CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   Phoenics (http://www.cfd-online.com/Forums/phoenics/)
-   -   buoyancy force due to concentration difference (http://www.cfd-online.com/Forums/phoenics/51981-buoyancy-force-due-concentration-difference.html)

arsei0707 December 8, 2005 10:57

buoyancy force due to concentration difference
 
I'm confused that in my sloving problem there is a gas-moisture mixture with combined thermal and concentration force in my momentum equation. However, when I validate my problem by using a published paper which is a double diffusive cavity, I can't get the exact profiles whatever streamlin, isothermal line, and iso-concentration in aiding or opposing buoyany flow. Therefore, I begin check the pure thermal buoyancy driven flow in a square cavity, and a pure concentration byoyancy driven flow. However, in a pure thermal buoyancy driven flow, I can get a similar velocity and temperature distribution. But, in a pure concentration difference flow within a square cavity, there is no flow driven in my cavity.

Therefore, how can I turn on or add my buoyancy force due to concentration difference to get a combined gas-moisture problem when the Boussinesq approximation is valid.

Mike December 14, 2005 06:11

Re: buoyancy force due to concentration difference
 
As I recall the Buossinesq buoyancy force provided as an option in PHOENICS is a function of temperature difference only. Are you using this option? Or have you implemented your own buoyancy source term as a function of both temperature and concentration difference? It seems to me that you must do the latter either by use of the INFORM facility or by use of GROUND coding.


All times are GMT -4. The time now is 05:03.