CFD Online Logo CFD Online URL
Home > Forums > Main CFD Forum

Divergence of trailing edge pressure?

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

LinkBack Thread Tools Display Modes
Old   December 6, 2007, 06:03
Default Divergence of trailing edge pressure?
Posts: n/a
Hi guys, I'm reading through a paper and the author frequently refers to the "divergence of trailing-edge pressure". I've got a rough understanding of aerodynamics but I don't know what this expression means.

If someone could please explain what it means then I'd be very grateful. Cheers, Bren
  Reply With Quote

Old   December 6, 2007, 07:11
Default clarification
Posts: n/a
sorry I just realised that my original question was perhaps a tad vague.

To put the expression into context:

"Pearcey shows how the trailing-edge static pressure controls the development of the steady transonic flow about a rigid airfoil and how the divergence of steady trailing-edge pressure may sometimes indicate the onset of unsteady separated flow"

Is a quote from the article. I don't understand what the author means by "divergence of steady trailing-edge pressure" - this is a physical phenomena and has nothing to do with numerical divergence.

Could someone please advise? Bren
  Reply With Quote

Old   December 6, 2007, 13:12
Default Re: clarification
Posts: n/a
I believe that all the terminology means is that the flow field prior to separation (at onset) is very sensitive to changes in the trailing edge pressure gradient. The upstream shock wave is not strong enough to induce separation by itself, but between the shock and the trailing edge the flow is in a precarious situation. A slight disturbance causing the pressure gradient to increase is sufficient to cause a major shift in the flow field and lead to the flow separating upstream of the trailing edge. In this case it can be thought of as divergent because a very small change in dp leads to a large-scale change in the flow field.
  Reply With Quote

Old   December 6, 2007, 18:57
Default Re: clarification
Posts: n/a
In experimental studies of 1980s, the "divergence of trailing edge pressure" implied an abrupt increase of the pressure against the angle of attack. See a paper by Lee B.H.K. in Progress in Aerospace Sciences, Vol. 37, 2001, page 158.
  Reply With Quote


Thread Tools
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 On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Pulsatile pressure inlet with pressure outlet a.lynchy FLUENT 3 March 23, 2012 14:45
ICEM aircraft mesh trailing edge difficulty MontyR ANSYS Meshing & Geometry 4 July 23, 2011 21:46
fluent add additional zones for the mesh file SSL FLUENT 2 January 26, 2008 12:55
pressure gradient term in low speed flow Atit Koonsrisuk Main CFD Forum 2 January 10, 2002 11:52
trailing edge problem Kuo Wei-Jen Main CFD Forum 2 April 14, 1999 10:09

All times are GMT -4. The time now is 00:08.