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.
Lynn E. Hanover
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
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