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MANFEIZHANG December 2, 2010 03:16

3D-naca0012 simulation
i want to simulate standard 3d-naca0012 airfoil by Fluent,the length of Z direction is 0.24m,but i meet some problems,when i want set the
report>>reference- values >>aera.... i don't know how to define ,because ,in the 2-D condition ,The area here is actually area per unit depth,however ,now is 3-D,can some one help me to set the aera?
if you could tell me what does aera mean in 3-D condition,it will be my great pleasure.
my regards ,thanks.

kdrbrk December 2, 2010 04:55

it is the value which you define in order to find coefficient.
Fluent calculates force, and converts it to coefficient with respect to reference values that you give.

it is up to you. generally for wings, reference area is the area viewed from above, =chord*span

MANFEIZHANG December 19, 2010 03:26

thanks so much ,Kdrbrk
if the 3-d airfoil has a angle of attack at 15 ,now, the aera will be chord*span *cos(15) , right or wrong ?

kdrbrk October 27, 2011 10:34

hi again, hope you are still there.
Sorry for a veeeery late reply, I was on my military duty, and come back recently.
you don't have to take cos(15) because it is "reference" area, and the given coefficient will be calculated as this area.

You can try and see yourself. You can write 1(one) for reference area and you get coefficient*area value.
force is only divided by (1/2*density*velocity^2) and you have (coeff*area)

lets say coeff*area = 100

if you say that ref. area is 50, your coeff will be 2
if you say that ref. area is 25, your coeff will be 4

but the net force will be same.

hope this helps.

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