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Old 08-13-2018, 11:46 AM   #1
TheSkipjack95
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Default 2 vs 3 bladed prop

Hello,

Quick question. I ran performance tests with both props to see if having a third blade made a difference.

Parameters tested : Takeoff distance, Initial climb, cruise.

From what I gather I should see better performance in the climb, but a loss of cruise speed.

However all measurements were the same between the propellers.
(200m, 5-6m/s, 270km/h)

Are the differences not yet implemented/purely cosmetic/non existant in the Yak52 ?
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Old 08-13-2018, 04:06 PM   #2
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Originally Posted by TheSkipjack95 View Post
Hello,

Quick question. I ran performance tests with both props to see if having a third blade made a difference.

Parameters tested : Takeoff distance, Initial climb, cruise.

From what I gather I should see better performance in the climb, but a loss of cruise speed.

However all measurements were the same between the propellers.
(200m, 5-6m/s, 270km/h)

Are the differences not yet implemented/purely cosmetic/non existant in the Yak52 ?

Also, there's a graphical glitch, at least with my GPU ( GTX 960 ) when the 3-blade version is chosen. Strange graphic artifacts in the "propeller disk"...
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Old 08-13-2018, 05:22 PM   #3
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Originally Posted by jcomm View Post
Also, there's a graphical glitch, at least with my GPU ( GTX 960 ) when the 3-blade version is chosen. Strange graphic artifacts in the "propeller disk"...
You mean this problem? https://forums.eagle.ru/showthread.php?t=217441
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Old 08-13-2018, 05:44 PM   #4
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Exactly bbrz!


Well, I'm on hold for patches... :-)
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Old 08-13-2018, 06:51 PM   #5
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Quote:
Originally Posted by bbrz View Post
Happens only with that particular skin...all others work well with the 3 blade prop
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Old 08-13-2018, 07:31 PM   #6
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Oh, it only happens to one of the skins ? I'll try with a few then... but since apparently there is no difference in performance, maybe I should rather wait for latter updates...
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Old 08-13-2018, 07:36 PM   #7
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Originally Posted by jcomm View Post
Oh, it only happens to one of the skins ? I'll try with a few then... but since apparently there is no difference in performance, maybe I should rather wait for latter updates...
Yep, the info is in the linked thread
Btw, since we don't know e.g. which blade angles the 2 and 3 bladed props are using, how do we know where the performance differences are?

Last edited by bbrz; 08-13-2018 at 07:38 PM.
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Old 08-14-2018, 10:01 AM   #8
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Originally Posted by bbrz View Post
Yep, the info is in the linked thread
Btw, since we don't know e.g. which blade angles the 2 and 3 bladed props are using, how do we know where the performance differences are?
Generally 3 bladed props allow to better output the engine power, ie give more thrust, which is why I tested climb rate ( at the same speed I would expect a higher VSI reading ).
However, they are draggier, ( more surface area bc of the third blade ) so I expect a lower cruise speed.

There's plenty of info on the web.

I don't know how all of this applies to the yak specifically, but I would assume that the military trainers use the two bladed prop because aerobatics aren't the primary use, but the privately owned aerobatic ones use the three bladed props because it's always nice to have some energy.

The question remains : is there supposed to be a difference in DCS, or is it purely cosmetic/no difference because of the design.
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Old 08-14-2018, 07:51 PM   #9
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Here's someone who owns a modded Yak-52 (taildragger, completely retractable main gear, 400hp engine, 3-bladed Mühlbauer prop) who also sais it has more thrust than the standard 2-bladed prop.

https://www.youtube.com/watch?v=pTxGuV6OFW8&t=4m10s

It's in German though, I guess most people won't understand what he's telling.
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Old 08-20-2018, 12:09 PM   #10
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BTW, how can we switch between the 2 blade and the 3 blade prop?
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