This simulation was inspired by The Slow Mo Guys’ video “90 ft. Vertical Spike Wave in Slow Mo” which shows the results of an experiment made by the FloWave Ocean Energy Research Facility. We use part of their video to compare results with our own simulation. https://www.youtube.com/watch?v=iWKFPTgkpXo&t=105s
The Vertical Spike Wave
The Vertical Spike Wave is the result of a concentric wave travelling towards its center. Depending on its velocity, the wave can collide in the middle and form a spike of water. This wave can be generated in a circular pool equipped of moving panels on the entire length of the perimeter that push in one coordinated motion the water towards the center. The pushers have to be activated simultaneously with the same motion in order to have the water travel in one single motion and collide at the same speed with the same energy. If the speed is high enough, the water will rise in the center of the pool in a high spike [Figure 1] and fall back splashing.
Model setup on FLOW-3D®
FLOW-3D was used to setup the simulation of the Vertical Spike Wave, then the result was post-processed on FlowSight. In order to model the circular wave, the mesh was defined on cylindrical coordinates. That allowed to simulate only a part of the pool [Figure 2] then to duplicate it later on Flow Sight to make it look like the entire pool was modeled.
Most of the measurements were given in The Slow Mo Guys’ video, so it was possible to give the simulation the real dimensions. The pool is about 50m wide and is equipped of 168 panels. We estimated that the pushers took 4s to motion back and forth once with an angle of 17.2°.
To setup the simulation, a pool was created simply on FLOW-3D using the basic geometry provided by the software, then the panel was imported as an STL file. The pusher was setup as a moving object [Figure 3] to which a motion defined in advance was applied. The water is completely still at first, and a single push is sufficient to create the vertical spike wave.
The overall motion and energy correspond to the reality with a very good precision. Some differences can be seen only in the disrupted front of the spike: its effects are negligible for our comparison but could be taken into account with a complete 3D and 2-fluid simulation.