This is the continuation of a research project a started a couple of years ago. Basically I'm looking for any knowledge or info anyone knows about, or any expertise anyone might have to help along the way.
In the 50's some Univ. did a bunch of glide tests on a Cruiseair and part of what they found was that the poor engine cooling air handling inside the cowl was costing a LOT of power, so the propulsion efficiency on Mr. Bellanca's fine airplane is pretty bad. I want to try to mitigate that problem and save gas/go faster. Supposedly the problem is worth 10 MPH. (I know a Money owner who picked up 11 knots with an external augmenter).
It turns out NACA has an (old) paper describing tests with ALMOST EXACTLY what would fit in the Cruiseair. It was quite effective and simple to construct. The net effect is to draw a slight suction on the cowl at the rear of the engine (aiding cooling air flow), but more importantly, it accelerates the cooling air exiting the cowl up to or above TAS, eliminating the drag from low-speed air exiting like a small barn door. The test rig also generated some thrust, apparently because of the cooler air sucked into the exhaust stream <and heated/expanded>. Basically the device blasts exhaust gas into the inlet of a large venturi inside the cowl (without raising the backpressure a measureable amt) which in turn sucks in the air from the cowl. The nice part about the NACA design is that it uses a rectangular, long, skinny shape specifically to be used inside the cowl of aircraft. Actually, it would be about half in/half out, but the shape fits the belly and works just as well as a round augmenter, according to NACA.
Along with this I would experiment with different air flow control inside the front of the cowl, etc. A look at any new aircraft shows how different they are in that regard.
So if anyone has info or contacts with someone who does, please pass it on. This is a slow process, but I hope to have something working in a year or so (or have abandoned the project as not useful).
The best part is that my AI is onboard!
In the 50's some Univ. did a bunch of glide tests on a Cruiseair and part of what they found was that the poor engine cooling air handling inside the cowl was costing a LOT of power, so the propulsion efficiency on Mr. Bellanca's fine airplane is pretty bad. I want to try to mitigate that problem and save gas/go faster. Supposedly the problem is worth 10 MPH. (I know a Money owner who picked up 11 knots with an external augmenter).
It turns out NACA has an (old) paper describing tests with ALMOST EXACTLY what would fit in the Cruiseair. It was quite effective and simple to construct. The net effect is to draw a slight suction on the cowl at the rear of the engine (aiding cooling air flow), but more importantly, it accelerates the cooling air exiting the cowl up to or above TAS, eliminating the drag from low-speed air exiting like a small barn door. The test rig also generated some thrust, apparently because of the cooler air sucked into the exhaust stream <and heated/expanded>. Basically the device blasts exhaust gas into the inlet of a large venturi inside the cowl (without raising the backpressure a measureable amt) which in turn sucks in the air from the cowl. The nice part about the NACA design is that it uses a rectangular, long, skinny shape specifically to be used inside the cowl of aircraft. Actually, it would be about half in/half out, but the shape fits the belly and works just as well as a round augmenter, according to NACA.
Along with this I would experiment with different air flow control inside the front of the cowl, etc. A look at any new aircraft shows how different they are in that regard.
So if anyone has info or contacts with someone who does, please pass it on. This is a slow process, but I hope to have something working in a year or so (or have abandoned the project as not useful).
The best part is that my AI is onboard!
