Hydrosystem with two tanks connected one after another

[Fu-Kwun Hwang]

I do not know what you really want? How can I help?

Please explain in detail what you really want to do? How you did it! and where it went wrong?
So I can check out the part which it was not working and try to find a solution for you.

[maxxb]

I need to make a representation of two tanks, show how that works with EJS. But I have some errors at the end and I don't understand why that didn't works. When I play the simulation, Nothing change and I don't know why. I found some errors in my precedent works so I send you the new.

[Fu-Kwun Hwang]

The problems I have found so far:
1. You did not provide initial value for H1 (in the Variables page). How can the EJS know what is the initial condition for H1?
2. Qi was not assigned with an initial value, either.

Computer can do what you tell it to do, but computer can not guess what you want to do (it is dangenous).
Unless there are some rule provided.

[maxxb]

I already changed that but I can show you because I am not in my workplace. If you want I send you tomorrow my work. Thanks for everything, that help me so much.

[maxxb]

Hi,
I send you my work.
I just want that my representation do the same things than yours, when I increase Qi, the speed increase, and when we arrived on the max, the system stop. But I don't know what I should take in the variables to do that. Could you help me please ?

[maxxb]

Sorry, I forgot to give you my work 

[Fu-Kwun Hwang]

Hi,
I send you my work.
I just want that my representation do the same things than yours, when I increase Qi, the speed increase, and when we arrived on the max, the system stop. But I don't know what I should take in the variables to do that. Could you help me please ?

I do not know what do you mean by "do the same things than yours"???
the speed increase :the speed of what
arrived on the max: what reach maximum???

Would you explain what you want to do in detail? I do not know how to help if I can not understand what you want.

[maxxb]

When I say when the speed increased, I just want to say that when you increased Qi, H1 and H2 increased faster, like the representation that you did on this topic for the other man !
For the max, I speak about the height maximum of H1 which is 36cm.
My problem is that I don't understand why my representation doesn't want to work. When I play the simulation, that doesn't work like I want (like yours simulation), and I don't understand why

[Fu-Kwun Hwang]

You GUI in the EJS is so complicated that I do not really understand it.
I saw the whole system is expanding when I run it.
I do not know what is going on.

You should re-assign those property value if it's background is not white.

You did not provide detail information about your system, size/shape ...
The GUI you have is not the same as the one I have created.
I do not know how it should look like. There is no way I can help if I do not know what it should be look like.
Sorry!


PS:
You do not need to add a new tube element for each segment,
if you define
px={0,0,0.5}
py={0.,0.5,0.5}
in variable tabs.

and assign px to Pos X and py to Pos Y for tube element, you will create two connected tube.
You can add more if you define px,py with more dimensions .

Why there are so many arrows in the GUI, you should be able to use a polygon to draw all connected segments.

[maxxb]

Hi,
Sorry but I don't know how to use really good EJS and so I don't know how to use polygone and how to reduce my number of tubes.
I told you that my GUI is like yours because I think it is. If you took yours, I just connected the out to the in. We don't care about the third reserve of water. It's just to better understand how works the project in real.

[Fu-Kwun Hwang]

The original simulation was created due to request from pavwell

I did check out your code. You said you want connect the output back to the input.
But I did not find such relation in your ejs model. I really do understand what you want in detail.

I can creat another one for you if you can provide me : at least a diagram with all dimension of the system
and all the related equations/ constrains.
There is no way that I can create a simulation without know detail information of the system to be simulated.

[maxxb]

But you have already this. There are in my work all the variables. And the equations related are here too. But I can't just take your work because I have some problems to understand what you did with the work for pavwell. I need to understand all because after will do a presentation of my work.
I give you all here.

(Qi-Cd1*alpha1*Math.sqrt(2*g*(H1-H2)))/A1=dH1/dt

(Cd1*alpha1*Math.sqrt(2*g*(H1-H2))-Cd2*alpha2*Math.sqrt(2*g*H2))/A2=dH2/dt

H1 max = 36cm
H2 max = 36cm

A1 = 256 cm2
A2 = 256 cm2

Cd1 = 0.15
Cd2 = 0.15

Alpha1 = 0.0008
Alpha2 = 0.0008

Could you do this representation with a 3.47 of EJS please.
Thank you ever so mutch.

[Fu-Kwun Hwang]

Hi,
Sorry but I don't know how to use really good EJS and so I don't know how to use polygone and how to reduce my number of tubes.
I told you that my GUI is like yours because I think it is. If you took yours, I just connected the out to the in. We don't care about the third reserve of water. It's just to better understand how works the project in real.

It seems that the only differences are dimension of the tube... etc.
Those two equations are the same form.
It seems that what you need is just change the value of variables in the original version.

Why the equations are the same if the output is connected to the input?
I believe the above equations should be modified if the output is connected to the input (a feedback loop).
That is the part which I do not understood!
Do you need the height as function of time graph h(t)?

[maxxb]

Yes please,
I need another thing. I need to could move tree flows, the first Qi, the enter, the second, to pass from the first to the second tank, and the third, to empty the second tank...
Sorry my teacher just told me that this morning.
But I think I don't need to change the level of the tanks...
Thanks

[Fu-Kwun Hwang]

You did not answer the information I need:

Why the equations are the same if the output is connected to the input?
I believe the above equations should be modified if the output is connected to the input (a feedback loop).
That is the part which I do not understood!

And I do not understand what you said:

need another thing. I need to could move tree flows, the first Qi, the enter, the second, to pass from the first to the second tank, and the third, to empty the second tank...

I need to could move tree flows , the first Qi, the enter???
to pass from the first to the second tank
to empty the second tank Do you mean a control to empty the second tank?

[maxxb]

Don't care about the equations, their good I'm sure. There is a third tank of water which is here to fill the first tank and to take the water from the second tank. So it's like your representation. It's independant.

For the next, in your representation, you could change the number of q1 with a bar. q1 represents the enter flux in the first tank. I just want the same thing but not only on the first tank, but on the second too. That mean tree bar like yours. The first exactly like q1, the second to increase or decrease the flux between the first tank and the second and the third to increase or decrease the flux to empty the second tank. The flux is representing by valves like on my representation, if you open more the valve, the flux increase and if you shut more the valve, the flux decrease.

I'm sorry if it was not clear before. I hope that is better now.

[Fu-Kwun Hwang]

I did some work for you.

1. You did not set the boundary of drawingPanel properly.
 I changed it to x: -1 t0 1 and y:0 to 2
2. There is something wrong with your code

Code:

if ( H1 >= H1max ) Qi = 0 ;
else if (Qi==0&& H1< 0.2)Qi=Qis;

It seems to work now. However, you should change variable values to fit with your case.

You use 12 arrows to represent pipes. It will be better if can use tube elements.

The 3.47 xml file is attached.

[maxxb]

Thanks ever so much... I think I have finished.
A final thing, I want to do like you in your first representation for pavwel. When H1 is on the max, Q1 stop and the tube of water disapear from the representation. I searched but I didn't found how do that. Could you explain me please ?

[Fu-Kwun Hwang]

There is a "Visible" property for all the EJS GUI elements.

You can define a variable (e.g. show) and assign either "true" or "false" under different condition in your code to make the element visible or hidden.

[maxxb]

I found easier, you just need to write contraint directly in the Visible of the elements and that works. Thank you ever so much. My project is finish.

[Fu-Kwun Hwang]

Yes. You can add java statement which return "true/false" value in the Visible property field.
I hope EJS(Easy Java Simulation) really help you create simulation you need easily. :-)

[pavwell]

Hello my friend
You helped me a few weeks ago with my two tanks system. I tried to add to this project control of hight of level H2. I added some new parameters and i modified eqautions. Please, could you review my EJS application and help me with this :

Please, could you help me witih adding 2D Drawables element which is valve for control over a fllow. This element will be with cooperation with high of level of TANK H2. On the bottom of my application pannel it could be new elementy with setting of H2 level. And then valve for control over the flow will be controling inflow so level of H2 tank will be stable.

Thanks a lot for helping me !!

[arafat0850]

thanks for your innovative solution.I want to do like you in your first representation for pavwel. When H1 is on the max, Q1 stop and the tube of water disapear from the representation. I searched but I didn't found how do that. Could you explain me please ?-*-

[Fu-Kwun Hwang]

I do not understand what is your question.
Could you explain it in more detail?

[fennyq]

i aslo need these info,many thanks

[perezpau1]

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