Blowback
Stuck_in_an_ATR
There is a simple analytical formula for rotors that calculates the blow back. It boils down to:
Blow back is proportional to the coning angle
Blow back is proportional to the forward speed
Manipulating the collective will influence the total lift/load on the rotor and as such the coning angle: the coning angle is proportional to the MR load, ie collective , so the blow back is proportional to the collective (please do not extrapolate this relation into the acrobatic regimes so to speak)
To put it figurative : think of an umbrella and the effects wind has on it. Rotor is of course a bit more complex, but it has a similar behavior.
Remark : this relationship has nothing to see with nose up or down, which is the consequence of the rotor lift on the hull and hull aerodynamics (horizontal stabilizers)
d3