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-   -   when the angle of attack =?, the total lift coefficient begin to decrease suddenly (http://www.cfd-online.com/Forums/main/63263-when-angle-attack-total-lift-coefficient-begin-decrease-suddenly.html)

liujmljm April 2, 2009 10:43

when the angle of attack =?, the total lift coefficient begin to decrease suddenly
 
when the angle of attack =?, the total lift coefficient begin to decrease suddenly. Here, I consider the NACA0012 airfoil, freestream air speed=30m/s

Timon April 3, 2009 03:18

ehmmm, stall?

liujmljm April 3, 2009 03:43

Quote:

Originally Posted by Timon (Post 211812)
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.

Timon April 3, 2009 04:07

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 ?).

liujmljm April 3, 2009 06:02

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

liujmljm April 3, 2009 06:04

Quote:

Originally Posted by Timon (Post 211821)
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

hhh August 3, 2012 05:46

velocity inlet in fluent
 
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


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