how to model thermal bubble inkjet

dwtme · November 21, 2012, 00:10

HI everyone,
I want to model thermal bubble inkjet. i don't know how to heat the liquids and generate bubble. I have used the model: bubble and phase change,heat transfer, surface tension , viscosity and turbulence. In the boundary condition i use wall
->thermal information->power:5e8, but it doesn't work .Only a small region of liquid near the wall increase temperature and doesn't have any bubble or phase change. The liquid i use is water(CGS unit at 20C)
In the phase change, I input the data below:
saturation pressure:1e6
saturation temperature:373
latent heat of vapor:2.257e6
gamma:1.4
accomodation coefficient:0.1
vapor specific heat:6.67e6
exponent temperature:1.182e-4
superheat temperature:0

can somebody teach me how to set the accurate model to run thermal bubble inkjet simulation?

best reards
Tim

dwtme · November 27, 2012, 20:14

by the way, my edition is v9.3!

JBurnham · December 4, 2012, 18:58

If the water is not warming up, I would suggest checking the thermal property coefficients of the water itself (Fluid 1): liquid specific heat CV1, liquid thermal conductivity CHV1. Also set heat transfer coefficient between wall and fluid HWALL1.

dwtme · December 12, 2012, 22:05

Dear JBurnham,
Thanks for your reply. I still have some questions.
(1)Do I need to creat a component as a wall or use the boundary condition setting"wall", what is the difference?
(2)"The heat transfer coefficient between wall and fluid " means the heat conduction coefficient of wall or fluid? Or does it have other meaning?
Thanks,
Best regards
Tim

JBurnham · January 7, 2013, 12:33

You can use either a component or a wall-type boundary, it is up to you. The component may be easier to use. The component-to-fluid heat transfer coefficient is described in the User Manual in some detail, including the ways in which FLOW-3D picks a coefficient if one is not defined.

November 21, 2012, 00:10	how to model thermal bubble inkjet?	#1
dwtme New Member Join Date: Nov 2012 Posts: 12 Rep Power: 2	HI everyone, I want to model thermal bubble inkjet. i don't know how to heat the liquids and generate bubble. I have used the model: bubble and phase change,heat transfer, surface tension , viscosity and turbulence. In the boundary condition i use wall ->thermal information->power:5e8, but it doesn't work .Only a small region of liquid near the wall increase temperature and doesn't have any bubble or phase change. The liquid i use is water(CGS unit at 20C) In the phase change, I input the data below: saturation pressure:1e6 saturation temperature:373 latent heat of vapor:2.257e6 gamma:1.4 accomodation coefficient:0.1 vapor specific heat:6.67e6 exponent temperature:1.182e-4 superheat temperature:0 can somebody teach me how to set the accurate model to run thermal bubble inkjet simulation? best reards Tim Last edited by dwtme; November 28, 2012 at 21:24.

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November 27, 2012, 20:14		#2
dwtme New Member Join Date: Nov 2012 Posts: 12 Rep Power: 2	by the way, my edition is v9.3!

December 4, 2012, 18:58		#3
JBurnham Member Jeff Burnham Join Date: Apr 2010 Posts: 95 Rep Power: 5	If the water is not warming up, I would suggest checking the thermal property coefficients of the water itself (Fluid 1): liquid specific heat CV1, liquid thermal conductivity CHV1. Also set heat transfer coefficient between wall and fluid HWALL1.

December 12, 2012, 22:05		#4
dwtme New Member Join Date: Nov 2012 Posts: 12 Rep Power: 2	Dear JBurnham, Thanks for your reply. I still have some questions. (1)Do I need to creat a component as a wall or use the boundary condition setting"wall", what is the difference? (2)"The heat transfer coefficient between wall and fluid " means the heat conduction coefficient of wall or fluid? Or does it have other meaning? Thanks, Best regards Tim

January 7, 2013, 12:33		#5
JBurnham Member Jeff Burnham Join Date: Apr 2010 Posts: 95 Rep Power: 5	You can use either a component or a wall-type boundary, it is up to you. The component may be easier to use. The component-to-fluid heat transfer coefficient is described in the User Manual in some detail, including the ways in which FLOW-3D picks a coefficient if one is not defined.