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Mechanical Engineering


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  1. Agreed, however, prop design is a very difficult thing to hide, so in this case, it's not really considered practical to try. Also, private engineering is miles ahead of these designs anyway. The days of the unshrouded prop are numbered, it seems. Shrouded props allow for far less turbulence around the prop edges, and a circular secondary wing allows for additional advantage to be taken of the Venturi effect as well. Lockheed-Martin is a bit behind the times as far as prop design goes. Much improvement can be seen in the stunt/recreation aircraft market over the Navy's examples, and the wide a
  2. It seems you're right. I did miss the point. My apologies. But to the propeller point, access to photos of the prop and scale of the photo is enough to generate enough data to clone said prop, test it, and alter it as necessary to generate a data table, then extrapolate from the results. The Navy may try to keep their designs and processes close to the chest, but there is no such thing as classified physics, so long as photos are widely available.
  3. A simple prop is nothing but a wing on a rotating shaft. The venturi principle causes water to flow faster along the leading edge of each individual "wing," thereby reducing pressure "above" the wing, generating thrust. If the prop shaft is held at a constant point relative to the hull, the force transfers into the skeletal ribbing under the solid hull, which can be thought of as a separate system in and of itself. Enough thrust pulses over a long enough period of time, in addition to the relatively low drag coefficient of the solid boat result in the movement of the ship system. There is a ba
  4. First, some background. I own an 84 Chevy S10 with a 2.8l V6. I've been fighting the stupid Verajet II carb since the day I bought it. It's been fairly reliable, but the power was always awful, it idled terribly, and didn't get nearly the gas mileage that I think a 1900lb vehicle should get, regardless the style of induction. Now, I am a fairly capable mechanic, and as such, I was not content to simply let this continue. No sir'ee, I had to fix it, so I went to my carb box, selected a suitable carb, (an autolite 2150 seemed appropriate) and proceeded to tear that Verajet off in a hurry. M
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