Wave elevation vs tank length

lingyo · October 27, 2013, 22:15

Hello.
I´m simulating waves.I know how to plot in a chart the wave elevation vs time.
but I can't figure out how to plot wave elevation(or wave profile) vs tank length,can anyone help?? thanks

ghorrocks · October 28, 2013, 04:13

Well, what actually is wave profile versus tank length anyway? You are trying to reduce a 3D field to a 1D line, so you have to do the reduction somehow - maybe sampling along a line, averaging across a profile or some other method. So let us know how you plan to do this reduction in dimensions and we will see if we can help you.

And please do not duplicate post again in future. I have deleted the duplicate post.

lingyo · October 28, 2013, 07:44

Thank you very much , Glenn.
My simulation is shown in fig.1
I did a plane and use expression"areaInt(WATER.Volume Fraction)@Plane/20[m]" to plot fig.2,and the chart is composed by wave profile vs time.
my question is,is it possible to plot the chart composed by wave profile vs tank length(x)like fig.3 ??
I can't chose "x" in X values when the xy-transient is selected.
If select xy,I can chose "x" in X values but I don't know how to express the Y values

ghorrocks · October 28, 2013, 16:46

You can do this in CFD-Post using a session file to generate the data points and export them so you can plot them elsewhere.

Also, as your waves are just about 2D then you can take the side plane and draw a VF=0.5 contour and that is your wave profile. You might be able to plot that line as an XY plot; or you can export the line and plot it in another package like matlab, excel or whatever you like.

Ivan Ahda · October 21, 2018, 04:55

Quote:

Originally Posted by ghorrocks

You can do this in CFD-Post using a session file to generate the data points and export them so you can plot them elsewhere.

Also, as your waves are just about 2D then you can take the side plane and draw a VF=0.5 contour and that is your wave profile. You might be able to plot that line as an XY plot; or you can export the line and plot it in another package like matlab, excel or whatever you like.

Could you tell me please how to plot it in 2D, wave elevation vs flowtime, step by step, i need it for my project, thanks

ghorrocks · October 21, 2018, 05:30

If you want a wave history at a point one way of doing it is to define a monitor point with the CEL function max(water.volume fraction*y). This assumes your liquid phase is called water and positive y is upwards.

Ivan Ahda · October 21, 2018, 05:41

Quote:

Originally Posted by ghorrocks

If you want a wave history at a point one way of doing it is to define a monitor point with the CEL function max(water.volume fraction*y). This assumes your liquid phase is called water and positive y is upwards.

How to do that? my simulation is 2D
i want to plot my simulation in CFD post

ghorrocks · October 21, 2018, 05:53

On second thoughts, I don't think my function on the last post will work

Where in your simulation do you want the wave height?

Ivan Ahda · October 21, 2018, 05:57

Quote:

Originally Posted by ghorrocks

On second thoughts, I don't think my function on the last post will work

Where in your simulation do you want the wave height?

i want to plot just like this

ghorrocks · October 21, 2018, 16:47

Sure, but at what point do you want to generate the height data from? The inlet or outlet boundaries are the easiest places.

Ivan Ahda · October 22, 2018, 11:29

Quote:

Originally Posted by ghorrocks

Sure, but at what point do you want to generate the height data from? The inlet or outlet boundaries are the easiest places.

from the inlet, could you help me to do that step by step?
my simulation is in 2D domain

ghorrocks · October 23, 2018, 20:29

I am not going to write a step by step guide. I don't have the time.

If you do a CEL expression for the area integral over the inlet boundary of the water volume fraction it will give you the area of the inlet under the water level. If the thickness of the inlet is known you then have the height.

Ivan Ahda · November 6, 2018, 02:51

Quote:

Originally Posted by ghorrocks

I am not going to write a step by step guide. I don't have the time.

If you do a CEL expression for the area integral over the inlet boundary of the water volume fraction it will give you the area of the inlet under the water level. If the thickness of the inlet is known you then have the height.

i dont have time too to understand your explanation so i search other explanation

Kathe · November 23, 2023, 15:50

Quote:

Originally Posted by Ivan Ahda

How to do that? my simulation is 2D
i want to plot my simulation in CFD post

Hi Ivan, I have problems with plotting the free surfaces as you show in your first image. Can you tell me how to do it, please?

kailashnadhrokkam · August 6, 2018, 12:12

Quote:

Originally Posted by lingyo

Thank you very much , Glenn.
My simulation is shown in fig.1
I did a plane and use expression"areaInt(WATER.Volume Fraction)@Plane/20[m]" to plot fig.2,and the chart is composed by wave profile vs time.
my question is,is it possible to plot the chart composed by wave profile vs tank length(x)like fig.3 ??
I can't chose "x" in X values when the xy-transient is selected.
If select xy,I can chose "x" in X values but I don't know how to express the Y values

create an iso surface and select volume fraction of water phase as your variable

Ivan Ahda · October 22, 2018, 11:25

Quote:

Originally Posted by lingyo

Thank you very much , Glenn.
My simulation is shown in fig.1
I did a plane and use expression"areaInt(WATER.Volume Fraction)@Plane/20[m]" to plot fig.2,and the chart is composed by wave profile vs time.
my question is,is it possible to plot the chart composed by wave profile vs tank length(x)like fig.3 ??
I can't chose "x" in X values when the xy-transient is selected.
If select xy,I can chose "x" in X values but I don't know how to express the Y values

could you tell me please how to plot like that, step by step, thanks
elevation vs flowtime

Kathe · November 23, 2023, 15:51

Quote:

Originally Posted by lingyo

Thank you very much , Glenn.
My simulation is shown in fig.1
I did a plane and use expression"areaInt(WATER.Volume Fraction)@Plane/20[m]" to plot fig.2,and the chart is composed by wave profile vs time.
my question is,is it possible to plot the chart composed by wave profile vs tank length(x)like fig.3 ??
I can't chose "x" in X values when the xy-transient is selected.
If select xy,I can chose "x" in X values but I don't know how to express the Y values

Hi, I have problems with contouring the wave elevation as you show in your first image. Can you tell me how to do it, please?

ghorrocks · November 23, 2023, 18:54

The images are just a iso-surface of volume fraction (of vf=0.5).

October 27, 2013, 22:15	Wave elevation vs tank length	#1
lingyo New Member chuan yu Join Date: Oct 2013 Posts: 2 Rep Power: 0	Hello. I´m simulating waves.I know how to plot in a chart the wave elevation vs time. but I can't figure out how to plot wave elevation(or wave profile) vs tank length,can anyone help?? thanks

October 21, 2018, 05:30		#6
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,718 Rep Power: 143	If you want a wave history at a point one way of doing it is to define a monitor point with the CEL function max(water.volume fraction*y). This assumes your liquid phase is called water and positive y is upwards. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

October 21, 2018, 05:53		#8
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,718 Rep Power: 143	On second thoughts, I don't think my function on the last post will work Where in your simulation do you want the wave height? __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

October 21, 2018, 16:47		#10
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,718 Rep Power: 143	Sure, but at what point do you want to generate the height data from? The inlet or outlet boundaries are the easiest places. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

October 23, 2018, 20:29		#12
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,718 Rep Power: 143	I am not going to write a step by step guide. I don't have the time. If you do a CEL expression for the area integral over the inlet boundary of the water volume fraction it will give you the area of the inlet under the water level. If the thickness of the inlet is known you then have the height. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

October 28, 2013, 04:13		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,718 Rep Power: 143	Well, what actually is wave profile versus tank length anyway? You are trying to reduce a 3D field to a 1D line, so you have to do the reduction somehow - maybe sampling along a line, averaging across a profile or some other method. So let us know how you plan to do this reduction in dimensions and we will see if we can help you. And please do not duplicate post again in future. I have deleted the duplicate post.

October 28, 2013, 16:46		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,718 Rep Power: 143	You can do this in CFD-Post using a session file to generate the data points and export them so you can plot them elsewhere. Also, as your waves are just about 2D then you can take the side plane and draw a VF=0.5 contour and that is your wave profile. You might be able to plot that line as an XY plot; or you can export the line and plot it in another package like matlab, excel or whatever you like.

November 23, 2023, 18:54		#18
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,718 Rep Power: 143	The images are just a iso-surface of volume fraction (of vf=0.5). __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Pressure for wave height in an Water Wave Tank	Cluain	CFX	8	December 6, 2021 03:58
[waves2Foam] Waves2Foam Related Topics	ngj	OpenFOAM Community Contributions	660	August 20, 2018 12:39
WAVE TANK star-ccm+ . wave height dampens. WHY?	muhsin	STAR-CCM+	3	October 9, 2012 13:24
Wave tank dynamic mesh	Doro	FLUENT	0	October 27, 2011 04:39
active wave absorb(about wave tank)	zhaochuangang	ANSYS	0	September 22, 2010 02:29