I beleive that right roll in the hover is an attempt at modeling translating tendency, however, it is way too extreme and does not seem to dissipate with forward airspeed as it should.
On Dissymmetry of lift.
As I have mentioned in another thread, dissymmetry of lift is caused by the forward airspeed of the aircraft adding airspeed to the advancing side of the rotor disc and subtracting airspeed from the retreating side of the disc. If nothing were done mechanically to solve this issue then helicopters would be limited to stationary hovering. Lucky for us Juan de la Cierva found the solution: Flapping hinges. Allowing the additional lift from additional airspeed on the advancing side to flap the blade up, and then down on the retreating side. This changes the Angle of Attack of the blade so that the rising advancing blade is creating LESS lift, and the retreating blade is creating MORE lift, despite the significant difference in airspeed. The end result is the lift vector is balanced on both sides of the disc. Ergo: No rolling moment in forward flight. At least, until you get the helicopter up to an airspeed where the flapping hinge can no longer compensate for the difference in airspeed, at which point, you would experience a vibration and oscillations followed by simultaneous roll to the left (on counterclockwise turning rotor systems) and a pitch up of the nose. This is called retreating blade stall, when the retreating blade side has lost so much airspeed due to the forward motion of the helicopter that it can no longer produce lift, and is the limiting factor in helicopter airspeed.
Questions are welcome. Comments will be tolerated as long as they are intelligent in nature.
More to come as I have time.
---------- Post added at 02:28 AM ---------- Previous post was at 12:44 AM ----------
OK, so I tested out the latest update. Here are my thoughts.
On the plus side, the obliteration of the null zone did a world of good. Now I can much more easily feel and see the flight characteristics for what they are rather than constantly over correcting my inputs and chasing the stupid thing all over the place.
Now that I can accurately feel the flight dynamics, lets address some issues.
Pedal control is WAAAAAY too light. Small inputs should yield rapid turns.
Though the helicopter will pitch very quickly with input, the actual ground movement is slow to respond. A real helicopter will slide left, right, foreward and back with almost imperceptible pitch changes. The helicopter should be moving over the ground alot more than it is pitching around its axis.
Please decrease the volume and increase the rate of the vibration occuring at ETL. It's a nice touch, but it does not achieve the intent if it doesnt look and feel right. I have said it before, the vibration experienced at ETL is more HEARD than felt, you would be better simulating the PANEL vibrating along with a rattling noise than having the whole helicopter shaking. It just doesn't look or feel right at all.
What on earth is that right rolling tendency in forward flight? As the helicopter moves into ETL an odd thing happens called Transverse Flow Effect, the front part of the rotor is moving into clean air and the the flow into the rotor system is more horizontal than vertical, however, the induced flow at the back of the rotor is increased and the flow is more vertical than horizontal, the result is a difference in angle of attack (and thus, lift) between the front and back of the disk, not entirely unlike what is occurring during dissymmetry of lift in forward flight, though for completely different reasons. Basically, the front part of the disk is in ETL and the back part is not. The effect of this is the vibration I mentioned earlier, as well as a pitch up and slight right roll of the helicopter. The pilot must push through this in order to gain airspeed. Once the ENTIRE rotor system is through ETL this effect goes away, and rather quickly. There should be no right or left rolling tendency in foreward flight unless VNE is exceeded.
Rate of turn in forward flight vs amount of bank angle is way off. A smaller bank should yield a higher turn rate than what is simulated. No pedal input should be necessary to aid in turns in forward flight.
It IS definitely starting to feel like a helicopter, just with some unusual behavior. Good job gentleman and please keep improving! Listen to what the pilots are all saying, I keep reading about the same issues over and over again.
Please watch my youtube videos. I have real helicopter footage as well as some very good helicopter simulator footage, the most recent being the DreamFoil R22 in alpha testing for X-Plane. This thing flies like a real R22. Watch carefully how it behaves compared to the TOH model.
Edited by nightsta1ker, 26 July 2011 - 02:31.