# boundary layer meshing

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

 October 24, 2001, 13:00 boundary layer meshing #1 santosh Guest   Posts: n/a hi, I am trying to simulate turbulent flow over an gas turbine blade.I tried to apply boundary layer at the blade surface to have better control while refining. when I used a particular boundary mesh I had problems in convergence.but,when I increased the no.of rows in the boundary layer and made it thick,the solution converged beautifully. Can somebody explain this phenomenon,and also give any advice on boundary layer meshing?

 October 26, 2001, 12:42 Re: boundary layer meshing #2 john Guest   Posts: n/a What was your y+ ? If it is too low and you use standard-wall-models, the "solution" often does not converge.

 October 28, 2001, 03:18 Re: boundary layer meshing #3 santosh Guest   Posts: n/a hi, thanks for the reply,but if the solution does not converge,and I compute the y+ after some iterations,will the y+ indicate the correct trend? santosh

 October 28, 2001, 08:50 Re: boundary layer meshing #4 Jonas Larsson Guest   Posts: n/a There is no clear answer to that, it depends on how "not-converged" your solution is and what causes it not to converge. However, you can quite easily estimate the y+. There is even a small java-script on the net which allows you to do it interactively - you can find a link to it on this site ( http://www.cfd-online.com/Resources/calcs.html#misc, the link is named "viscous grid spacing calculator").

 October 29, 2001, 08:42 Re: boundary layer meshing #5 david Guest   Posts: n/a A) u can mesh based on y+ and y* B) what do u mean by correct trend ? do u mean if it is 600 at some stage of calculation, does it mean the correct solution even though it decreases over large number of iterations ? DC

 October 31, 2001, 08:53 Re: boundary layer meshing #6 santosh Guest   Posts: n/a hi, by correct trend what I mean is that say,the calculation proceeds to 200 iterations and then diverges,if I estimate y+ value at this point,how correct is this estimate? santosh

 November 1, 2001, 18:54 Re: boundary layer meshing #7 david Guest   Posts: n/a A) At any stage you calculate y+, it will give the correct value B) At that point even though it's within (if) the limit, it doesn't necessarily mean that the solution of the prob is correct

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post Saturn CFX 45 February 8, 2016 05:42 didiean FLUENT 2 January 16, 2012 22:39 sophie-l Main CFD Forum 1 May 20, 2009 22:18 Andrew Berner FLUENT 1 August 28, 2007 17:39 Tudor Miron CFX 15 April 2, 2004 06:18

All times are GMT -4. The time now is 09:34.