Multi-Species Jet

tonyhamshaw · July 16, 2009, 04:54

I'm investigating the different effects of modelling a jet as different species. It is a 3d simulation with the lower surface bounded by a wall, and the upper surface as a pressure inlet. The inlet and outlets to the left and right respectively are pressure inlets and outlets, again, respectively.

The hot jet runs along the lower domain, parallel to the wall whilst two more flows, both at almost identical pressure and temperature are placed overhead of the jet.

Having modelled the jet as hot gas, I'm interested in modelling it as three cold streams, using different molecular weight to represent the hot jet (ie hydrogen/air or helium/air mix to reduce its density). How can I go about setting this up in FLUENT?

Thanks in advance

tonyhamshaw · August 5, 2009, 11:02

Bump - anyone?

alekpopob · August 6, 2009, 15:12

What do you want to see in that modeling?
Anyway basically there are 'multiphase models' in Fluent.
You can define several fluids in one problem.

If the temperature is enough high to initiate combustion, you must condiser combustion modeling either.

tonyhamshaw · August 7, 2009, 04:19

Thanks for your reply! Mainly the flow behaviour around in the nozzle, but also the decay characteristics of the core plume: total temp, pressure and perhaps in the future some form of acoustic properties. I've established the need to specify non-reacting species transport, but as of yet cannot figure out how to specify different percendate mixtures of each component gas.

Any ideas?

T

alekpopob · August 8, 2009, 05:45

I understood.

But, first of all, you must read tutorials and user guides about multiphase modeling.
If you do not consider reaction flow, that's still OK. Just find some examples about multiphase problems.

After you will enable multiphase modeling in Fluent, you can define different molecules at inlet and outlet in 'define boundary'.

Remember! solving multiphase model is not easy. it easily goes to unstable.

A.... at first.... read tutorials and user guides. It is the best way that you understand how it works in Fluent.

July 16, 2009, 04:54	Multi-Species Jet	#1
tonyhamshaw New Member Tony Join Date: Jul 2009 Posts: 3 Rep Power: 16	I'm investigating the different effects of modelling a jet as different species. It is a 3d simulation with the lower surface bounded by a wall, and the upper surface as a pressure inlet. The inlet and outlets to the left and right respectively are pressure inlets and outlets, again, respectively. The hot jet runs along the lower domain, parallel to the wall whilst two more flows, both at almost identical pressure and temperature are placed overhead of the jet. Having modelled the jet as hot gas, I'm interested in modelling it as three cold streams, using different molecular weight to represent the hot jet (ie hydrogen/air or helium/air mix to reduce its density). How can I go about setting this up in FLUENT? Thanks in advance

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August 5, 2009, 11:02		#2
tonyhamshaw New Member Tony Join Date: Jul 2009 Posts: 3 Rep Power: 16	Bump - anyone?

August 6, 2009, 15:12		#3
alekpopob New Member Join Date: Jul 2009 Posts: 4 Rep Power: 16	What do you want to see in that modeling? Anyway basically there are 'multiphase models' in Fluent. You can define several fluids in one problem. If the temperature is enough high to initiate combustion, you must condiser combustion modeling either.

August 7, 2009, 04:19		#4
tonyhamshaw New Member Tony Join Date: Jul 2009 Posts: 3 Rep Power: 16	Thanks for your reply! Mainly the flow behaviour around in the nozzle, but also the decay characteristics of the core plume: total temp, pressure and perhaps in the future some form of acoustic properties. I've established the need to specify non-reacting species transport, but as of yet cannot figure out how to specify different percendate mixtures of each component gas. Any ideas? T

August 8, 2009, 05:45		#5
alekpopob New Member Join Date: Jul 2009 Posts: 4 Rep Power: 16	I understood. But, first of all, you must read tutorials and user guides about multiphase modeling. If you do not consider reaction flow, that's still OK. Just find some examples about multiphase problems. After you will enable multiphase modeling in Fluent, you can define different molecules at inlet and outlet in 'define boundary'. Remember! solving multiphase model is not easy. it easily goes to unstable. A.... at first.... read tutorials and user guides. It is the best way that you understand how it works in Fluent.