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Yak-52 PFM verification Discussion


WildBillKelsoe

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who cares about parasites... carry on man good work! cant wait!

AWAITING ED NEW DAMAGE MODEL IMPLEMENTATION FOR WW2 BIRDS

 

Fat T is above, thin T is below. Long T is faster, Short T is slower. Open triangle is AWACS, closed triangle is your own sensors. Double dash is friendly, Single dash is enemy. Circle is friendly. Strobe is jammer. Strobe to dash is under 35 km. HDD is 7 times range key. Radar to 160 km, IRST to 10 km. Stay low, but never slow.

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Very nice Yo-Yo! Looking forward to this!

i7 7700K | 32GB RAM | GTX 1080Ti | Rift CV1 | TM Warthog | Win 10

 

"There will always be people with a false sense of entitlement.

You can want it, you can ask for it, but you don't automatically deserve it. "

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Thank you! Very interesting!

"Long life It is a waste not to notice that it is not noticed that it is milk in the title." Amazon.co.jp review for milk translated from Japanese

"Amidst the blue skies, A link from past to future. The sheltering wings of the protector..." - ACE COMBAT 4

"Blessed be the LORD my strength, which teacheth my hands to war, and my fingers to fight"-Psalm 144:1 KJV

i5-4430 at 3.00GHz, 8GB RAM, GTX 1060 FE, Windows 7 x64

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As Yak-52 is not really suitable for any combat simulation and is a very special DCS product, I can show the backstage of the tuning and verification process regarding flight test results.

And this will be a debut unveiling the measured and simulated flight parameters - numerical and coincided at one graph.

The first post will be about its roll rate.

The test was a pure aileron roll starting from a climb to perform 4 full rolls. The rolls started with maximal fast full stick deflection, proceeds with full ailerons and ends with maximal fast stick release (not perfect in both tests though - the real test input was a bit delayed and the DCS test seemes to be overcompensated).

The atmosphere conditions in DCS were set identical to real during the test.

This test allows to check initial roll acceleration (MOIx vs aileron power), steady roll rate (aileron power vs damping) and roll damping (MOIx vs damping). Additionally we obtained roll rate vs speed, and these two parameters (the first divided by the second) can give a ratio that is proportional to so called spiral coefficient (TAS must be used and the wingspan to get it). It is not s necessary to use this spiral coefficient in our case though.

 

For those who never saw experimental recordings from the real world :) - the sinusoidal high frequency noise over the curve is a vibrational part. It was not filtered to better preserve phase and time of the original record.

 

We can clearly see that the model initial angular acceleration is in good accordance with the test results, see

Fig. 4. The deceleration at Fig 2 is in a good accordance to regarding to slightly different control input.

As the initial pitch of both tests were not identical, the speed during the tests is different too, so to compare the roll rate we need to divide roll rate to IAS (Fig. 2).

It is interesting that the real plane has very tiny spiral coefficent slope to high IAS (see the trendline). I can suggest that it could be due to aileron linkage elasticity or wing elasticity or both. As it is barely noticable even a the diagram, I do not think it should be reproduced in the model :)

 

And, finally, I'd like to claim that the results represent current stage of model tuning, WIP.

 

P.S. The uneven (sinusoidal) low frequency at the roll rate is a result of he fact that the X-axis of the sensor was not exactly aligned with the plane axis, so it must be disregarded as a parasite effect.

 

Can you say anything about the engine start dynamics yet? That is something i am really interested in!

"Long life It is a waste not to notice that it is not noticed that it is milk in the title." Amazon.co.jp review for milk translated from Japanese

"Amidst the blue skies, A link from past to future. The sheltering wings of the protector..." - ACE COMBAT 4

"Blessed be the LORD my strength, which teacheth my hands to war, and my fingers to fight"-Psalm 144:1 KJV

i5-4430 at 3.00GHz, 8GB RAM, GTX 1060 FE, Windows 7 x64

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  • ED Team
Can you say anything about the engine start dynamics yet? That is something i am really interested in!

 

It is almost the same "slow" model working in all our piston engines. The air start was added, so the air from the air system is injected over pistons driving the engine.

Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів

There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.

Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

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  • ED Team
do you plan to implement the new pistol engine model to previous ww2 birds?

 

Yak-52 got the standard model similar to the previous WWII planes. The model is sophisticated enough starting from the Mustang, and any new model gets only its own differencies the real engine has. For example, MBG and air mass flow oriented MP control for Dora, variable speed blower for DB-60x, etc.

Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів

There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.

Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

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It is almost the same "slow" model working in all our piston engines. The air start was added, so the air from the air system is injected over pistons driving the engine.

 

Oh, ok thank you!

"Long life It is a waste not to notice that it is not noticed that it is milk in the title." Amazon.co.jp review for milk translated from Japanese

"Amidst the blue skies, A link from past to future. The sheltering wings of the protector..." - ACE COMBAT 4

"Blessed be the LORD my strength, which teacheth my hands to war, and my fingers to fight"-Psalm 144:1 KJV

i5-4430 at 3.00GHz, 8GB RAM, GTX 1060 FE, Windows 7 x64

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Exciting stuff, can't wait for this module and thanks for the behind the scenes peek. Very interesting.

The FALSE is real, but it's not THRUTH right?

 

Intel i7 8700K OC4.4GHz | 16GB | GTX1080Ti | Logitech G940 | TrackIR5 |

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There is a IRL stunt pilot here who said it will be interesting to see how well modeled negative flight/airflow will be, stunts like the Bell Tailslide etc.

 

This was posted below in the Christen Eagle II threads below, but would like to know if this can be closely modeled in the FM's? for the Yak-52 or any aircraft in DCS.

 

As the owner of a Pitts S1S and a regular aerobatic competitor, I wish you well with the Eagle. It is a nice machine. Nothing like a Pitts of course, but nice!biggrin.gif

 

Aerobatics is my passion. Flight sims are a hobby. I have found that attempting to mix the two to be a big fat failure. Flight sims, and DCS in particular, do an amazing job mimicking flight smack in the middle of the envelope where 99% of pilots spend 100% of their time but they do a horrible job of modeling flight in the nether regions, areas of stalled and reversed airflow. Most of competition aerobatics is spent here. As a test bed to improve this situation, I see the Eagle as an excellent choice. I am certain that I am not the only DCS user who has actually flown it. It's commonality makes real world comparisons easy to get. The risk is that it will only serve to highlight how weak DCS can be. No one here flies a Bf109 so any doubt can be explained away. That luxury will not exist for the Eagle.

 

As far as I'm concerned, I still think DCS is miles ahead of any other sim on the market, especially when it comes to the FM's and at the edge of the flight envelope.

 

 

This is going to be sickening in VR if able to perform like that:cry:

 


Edited by David OC

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Chuck's DCS Tutorial Library

Download PDF Tutorial guides to help get up to speed with aircraft quickly and also great for taking a good look at the aircraft available for DCS before purchasing. Link

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  • 4 months later...

I have a question regarding control forces.

 

I know it's a very complicated issue, but there are multiple aircraft in DCS, most notably the Spitfire, which when left without any control axes tweaking, are extremely touchy on the controls and even unstable in some cases.

The 109 has seen the implementation of a control deflection limitation with speed, so as to stiffen the response and give it a very comfortable weight.

 

My question then is : Is that "issue" also considered in the case of the Yak-52 ? My understanding is that it's DCS' current physics research airframe.

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  • 8 months later...
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