CFD Online Discussion Forums

CFD Online Discussion Forums (
-   Phoenics (
-   -   Who knows the gas property (

mjh September 15, 2004 09:44

Who knows the gas property
In the PROPS file, the name of the gas NO. 30 is Ideal gas Law for mixture of 3 gases (ENUL=3.6E-5/GRHO).

Who can tell me what kind of the gases are the 3? Are they oxygen, nitrogen and steam.

A User September 20, 2004 06:25

Re: Who knows the gas property
Extract From the gxdens file in phoenics/d_earth/d_core below. Look in C:/phoenics/d_earth/d_core/GXDENS.htm for IGRND=5 The code in this routine may help explain.

C.... Ideal-gas law for mixture of the three chemical 'species' fuel, C oxidant and product involved in the simple chemical reaction C model (Parameters RHOA,RHOB and RHOC are the molecular weights C of fuel, oxide and products respectively): c

Carlos September 22, 2004 21:40

Re: Who knows the gas property

N.o 30 is the gas mixture used to achieve the physical properties necessary to SCRS (also called three gases model). I think that, by default, they consider the three gasses to be: methane, air and products (see SCRS entry in enciclopaedia). However, it can be changed to be the reactional system you want (even via VR Editor you can do that).

Other option: if you just want to use a mixture of gases that changes its composition throughout time (without any reactions), I think it would be better to create two scalars and combine them with air or oxigen (that would be the domain material), for instance. Then you will need to write an equation that correlates physical properties and these scalars or you can use a phoenics ground code that becomes availabe at properties when scalars are set.

Write to my e-mail if you need more details, ok?


mjh September 23, 2004 09:31

Re: Who knows the gas property
It's very kind of you two to help me with the problem.

Carlos Eduardo September 27, 2004 20:19

Re: Who knows the gas property
Sorry for the delay. I will be sending you an e-mail tomorrow (when I will be at the computer that has PHOENICS). Regards,

Carlos September 29, 2004 18:07

Re: Who knows the gas property
Have you received my e-mail?



All times are GMT -4. The time now is 03:43.