Recent content by Swampyankee

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    Debunking the "Meredith Effect"

    Given the low temperature (no more than about 400 K), low pressure ratio, and pressure loss for n the radiator core, possible thrust is very low. I calculated a value of about 35 newtons (8 lbf) for a P-51 at maximum speed and Mach number which would provide the best compression, but did not do...
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    Two-seat WWII warbird replica candidates?

    Fairey Firefly. Supermarine Walrus. Curtiss SBC (not SB2C) Helldiver
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    Platform and twist distribution are more important than airfoil for an aircraft's stall behavior.
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    Cessna 182 production restarted

    There are companies that specialize in building cars that are, functionally, no better or even inferior to mid-range Buicks[1] but that sell for ten times or more the price. A lot of purchasing decisions are not based on rational thought.
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    Reduction drives

    "Bring money; we can do anything!": Unofficial motto of mechanical engineers everywhere. Getting reduction gearboxes correct is quite difficult, more so with piston engine engines than turbines, as quite a few issues are due to the pulsations intrinsic to reciprocating pistons (these may not...
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    Re-drives Belt or Chain ?

    I wouldn't have any first hand information on that; while there was a (failed) attempt to have the LT101 built by Williamsport (they failed miserably; they didn't have the equipment or skills), there was very little interaction between Williamsport (where they built little motors with stuff...
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    Re-drives Belt or Chain ?

    The ALF502 I was test engineer on used a planetary gear set with 17,500 rpm input and 7600 rpm output, carrying about 8,000 hp. P&WA uses them on their slightly larger geared turbofan (one wonders how many ex-AVCO people worked on that...) On the other hand, I would be surprised if anyone...
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    Fraudulent License?

    I suspect that if the aircraft's owner knows that the signature purported to be that of an A&P wasn't, that owner is liable if anything happens. Since the OP is aware of this, one must assume the owner is cognizant. I also suspect that the person who fraudulently signed as an A&P may be...
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    Cantilever high wing examples

    There’s a tradeoff between a braced wing and a cantilevered wing (he says preaching to the choir) whether high or low, but a braced low wing has more aerodynamic problems, as the brace on a low wing is acting in compression, so it has to be bulkier, and the suction side of an airfoil is more...
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    Riblett on Twist

    In this case (and in the case of the 230xx airfoils) he's wrong; the increase in lift coefficient towards the tips of a finite wing is predicted by vortex lattice, lifting surface, and lifting line analyses and supported by wind tunnel test data; it happens even if the wing is not tapered.
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    Legal question about copyright

    Cm Been in use for at least 100 years: Pumped-storage hydroelectricity - Wikipedia
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    Static thrust

    Having worked in prop and helicopter rotor aero for several years, I can say that we never talked about torque. The structures and gearbox guys did, because, well, bolts, bending moments, and sizing shafts and things like that.
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    Pitch vs angle

    Pitch and radius have to be in the same units (inches, meters, feet, furlongs, whatever). The angle returned from arctan will be in radians or degrees, depending on how your calculator's set. In a spreadsheet, it will return radians.
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    How to do what I want without using a 3LS design ?

    Forward sweep isn't common because it tends to require much more torsional stiffness. While there are advantages, especially at high angles of attack, when compared to sweep back, a swept-forward will will need to be much stiffer than a straight or swept back wing to avoid aeroelastic...
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    How to do what I want without using a 3LS design ?

    Instead of the Do335 layout, try that of the Do28: