CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > General Forums > Main CFD Forum

Reference Velocity Calculation & Convergence Problem

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   January 29, 2011, 14:42
Exclamation Reference Velocity Calculation & Convergence Problem
  #1
New Member
 
Aerospace Engineer
Join Date: Jun 2009
Posts: 6
Rep Power: 17
hasan_hzl is on a distinguished road
Hi all,

I am trying to simulate pitching/plunging motion cases in hover (no free-stream velocity, all BC's are pressure outlet, laminar case) Yet, I have some problems as:

1) I confused a little on reference velocity value to be used in force coefficient's calculations in pure pitch motion case (pure pitch motion is defined as alpha=30*pi/180*sin(w*t)). Since in my simulations there is no free-stream velocity, i assume that V=2*pi*freq*(c/4) where c/4 is my rotation location. Is it a good idea to use this assumption? Or there is a better definition for this velocity?

2) Nearly all of my cases do not convergence still after 10 periods of simulation. Can it be because I simulate in water using laminar (Re~1000 in my simulations) solver? Is there a tricky way to get converged solution cases as using bla bla model, using bigger domain, etc..?
hasan_hzl is offline   Reply With Quote

Reply


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
mass flow in is not equal to mass flow out saii CFX 12 March 19, 2018 06:21
Problem with centrifugal pump calculation Michiel Main CFD Forum 2 June 17, 2012 22:32
Problem Interface Solid Fluid with wall velocity Solver v12 hills1 CFX 2 October 12, 2009 06:36
CONVERGENCE PROBLEM - oil boiler MM FLUENT 1 February 15, 2007 06:24
convergence problem with SIMPLER NURAY KAYAKOL Main CFD Forum 1 February 24, 1999 14:43


All times are GMT -4. The time now is 15:54.