|
[Sponsors] |
Total pressure boundary condition at inlet:how to sustain inlet pressure in cfx |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
March 10, 2014, 05:59 |
Total pressure boundary condition at inlet:how to sustain inlet pressure in cfx
|
#1 |
New Member
Join Date: Feb 2014
Posts: 21
Rep Power: 12 |
Hi All,
I have selected Total pressure of 1.4MPa at Inlet in ANSYS CFX software. I am modeling a Nitrogen gas flow through convergent-divergent DeLaval Nozzle. I set a areaAve(Pressure) monitor at inlet in solver control monitors. After 3 4 iterations the inlet monitor shows drastic drop of pressure form 1.4e6 Pa to 2e5Pa. How can I imposed a constant total pressure boundary condition at Inlet? Please help... |
|
March 10, 2014, 16:18 |
|
#2 |
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,703
Rep Power: 143 |
You imposed constant total pressure. You are monitoring pressure. The difference is the dynamic head. If your monitor on total pressure it should be your boundary value setting.
|
|
March 10, 2014, 22:52 |
|
#3 |
New Member
Join Date: Feb 2014
Posts: 21
Rep Power: 12 |
Thanks ghorrock for your response.
Can you suggest me about the expression of total pressure monitor? |
|
March 11, 2014, 06:29 |
|
#4 |
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,703
Rep Power: 143 |
areaAve(Total Pressure)@inlet
Look in the CFX reference manual for a full list of available variables and their names. |
|
March 15, 2014, 22:28 |
|
#5 |
New Member
Join Date: Feb 2014
Posts: 21
Rep Power: 12 |
Thanks ghorrock,
I have solved the total pressure issue. But another problem occurred with total temperature. When I set the total temperature expression at inlet it is just showing a flat line at 0 value. The total temp at inlet is set to 550 deg C. Please see the attached picture and reply. Thanks in advance. |
|
March 16, 2014, 04:37 |
|
#6 |
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,703
Rep Power: 143 |
Have you seen the y scale size? Maybe you should put the temperature curve on another plot with more appropriate scaling.....
|
|
March 17, 2014, 20:53 |
|
#7 |
New Member
Join Date: Feb 2014
Posts: 21
Rep Power: 12 |
Thanks ghorrocks- I have separated the plots and now it is better.
Can you suggest that how can I put the pressure monitors on different locations over the length of nozzle. At the moment I put the monitor on inlet and it is showing. I need to check the pressure on throat section which is at 81.2 mm linear distance from inlet. Also one pressure monitor at exit of nozzle which is at 151.2 mm distance form the inlet. How can I set the pressure monitor at these distances ? please suggest.I am CONFUSED... |
|
March 17, 2014, 22:44 |
|
#8 |
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,703
Rep Power: 143 |
Try a monitor point set at a specific XYZ location.
|
|
March 18, 2014, 04:06 |
|
#9 |
New Member
Join Date: Feb 2014
Posts: 21
Rep Power: 12 |
This is the problem. I am unable to find from where and how can I set specific location at nozzle length.
I tried the option imprint but it is not showing and inactive in my model because my model geometry have frozen bodies. Please suggest? |
|
March 18, 2014, 06:27 |
|
#10 |
New Member
|
Have you created monitoring points using XYZ values at CFX Pre during job set-up along with monitoring variables? The option is available in Monitoring Tab CFX Pre.
|
|
March 18, 2014, 16:47 |
|
#11 |
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,703
Rep Power: 143 |
You do not set up monitor points in the meshing. You set it up in CFX-Pre.
|
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
convergenceof natural convection prob. in cfx | cpkewat | CFX | 15 | January 31, 2014 06:29 |
Question about heat transfer coefficient setting for CFX | Anna Tian | CFX | 1 | June 16, 2013 06:28 |
Low Mixing time Problem | Mavier | CFX | 5 | April 29, 2013 00:00 |
Pressure Inlet Boundary Condition | Prasad | FLUENT | 6 | April 9, 2013 21:32 |
Question about pressure inlet boundary condition. | Alina | FLUENT | 1 | November 30, 2007 07:39 |