Postpossecing of FREE-SURFACE ELEVATION
Dear all,
I try to measure the free-surface elevation of water for my case. And I read the introduction about how to numerically commute free-surface elevation.
But I am not sure whether it will compute the splash of water to regard as the free-surface elevation, or not?
I think it will.
As shown in Fig.1 below, the position I measured is under the splash (red dot) at the 24th step (0.05s/step), but the waveform obtained seems unreasonable. In Fig.2 the amplitude of the first wave is 0.016 at the 23rd stepbut becomes 0.13m suddenly at the 24th step.
Fig.1
Fig.2
Looking forward to your reply. Many thanks.
Kind regards,
Lucy
Comments
It does seem to be the case. This is due to the way the gauge system works using this principle only in one direction (vertical Z). This is also why this case gets a "break" in the white line of gauges:
https://www.youtube.com/watch?v=UyqjJy_vwcw
If you really want to handle this, you would perhaps need to use a 2D grid of measurements points and then "block" out the shape of the wave profile and some coding to check if it is a splash or not.
Personal comment; your simulation looks interesting.
Kind regards
hi, @Asalih3d
Thank you for your comment and interest in my simulation.
As you say, I can try to use a 2D grid of measurements points and then "block" out the shape of the wave profile. You mean I can cut a 2D section from my 3D simulation, right?
Due to I just started learning Dualsphysics, I am trying to achieve it. But, I still don't know how to do it. Could you mind recommending some reference materials to help me learn how to do it?
Many thanks
Exactly, imagine a plane discretized with measurement points cutting through the domain in such a way that you get a "side view" of the simulation. This would then allow you to "block" out the shape, and using programming getting a rough idea of splashes etc. if your plane is discretized fine enough.
For resources on doing this look at the partvtk_out documentation and @Hannes beautiful answer here, he can probably guide you a bit better than I can too:
https://forums.dual.sphysics.org/discussion/1948/isosurface-to-generate-a-contour
Kind regards
Hi @Asalih3d ,
Thank you for your reply. This is very useful to me.
Meanwhile, I have a question about the measurement tool of elevation wanna discuss with you and @Alex. As we know, we can set different dp of particle for our model. But I don’t know whether there is a measurement error in the elevation measurement. If so, how do we know the accuracy of the elevation measurement, and is it related to dp?
Kind regards,
Lucy
Say you have a dp = 0.05 m. What you could do then is making the plane with different resolutions of dx = dp, dx = dp/2, dx = dp/4 and even trying the other way too dx = 2*dp, dx = 4*dp, etc. to get a better understanding of what the effect is. As dx approaches zero, the measured values should start to converge.
In my practical experience I always use either dx = dp or finer. You can make it as fine as you want in theory, you will never pull more information out, but you will have a finer grid to use for something else afterwards if you so wish / need.
Kind regards