# Mass-average V.S Area-average

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

 March 19, 2009, 08:59 Mass-average V.S Area-average #1 Senior Member   Rikio Join Date: Mar 2009 Location: SH, China Posts: 182 Blog Entries: 1 Rep Power: 9 Hi, all, I am facing a problem, the total pressure increased before entering the comprossor wheel. Yes, I am doing an analysis on a compressor. Total pressure was area-averaged. And it decreases if mass averaged. Obviously, the later is the right trend we should get. Well, which qualities could be weighted by mass? And which by area? I can not figure it out. Please show me the differences between the two methods. Thanks for any information, thank you !

 March 20, 2009, 17:12 #2 Member   Pratik Mehta Join Date: Mar 2009 Posts: 32 Rep Power: 9 hi, There was a similar question or doubt before and here is the link for the same mass & area average I hope this will make i clear for you Best of luck pratik

 March 20, 2009, 22:19 #3 Senior Member   Rikio Join Date: Mar 2009 Location: SH, China Posts: 182 Blog Entries: 1 Rep Power: 9 Pratik， Thanks for your information. I know more about them now. But I am not sure that I could make the right decision on other qualities next time. Do you think this is related to the intensive & extensive parameters? Saying, if the quality is a intensive parameter, area-average could be used, and mass-average for extensive parameter. Do you agree with me?

 March 23, 2009, 04:58 #4 Member   Pratik Mehta Join Date: Mar 2009 Posts: 32 Rep Power: 9 Hi, When you take an average of certain quatity like Total Pressure in your domain where there exist recirculations or separations like in wake region, under such case area averaging will not give you correct output numerical value, but when you are considering abs mass flow averaging , it is the correct method . I believe this is specifically true for Total Pressure calculations. When you want to know say velocity values, you have to always take area average over the cut plane. Here Mass flow averaging will give you very high value, using which you cannot retrieve the mass flow value ( if you want you can cross check it ). I hope this info helps , regarding you concern of intensive properties , ya i think taking an area averaging or mass flow averaging shouldn`t make any change when you want to derive a numerical value of an intensive properties. But for extensive properties you have to careful . Best regards pratik

 March 24, 2009, 01:47 #5 Senior Member   Rikio Join Date: Mar 2009 Location: SH, China Posts: 182 Blog Entries: 1 Rep Power: 9 Pratik, thanks very much for your kindly help... Best regards to you.

 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 henry CFX 8 September 30, 2016 03:26 giogio FLUENT 4 September 25, 2012 01:36 Tushar FLUENT 0 February 6, 2009 00:55 Tushar Main CFD Forum 0 February 4, 2009 05:37 Peter N CD-adapco 3 February 4, 2007 08:12

All times are GMT -4. The time now is 18:18.