CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT

Reversed flow using pressure inlet and outlet?

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 28, 2018, 16:20
Default Reversed flow using pressure inlet and outlet?
  #1
New Member
 
Anonymous
Join Date: Sep 2018
Posts: 1
Rep Power: 0
here_for_help is on a distinguished road
The system I'm trying to model involves two immiscible liquids (one on top of the other) and an inlet and outlet at the bottom of the container, which feeds and empties, respectively, the bottom liquid. The fluid flow is driven by a pump downstream of the outlet, which creates suction and pulls the liquid from the container and recirculates it into the inlet, thus having a constant flow rate. In my simulation, I am attempting to see how the flow profile changes by changing the suction pressure.
Currently, I'm modeling the inlet and outlet as pressure inlet and outlets. For the Gauge Total Pressure on the inlet, I am inputting the hydrostatic pressure at the top of the inlet. For the Gauge Pressure on the outlet, I am inputting a lower value so as to create a pressure difference between the inlet and outlet. I am also specifying that the backflow direction is normal to the boundary and based on total pressure, with a volume fraction of 1 for the flowing liquid.
The solution converges relatively well and the flow profile is generally as expected, except for the reversed flow at the inlet and outlet. To give more detail, ~ the top half of the inlet is flowing liquid into the container, while the bottom half is draining it, and at the outlet, only the bottom ~ 1/3 is actually draining liquid out, while the top 2/3 flows liquid in. I've tried changing the inlet's Gauge Total Pressure to the hydrostatic pressure at halfway the inlet and at the bottom of the inlet with the same results, making it 0, specifying a supersonic/initial gauge pressure, and nothing seems to work. Any ideas?
here_for_help is offline   Reply With Quote

Reply

Tags
pressure inlet, pressure outlet, reversed flow


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pressure Outlet Targeted Mass Flow Rate LuckyTran FLUENT 1 November 23, 2016 11:40
Setting both inlet and outlet with pressure boundary conditions ahmadbakri CFX 0 July 1, 2015 05:06
Inlet and Outlet Pressure condition for Compressible Flow in FLUENT rsdsaurav FLUENT 1 May 17, 2015 15:19
simple model, difficult outlet Eric CFX 7 May 23, 2014 09:13
How can I prevent reversed flow from outlet Pressure Boundaries in Fluent 6.3 ? kalash FLUENT 0 September 20, 2013 14:06


All times are GMT -4. The time now is 22:34.