CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > CFX

CFX SCO2 turbine temperature

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 6, 2014, 09:06
Default CFX SCO2 turbine temperature
  #1
New Member
 
Cafard
Join Date: Jun 2014
Posts: 29
Rep Power: 11
Cafard is on a distinguished road
Hi all,
I try to simulate a SCO2 radial turbine,and the condition are:
1.)Inlet:1MPa(static),reference pressure:12MPa,500K(static)
2.)Outlet:0.01 kg/s (1passage [total:11])
3.)Material>reference state property>
reference temperature:500K
reference pressure:12MPa
4.)time scale:2.5e-4
5.)model size=60mm H=30mm
6.)mesh:1.2e5 nodes(quality good)

The simulate result was finish at timesteps 5000,residuals was 1e-6 and no vibration.
The boundary condition:
a.)Outlet pressure : 0.86MPa
b.)Outlet temperature : 499K
c.)max. velocity(inlet) : 40 m/s

My question is why the outlet temperature still near 500k,temperature shuld decrease.I have read the Ansys FAQ,but still not solve the question.

By the way,is the reference state property right?
Cafard is offline   Reply With Quote

Old   August 6, 2014, 09:19
Default
  #2
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,665
Rep Power: 143
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
Then you have not modelled the heat transfer correctly. What wall boundary conditions are you using? What temperature are you expecting at the outlet? Why are you expecting it?
ghorrocks is offline   Reply With Quote

Old   August 6, 2014, 10:30
Default
  #3
Senior Member
 
Join Date: Jun 2009
Posts: 1,788
Rep Power: 31
Opaque will become famous soon enough
May I ask why are you using Static Temperature inlet condition ?

Similarly, why static pressure and not Total Pressure ? I assume you meant 1MPa gauge pressure since you are using a reference pressure of 12MPa, correct ?

Not sure what exact material you are using (incompressible, or compressible ?). An incompressible fluid will pass through the turbine and the temperature rise will be minimal (if any).

Have you tried running the "Axial Turbine" tutorial provided in the installation ?
Opaque is offline   Reply With Quote

Old   August 6, 2014, 12:02
Default
  #4
New Member
 
Cafard
Join Date: Jun 2014
Posts: 29
Rep Power: 11
Cafard is on a distinguished road
the wall condition is adibadic

because I want to simulate supercritical CO2,so I use real gas material which is compressible gas.

by the reference paper (SCO2 brayton cycle),after the turbine the outlet temperature should decrease,but not just decrease 1K

the static state condition just I set,by the way,could I solve my question by set total state condition ?
Cafard is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Calculation of the Governing Equations Mihail CFX 7 September 7, 2014 07:27
Simulation of Water Turbine with CFX hydroturbines CFX 0 July 23, 2014 16:58
convergenceof natural convection prob. in cfx cpkewat CFX 15 January 31, 2014 07:29
Verifying results for a wind turbine blade simulation in ANSYS CFX Joystix CFX 3 April 27, 2012 18:52
simulation Axial flow turbine using CFX dia aisa CFX 3 May 2, 2008 03:45


All times are GMT -4. The time now is 10:56.