Engine controls, management, RPMs and Manifold pressures

[Juuba]

EDIT;

posted in Reddit also:

 

 

I don't have the FW-190D-9 yet.

But, reading from the FW-190D-9 Flight manual, they talk about power settings at different RPMs.

I've always thought that Kommandogerät (whatever it was in the Jumo-versions) took care of all that, while the pilot just "input" his desired power output Manifold Pressure (ATA) level with the throttle.

 

Two excerpts from the manual:

 

First, they talk about the power settings on page 94:

 

Power Settings

 

Emergency Power (increased take-off power) 3,250 RPM only below 1,000m on 213A-G1 by pulling the MBG-emergency pull or as intermediary solution on 213-A RS by operation of a cock in the manifold pressure line. Hereby the manifold pressure increases by 0.2 ata while maintaining constant engine speed/RPM.

 

At the latest 3 min after takeoff, reduce to combat power and slightly push flight stick forward.

 

Throttle position can be fixed by turning the handgrip on lower left.

 

Throttle Position / Power Output / RPM / Permissible Time / Fuel Consumption Liter/hour:

 

• 90° command angle / Emergency Power (increased take-off power)* /
  
• 3250 / 3min / 620 -20
  
• 90° / Take-Off, Combat and Climb Power / 3250 / 30min / 590 +20/-40
  
• 75° / Continuous Power / 3000 / constant / 530
  
• 60° / Economy I / 2700 / constant / 375
  
• 47° / Economy II / 2400 / constant / 285
  
• 34° / Economy III / 2100 / constant / 215
  
• 0° / Idle (in flight) / app. 1200 / - / -
  
• 10° / Engine Stop position / - / - / -
  

But, already on pages 25-26 they talked about the "Bediengerät" (engine control unit):

 

Bediengerät (Engine Control Unit)

The Junkers Jumo 213 engine comes equipped with a "Bediengerät" (engine control unit). It is similar in function to the "Kommandogerät" (command device) used on BMW-801-powered earlier variants of the Fw 190.

 

The "Bediengerät" is a hydromechanical multifunction integrator that dramatically simplifies engine control. While in most other contemporary aircraft the pilot had to constantly operate a slew of levers to manage throttle level, propeller pitch, fuel mixture, and supercharger stages, the "Bediengerät" takes the majority of the workload away. The pilot simply has to move the throttle lever to set the desired manifold pressure. The "Bediengerät" takes care of the rest, setting all other parameters to allow the engine to properly operate at the desired manifold pressure, given the current flight conditions.

 

The gauge used to monitor desired supercharger pressure is the Supercharger Pressure Gauge to the right of the front dashboard labeled "ATA" (for "Absolute Technische Atmosphäre", an obsolete unit of pressure).

 

Additional controls are also available that allow for some Engine Control Unit parameters to be manually finetuned.

So, TL;DR;

Why is the manual talking about Power settings at what ever RPM, when the Bediengerät (Engine Control Unit) takes care of all that?

Edited September 16, 2014 by Juuba
layout

[Altflieger]

The manual for the 190 is a work in progress, it's an interesting read but next to useless as it stands.

The position of the throttle lever, rpm and fuel consumption is for your information. You should KNOW this information, your life depends upon it. One engine, no petrol, not good.

Example:

Bomber stream crossing Dutch coast, you in Fw190 at Berlin. When do you take off to intercept? How long to get to 35 000ft? What throttle setting would you use? If you climb at lower power setting and take off earlier will this increase your time in combat? Etc, etc...

 

But with maps 390x390km, none of this currently matters. (Wags please note:))

[Flying-Kane]

"The pilot simply has to move the throttle lever to set the desired manifold pressure. The "Bediengerät" takes care of the rest, setting all other parameters to allow the engine to properly operate at the desired manifold pressure, given the current flight conditions."

 

As i mentioned it in another thread, it's nonsense for the Jumo 213.

 

The Jumo was operated only by rpm and observing the fuel consumption.

 

The gauge for Manifold pressure was only for monitoring purposes.

[Skulleader]

90° command angle / Emergency Power (increased take-off power)* /

3250 / 3min / 620 -20

90° / Take-Off, Combat and Climb Power / 3250 / 30min / 590 +20/-40

75° / Continuous Power / 3000 / constant / 530

60° / Economy I / 2700 / constant / 375

47° / Economy II / 2400 / constant / 285

34° / Economy III / 2100 / constant / 215

0° / Idle (in flight) / app. 1200 / - / -

10° / Engine Stop position / - / - / -

 

Hello guys,

 

I've read your explanations but I not sure that I've well understand the story about the degrees from this text.

 

Please can you tell me if the degrees are the positions of the throttle.

 

Here I join you one quick screenshot where I've drew the position of these degrees, please can you tell me if it's correct or not ?

 

A great thanks in advance, Skull.

 

[Derbysieger]

@Skull: That is just copy&pasta from the flight manual.

 

As I said on reddit, the quote from p. 25 of the flight model seems to be plain wrong.

I would agree with Kane that it is nonsense in regard to the Jumo 213.

Edited September 16, 2014 by Derbysieger

[Flying-Kane]

I want to add, that the sim models the MBG/Jumo 213 right.

 

Only the manual in this regard is wrong.

[Juuba]

Okay, so I was wrong and the Jumo is different.

 

Thanks! :D

[Juuba]

"The pilot simply has to move the throttle lever to set the desired manifold pressure. The "Bediengerät" takes care of the rest, setting all other parameters to allow the engine to properly operate at the desired manifold pressure, given the current flight conditions."

 

As i mentioned it in another thread, it's nonsense for the Jumo 213.

 

The Jumo was operated only by rpm and observing the fuel consumption.

 

The gauge for Manifold pressure was only for monitoring purposes.

 

Can you link the other thread, please?

 

Nvm, i think I found it: http://forums.eagle.ru/showthread.php?p=2126673#post2126673

Sources I would like to see, of course, but it seems like this.

Edited September 16, 2014 by Juuba
found it.

[Flying-Kane]

Sources?

 

-Jumo 213 Manual, there's all explained in detail

-Die deutsche Luftfahrt - Flugmotoren und Strahltriebwerke (ISBN: 3-7637-6128-4)

 

By the way, Yo-Yo explained it in the Jumo 213 engine thread as well (http://forums.eagle.ru/showthread.php?t=114094).

[Juuba]

Thanks..

 

 

One more thing I'm curious... Where and How does the pilot in cockpit tell the Fuel Consumption rate ?

 

 

EDIT: Added this: in the first post, he is talking about RPM and ATA values... so what gives??!

Edited September 17, 2014 by Juuba

[Juuba]

Browsing forward in the thread, I find more and more info that shows RPM and Manifold pressures... SO when and where did the fuel consumption rate come in to the manual, and WHY.

 

And more so: How does the pilot tell the rate in cockpit?!

 

My guess is: He cant.

 

EDIT:

I don't want to sound angry or stupid :D

English is not my main language..

 

I just really want to know the "what and why and how" :D

Edited September 17, 2014 by Juuba

[Juuba]

Now that I've read thru the threads, it does seem that the ATA is not a player in this Jumo 213A.

 

Just a weird step away from the traditional DB and BMW fighter world.

 

Live and learn.

 

Thanks for this, sorry for the rant. :D

[Flying-Kane]

You are right.

 

The manifold pressure was important to ground crews, for maintenance reasons. It's explained in the Jumo manual.

 

BMW and Daimler engines were controlled by manifold pressure.

The pilot chooses a certain pressure value and all other settings (rpm, propeller pitch etc.) were changed to meet the right conditions.

[Juuba]

You are right.

 

The manifold pressure was important to ground crews, for maintenance reasons. It's explained in the Jumo manual.

You mean the "fuel consumption was important, for maintenance.." I believe?

 

BMW and Daimler engines were controlled by manifold pressure.

The pilot chooses a certain pressure value and all other settings (rpm, propeller pitch etc.) were changed to meet the right conditions.

 

Yes, and that's why I was wondering, especially with the manual explaining the "Bediengeräte" as similar to what BMW had.

[Flying-Kane]

You mean the "fuel consumption was important, for maintenance.." I believe?

 

No, i mean the gauge for the manifold pressure.