I did a graphic this morning on various rad configurations
and their pros and cons.

Here it is. I am open to comments.


Paul Lamar

"Del Johnson, North Point Solutions, Inc" wrote:

What about exploring some concepts using exhaust augmentation

to round out

the discussion of cooling configurations.  I'm seriously

considering using

it in the Glastar.  Although the Glastar is capable of

respectable cruise

speeds it is a STOL plane and has some great slow speed handling
characteristics. I'm looking at exhaust augmentation to meet the cooling
requirements when flying at slower speeds as well as reducing

cooling drag

at cruise speeds.  I have a fair amount of room in front of the

firewall to

work with (see attached firewall drawing).  I'm just finishing up with
hanging the engine and hope to have a working exhaust

augmentation system

ready for static testing early next year.

It looks like there would be room to install part or all of the exhaust
augmentor plumbing under the cowling with the intake at a

forward position.

I'm open to any ideas.  I would welcome more discussion on the exhaust
augmentation topic and to hear more from the few builders that are also
considering this option.

Thanks

Del Johnson

Will be interesting to measure the pressures and flow when you
get it flying. Should work fine at 0-100 MPH speed ranges. The
effectiveness of an exhaust augmentation, by its very nature,
is reduced as the aircraft speed increases.

Paul Lamar

Your last statement is true for all cooling systems.  You have more than
enough airflow for cooling at cruising speeds but you size your openings for
worst case senario (climb out, ground taxing & runups).  If exhaust
augmentation works like the research papers and Contact articles suggest you
get a boost in cooling effect when you apply power (when you need more
cooling).  It has the potential of reducing cooling drag for the faster
flying machines because the air intake openings can be smaller.

P.S.  The Glastar is slower than the RV's but should be able to do 175+ mph
max and 155-160 mph cruise, assuming that it isn't equipped with floats.

Del Johnson

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