Droplet Size and Velocity Measurement

AS_Aero · May 16, 2017, 11:04

Hi All

Does someone have experience in doing Droplet size and velocity measurement in CFX for multiphase ? I also want to know if you can get the droplet size and velocity by doing VOF model ? Kindly let me know. Thanks in advance.

ghorrocks · May 16, 2017, 18:34

If you are doing VOF (which strictly speaking CFX does not do, it has a different free surface model) then to get parameters like drop size and velocity- you will need to write a routine to extract that from the data. This is not straight forward.

AS_Aero · May 17, 2017, 03:58

Ok So what is the other models in cfx which can predict the droplet and velocity distribution ? Like some Eulerian or Lagrangian Particle tracking ?

ghorrocks · May 17, 2017, 05:28

Yes, both Eularian and Lagrangian particle tracking can predict droplet velocities and sizes for some types of flows.

AS_Aero · May 17, 2017, 06:53

But there is no tutorial to start with understanding how to set up the case.

ghorrocks · May 17, 2017, 07:07

There are tutorials on the basics of Eularian and Lagrangian particle flows in the CFX tutorials on the ANSYS Customer webpage.

But there is nothing specifically on spray break up models or other similar advanced models. ANSYS support will have some examples of these, you would need to contact them. But as these are advanced models they do not have beginner tutorials - as they are not beginner physics models. You are expected to be able to work out how to use these models from the description in the documentation and the theoretical model it uses. You are expected to already be familiar with the basics of Eularian and/or Lagrangian models.

May 16, 2017, 11:04	Droplet Size and Velocity Measurement	#1
AS_Aero Senior Member Join Date: Mar 2013 Location: Germany Posts: 357 Rep Power: 14	Hi All Does someone have experience in doing Droplet size and velocity measurement in CFX for multiphase ? I also want to know if you can get the droplet size and velocity by doing VOF model ? Kindly let me know. Thanks in advance.

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May 16, 2017, 18:34		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,746 Rep Power: 143	If you are doing VOF (which strictly speaking CFX does not do, it has a different free surface model) then to get parameters like drop size and velocity- you will need to write a routine to extract that from the data. This is not straight forward.

May 17, 2017, 03:58		#3
AS_Aero Senior Member Join Date: Mar 2013 Location: Germany Posts: 357 Rep Power: 14	Ok So what is the other models in cfx which can predict the droplet and velocity distribution ? Like some Eulerian or Lagrangian Particle tracking ?

May 17, 2017, 05:28		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,746 Rep Power: 143	Yes, both Eularian and Lagrangian particle tracking can predict droplet velocities and sizes for some types of flows.

May 17, 2017, 06:53		#5
AS_Aero Senior Member Join Date: Mar 2013 Location: Germany Posts: 357 Rep Power: 14	But there is no tutorial to start with understanding how to set up the case.

May 17, 2017, 07:07		#6
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,746 Rep Power: 143	There are tutorials on the basics of Eularian and Lagrangian particle flows in the CFX tutorials on the ANSYS Customer webpage. But there is nothing specifically on spray break up models or other similar advanced models. ANSYS support will have some examples of these, you would need to contact them. But as these are advanced models they do not have beginner tutorials - as they are not beginner physics models. You are expected to be able to work out how to use these models from the description in the documentation and the theoretical model it uses. You are expected to already be familiar with the basics of Eularian and/or Lagrangian models.