Incorrect velocity profile

MGabr · June 24, 2013, 11:25

Dear friends
I am modelling fluid flow through an orifice in Ansys CFX 14 and my inlet pressure is 6000 KPa with mass flow rate 30.907 L/s , i had defined inlet ,outlet, wall boundaries and adjusted my messing with inflation near wall . Although that the velocity profile starts form 1.5 m/s not from zero.
Does anyone has idea about solving this problem
If you need any data to help you in identifying this problem , just let me know

Thanks in advance
best regards

mjgraf · June 24, 2013, 16:10

the solver is calculating the Q/A at the inflow boundary.

thinking about it another way, elaborate on profile starts at 1.5 m/s and not from zero. do you mean near the wall or the average velocity at the inflow boundary?

ghorrocks · June 24, 2013, 21:10

If your question is why isn't the velocity at the wall zero - then plot hybrid variables and it will be zero. You are showing the conservative values and these are located slightly off the wall and are therefore not zero.

MGabr · June 25, 2013, 15:33

Dear mjgraf ; thanks for your reply , i mean the velocity at the wall is 1.5 m/s not zero

MGabr · June 25, 2013, 15:44

Dear ghorrocks: Thanks for your answer. 10^8 Thanks for you

June 24, 2013, 11:25	Incorrect velocity profile	#1
MGabr Member Mahmoud Gabr Join Date: Aug 2012 Location: Egypt Posts: 30 Rep Power: 14	Dear friends I am modelling fluid flow through an orifice in Ansys CFX 14 and my inlet pressure is 6000 KPa with mass flow rate 30.907 L/s , i had defined inlet ,outlet, wall boundaries and adjusted my messing with inflation near wall . Although that the velocity profile starts form 1.5 m/s not from zero. Does anyone has idea about solving this problem If you need any data to help you in identifying this problem , just let me know Thanks in advance best regards

June 24, 2013, 21:10		#3
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	If your question is why isn't the velocity at the wall zero - then plot hybrid variables and it will be zero. You are showing the conservative values and these are located slightly off the wall and are therefore not zero. petrosdd likes this.

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June 24, 2013, 16:10		#2
mjgraf Senior Member Join Date: Dec 2009 Posts: 131 Rep Power: 19	the solver is calculating the Q/A at the inflow boundary. thinking about it another way, elaborate on profile starts at 1.5 m/s and not from zero. do you mean near the wall or the average velocity at the inflow boundary?

June 25, 2013, 15:33		#4
MGabr Member Mahmoud Gabr Join Date: Aug 2012 Location: Egypt Posts: 30 Rep Power: 14	Dear mjgraf ; thanks for your reply , i mean the velocity at the wall is 1.5 m/s not zero

June 25, 2013, 15:44		#5
MGabr Member Mahmoud Gabr Join Date: Aug 2012 Location: Egypt Posts: 30 Rep Power: 14	Dear ghorrocks: Thanks for your answer. 10^8 Thanks for you