>> Hi and welcome to the Product Design Show.
I'm Allison Toepperwein. >> And I'm Vince Penman.
This is the surfing episode, yeah, where we explore how engineers create indoor waves.
>> Bruce McFarland, engineer inventor at American Wave Machines,
talks to us about how they developed an innovative technology called SurfStream.
This waterpark environment provides surfers with an incredible indoor ride.
Bruce got his inspiration for this technology from the idea of surfing a standing wave on a river
and the dream of an endless ride.
We're going to look under the hood of this impressive system
and explore its design from a fluid dynamics perspective.
To do that, we'll need to reach all the way back to our university fluids class
and revisit the natural phenomenon known as a hydraulic jump, the major principle
in which the surfing wave machine is designed.
>> Hydraulic jump is a phenomenon that naturally occurs in open channel water flow.
When a moving flow of water releases into an area of lower velocity flow, it slows down very quickly.
The kinetic energy of the flow is converted to potential energy
in the form of a wave known as a hydraulic jump.
An example of an everyday hydraulic jump is the stationary circular wave
that forms around a stream of water as it flows out of the tap and contacts a flat surface.
The jump is characterised by fast moving water before the jump, where there is also low water height
and a smooth flow, and a slower flow after the jump, where there is also higher water depth
and a more turbulent flow.
>> To make a standing surf wave, engineers use stationary submerged objects
to direct the moving water upwards.
The shape of the object is altered to create different types of flows.
The determination of this shape involves complex calculations which we've love to do
but Vince forgot his calculator.
>> The SurfStream system starts with a series of pumps in one end of a pool
that push out a smooth, flat, fast flow of water.
This water is forced over a contoured bottom that includes a spoiler
that is shaped much like a spoiler on the rear of a car.
The water then encounters a smooth bump Bruce calls a foil.
When the water is forced over these contours, the hydraulic jump is formed between a spoiler and the foil.
>> What really sets the man made waves apart is that they are standing waves, unlike the waves in the ocean.
When surfing on the hydraulic jump, a rider has to manage the dynamic relationships
between water streaming over the jump, the nonholonomic constraints of the board surfaces
acting on the water, and the gravity vector.
Now you know why we just say surfing.
The result is an infinite ride in a finite space that feels like surfing a wave in the ocean.
>> The standing wave can be adjusted to different shapes, including left and right barreling waves,
stable beginner waves and natural standing waves which are deeper and more challenging.
This is accomplished by changing parameters such as incoming flow rate, the incoming channel width and
the contour of the bottom including the spoiler and the foil.
The team at American Wave Machines selected Creo's direct modeling to manipulate these parameters
because it allows them advanced surfacing features and rapid design changes.
For example, if you want to change a barreling wave from right to left,
a mirror image of an angled spoiler replaces the original.
The angled barrier allows the water to be pushed sideways as well as forwards,
creating a wave in which the water is pushed to one side in a curl, much like a wave found naturally in the ocean.
>> So now you must be wondering, where does the water come from?
The answer? The water is circulated continuously.
On a curling wave, for example, the water is pushed to one side of the pool called the Venturi area.
The water has to escape so as not to accumulate and destroy the wave effect.
This water is forced along this Venturi channel and exits through a series of drains
which feed back to the pumps, thus completing the cycle.
>> You can try a free for lifetime version of Creo's direct modeling yourself,
the same software the team at American Wave Machine used to design the SurfStream environments.
Just go to ptc.com/go/modelingpe.
>> If you like the show, please give it a Like on Facebook, subscribe on YouTube or give us a rating on iTunes. 00:04:29.800,00:00:32.799 We'll see you next week for more great design engineering.