Jump to content
Sign in to follow this  
FDEdev

constant speed prop sound still wrong like in FSX/P3D?

Recommended Posts

22 hours ago, J35OE said:

Huh?  How can engine RPM differ from prop RPM???

The prop is not always connected directly to the engine's crankshaft, but is sometimes driven via a gear reduction system, and prop speed is controlled by either a mechanical or hydraulic governor to maintain a selected speed by varying the pitch of the blades.

The engine spins (just like a car engine) based on fuel flow and the air mixture through the venturi, or fuel pressure controlled by the injector system in the case of a fuel-injected engine. Rather than measuring engine RPM, instead engine power is measured/reported in terms of manifold pressure.

See: http://www.boldmethod.com/learn-to-fly/aircraft-systems/how-a-constant-speed-prop-works/

 


Fr. Bill    

AOPA Member: 07141481 AARP Member: 3209010556


     Avsim Board of Directors | Avsim Forums Moderator

Share this post


Link to post
1 hour ago, n4gix said:

The prop is not always connected directly to the engine's crankshaft, but is sometimes driven via a gear reduction system, and prop speed is controlled by either a mechanical or hydraulic governor to maintain a selected speed by varying the pitch of the blades.

Even if the prop is not always connected directly to the engine's crankshaft and a reduction gear is involved, it's still a fixed ratio!

To include geared engines it looks like I have to rephrase my statement:

Propeller RPM can not be controlled independently from engine RPM, regardless if it's a constant speed or fixed pitch propeller.

Share this post


Link to post

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  
  • Tom Allensworth,
    Founder of AVSIM Online


  • Flight Simulation's Premier Resource!

    AVSIM is a free service to the flight simulation community. AVSIM is staffed completely by volunteers and all funds donated to AVSIM go directly back to supporting the community. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. Thank you for your support!

    Click here for more information and to see all donations year to date.
×
×
  • Create New...