Serious Deviation between game and real ka50 flight model - Page 4 - ED Forums
 


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Old 06-20-2017, 10:31 AM   #31
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Yes I think my best was about 650 km/h dive with a pull out. bahaa This was BS1 tho and i've never tried to repeat the experiement in BS2..
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Old 06-20-2017, 10:55 AM   #32
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Quote:
Originally Posted by Fri13 View Post
Yes.... You can do all the things when you push collective down.

Doing backside flip at 300km/h speed starting at 20m altitude ain't a problem when you only initiate the maneuver with collective and immediately push it down while the fuselag and wings completes the backflip.

Then it is only critical to know at what point you start to pull collective again to avoid crashing ground after quick dive.

But what is talked in the manuals is the distance between rotor disks while you are actually pulling collective instead having them just autorotating.

The skill required to master is to know how much collective you need at what maneuvers and speeds so you have the controllability but you do not collide blades.

At higher speeds helicopters fly like an airplane and having a turning tail assists a lot as we can even more do all kind turns and flips without using so much the rotors as we do have slight gliding capabilities.
It's not only the collision of the blades here, it's also the G force tolerance on other parts of the rotor hub. If you were to ask ED to change anything here, it would be just the animation of the blades and how close they are seen perhaps at the higher speeds.

Have the blades further apart and still exploded them when the structural limit is reached (Something failed). Doesn't bother me, I'm not hanging out the door looking at the hub when doing 330km/h. Oh that's close....Boom!




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Last edited by David OC; 06-20-2017 at 11:51 AM.
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Old 06-21-2017, 06:44 PM   #33
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Quote:
Originally Posted by Fifou265 View Post

in game at 280km/h it looks like less than 100mm , about to collide

irl :
at 0 km/h clearance is 1400mm
I guess you should have double checked your measurements before claiming the "great errors" for the community.

First of all, the clearance is 1500 mm (Fig 10, ERF1998-vol1-AD05.pdf) for 0 kph.

Then, I can not see your "100 mm" at 280. The valued researcher would fly a mission with steady speed then start the track and using slow-mo catch the moment of two blades are at the closes distance. Just one under another or close to it. Then, moving the camera as far as it is possible he would set the neccessary zoom (FOV) and place the camera using both F2 and Alt-F2 rotations just between the rotors on the pole.

And he would take a ruler and using inter-hub distance as a reference he would get approx. 610 mm and not the "100 mm" (600% error!!!).

The thing the valued researcher can not do is to obtain real blade tip log from the simulation, but I can.
This log obtained form in vitro tool is for 280 kph and the collective pitch rotor AoA close to the simulation. Later I can obtain it just from the simulation that uses just the same calculation model as the tool.

Of course, the REAL TIME model used in Ka-50 (for average PC of 2005, by the way) did not use true aeroelasticity and detailed wake model as non-real time models used in the references by Kamov company...

But it does use true aerodynamic and mechanical simulation of each blade using the shortest dt we can afford.

But the result of it is quite good for the real time, single PC simulation.
If the simulated helicopter performs the same aerobatics as real without blade collisions - it's a good FM, right?

https://youtu.be/QFGjSqQzDXs

https://youtu.be/U8vVRuMfBNE
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Ніщо так сильно не ранить мозок, як осколки скла від розбитих рожевих окулярів
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Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me
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Old 06-21-2017, 08:35 PM   #34
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Excellent post Yo-Yo
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Old 06-22-2017, 06:18 AM   #35
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Thanks for the explanation Yo-Yo!
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Old 06-22-2017, 09:54 PM   #36
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It's called a helicopter that's been sitting out on some god forsaken FARP for who knows how long, with the occasional odd replacement of parts and maintenance. Probably closer to REAL life than we think.
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Old 06-23-2017, 03:21 AM   #37
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Thanks for the info about the Black Shark's FM modeling Yo-Yo, always interesting to see how these FM's are modeled.

She is one very elegant lady, more than just physics equations, the FM is true SimArt, as seen here in the video you posted.

This guy has some awesome skills.




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Old 06-23-2017, 09:29 AM   #38
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What a masterpiece of smooth flying skills !

After hundreds of hours in the Ka-50 I am still miles away from those smooth skills.

A delight to watch, a true landmark for any Ka-50 Pilot out there indeed.


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