Three phase modelling
 

Please Help with(CFX-4.3),

I am a new CFD user, i have been able to create geometry and command files and run the solver with 1-phase and 2-phases models. However, I now have problems with three phase, the third phase being particles with a volume holdup of about 5%.

The problem is, if i perform check in set-up menu, I get an error mmessage that ">> OPTIONS PARTICLE TRASPORT HAS BEEN SET AND
:>OPTION

THE NUMBER OF PHASES 2 IS GREATER THAN 1

I had tried to ignore the message and when I ran the solver i got the error message that: INSUFFICIENT CHARACTER WORK SPACE, INCREASE THE SPACE DIMENSION.

How do i increase the work space?? Why must the number of phases NOT BE GREATER THAN 1?

Thanks in advance.

Keny

Re: Three phase modelling
 

Hello!

Two things:

According to the manual you cannot have Lagrangian particles and multi-phase at once.

Having deleted this option, if you increase your total character work space under SET LIMITS, it should be fine (see manual)...

Herve

Re: Three phase modelling
 

hello, everyone! If the .geo file has been done in BUILD module, you may not set the option at >>SET LIMITS. Please refer to page3-63 of the manual.

Re: Three phase modelling
 

Hi all,

Dingding is right. Mine is a 'geo' file of Build module. I can not set limits as suggested by Herve.

How does one specify the phses if you are dealing with solid particles, gas and liquid? Conventionaly that is a 3-phase system. CFX4.3 does not want to understand that. I believe their is a way out.

Keny

Re: Three phase modelling
 

Hi

Page 3.63 says "In a normal run of the program using a geometry file obtained from a pre-processor, the size of the problem is set automatically from the size of the geometry, although occasionally extra work space will be required." In your case the extra work space seemed to be required.

As to your 3 phase problem the simplest way out will be to define 3 phases, a continous liquid (1), a disperse gas (2), and a dispersed solid (3)phase.

JohnR

Re: Three phase modelling
 

johnr,

thanks a lot John, I was a bit disappointed with cfd modelling so I took time out (off). After a rest I want to start again, now fresh.

keny