breaking waves

Posted by: Borzki

breaking waves - 08/27/19 12:04 AM

Hello Stressers and Sub-sea Pipeline Specialists,

Just a general question based on your experience on subsea pipelines. Are you encountering in your professional practice breaking waves? Or the wave theories in most of the beam element software is sufficient to consider which does not address breaking waves? Just want to have an idea if I need to widen my scope of study to enter into offshore pipeline field.

Pardon if my question is too general.

Just correct me if there is any error in my statement above.

Thanks & Warm Regards,
Posted by: Michael_Fletcher

Re: breaking waves - 08/27/19 09:05 AM

My opinions are thus:

If you're building a line on the beach, probably.

In the deep sea, natural breaking waves are likely less of a hazard than the waves themselves.

However, also in the deep sea, it's uncommon any meaningful guidance or attention to unnatural breaking waves for pipelines to be made - only for the hull.

For example:

[video:youtube]https://youtu.be/ip62Dn-CpbY?t=276[/video]
Posted by: Borzki

Re: breaking waves - 08/27/19 08:29 PM

Thanks Michael for your opinion. And also for sharing the video. This is indeed a very interesting topic. If I am not mistaken, usually this wave data is available from naval architects? How do you usually obtain those wave data, marine growth and current data in a project?

Any other opinion is greatly appreciated.

Just correct any wrong statement I've made.

If I'm not mistaken the videos below are CFD simulation of breaking waves.

https://www.youtube.com/watch?v=01NnxxR9ydg

https://www.youtube.com/watch?v=V_zv-JZ8Dpo

Cheers!!!
Posted by: Michael_Fletcher

Re: breaking waves - 09/03/19 12:57 PM

I suppose it just depends. Typically, the end user provides this information, but the US has a number of buoys in various regions around the US to pull hard data from.

With respect to marine growth, they may have plans to maintain and remove, or they may install an anti-growth paint. Either their equipment will get a very minor, thin coat, or if they choose to let it go, it'll look like the world's ugliest prom dress.

With regards to the 2 videos, they both very simplistically simulating the waves on a beach.

You might find this video to be interesting, although perhaps not exceptionally helpful. My takeaway, though, is that breaking waves just aren't as powerful as normal waves, but you could argue they strike in a more concentrated point higher up... sometimes.

https://youtu.be/SWhPJmfLzNo
Posted by: Michael_Fletcher

Re: breaking waves - 09/03/19 01:01 PM

And here's another similar video, but with different "natural" obstructions. You could imagine that one pipe next to a hull could be somewhat chaotic, but then add several pipes in the same area.

https://youtu.be/BzKNKPpNMB8
Posted by: Borzki

Re: breaking waves - 09/03/19 08:11 PM

Thanks Michael for sharing the two videos. You're right in saying that breaking waves is more of a concern in shallow water near the beach.

I've found this video on youtube regarding the experiment of wave slamming forces on truss structures in shallow water.

https://www.youtube.com/watch?v=3Wk7rOQgsIY

Any other opinion is greatly appreciated.

Cheers!!!