How do I find the three factors of the hinge moment coefficient?

Question

How do I find the three factors $c_{h0}$, $c_{h\alpha}$ and $c_{h\eta}$?

Use eta ($\eta$) for deflection. Use XFOIL to determine the coefficients. — Peter Kämpf, Oct 15 '16 at 07:48
i apologize, may i have the tutorial XFOIL for calculate coefficient moment? actually i never use XFOIL. thank sir. — Ade Firmansyah, Oct 18 '16 at 18:50

score 3 · Answer 1 · answered Oct 19 '16 at 23:25

First download and install xfoil from this site http://web.mit.edu/drela/Public/web/xfoil/
if you use ubuntu - sudo apt-get install xfoil

user manual and typical session inputs are also there. please refer to them as you haven't used it before.

And there are many video tutorials in youtube.
[Link removed I cant put more than 2 links here- Just search xfoil tutorial in youtube]

For this specific case;

open your airfoil in xfoil
xfoil name.dat
Set the flap as you want enter GDES and FLAP and follow the prompts.
Type these commands in sequence
exec
[enter]
pane
Enter OPER menu and set the RE number
oper
visc 1e6 (1 million Re for this case)
type these commands in sequence
hinc (hinge moment togle enabled)
pacc (accumilate polar - give a file name)
aseq 0 10 0.5 ( sequence of alfa to run - here from 0 to 10 in 0.5 increase)
Open the resulting file. which has two coloums along with other parameters to show alfa and hinge moment. (first and sixth)

plot it or linearize it or whatever you like to do to find the above parameters.

PS: Another suggestion is XFLR5. It is same as XFOIL but with GUI. you may find it easier.

1 Answers1