I am designing a model rocket and am using 3 B6-4 Engines. Inevitably there will be perturbation of its trajectory by wind and engine/thrust inconsistencies. The way that I currently understand the Centre of mass (CM) and Centre of pressure (CP) in terms of correcting an altered trajectory, is that the lift acts through the CP to create a torque about the CM in the opposite direction to the torque that initially caused the rotation of the rocket.
So, say there is a constant clockwise torque of x Nm, I need to create a counterclockwise torque of (x + a) Nm. What should the value of a be? Is it a proportion of x? The value of a needs to be great enough that it sufficiently causes the rocket to right itself and overcome equilibrium, but it can't be large enough that it causes significant overcompensation (causing the rocket to pass vertical by its momentum).
Also, what sort of torque values are likely to be induced to the rocket from wind and engine/thrust inconsistencies. Are the fins or other mechanical attributes of a rockeet realistically sufficient to create enough "counter-torque"? What about adjustable fins?
Cheers, Harry
So, say there is a constant clockwise torque of x Nm, I need to create a counterclockwise torque of (x + a) Nm. What should the value of a be? Is it a proportion of x? The value of a needs to be great enough that it sufficiently causes the rocket to right itself and overcome equilibrium, but it can't be large enough that it causes significant overcompensation (causing the rocket to pass vertical by its momentum).
Also, what sort of torque values are likely to be induced to the rocket from wind and engine/thrust inconsistencies. Are the fins or other mechanical attributes of a rockeet realistically sufficient to create enough "counter-torque"? What about adjustable fins?
Cheers, Harry