## C.G. displacement influence

## C.G. displacement influence

(OP)

Hello,

I am trying to develop a MatLab program that mathematically models an aircraft in trim flight. Everything fine so far, except that the reference system used does not coincide with the centre of gravity. I denoted the distances from the origin of the reference system to the centre of gravity with CGX, CGY and CGZ. However, CGY=0.

Now, how does these distances affects my equations of motion and the aircraft's derivatives? Thanks!

I am trying to develop a MatLab program that mathematically models an aircraft in trim flight. Everything fine so far, except that the reference system used does not coincide with the centre of gravity. I denoted the distances from the origin of the reference system to the centre of gravity with CGX, CGY and CGZ. However, CGY=0.

Now, how does these distances affects my equations of motion and the aircraft's derivatives? Thanks!

## RE: C.G. displacement influence

## RE: C.G. displacement influence

Well, I have the stability and control derivatives for my aircraft, all calculated with respect to the c.g. assumed at the origin of the body axes (nominal c.g.). Now I found out that the final c.g. is displaced in the Ox and Oz directions by some distances. I believe this will affect the derivatives I obtained so far, I just don't figure out how it affects them mathematically.

## RE: C.G. displacement influence

## RE: C.G. displacement influence

## RE: C.G. displacement influence

but this is only part of the problem ... you're changing the power and maybe the line of thrust ... this'll affect the stability of the plane.

a "forward" fin ?

i'd look into a text on airplane stability and control ... something like "etkin".

## RE: C.G. displacement influence

http:/

particularly a graduate course in "aircraft stablility and control"