Speed & Climb Rate Graphs

Discussion in 'Technical Requests' started by Zipper730, Jan 6, 2017.

  1. Zipper730

    Zipper730 Member

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    It's amazing how the charts and graphs from nation to nation and even within different branches of a nation vary: The US Navy for example generally have pretty well written charts, often easy to read and things of that sort; the US Army Air Force on the other hand has some quality issues, some of them are damned near illegible.

    I'm curious if anybody has ever transcribed the graphed data for speed across the altitude range (engine power, true airspeed with position error corrections), and climb-rate (engine power, true airspeed with position-error correction) up to the service ceiling and stuff like that into graphs that are of high quality and easily legible.
     
  2. GregP

    GregP Well-Known Member

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    As far as I know, there are no sources that "collect" these data in one place. Anyone who did would have very good material for a book that could be profitable if it turned out to be mostly correct. Part of the problem is most US and British sources have data every 5,000 feet and most German, Soviet, and Japanese data you can find are at units of 1,000 meters, so there are no charts that speficy the data at the same altitudes and units as the other side.

    To collect the data, you'd need one set in English units and one in metric, and the the speed and climb charts where the supercharger has to change speeds will all need to be done manually and they don't follow a smooth curve. They would need piecewise equations for the segments taht follow a function line. I's estimate maybe 4 equations for a 2-speed supercharger, with boundary conditions specified to assure no chart discontinuities.

    It's certainly doable, but will take a lot of work!

    If I did it, it would very certainly not be supplied as a "freebie!" But I'd advertise that it was available, for sure, in printed form only. Once you release an electronic copy, you'll see almost no more sales! I know too many people who have had that happen to them.
     
  3. tomo pauk

    tomo pauk Creator of Interesting Threads

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    Jeff (Corsning) has the data, posted mosty on this forum. The speed and climb rate is listed per each full kilometre, starting with sea level. Tabulating the data into a spreadsheet should not be the problem, apart from the time used, and spreadsheet programs can derive graphs from that.
    Engine power at range of altitudes is a bit of problem, since the power graphs do not involve ram effect, while aircraft flying at speed invoke the ram effect. Nothing big of a problem, but care should be taken.
     
  4. Zipper730

    Zipper730 Member

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    I'm thinking that would be a really cool idea. I'd be quite interested in such a project.

    There's gotta be some good that could come out of it.
    Could be useful for flight-sim games
    That's a good point, however there's gotta be some way to estimate these things
    • Pilot reports & accounts
    • Estimation of horsepower to speed (if I recall there was a cubic relationship from horsepower to speed or vice-versa), and aircraft critical altitudes are usually specified which covers ram compression
    • I know how to convert feet to meters and kilograms to pounds and liters to gallons and imperial gallons to gallons and all that, tedious as it is, I can do it.
    I'm not an expert at graphing curves.
    At the penalty of sounding stupid (math was not my strong suit): What is a piecewise equation, and a function line?
    Now if I did it, it'd be a freebie: I'm not in it for money, I'm an aviation buff and in it for providing helpful information for other aviation buffs


     
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