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carburetter ram air control has no effect


a.miedlig
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Dear sirs,

I think at the moment the merlin engine power cannot make use of the ram air effect of typical aircraft speed. So the engine power at altitude only represents the power value of the turbocharged engine without any ram air effect. So the p51 has not enough power alt altitude e.g. at 30000 feet.

I think its a broken link to a not functioning ram air control lever.

 

I hope you can fix it in the future.

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The ram air system works, however, the levers to turn it off and to switch on warm air are not yet functional, AFAIK.

 

At the moment, the RAM air system is constantly on.

Good, fast, cheap. Choose any two.

Come let's eat grandpa!

Use punctuation, save lives!

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At the moment i am not able to fly the p51 at 28000 ft with high speed (that means using ram air effect) and achieving a manifold pressure of anything over or near by 60 in hg. (manual says 67 in hg in war emergency power)

 

i dont think you can.

 

So what have i misunderstand ?

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  • ED Team
At the moment i am not able to fly the p51 at 28000 ft with high speed (that means using ram air effect) and achieving a manifold pressure of anything over or near by 60 in hg. (manual says 67 in hg in war emergency power)

 

i dont think you can.

 

So what have i misunderstand ?

 

I think, something's wrong in the manual. The critical altitude for 67" at max speed is 26000, not 28000.

28000 is for 61". It is the numbers from TSCEP5E-1908 report.

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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what so ever

 

at the moment no one is able to gain even this low value

 

the achievable values in this simulation are in my opinion those without ram air effect. Those values can be read in the original flight manual you presented by the link

http://aviationshoppe.com/manuals/v-1650_engine_packard/merlin.html

 

but these values are values from the engine without thinking of a plane and a congruent speed in the air .

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what so ever

 

at the moment no one is able to gain even this low value

 

the achievable values in this simulation are in my opinion those without ram air effect. Those values can be read in the original flight manual you presented by the link

http://aviationshoppe.com/manuals/v-1650_engine_packard/merlin.html

 

but these values are values from the engine without thinking of a plane and a congruent speed in the air .

 

Do you know what critical altitude is?

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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its the altitude at which the blower isn´t any longer able to hold the nominal manifold pressure at which the engine is rated, that means above the critical altitude the manifold pressure ist steadily decreasing an so the engine output.

 

so you say: we have an critical altitude 2. stage blower on, normal speed, for the p51 of 26000 ft and 61 in hg (which i think is correct with ram)

 

But the simulation doesn´t reproduce it. i only can achieve about 50 in HG. ?!

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its the altitude at which the blower isn´t any longer able to hold the nominal manifold pressure at which the engine is rated, that means above the critical altitude the manifold pressure ist steadily decreasing an so the engine output.

 

so you say: we have an critical altitude 2. stage blower on, normal speed, for the p51 of 26000 ft and 61 in hg (which i think is correct with ram)

 

But the simulation doesn´t reproduce it. i only can achieve about 50 in HG. ?!

 

What does it mean - normal? What was IAS exactly?

I suggest that IAS in your test was not maximal ( 280-290 mph) so the ram pressure was insufficient.

 

Anyway, you can calculate the equivalent baro altitude with rammed air using this equation

 

delta P (Pa) = 0.5 * Rho *TAS^2 (m/s) , where Rho means air density at actual altitude.

 

Then take standard atmosphere table and find the gradient of atmospere pressure dP/dH (Pa per metre) near the actual altitude.

Then divide delta P to this gradient. It will be critical altitude bonus due to rammed air. Or if you subtract it from the actual altitude you can find engine performance (MP, power) referring to the tables for unrammed air (the rammed air is warmer but it can be neglected)


Edited by Yo-Yo

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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THey are functional (delete old INPUT) and we have bound them to axes.

But as icing is not finished they are almost useless.

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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I can move the levers, but I understood they have no effect in the sim because RAM air is always on. :)

 

The ram air system works, however, the levers to turn it off and to switch on warm air are not yet functional, AFAIK.

 

At the moment, the RAM air system is constantly on.

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Yesterday, I was on the 104th DCSW server in a P-51. When at 20000ft, I had no effect of using NON RAM air on the carburetor temperature, it was always at -20ºC. Probably because of NON RAM air not being employed...

 

At least I'm not breaking the engine when maintaining continuous 36'' manifold pressure and 2400rpm :)


Edited by Xpto

104th Cobra

[sIGPIC][/sIGPIC]

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THey are functional (delete old INPUT) and we have bound them to axes.

But as icing is not finished they are almost useless.

 

Are you certain that made the release?

Good, fast, cheap. Choose any two.

Come let's eat grandpa!

Use punctuation, save lives!

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  • ED Team
Yesterday, I was on the 104th DCSW server in a P-51. When at 20000ft, I had no effect of using NON RAM air on the carburetor temperature, it was always at -20ºC. Probably because of NON RAM air not being employed...

 

At least I'm not breaking the engine when maintaining continuous 36'' manifold pressure and 2400rpm :)

 

NON RAM do not heat the air. Try to fly at 30000 at 250-300 mph and then switch to UNRAMMED

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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What happens when RAM is shut off in flight? You should get some changes in MP and engine Temp, correct?

 

You will lose dynamic pressure. If you are flying at 170 mph it will have almost no effect to MP. If you are flying 250-300 mph it will ruin your energy :)

 

And, by the way, air heating is bugged, sorry. Will work soon. But the only effect you can see will be unwanted mixture leaning at high altitude (see manual).

 

So, the engine temperatures (water and oil) will suffer.


Edited by Yo-Yo

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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