerodynamic leather suit to skate in and did a lot of real-world testing in Switzerland to gather data on a road with very consistent conditions.” – Pete Connolly

In order to optimise his suit, board, helmet, and body position, Pete underwent multiple sessions of real-world and wind tunnel testing.

Wind tunnel testing of Pete’s gear and tuck position

Wind Tunnel Testing: Benefits and Limitations

With a new goal set, Pete and his team went to the HEPIA wind tunnel in Geneva, Switzerland to further undergo testing of equipment and body positions to ultimately reduce drag and any areas of re-circulation. Unlike other resistance forces like friction, drag depends directly on the drivers speed and increases with the cube of velocity and linearly with frontal area.. Wind tunnel data was used to determine where drag and air resistance was creating a negative impact.

“My time in the wind tunnel was greatly beneficial, while I managed to improve my overall drag training in the tunnel, it shared the same limitation as real-world testing; you can only see the overall drag we create… My goal with modelling and running simulation is to establish if there are any key hotspots that we can hone in on to result in the best improvements possible, rather than investing into improving an aspect of our body positions or equipment that may not make the most difference.” – Pete Connolly

Aerodynamic design testing in HEPIA wind tunnel in Geneva, Switzerland

Pete and his team decided to combine their wind tunnel testing efforts with online simulation, to identify high benefit/quick fix areas with a focus on improving these aspects. By utilizing CFD analysis, future training, development, and testing can be more targeted to essentially increase speed by combining real-world, wind tunnel, and online simulation efforts—the aerodynamic testing trifecta.

Full-scale wind tunnel testing of front-tuck position for downhill skateboarding

The New Challenge: Online Aerodynamics Simulation

To jump-start this process, World Champion Downhill Skateboarder and industrial design specialist Martin Siegrist lent his assistance by creating a full 3D scan of Pete and his board in his record-breaking stance. Using this CAD model, Pete then got in touch with SimScale to begin some initial online simulation to integrate his real-world and wind tunnel data with virtual insights.

Pete’s body and skateboard CAD from Martin Siegrist

Downhill Skateboarding Meets SimScale

Pete’s need for speed brought him and his CAD model to SimScale to virtually test the aerodynamics of his kit.

“What I wanted from using simulation was to learn what part of the design to focus on to make the biggest difference. You can spend a lot of time focusing on all the little things to make moderate changes, but with simulation, you can pinpoint the area that needs to be modified the most.” – Pete Connolly

Velocity plot of Pete and his board (Source: SimScale)

The Initial Simulation Results

The external aerodynamic analysis found areas of recirculation on Pete’s body from post-processing the results of both velocity and pressure plots at various planes in the transient simulation.

Velocity plot from waist level from Pete’s body position

What’s Next for Pete in Downhill Skating?

With the new findings from the simulation data, the next steps lead to another full body scan testing different hand and board modifications, followed by more real-world, wind tunnel and virtual testing—and hopefully some more broken records for downhill skateboarding to follow!

“For me I wish to push it even further and break the 100mph—quite an ambitious goal but one I feel is achievable… improving on my current record is something I already believe I can achieve.” – Pete Connolly

The post Computational Fluid Dynamics and Downhill Skateboarding… really? appeared first on Lush Longboards UK | Cruisers | Downhill | Freeride Skateboards since 1999.

Bristol Board Meeting 2018 – What a blast!

This year’s Bristol Board Meeting was a blast!

Around 100 skaters turned up for a day out on boards of all shapes and sizes in perfect weather.

Update 22/11/2018:

We have hit a huge £2,430.50 raised for Clic Sargent this year!!! That’s way more than our target!!

Huge thanks for everyone who put the effort in, and to everyone who donated in support!

Also massive thanks to all the Raffle Sponsors for their prize donations!

See you next year!!!

Update 16/11/2018:

The winners of our competition are:

Neil Adams wins the Hackbrett Wasser deck, having raised a whopping £940.50!!!
Ben Dorney wins a set of Orangatang Kegels having raised over £240!!

Awesome effort from these two, well deserved winners!!

Update 26/10/2018:

A couple of raffle winners have very kindly agreed to re-donate their prizes in order to raise even more money for Clic Sargent!

So we’re running a competition for the most amount of money raised via the event.

  • 1st Prize: The person who raises the most will win a Hackbrett Wasser deck!
  • 2nd Prize: The person who raises the second largest amount will win a set of Purple Orangatang Kegels!

Please get your donations in to our Justgiving page. If someone is donating on your behalf, please ask them to put your name on their donation. If there are already some donations on the Justgiving page that you’d like to claim as yours, email us and we’ll add to your running total!

We’ll announce the winner on the 15th November, so please get your donations in before this date!

Update 25/10/2018:

The raffle raised £985 – so we have a total of £1,510 on our Justgiving Page right now! Congratulations to all the winners and massive thanks to everyone who entered!!

Update 24/10/2018:

Check out the edit from Plymouth Uni Skate Society, who were flying a drone over the pumptrack for a lot of the day! If you’re longboarding in Plymouth be sure to hit them up!

It’s 13 miles from Bath to Bristol along the cycle path. The bit just outside Bath was really a treat, skating through some beautiful countryside in glorious autumn sunshine!

“How long does it take to skate 13 miles?”

“It depends how many pubs you stop at along the way!”

Parts of the cycle path have benefitted from a resurface in recent years – which was a welcome rest from the incessant foot buzz!

A welcome rest at the halfway cafe!

Everyone got some laps in at the newly-surfaced Hillfields Pumptrack. We’re stoked to see more tarmac pumptracks appearing in the UK!

This year’s prize stash was bigger than ever! With brands like Lush, Cult, Sabre, Loaded, Orangatang, Arbor, Z-Flex, Hackbrett and Vandem Longboard Shop, there were a lot of stoked faces, and raffle tickets added significantly to the total raised for Clic Sargent.

The youngest skater to do the 13 mile push was just five years old! We thought she was worthy of this Arbor deck as a prize… she was super happy!!

Everyone crowded into Vandem Longboard Shop on the way back home…

Massive thanks to everyone who came and skated, you made the day what it was!!

Keep your eye on this post for more updates and look out for next year’s event!

Bristol Board Meeting Page

The post Bristol Board Meeting 2018 – What a blast! appeared first on Lush Longboards UK | Cruisers | Downhill | Freeride Skateboards since 1999.