Mailing List flyrotary@lancaironline.net Message #56229
From: Bill Schertz <wschertz@comcast.net>
Subject: Re: [FlyRotary] Re: Renesis Question
Date: Sun, 14 Aug 2011 08:34:13 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
One other comment on boosting – bear in mind that I am NOT boosting my 13-B.
 
If you use a supercharger, then the engine has to produce the extra power to run the supercharger. That means more fuel burn, and more heat to be rejected by the engine. So to get an increased power to the propeller, you have to generate the desired increase, plus the supercharger power.
 
If you use a turbo charger, the boost energy comes from unused energy in the exhaust stream, but you end up with increased mass under the cowl that is glowing cherry red.
 
 
Bill Schertz
KIS Cruiser #4045
N343BS
Phase one testing Completed
 
Sent: Sunday, August 14, 2011 6:36 AM
Subject: [FlyRotary] Re: Renesis Question
 
Sam, As you find in this "hobby" there  are always trade offs.  First, technically there is no reason you could not do what you propose - however, you will add weight and complexity.  A poor intake affects both N/A and forced induction - its just with forced induction you are paying in a different way to overcome any defficiencies in your intake.
 
If going that route, I personally would prefer the centrifugal type belt/gear driven blower over the roots type which has historically had the poorest efficiency.  On the other hand, if you are not going to "boost" above ambient pressure - then I think I would concentrate on getting a good N/A intake.
 
Good luck on your project whichever decision/approach you take.  Super and Turbo chargers have both been used successfully.
 
just my $0.02\
 
Ed
 
Sent: Sunday, August 14, 2011 1:01 AM
Subject: [FlyRotary] Renesis Question
 
I think my brain has had a meltdown: I am thinking about "supernormalizing" the Renesis engine. Is this even possible. The idea is to use a by-passable positive displacement type blower (roots type...probably an eaton m90) fed to an intercooler that then sends air to the engine. If my thinking is correct, and it probably isn't, this would eliminate the complex N/A intake, while not over-boosting the Renesis engine. Also, the supercharger being a positive displacement blower would in theory produce more boost than is needed by the engine at all rpm levels, eliminating the "peeky" torque of boosted engines. The excess (above standard intake) pressure would be controlled via an automatic or manual waste-gate. Please shoot my idea down if it is insane, but i would like some constructive criticism if it is available.
 
Sam
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster