Aerodynamics Influence Coefficents, AIC
 

Hi,

What are these Aerodynamic Influence Coefficents and how we can get these from Unsteady pressure distribution using FFT.

Thanks

Re: Aerodynamics Influence Coefficents, AIC
 

Are you talking about something Aeroelastic or just Aerodynamic?

Re: Aerodynamics Influence Coefficents, AIC
 

That's related to AeroElasticity

Re: Aerodynamics Influence Coefficents, AIC
 

hi, have a look at www.aero.polimi.it/~cavagna under the publications section. Luca

Re: Aerodynamics Influence Coefficents, AIC
 

I'm not able to go further because it's not my field. You should follow the Luca's link.

Re: Aerodynamics Influence Coefficents, AIC
 

Hi,

Thanks a lot, I will be looking on these papers.

Re: Aerodynamics Influence Coefficents, AIC
 

Thanks,

That might help!

Re: Aerodynamics Influence Coefficents, AIC
 

The classic definition of aerodynamic influence coefficients is that the the A_ij component of the coefficent matrix relates the velocity potential at a point "i" to the "downwash" w at a point j(normal velocity on the wing) ie:

phi_1=A_11*w_1+A_12*w_2+A_13*w_3+..... phi_2=A_21*w_1+A_22*w_2+...

etc

you can also think of them as relating the force at point f_i to the downwash at a point j ie

f_1=B_11*w_1+B_12*w_2+B_13*w_3+..... f_2=B_21*w_1+B_22*w_2+...

the A_ij(and B_ij) are functions of Mach number and reduced frfequency.

As far as determining them from unsteady pressure measurements you would need additional data such as surface velocities I believe. A search of the literature should come up with numerous methods for approximation these coefficients numerically.