[ghorrocks]

Sorry, I forgot that this was applied to a VOF model. Yes, you need a VOF model for the free surface and Lagrangian particles for your particles to track.

[pashazanousi]

Originally Posted by ghorrocks

Sorry, I forgot that this was applied to a VOF model. Yes, you need a VOF model for the free surface and Lagrangian particles for your particles to track.

How I can imlplement the lagrangian particles to VOF Model?

[ghorrocks]

Look at the tutorial examples to see how to set up a particle tracking simulation.

Don't ignore the convection only additional variable suggestion I made right at the start. This approach is MUCH easier to implement and might be good enough for you.

[pashazanousi]

I didn't find any tutorial about particle tracking...I'm really confused...
I tried some thing but didn't get result....What should I do?
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1.png

2.png

3.png

4.png

[Gert-Jan]

You only defined how particle look like and their interaction with air.
But where do you inject them?

[pashazanousi]

Originally Posted by Gert-Jan

You only defined how particle look like and their interaction with air.
But where do you inject them?

I don't want do Inject them...I want some particle to plot their path vs simulation time...If I define Inection region I should more than 100 region...let's assume I create region...I define mass flow rate and injection velocity and then what happen?...I get the desire result?...How I plot the particle path?

[ghorrocks]

First of all, let me repeat this for the third time:

Don't ignore the convection only additional variable suggestion I made right at the start. This approach is MUCH easier to implement and might be good enough for you.

If you are having problems with the Lagrangian particle approach you should do this approach as it is much simpler.

And regarding Lagrangian particle tracking - all the basics are covered in the CFX tutorials available in the CFX documentation and the ANSYS Customer webpage. This includes how to set them up and how to visualise them.

I also recall saying previously that you cannot use an injection region to place your particles. The ONLY way to place particles in specific locations is using a user fortran routine.

[pashazanousi]

Thank you ghorrocks;
I want to learn Fortran for cfx...I'm looking for a Tutorial...a proper one...

[pashazanousi]

I define a material with Water at 25 properties.
I define a injection region.
Simulation time:0.02 [s],Step:0.01 [s]
But error occur and the result is unacceptable...
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[ghorrocks]

We are wasting our time here. Can you please try the additional variable approach I have suggested? The Lagrangian particle approach is not simple and you will need a lot more experience in CFD before you will get that working.

I am not going to help you further on this thread if you persist with the Lagrangian particle tracking. I will only assist you with the additional variable approach.

[pashazanousi]

Originally Posted by ghorrocks

We are wasting our time here. Can you please try the additional variable approach I have suggested? The Lagrangian particle approach is not simple and you will need a lot more experience in CFD before you will get that working.

I am not going to help you further on this thread if you persist with the Lagrangian particle tracking. I will only assist you with the additional variable approach.

thank you for your attention...
How I can create velocity vector,start from end point of previous step Vectors?

[ghorrocks]

I don't understand your question, can you ask it again please? I also do not understand what relevance it has to this thread.

[pashazanousi]

Originally Posted by ghorrocks

I don't understand your question, can you ask it again please? I also do not understand what relevance it has to this thread.

Sorry...I made it hard...I want to plot velocity vectors in each step in same figure...what should I do in each step plot vector from same seeds...
I have 3 new Question?...
1-what do int() and sum() functions do?
2-How I can define a expression with algebraic equations?
3-I want to plot acceleration,I should use differential equation or I want use Integral to obtain displacement of a particle from velocity...I can use Integral or differential to define variable or expression?
thanks for your attention

[ghorrocks]

Plotting velocity vectors is a basic post-processing task. The vectors are drawn at seed points. This is all covered in the CFX tutorials. You really should do the tutorials so you understand the basics.

1) I assume you are asking about the CEL expressions. These are all described in the CFX reference guide.

2) This is covered in the CFX tutorials. Please do them, you are wasting everybody's time unless you know the basics.

3) Acceleration of what?

[pashazanousi]

Originally Posted by ghorrocks

Plotting velocity vectors is a basic post-processing task. The vectors are drawn at seed points. This is all covered in the CFX tutorials. You really should do the tutorials so you understand the basics.

1) I assume you are asking about the CEL expressions. These are all described in the CFX reference guide.

2) This is covered in the CFX tutorials. Please do them, you are wasting everybody's time unless you know the basics.

3) Acceleration of what?

Thank you...
I'm sorry... I search tutorial but I couldn't understand something and sometimes I ask simple Questions.. I'm really sorry...
I want to create a point that It's position is function of a variable...
I explain more... I want to plot a particle path...
Let's assume Initiall position is (X, Y) ...
Then Next step Position will be as follow:
x=X+U*t
y=Y+V*t
t: constant time step
U:Velocity x direction
V:Velocity y direction
If I can define the point with (x, y) then I can plot the particle path...
Even I can make animation of trajectory...
It is possible to define point like this?

[pashazanousi]

This question was long ago, but it is worth saying that I plotted particle paths using Ansys's Ensight. It is a post-processing module in Ansys Workbench. It calculates particle path in a few simple steps and illustrates particle movement as animation. It offers various visual options you can customize for the desired results.