Blade angle change with rudder Still reversed !

[P3CFE]

Hello again,

 

I know there has been a long discussion about this all ready, but.. the bug is still there ?.

 

In both of the next situations:

 

1- On the ground + no engines on + rotors standing still + pushing rudder pedals.

2- Powered Flight + level flight + pushing rudder pedals.

 

One rotor is increasing blade angle, and the other is decreasing pitch.

In the simulator the animation of this is reversed....so the rotor that should increase pitch, shows it is decreasing pitch.

 

Would be great if it could be fixed to make the sim even more realistic.

 

Greetings.

 

John

[sobek]

What is your expectation and how is it depicted in the sim?

[P3CFE]

Sorry, but can not make it any clearer then in my first threat.

 

The only thing i can add, is a second proof that the blade angle movement of the rotor with yaw pedal movement is reversed.

 

When you look at the coning angle of the rotors during yaw pedal movement, you will see it changing.

If you then for example look at the rotor that is getting a higher coning angle and pause the sim,

You wil see that that specific rotor (with the higher coning angle) is having a lower blade angle then the other rotor (which is having a lower coning angle).

 

The rotor with the higher cone angle should have a higher blade angle, what causes more lift and thus lifts the blade(s).

 

So the blade angle animation during rudder input is swapped in the sim.

 

Hope this makes the observation clearer.

 

John

[P3CFE]

What is your expectation and how is it depicted in the sim?

 

Oke, i now see where i could be somewhat clearer in my first post.

 

Starting from a balanced situation, Level flight and Heading steady ,no Yaw action.

 

What should be happening, when giving a right rudder input is:

 

Blade angle of the lower rotor (rotating left), should increase pitch and blade angle of the top rotor (rotating clockwise) should decrease.

 

As a result, this requires a higher torque to drive the lower rotor and a lower torque to drive the upper rotor.

 

The increased torque added to drive the lower rotor to the left produces a reaction force that turns the fuselage to the right.

The decreased torque needed to drive the top rotor to the right reduces the reaction force that forces the fuselage to the left and so, it leaves a winning torque to the Right.

 

What i see in the sim. is that only the Blade angle animation is swapped, the rest of the visual and mechanical reaction are good.

 

 

Hope this helps,

 

John

Edited May 23, 2016 by P3CFE

[P3CFE]

What is your expectation and how is it depicted in the sim?

 

Hello Sobek,..Just curious what your opinion is after reading my vision on it.

 

You agree it is a bug ????

[Isegrim]

Think about yaw behaviour while Autorotating.

[sobek]

2 things:

 

First, as Ise has alluded, in unpowered conditions, the rotor system has to switch rotors for yaw input (or else the yaw behaviour would reverse for the pilot), so when watching the helo on the ground unpowered, it is correct if the reaction is reversed.

 

Second, how do you measure blade AoA? Are you aware that coning/flapping has a big impact on the individual blade AoA? I'm afraid that visual perceptions might be misleading in this case.

[P3CFE]

Think about yaw behaviour while Autorotating.

 

Before whe go to that situation, I would like to get an opinion of the powered flight situation.

 

If whe switch to the Autorotation discussion now, i'm shure it is getting harder to designate the bug.

 

With all that is talked about it, I think it is time to defenately conclude that there is a bug or not... .so that it can be fixed........ or not !

[P3CFE]

2 things:

 

First, as Ise has alluded, in unpowered conditions, the rotor system has to switch rotors for yaw input (or else the yaw behaviour would reverse for the pilot), so when watching the helo on the ground unpowered, it is correct if the reaction is reversed.

 

Second, how do you measure blade AoA? Are you aware that coning/flapping has a big impact on the individual blade AoA? I'm afraid that visual perceptions might be misleading in this case.

 

In the situation I described with the right rudder action (powerd flight), before I applied right rudder the visual coning an blade angle (visual when paused) viewed from the side in external view was stable.

 

The only thing at that moment what could change the coning angle in this situation is an increased or decreased blade angle, thereby AoA and thereby lift.

 

What I see in the sim at the moment I apply rudder to the right is that the rotor with the coning angle getting higher, shows (when paused at that moment) a smaller blade angle.

 

This can't be right.

 

Hope you wil reply

 

John

[sobek]

I think this is just an incident where visual clues are prone to misinterpretation because AoA is too hard to gauge.

 

Does anybody know if the animation arguments of both swashplates can be exported? That would yield a definitive answer.

[P3CFE]

I agree it is hard to see, but specially the difference in blade angle between full left and full right rudder, starting from a stable powered flight situation, shows the animated blade angle difference at that moment.

 

It would be great if one of the dev's of the beautiful Ka50 could reply to this an give the data.

 

Somehow, though really not that important, it would make this Ka50 sim even more perfect.

I'll give it a rest now..and see what it will bring.

 

Greetz

John