Discharge coefficient in function of pressure ratio

Roland R · September 21, 2012, 05:36

Hello,

I calculated compressible high speed flow in steady state.
I determined the discharge coefficient from the results in case of some pressure ratio (pi = 0.6 - 0.125). Based on my calculations, the discharge coefficient is constant in this range. (alha = 0,85) The discharge coefficient was investigated at the full geometry.
What do you think about this? Can it be correct? Is there pressure ratio range where the discharge coeff. changes in the function of pressure ratio?

Thanks
Roland

ghorrocks · September 24, 2012, 21:58

Discharge coefficients can be either constant over pressure ratio or variable. It depends on the details of the set up.

September 21, 2012, 05:36	Discharge coefficient in function of pressure ratio	#1
Roland R Senior Member Roland Rakos Join Date: Mar 2009 Posts: 131 Rep Power: 17	Hello, I calculated compressible high speed flow in steady state. I determined the discharge coefficient from the results in case of some pressure ratio (pi = 0.6 - 0.125). Based on my calculations, the discharge coefficient is constant in this range. (alha = 0,85) The discharge coefficient was investigated at the full geometry. What do you think about this? Can it be correct? Is there pressure ratio range where the discharge coeff. changes in the function of pressure ratio? Thanks Roland

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Water subcooled boiling	Attesz	CFX	7	January 5, 2013 03:32
channelFoam for a 3D pipe	AlmostSurelyRob	OpenFOAM	3	June 24, 2011 13:06
Constant velocity of the material	Sas	CFX	15	July 13, 2010 08:56
Version 15 on Mac OS X	gschaider	OpenFOAM Installation	113	December 2, 2009 10:23
Total pressure to static pressure ratio	roadracer	Siemens	1	April 17, 2003 05:31

September 24, 2012, 21:58		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,700 Rep Power: 143	Discharge coefficients can be either constant over pressure ratio or variable. It depends on the details of the set up.