# why absolute pressure and temperature limited to 1.000000e+00?

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

 January 27, 2010, 16:51 why absolute pressure and temperature limited to 1.000000e+00? #1 New Member   wild Join Date: Dec 2009 Posts: 11 Rep Power: 9 Dear all, I am running a case of two counter rotating wheel in a chamber(adiabatic) to compress air (ideal gas), I am meeting the problem of absolute pressure and temperature limited to 1.00000e+00 for a lot of cells. Whenever I switched the air into constant density but keep energy equation on, there is no problem for the calculation; I checked the fluid characteristics, it looks like both wheels rotate very well, and give me some good result for constant density gas. The problem lies in solving energy equation. Can any one give me some hint how to overcome this difficult? it bothers for quite a while, any hint would be highly appreciated. thanks! Reference for the settings: Geometry description starting from the inlet flow: 1. flow inlet --> front chamber flowing zone --> 1st axial impeller(rotating) --> small gap before 2nd wheel --> 2nd wheel(counter rotating) --> back chamber flowing zone --> outlet 2. all of these flowing zone sections have the same out diameter ANSYS 12-FLUENT 1. Pressure-based, absolute velocity formulation, steady case 2. viscous model selected as standard k-e 3. material selected as idea gas with specific Cp, viscosity 4. fluid inside of two wheels specified as moving reference frame 5. pressure inlet, pressure outlet with static pressure and backflow temperature specified, 6. two impeller wheel are chosen as moving wall which have 0 relative velocity to the adjacent zones. 7. faces between rotating wheel zone and fluid flowing chamber zone are interface 8. simple scheme with least square cell based gradient, and 1st order wind for other parameters 9. URF are set as default

 January 28, 2010, 02:25 #2 New Member   Mas Join Date: Jan 2010 Location: Japan Posts: 24 Rep Power: 9 I'm sure you'll find many answers to that question in this forum if you search. Generally, I think you should increase the quality of your mesh. __________________

 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 Mihail CFX 7 September 7, 2014 06:27 Asashi FLUENT 3 July 18, 2014 09:51 Shamoon FLUENT 1 August 31, 2007 15:09 Radwa FLUENT 2 July 3, 2006 00:19 chong chee nan FLUENT 0 December 29, 2001 06:13

All times are GMT -4. The time now is 03:11.