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

Having problems with mixed convection

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   July 12, 2017, 12:32
Lightbulb Having problems with mixed convection
  #1
New Member
 
Join Date: Jan 2016
Posts: 7
Rep Power: 5
thewitcher745 is on a distinguished road
Hello, I have a project for studying the case of a concentric annulus with a moving core (2 concentric cylinders), through which the fluid flows. There is a gravitational field being exerted perpendicular to the axis of the cylinders. The inner cylinder is spinning at constant speed and there is a temperature difference between the two cylinders (the inner cylinder has a higher temperature.) I want to study the effects of mixed convection on temperature and velocity contours on various lengths in the tube.

The problem arises after I want to reach a solution. Firstly, the solution does not converge very easily. I have turned on gravity, set the density calculation method to Boussinesq, set operating temperatures, set the pressure discretization method to PRESTO! and I have a good structured, consistent mesh. After a while the solution doesn't meet the convergence criteria but rather the residuals reach a point and only fluctuate around one value, and also the result does not contain a clear effect of natural convection as the contours seem very symmetrical around the cylinders' axis except certain points, which go away after a certain length.

How do I fix the convergence and the results? And how do I make sure the effect of convection is clearly seen?
thewitcher745 is offline   Reply With Quote

Reply

Tags
concentric annulus, convection, fluent, mixed convection, natural convection

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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
Fluent Mixed Convection Problem cfdsolver1 FLUENT 7 September 19, 2016 05:58
Convergence - Mixed Convection - Circular Cylinder Aarthy Meena FLUENT 1 August 16, 2016 13:31
mixed convection in triangular cavity imipramine FLUENT 0 January 21, 2013 05:33
solving mixed convection flows tom Main CFD Forum 0 October 30, 2008 15:08
problems in natural convection nabeel FLUENT 19 August 6, 2004 01:52


All times are GMT -4. The time now is 10:33.