Recent content by Windnsails

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    Archimedes pump

    If you look at the center of gravity for each pocket of captured water, you will find that it is off center from the shaft. The eccentricity will cause a torque to the shaft that must be overcome just to hold the pipe screw stationary. As soon as you turn the crank to raise the pockets of water...
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    Making an aerofoil with a cantilever

    I did not race IOR but I raced in the Big Boat fleet locally in Seattle for several years as Jib, Spinaker and Main Trimmer. We did similar to what Baluncore mentioned for land-based craft. Our main sail draft was determined by wind speed and relative direction together with outhaul tension...
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    The principle behind throttling valves

    Bottom line is that the pressure loss is due mostly to turbulance. Think of a venturi - full line size squeezes to something less and then expandes gradually to keep stream lines as close to parallel as "practical". Now squeeze the throat of the venturi to something very small. The...
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    Axial load strength of PVC pipe

    Solvent welded joints on Sched 40 PVC pipe can withstand full atmospheric vacuum (only 14.7psi and hoop stress is practically negligible for all diameter-thickness ratios). However, gasketed PVC pipe joints should not be relied upon to withstand vacuum since buckling at the pipe ends may occur...