That is one radical looking bi-plane – for
sure.
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Lynn Hanover
Sent: Sunday, March 07, 2010 10:48
AM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Paul Lipps
propellers
Here is a picture of that same Biplane showing an
alarming use of the same idea to build a whole wing. The cowl has enough
good stuff going on, to keep me busy for months.
When the windscreen is far enough back then the cowl
top remains a low pressure area and
cooling airflow out of top vents is much improved, so
intake holes can be even smaller.
Plus after flight cooling is quick and in cowl baking
is reduced.
Not seen is that the lower wing is a Gull wing plan
form for short stiff/light gear, and greater distance between wings for less
interplane interference, so, the smaller lighter wings and small wing area work
better. The stager makes for less CG sensitivity , so a lower tail area works,
and the tiny fuselage cross section makes for lower wetted area.
The prop tips on Paul Lipps little plane are protected
with tennis balls to protect the blades from damage, and passersby from injury.
The tips are as if kitchen butcher knives.
I got to hear one of his lectures at Gene NV. At the
Contact magazine alternative engine roundup. I am afraid that he has forgotten
more about props than I will ever learn.
I believe you are correct, Lynn
There were a couple of fairly recent developments that I thought
held some promises in prop design, but they do not appear to have panned out.
One was the “bi cambered” prop blade which as best I recall was
suppose to provide more thrust – I believe it did lower the Prop noise
somewhat, but the increased thrust does not seem to have developed.
The vortex generators (of one type or another) on the prop blades –
the one most commonly seen were the dimpled or holey tape. Again have not
seen that recently
Then the one that looked to have the most promises was the
Lipps prop blade – narrow near the hub and tip and broad near the mid
section. I really seem to prove itself in racing – but have not hear of
it bring that apparent promise of improved performance to the common crowd.
http://www.biplaneracing.com/files/Issue77_8-13.pdf
That about all I can recall recently
Ed