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Diving the Camel

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5 hours ago, unreasonable said:

Some more diving Camel results for terminal velocity ignoring break up - engine off at various weights.

 

Conditions:

 

1) QMB Kuban Autumn map, 12:00hrs, weather all off.

2) Plane mods - Aldis, gauge, light, wing cut out.

3) Unbreakable and Invulnerable in realism.

4) Full ammunition

5) Fuel settings: Full, 48%,12%

 

Plane dived five times for each fuel setting.

 

- Start 5,000m

- Engine off (E)

- As close to zero Gs on HUD as possible

- Feet off the rudder

- Note IAS in kph when passing 3,048m

 

There is very severe vibration and instability in pitch at these speeds, sometimes with up to +/- 2 Gs on the meter. So I took the best four out of five for the calculation of the mean result. (It would be a couple of mph slower otherwise).

 

Comparison to modelled results:

 

For the modelled results I took the RAF SE5a results in report 492 (in the SE5a thread) and solved for Cd*A

Taking the FC spec page wing area for the SE5a as A, solved for Cd

For the Camel, used the FC spec page wing area for A and assuming the same Cd as the SE5a (It would not surprise me if it was actually slightly lower in reality).

Then calculated the terminal velocities for the Camel at the test weights.  

 

RESULTS

 

1535633918_Cameltestresults.thumb.JPG.af5064de606e477b8fc252b9c9c1b185.JPG

 

Note that the Camel carries a lot of fuel - I expect the speeds players could achieve in practice would be at the lower end of the range - even when invulnerable - since your fuel state would be low either in typical MP fashion, or in SP after a long climb. In addition, these highest speeds would be completely useless in combat in the game, as the plane is so unstable: you certainly could not aim the guns. So I agree that having the Vne a little low makes little or no tactical difference unless the vibration is also much reduced.

 

 

Thanks for doing the testing @unreasonable, in addition I’m of course happy about your calculated terminal speed estimates for the Camel since they in some sense provide an independent confirmation to the C++ simulations which also land in 240 mph region. ;)

 

About the instability, I agree that even if the speed for damage is translated upwards, so should the speed at which the shaking starts. I don’t think it should be removed altogether though since it’s probably even realistic that you may get some stick shaking when you approach damage speeds but notice that none of the pilot accounts either for the S.E.5a or Camel mention any shaking but we need cues in-game so from that perspective it’s a nice feature of the game.

 

So to conclude, IMHO moving the breakup/damage speed higher and then also moving the onset of stick shaking to say, 5-10 mph before that would be nice I think. For the S.E.5a it seems easier to set these speeds since we have the RAE data and in this case IMHO a ballpark based on the RAE R&M 492 report could be say damage speed 270-290 mph and stick shaking at say 260-280 mph. For the Camel it seem more difficult to come up with a good number though but I guess one could do some sort off offset from the S.E.5a results but having done that how do you set the limits for the Fokkers, SPADs and Pfalzs etc? Not an easy task of course but still, I think both realism and game play would benefit from a general increase of the shaking and damage onset speeds. On top of this the engine model should also be updated for the same reasons I think: Both realism and game play would benefit if the in-game engine models were tuned so that they are not quite as prone to blowing up in a dive as they are today.

 

Edited by Holtzauge
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Test results for SE5a - same conditions, engine off, (one less thing to worry about), radiator shut.

 

1969488322_SE5atestresults.thumb.JPG.6604b99377174b91f9b7c00f4f1bf749.JPG

 

The test results were really very close to the RAE estimate which is at a slightly lighter weight than FC at 100% fuel and ammo. I found the SE5a much more stable in pitch at full speed than the Camel, so did not need to throw away one from each set of five tests, but hitting pause at exactly 10,000ft is still tricky! So these are means of five runs and there is still a small measurement error, maybe +/- 2 mph.

 

The fuel state makes less of a difference purely because the SE5a carries less proportionately to it's weight. BTW in the Camel case I assumed the oil weight is unchanged in the game, although in RL it is a total loss system. 

 

Add in 10-15mph (?) for the propeller and that puts an absolute cap on the FC SE5a's speed at ~285mph IAS (edit: on a Standard Day). On the face of it 494 appears to be saying there should be no damage at this speed. 

Edited by unreasonable
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7 hours ago, unreasonable said:

Test results for SE5a - same conditions, engine off, (one less thing to worry about), radiator shut.

 

1969488322_SE5atestresults.thumb.JPG.6604b99377174b91f9b7c00f4f1bf749.JPG

 

The test results were really very close to the RAE estimate which is at a slightly lighter weight than FC at 100% fuel and ammo. I found the SE5a much more stable in pitch at full speed than the Camel, so did not need to throw away one from each set of five tests, but hitting pause at exactly 10,000ft is still tricky! So these are means of five runs and there is still a small measurement error, maybe +/- 2 mph.

 

The fuel state makes less of a difference purely because the SE5a carries less proportionately to it's weight. BTW in the Camel case I assumed the oil weight is unchanged in the game, although in RL it is a total loss system. 

 

Add in 10-15mph (?) for the propeller and that puts an absolute cap on the FC SE5a's speed at ~285mph IAS (edit: on a Standard Day). On the face of it 494 appears to be saying there should be no damage at this speed. 

 

Nice to see that the "invulnerable" FC dive results for the S.E.5a align so well with the RAE R&M 492  report. So based on this it looks like the Newtonian force modeling is pretty much spot on in-game which is good news indeed. So basically, if we are to believe Cpt. Conningham and the RAE (implicitly as least!), then it's "simply" a question of moving the speeds at which shaking and damage starts to occur to higher levels in-game? I would guess that is very good news indeed since I suspect that fine tuning the aerodynamic force modeling is much harder than changing the stick shaking and damage modeling since my guess is that those are "simply" scripted to speed limits meaning they should be easy to change!

 

Grabs hat starts running.....

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On 1/10/2021 at 8:09 AM, SYN_Ricky said:

In Chad Bowyer's "Sopwith Camel - King of Combat" there is a section where he presents notes that Captain Ronald Sykes DFC, wrote about flying the Camel (150 HP BR1 engine). One is about diving, I join a screenshot of the excerpt.

 

cameldive.jpg.158ea9c49c8a016882c0d8df5d99ab05.jpg

 

I wondered about this and can conceive of two possibilities. Perhaps diving caused the pick-up inside the tank to be exposed to vapour.  Once the fuel in the line was expended, the tank pressure would have vented through the fuel line and carb jet.  Alternatively it could be that the Rotherham pump has an RPM limit above which it stops working properly. 

Any other theories?

 

 

 

 

 

 

 

 

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