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-   -   What should be the reference area for a 2d Airfoil Analysis (https://www.cfd-online.com/Forums/fluent/90102-what-should-reference-area-2d-airfoil-analysis.html)

nikhiljohn June 30, 2011 11:57

What should be the reference area for a 2d Airfoil Analysis
 
I have an airfoil (2d) of chord length 1 meter. The length of the camber line is 1.06m. The cross sectional area (2d enclosed area) is 0.17 meters. What should I give as the reference area if fluent for getting the correct cl.

Thanks everyone in advance for your help.

AdrienL July 1, 2011 10:11

Most of the time Airfoils use the square of the chord length as the reference area

Sincerly

Adrien

nikhiljohn July 1, 2011 11:46

Thanks You

smab November 24, 2011 00:23

I have my NACA 23015 airfoil(flow speed 36m/s) which has a chord length of 100mm, max thickness 15.05mm,...
after scaling the grid to metres...what should be the reference values for area, length and depth...
i am unable to obtain correct values for Cl and Cd...please help
its very urgent....:(

nikhiljohn November 24, 2011 16:13

Refrence Area
 
The reference area should be your chord length (after scaling) and leave the length and the depth with the default values.

Far March 13, 2016 21:30

Just want to add something.

Reference area is Length and depth. Since depth is taken as 1, therefore reference area for 2d airfoil is taken as c * 1 = Chord length

pappusam January 10, 2020 02:19

Quote:

Originally Posted by AdrienL (Post 314407)
Most of the time Airfoils use the square of the chord length as the reference area

Sincerly

Adrien

kindly could you tell me, from where you have taken this? (i.e. ref. area = square of the chord length)

NonStopEagle January 12, 2020 06:29

Quote:

Originally Posted by pappusam (Post 754267)
kindly could you tell me, from where you have taken this? (i.e. ref. area = square of the chord length)

Alright so, for an airfoil (i.e a 2-d section of a wing), the formula for cl is,
cl = lift/(0.5)*rho*(v^2)*c
where c is the chord length. Since there is no depth in a 2-d simulation, the depth value in the reference values is set to 1. reference area in fluent then has to be the length that you input (i.e. the chord length).
the reference area then becomes,
reference area = length*depth = chord*1 = chord.
So if you are running a 2d simulation of an airfoil, no matter the camber, always take the reference area as the chord.

Narendhiran_IIT_Madras November 15, 2023 01:13

Hi everyone,
I need some clarity on the reference area calculation of 2D airfoil in fluent
For example: Chord =0.1 m, then reference area = chord * depth.
By default(2D airfoil) depth =1. i.e.1 m
so, ref area = 0.1*1=0.1 m^2, Physically it represents an airfoil with chord 0.1 m and depth(span)=1 m...

So my question is "Does the default depth value(=1) for 2D airfoil gives correct reference area?"

orborneee November 20, 2023 02:43

Quote:

Originally Posted by Narendhiran_IIT_Madras (Post 860049)
Hi everyone,
I need some clarity on the reference area calculation of 2D airfoil in fluent Super Mario
For example: Chord =0.1 m, then reference area = chord * depth.
By default(2D airfoil) depth =1. i.e.1 m
so, ref area = 0.1*1=0.1 m^2, Physically it represents an airfoil with chord 0.1 m and depth(span)=1 m...

So my question is "Does the default depth value(=1) for 2D airfoil gives correct reference area?"

The exercise is really difficult, I'm still working on it step by step


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