CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   FLUENT (http://www.cfd-online.com/Forums/fluent/)
-   -   pressure distribution in a closed container (http://www.cfd-online.com/Forums/fluent/32728-pressure-distribution-closed-container.html)

prasanth December 17, 2003 00:13

pressure distribution in a closed container
 
HAI,

1).In a closed cylindrical tank completely filled with liquid, if we give intial pressure distribution of static head using custom field functions, it was taking the profile while patched. When on heating on cylindrical surface(i.e., during iteration), pressure is going to normal operating conditions, i.e. in the range of atm. pressure...why is it so? is it not taking initial condition?

2) One more thing, In tha above case, a little positive gradient is achieved in pressure along height, which is acceptable. but when patch liq heiht only to 80% and remaing 20% with vapor,also same as above, but it is showing -ve gradient towards interface and going in +ve direction from there to the top? why its happening like that?

Advance thanks for any kind information.

Prasanth


prasanth December 17, 2003 12:01

Re: pressure distribution in a closed container
 
I guess people have not understood my query. Let me say in another way:

1) take an axisymmetric model of a cylindrical tank. take that it is fully filled with liquid. now taking all the steps for natural convection, by applying constant heat flux on side-wall, etc.;create a custom field as rho*g*(height-coordinate in g dir)(i,.e., rho*g*h].patch this custom field as pressure on the fluid zone after initializing. then see the pressure profile along the axis. now after some iterations again see the pressure profile. I observed as it going in the range of operating pressure instead of taking the patched pressure distribution as initial stage.

So, can you sort out my problem. If any understand this, I will post my second question

Thanks in Advance Prasanth

Venkatesh December 21, 2003 07:52

Re: pressure distribution in a closed container
 
I feel you have not swithced on the gravity.

prasanth December 21, 2003 08:21

Re: pressure distribution in a closed container
 
without gravitation, we cant simulate natural convection. i have selectewd it. with regds prasanth


All times are GMT -4. The time now is 23:02.