After much research and following the list discussion for the past several
months, it's been determined that the rotary engine is our best, lightest
and cost effective solution to an engine for an extreme altitude powered
parachute. The payload is a manned suborbital spacecraft.

There are a few different questions below. I appreciate advice, comments,
and suggestions. Please contact me as well if you are interested in
participating in the engine building. We are looking for partners, seasoned
veterans... for this part of the program.
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What is the nominal (no turbo boost) Hp output from a single rotor section.
I imagine this varies between the different models. I've seen figures of 50
Hp through 150 Hp for a single rotor but not sure of what model it refers
to?

This ultimately leads to a question I have as to how many rotors one can
linear gang together if you want very large Hp output.

We have a near term need for a 300 to 600 Hp engine (300 Hp if we use two
engines separately and 600 Hp if we only use one).

The Hp output is at sea level with no turbo boost.

The application is a powered parachute with a heavy lift capability (about
7000 lbs gross lift).

The first target altitude is 35,000 ft then 40,000 ft - 50,000 right up
through 65,000 ft.

Obviously as the altitude gets higher additional turbo charging will be
necessary. We need to keep the cost reasonably under control on the engine
building i.e. not a grass roots engine development program budget.

We want to use existing rotary engines with COTS turbos and control software
/ hardware already developed for altitude compensation - integrating all
together.

Reliability is important as always in aviation as this is a manned
application, however the powered parachute by definition already has the
parachute deployed should there be an engine failure at any altitude.

Some facts and figures we are aware of:

A 5000 lb gross weight UAV powered parachute has flown to 50,000 ft. The
engine was a 250 Hp diesel (Delta hawk - heavy!) super charged and turbo
charged. The engine power output was 60% at 35,000 ft and 40% Hp at 50,000
ft.

The manufacturer recommended to us that we should have higher overall Hp for
a 50,000 ft plus altitude with 500 total Hp at sea level for a 5000 lb gross
vehicle and 60% and 40% respectively.

For our 7000 lb gross weight we believe we need 600 Hp at SL and between 25%
to about 40% Hp at 50,000 ft depending on which numbers one believes.

65,000 ft would be in the 50% to 60% Hp range plus.

One of the earlier UAV's (regular wings) used a triple turbo charged 100 Hp
Rotax to achieve 65,000 ft. It's power output at 65,000 ft was 100%. The
high aspect ratio wing and lower overall drag helped to achieve this low
overall Hp need. The gross weight was about 2500 lbs.

Longer term we are looking to use LNG (liquid methane) as the fuel - must
also run on regular gas for ferry purposes.

Phase 2 is a 3000 Hp engine SL with about 60% plus power output at 65,000
ft.

Phase 3 is a 6000 Hp engine SL with about 60% plus power output at 65,000
ft.

Overall that's a lot to chew on. All inputs and guidance apreciated. Thanks
for taking the time to review.

Cheers,
Brian
--------------------

Brian Feeney
DreamSpace and The da Vinci Project
bfeeney@davinciproject.com
http://www.davinciproject.com

One rotor Mazda HP depends mostly on porting and manifold
design. A P-port is the best. See:
http://www.youtube.com/watch?v=LkKw72dZ2yc

Four rotors on one e-shaft seems to be the upper limit.
600 HP for a normally aspirated (NA) four rotor is doable.
Higher HP if turbo charged. Up to 1600 HP. Cooling is critical.
I recommend buying this book. http://www.rotaryeng.net/cooling.html

For certified rotaries see http://www.mistral-engines.com/

Paul Lamar Back in the U.S.