Paul,

    Any idea of the thermal efficiency of the rotary engine?

    Or if we have reliable fuel flow and horsepower figures we can figure
    it out using the formula:

    TE = 0.1338 8 * HP / FF (in pph)



    Regards,

    Gordon.

    Somewhere aroud 28%.

    Paul Lamar


    Paul,

    Can we assume that the turbocompound engine should see about 35
    percent? This would represent about a one-third increase, due to the
    energy recovered.

    Btw, I'm surprised at the 28 percent figure. This is about the same
    as the air-cooled Lycoming. The Continental IO-550 used in Columbia
    350 works out to about 31 percent, which is very very good.



    Regards,

    Gordon.



    Probably not quite that high. 35% that is.
    Here are some heat balance charts.

    --
    Paul Lamar ...No rotor no motor.


    Paul,

    That Merlin engine is 29.6 percent -- pretty good.

    Your chart for the R3350 TC shows very low thermal efficiency of 17
    percent because air fuel ratio is a rich 10 : 1 at take-off power.

    Here's another chart on the R3350 TC from that same SAE paper, but
    this one at a lean air-fuel ratio of about 18 : 1 at cruise power.
    Here we see 29.7.

    Interesting that this is no higher than the supercharged Merlin
    engine that is not turbocompounded. One would assume the TC engine
    would be better. Any thoughts?



    Regards,

    Gordon.

What altitude is that? Different test, different methods, different
times etc., etc..

Paul Lamar ...No rotor no motor.

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