Mailing List flyrotary@lancaironline.net Message #49939
From: George Lendich <lendich@aanet.com.au>
Subject: Re: [FlyRotary] Re: rpm vs Power was : Throttle limits was Re: N.A. Renesis to turbo
Date: Wed, 10 Feb 2010 10:07:23 +1000
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Monty,
Prop efficiency climbs (so I'm told) until it reaches speed of sound, so I believe some try to take the prop  as close to 3,000 rpm as possible, yet some stay a conservative 2,700 rpm, what do you suggest, given all the variables.
George (down under)
----- Original Message -----
Sent: Wednesday, February 10, 2010 9:55 AM
Subject: [FlyRotary] Re: rpm vs Power was : Throttle limits was Re: N.A. Renesis to turbo

Al,
 
5-6 more than he got or 5-6 more than base line?
 
You also have to take into account that prop efficiency falls off pretty steeply with increased speed and rpm. Especially if the tips start to go transonic. There are some airplanes out there with CS props that will go slower with the engine at redline, even though the engine is making more power, because the prop is eating all of the extra and then some.
 
Hate to see you selling your plane, she's a beauty. Wish I had the dough. Looking forward to the next project...there will be a next one won't there ;-). 
 
Monty
----- Original Message -----
From: Al Gietzen
Sent: Tuesday, February 09, 2010 5:47 PM
Subject: [FlyRotary] Re: rpm vs Power was : Throttle limits was Re: N.A. Renesis to turbo

Subject: [FlyRotary] Re: rpm vs Power was : Throttle limits was Re: N.A. Renesis to turbo

 

Hp = C*V^3

 

Is that simple enough?

Simple enough – and with some other numbers Ed gave I compute he should get 5-6 kts more top end.

Al



No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.5.435 / Virus Database: 271.1.1/2677 - Release Date: 02/09/10 07:35:00
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster