Injecting gas

S1m0n1 · March 22, 2013, 10:53

Hi all,

I want to inject different gases into a room similiar to how you inject particles. I want to inject gases like carbon monoxide and see which sections of the room have higher concentrations compared to others.

Can someone help me with injecting a gas?

Thanks

diamondx · March 22, 2013, 10:55

you will have to copy paste the material of carbon monoxide in the material list. then activate DPM and selecting what kind of injection you want. How much knowledge you have about this. if none, i suggest you to start by some tutorials about injections...

S1m0n1 · March 22, 2013, 11:13

Ok, so I guess my question is what size diameter should I set for carbon monoxide? or any gas?

I've injected different particles before, I wasn't sure if injecting particles and gas was the same thing.

Thanks for your reply.

diamondx · March 22, 2013, 11:21

oh wait, i'm sorry your injecting gas here... my bad...i think droplet are related to liquid fuel. i've never tried to inject gas before

let me look into it too. sorry about that

S1m0n1 · March 22, 2013, 11:25

Haha no problem. I tried googling it but I couldn't really find anything on injecting different gases.

oj.bulmer · March 22, 2013, 11:49

The automised drops of liquid in gas, or solids in liquid/gas hold themselves together as they travel. Thus, they can be represented as point masses and Langrangian equation are solved.

If you inject gases, they will try to diffuse and wander, and in doing so, will lose the initial structure of "gas particle" or whatever we call it.

Are you sure DPM is a right way for it? How about Eulerian models?

OJ

S1m0n1 · March 22, 2013, 11:51

I am not sure if DPM is the right way. I'm relatively new to FLUENT and I've never tried injecting gas. I can look into Eulerian models and see if that is what I am looking for.

Thanks for the suggestion.

Yanlong Li · March 23, 2013, 06:40

I do not know whether I understood what you want. If you wanna inject two or more different kind of particles, you can use User Variables -> Number of Scalars, it's like UDM for a computional cell, means UDM for every particle.
eg:
if you have two kind of particles: a and b. you can set the "Number of Scalars" as "1", when you inject particle a, set the User Variable as "1"; when you inject particle b, set the User Variable as "0" by macro:P_USER_REAL(p,0) = 0. Thus you can tell apart a and b by accessing the variable.

S1m0n1 · March 25, 2013, 11:30

I am trying to inject a gas at the inlet and see how long it takes to reach the outlet or how long it takes to diffuse. Then I will be able to see the contour of gas concentration and where it is greatest.

asal · April 3, 2013, 05:46

Hello!

I have the same question.
I try to inject some water droplets from the surfaces of human body in a room. I need to inject 200 droplet per min and see the concentration in certain part of the room. I try some tutorials, but I cannot succeed. can anyone assist me here?
thanks in advance for your help.

March 22, 2013, 10:53	Injecting gas	#1
S1m0n1 Member Join Date: Sep 2012 Posts: 40 Rep Power: 14	Hi all, I want to inject different gases into a room similiar to how you inject particles. I want to inject gases like carbon monoxide and see which sections of the room have higher concentrations compared to others. Can someone help me with injecting a gas? Thanks

March 22, 2013, 10:55		#2
diamondx Super Moderator Ghazlani M. Ali Join Date: May 2011 Location: Tokyo, Japan Posts: 1,385 Blog Entries: 23 Rep Power: 29	you will have to copy paste the material of carbon monoxide in the material list. then activate DPM and selecting what kind of injection you want. How much knowledge you have about this. if none, i suggest you to start by some tutorials about injections... __________________ Regards, New to ICEM CFD, try this document --> https://goo.gl/KAOIwm Ali

March 22, 2013, 11:21		#4
diamondx Super Moderator Ghazlani M. Ali Join Date: May 2011 Location: Tokyo, Japan Posts: 1,385 Blog Entries: 23 Rep Power: 29	oh wait, i'm sorry your injecting gas here... my bad...i think droplet are related to liquid fuel. i've never tried to inject gas before let me look into it too. sorry about that __________________ Regards, New to ICEM CFD, try this document --> https://goo.gl/KAOIwm Ali

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March 22, 2013, 11:13		#3
S1m0n1 Member Join Date: Sep 2012 Posts: 40 Rep Power: 14	Ok, so I guess my question is what size diameter should I set for carbon monoxide? or any gas? I've injected different particles before, I wasn't sure if injecting particles and gas was the same thing. Thanks for your reply.

March 22, 2013, 11:25		#5
S1m0n1 Member Join Date: Sep 2012 Posts: 40 Rep Power: 14	Haha no problem. I tried googling it but I couldn't really find anything on injecting different gases.

March 22, 2013, 11:49		#6
oj.bulmer Senior Member OJ Join Date: Apr 2012 Location: United Kindom Posts: 473 Rep Power: 20	The automised drops of liquid in gas, or solids in liquid/gas hold themselves together as they travel. Thus, they can be represented as point masses and Langrangian equation are solved. If you inject gases, they will try to diffuse and wander, and in doing so, will lose the initial structure of "gas particle" or whatever we call it. Are you sure DPM is a right way for it? How about Eulerian models? OJ

March 22, 2013, 11:51		#7
S1m0n1 Member Join Date: Sep 2012 Posts: 40 Rep Power: 14	I am not sure if DPM is the right way. I'm relatively new to FLUENT and I've never tried injecting gas. I can look into Eulerian models and see if that is what I am looking for. Thanks for the suggestion.

March 23, 2013, 06:40		#8
Yanlong Li Member Yanlong Li Join Date: Jan 2013 Location: BeiJing Posts: 47 Rep Power: 13	I do not know whether I understood what you want. If you wanna inject two or more different kind of particles, you can use User Variables -> Number of Scalars, it's like UDM for a computional cell, means UDM for every particle. eg: if you have two kind of particles: a and b. you can set the "Number of Scalars" as "1", when you inject particle a, set the User Variable as "1"; when you inject particle b, set the User Variable as "0" by macro:P_USER_REAL(p,0) = 0. Thus you can tell apart a and b by accessing the variable.

March 25, 2013, 11:30		#9
S1m0n1 Member Join Date: Sep 2012 Posts: 40 Rep Power: 14	I am trying to inject a gas at the inlet and see how long it takes to reach the outlet or how long it takes to diffuse. Then I will be able to see the contour of gas concentration and where it is greatest.

April 3, 2013, 05:46		#10
asal Senior Member Astio Lamar Join Date: May 2012 Location: Pipe Posts: 186 Rep Power: 14	Hello! I have the same question. I try to inject some water droplets from the surfaces of human body in a room. I need to inject 200 droplet per min and see the concentration in certain part of the room. I try some tutorials, but I cannot succeed. can anyone assist me here? thanks in advance for your help.