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  • if the JetCat P200-SX Turbine  so bad would you recommend the  Behotec B300F from http://www.altecare.com/behotec300.htm

  • er yes, the piston engine will always be more efficient! That's why all the existing Gas turbine cars and trucks are in museums now!
    Aircraft gain their advantage by using TurboFans (kind of mix of turbojet and large lower reving fan)flying at high altitude and carrying a load of passengers, then fuel per passenger per 100 miles becomes very economic looking.

    Avionics, Not sure where you got 200 N from, I see the quote as 200 Lbs cargo, that would need (in turbojet terms) at least a reliable 230 Lbs or 1000 N thrust, that relates to a Mass Flow required of about 3 kg/sec.
    with a stator outlet temp of 1080 k (bordering on the need for Turbine cooling) An engine that size would be more powerful that the average commercial APU... A seriously major project

  • That aircraft uses a rotor which is a completely different proposition, efficiency will be much higher than with turbojets!
    pure Turbojets move a small amount of gas at high velocity which makes them inefficient
    A rotor moving a large amount of air at slow velocity is much more efficient, say 2.5 times as a rough idea.
    Regardless of type of driving engine, the thrust to weight becomes much better hence lower engine outputs can be used.

    No doubt the control in the Cypher is rotor blade pitch adjustment which is a much easier project for computer control.
    To drive a rotor It would be hard to beat the efficiency of a piston engine and gearbox, at the size your thinking of. Smaller then electric motors become the ideal solution.

    The Cypher looks a good Project' Go for it!!!

  • ok if turbine are that hard to control would you recommend rotary engine for this type of project.

    i have herd that the best power to weight ratio engine are rotary engine, just look at the Sikorsky Cypher made by Sikorsky Aircraft it has just 53 hp made by a rotary engine but it can lift 300-340 lb (136-154 kg)

  • Alex,

    Far be it for me to discourage ambition, although I feel I need to save you a lot of work and expense!

    200 Lb is well out of the range of the available microturbines, and using several just multiplies the crash risk as only one needs to fail at any time for the lot to come down, with all that hot metal around, this would have a very good chance of ending in a nice fire.
    Have you calculated the weight of fuel needed?
    Gas turbines need spool up time (regardless of manufacturers hype) How is this lag in accel/deccel going to be programmed into any flight system?


    As Brian mentioned 1/2 rpm doesn't relate to 1/2 thrust, rpm is incidental to the particular engine design. Off design is normally referred to as percentage of normal full throttle, or (% full mass flow). Presumably you want a thrust variation for control, and as most GTs normal design operation is at about say 80~90% of full power, mean that you would need engines rated at nearer 250 Lb thrust, possibly higher, to be able to regulate them reliably at the required 200 Lb thrust.

    Just out of interest there are no torque effects with gas turbines...

    I'm quite familiar with these as I've spent the last 12 years developing and testing micro turbines (as a full time hobby)

    Forget 200 Lbs, just getting an unladen gt powered vto airframe (reliably) flying under computer control (I mean takeoff, hover, transition to flight, to land) would be an astounding achievement...

  • what turbine/turbine cnc plans would you recommend for lift 200 lb of cargo. it does not jave to be 1 turbine it can be multi turbine but all together well make 200lb of life power. Also when i say lift i mean vertically lift 200lb
  • the engine i am talking about is the JetCat P200-SX Turbine from http://www.troybuiltmodels.com/items/JCATP200SX.html
  • so it could lift 25 lb at half rpm without a problem, just asking but what is static thrust is it just what is the max thrust a turbine can do?

  • Is it static thrust?

     

    If so then this is how much it can lift less total weight of itself if used in vertical direction.

     

    No doubt though this would be at full RPM and at say half the numbers would drop off considerably.

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