How can I patch and define one of the phases in multiphase flow simulation

amir2920 · May 4, 2014, 23:59

Hi,

I want to define an air drop in water. How can I define the circle (in 2D) flow for that? Thanks.

ping · May 7, 2014, 06:12

in the normal way you create 2d cases in starccm+ - create it in 3d then convert the x-y face at z=0 to 2d

in your case you would have two parts - a block with a hole where you want the drop and the hole filled - ie a cylinder, which you turn into regions and mesh then convert to 2d

you might be able to do it with imprinting a circle on the z=0 face so you get a separate boundary there - needs testing

Miki12 · May 8, 2014, 01:21

Hi Ping,

I have also a question in the same subject. For one droplet, it might work but if you have several droplets (like 1000-10000) and you want to simulate them, do you have to create several parts?

Thank you so much,

Miki

ping · May 8, 2014, 05:35

that would be very tedious so you would instead use the normal lagrangian parcel methods which are designed to inject millions of particles

amir2920 was refering to using the vof method for just one or a few drops and this can be initialized in a number of ways

vof can be used for lots of drops but the cell size needs to be similar or better still much smaller that the particle size

amir2920 · May 26, 2014, 05:20

I defined the droplet using the field function. Do you know how can I specify an initial velocity for this droplet? Thanks,

ping · June 2, 2014, 03:42

since i assume you are still using the vof method to create a drop then you need to specify the velocity as an initial velocity in the physics and again this could be done as a field function for example applied locally to just around where the drop is located

May 4, 2014, 23:59	How can I patch and define one of the phases in multiphase flow simulation	#1
amir2920 Member Join Date: May 2009 Posts: 58 Rep Power: 16	Hi, I want to define an air drop in water. How can I define the circle (in 2D) flow for that? Thanks.

May 8, 2014, 01:21	Several Droplets	#3
Miki12 New Member Join Date: Jan 2014 Posts: 13 Rep Power: 12	Hi Ping, I have also a question in the same subject. For one droplet, it might work but if you have several droplets (like 1000-10000) and you want to simulate them, do you have to create several parts? Thank you so much, Miki

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May 7, 2014, 06:12		#2
ping Senior Member Ping Join Date: Mar 2009 Posts: 556 Rep Power: 20	in the normal way you create 2d cases in starccm+ - create it in 3d then convert the x-y face at z=0 to 2d in your case you would have two parts - a block with a hole where you want the drop and the hole filled - ie a cylinder, which you turn into regions and mesh then convert to 2d you might be able to do it with imprinting a circle on the z=0 face so you get a separate boundary there - needs testing

May 8, 2014, 05:35		#4
ping Senior Member Ping Join Date: Mar 2009 Posts: 556 Rep Power: 20	that would be very tedious so you would instead use the normal lagrangian parcel methods which are designed to inject millions of particles amir2920 was refering to using the vof method for just one or a few drops and this can be initialized in a number of ways vof can be used for lots of drops but the cell size needs to be similar or better still much smaller that the particle size

May 26, 2014, 05:20		#5
amir2920 Member Join Date: May 2009 Posts: 58 Rep Power: 16	I defined the droplet using the field function. Do you know how can I specify an initial velocity for this droplet? Thanks,

June 2, 2014, 03:42		#6
ping Senior Member Ping Join Date: Mar 2009 Posts: 556 Rep Power: 20	since i assume you are still using the vof method to create a drop then you need to specify the velocity as an initial velocity in the physics and again this could be done as a field function for example applied locally to just around where the drop is located