How to add the certain force on the free surface ?

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Bu Ningbin

Bu Ningbin

September 10, 2010 6:37am UTC

How to add the certain force on the free surface ?

Hi,

The problem is that:
I want to simulate a electrohydrodynamic (EHD) phenomenone , a nozzle with full water in a electrostatic field, the the water is polarized and deformed the Taylor cone. The models include the level set -laminar flow and electrostatic.The coupling variables is Fx and Fy, which depends on the surface charge density and electric field. The force only at the the surface existed. How to define this force? in another word, it's maybe a universal problem that, the Maxwell surface tension how to act on the free surface.

Thank you.

abubob

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Luewton Agostinho

Luewton Agostinho

March 21, 2011 11:06am UTC in response to Bu Ningbin

Re: How to add the certain force on the free surface ?

Dear abubob...

I saw your question on the comsol forum. I am working exactly with the same kind of modeling but I could not find so far any good example with Comsol. I understood you are working with cone-jet mode. I am trying to model the simple-jet, which is the same with higher flows. Maybe we could discuss a bit and see if we can help eachother to find our way using Comsol. Please let me know if you would like to talk a bit further about this.
Kind regards
Luewton Lemos (luewtonlemos@gmail.com)

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Bu Ningbin

Bu Ningbin

March 22, 2011 1:01am UTC in response to Luewton Agostinho

Re: How to add the certain force on the free surface ?

Dear Luewton Lemos
I'am glad to talk with you. In the past months,I have simulated the cone, but the problem is also existed.The following examples are useful, inkjet nozzle. In simulation, the interface is a thin layer, the physcics parameters should be smooth( density ,visicosity , permitivity) , the div of Maxwell tensor is body force, so the whole regions,can add this force, but only the interface is valid. Another problem is the convergence. The solver should be adjusted, I'm working for this.If you have any questions, we can talk together. Good luck.

bu ningbin

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Kok Hing Chong

Kok Hing Chong

August 5, 2011 6:29am UTC in response to Bu Ningbin

Re: How to add the certain force on the free surface ?

Hi,
I am new to this Comsol, as well as finite element simulation, just graduate form degree, now working on electrospray as well. I am still beating around the bush, try to understand the Physics that can be used in electrospray. Mind anyone me give me suggestions? Although Comsol supposed to give friendly GUI but no in electrospray, which deals with electrophoresis with two phase flow, as you mentioned the surface force on droplets and being charged.

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Ahmed Eissa

Ahmed Eissa

July 17, 2012 8:43pm UTC in response to Bu Ningbin

Re: How to add the certain force on the free surface ?

Hi Bu
I am working on the same problem.
How did you manage to model the leaky feature of the jet? Did you use electric current (ec) instead of electrostatic? Did your result match what Taylor got in his 1964 paper?
Many thanks
Ahmed

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