# when the angle of attack =?, the total lift coefficient begin to decrease suddenly

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 April 2, 2009, 10:43 when the angle of attack =?, the total lift coefficient begin to decrease suddenly #1 Member   Jianming Liu Join Date: Mar 2009 Location: China Posts: 71 Rep Power: 17 when the angle of attack =?, the total lift coefficient begin to decrease suddenly. Here, I consider the NACA0012 airfoil, freestream air speed=30m/s Last edited by liujmljm; April 2, 2009 at 21:44.

 April 3, 2009, 03:18 #2 Member   Join Date: Mar 2009 Posts: 44 Rep Power: 17 ehmmm, stall?

April 3, 2009, 03:43
#3
Member

Jianming Liu
Join Date: Mar 2009
Location: China
Posts: 71
Rep Power: 17
Quote:
 Originally Posted by Timon ehmmm, stall?
here the airfoil is fixed. we conpute the flow with different attack angles from 0 degree to 18 degree. we want to know when the lift begins to decrease.

 April 3, 2009, 04:07 #4 Member   Join Date: Mar 2009 Posts: 44 Rep Power: 17 Okay, I misunderstood your question. Well that depends on the Reynolds number, so you need to provide the chord length of your airfoil and the flow conditions (standard athmospheric ?).

 April 3, 2009, 06:02 #5 Member   Jianming Liu Join Date: Mar 2009 Location: China Posts: 71 Rep Power: 17 air density =1.225; temperature T0=273.16; chord length of NACA0012 airfoil is 300mm. freestream air speed=30m/s viscous coefficient mu=1.7161e-5 Reynolds number:70946

April 3, 2009, 06:04
#6
Member

Jianming Liu
Join Date: Mar 2009
Location: China
Posts: 71
Rep Power: 17
Quote:
 Originally Posted by Timon Okay, I misunderstood your question. Well that depends on the Reynolds number, so you need to provide the chord length of your airfoil and the flow conditions (standard athmospheric ?).
air density =1.225;
temperature T0=273.16;
chord length of NACA0012 airfoil is 300mm.
freestream air speed=30m/s
viscous coefficient mu=1.7161e-5
Reynolds number:70946

 August 3, 2012, 05:46 velocity inlet in fluent #7 Senior Member   kunar Join Date: Nov 2011 Posts: 117 Rep Power: 14 Dear friends, In fluent, For analysis of 2D naca0012 airfoil velocity inlet we give vcostheta in x component & vsintheta in y component, v is inlet velocity. 1)here i start analysis of 3D wing, for that i take naca 0012 airfoil & extrude 100mm, in gambit and analysis in fluent i have doubt how to set velocity inlet, here i consider my velocity is 50m/s, then what is xyz component,please let me know. 2)if you consider 3D wing, (vtantheta for z component) is correct or wrong, please let me know. 2) how to find angle of attack for 3D wing? please let me know