Results of CFX Simulations

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

 June 26, 2011, 18:00 Results of CFX Simulations #1 New Member   AyAhSof Join Date: Jun 2009 Posts: 8 Rep Power: 9 Helo, I've done simulations, usin' CFX, on rotor passages. In the results i have noticed negative pressure values. I know that negative velocity values means that the fluid particule is movin' in the opposite direction, but i dont understand the meanin' of negative presuure values. Also, in papers reserchers show countours containin' regions of negative pressure. NB: I'm speakin' about countour pressure values, not values of pressure difference witch can mean that the flow is in opposite direction. I'll be gratefull if somebody explaine to me this. Thanks.

 June 26, 2011, 18:35 turbomachinery velocity diagram in CFX #2 New Member   AyAhSof Join Date: Jun 2009 Posts: 8 Rep Power: 9 Hello, Usin' CFX Simulations on compressor passages, I have difficulties understandin' the absolute velocity and the relative velocity knowin' that in my results i have countours of Cm; W; velocity; ... I know that C=W+u; when C absolute velocity W relative velocity u speed of rotor, but in CFX documentation, i have found somewhere (with figures) the decompostion of V to streamwise velocity; spanwise velocity; circumferential velocity or to axial velocity; radial velocity, circumferencial velocity and also to Blade to blade velocity ...etc. So is V absolute or relative velocity; or can we say that C= (that V)+u; and how can we obtain in resutls Cu velocity; Cr velocity; Wu velocity; Wm velocity; Wr velocity. Can somebody help me understandin' this, or tell me in what part exactly of CFX documentation can i found the details of that (maybe i didn't searche well in it).

 June 26, 2011, 21:19 #3 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 12,715 Rep Power: 99 Pressure is measured relative to a reference pressure. A negative pressure simply means the pressure is less than the reference pressure. If the reference pressure is one atmosphere then a nagative pressure simply means a vacuum.

 July 9, 2011, 06:15 meanin' of Negative pressure values #4 New Member   AyAhSof Join Date: Jun 2009 Posts: 8 Rep Power: 9 Dear Ghorrocks, Thank you so much for helpin' me understandin' negative pressure values.

 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 famarcfd ANSYS 0 March 24, 2011 05:16 nasdak CFX 1 April 14, 2010 13:22 mike CFX 8 May 7, 2007 14:54 MatjazR CFX 1 October 17, 2005 09:07 Mel CFX 1 August 8, 2005 18:47

All times are GMT -4. The time now is 00:12.