Recent content by Jean - Claude

  1. Jean - Claude

    Ignition damping box

    I have a Rotax 503, and I still do not understand what the "ignition damping box" is for. Someone can help me ? Thank you
  2. Jean - Claude

    Old Vs Modern. T/O Length.

    In add, the articulated three-bladed rotors of the old autogiros allowed high conicity without vibration, hence the possibility of low rotational inertia beneficial to the rapid reaching of the takeoff rpm
  3. Jean - Claude

    Old Vs Modern. T/O Length.

    In add, the articulated three-bladed rotors of the old autogiros allowed high conicity without vibration, hence the possibility of low rotational inertia beneficial to the rapid reaching of the takeoff rpm
  4. Jean - Claude

    Old Vs Modern. T/O Length.

    The articulated three-bladed rotors of the old autogiros also allowed high conicity without vibration, hence the possibility of low rotational inertia beneficial to the rapid reaching of the takeoff rpm
  5. Jean - Claude

    Old Vs Modern. T/O Length.

    Eddie, When the rrpm accelerates because of the forward speed, it is already phase 2 (auto-rotating). However, it is the phase 1 (anti-rotative) that wasts the run. During this phase, it is better to have a rotor tilted forward, at least not backwards
  6. Jean - Claude

    Old Vs Modern. T/O Length.

    Actuel gyroplane pilots have a procedure of short takeoff less efficient than in the old days. During the anti-rotative phase of the first few seconds, the highly pre-launched rotor is too nose up. The rotor too much moderates the forward acceleration while loses more of rpm. So, it their...
  7. Jean - Claude

    use citroen 2cv dyane engine for gyrocopter

    A 4-stroke 40 HP car engine is too heavy for a gyrocopter. But the old Citroën GSA engine, with a belt reducer, is enought for a one seat gyroplane (60 HP). In addition, its integrated hydraulic pump can to power a small hydraulic motor for the rotor launcher.
  8. Jean - Claude

    Aerodynamic controlled blade twist/pitch

    David What matters are the lbs / sq.ft. The reduction in diameter dramatically increases the power required. This is not compensated by the reduction of the blade load. In hover your two bladed rotor will need 31.5 hp while your three bladed rotor will need 41.3 hp
  9. Jean - Claude

    Aerodynamic controlled blade twist/pitch

    David It seems to me you forget the increasing of induced speed . If you reduce the length of the blades to keep them the same blade loading, then you need more hp, because of a higher disk loading.
  10. Jean - Claude

    New chinese engine

    How will we produce more clean electrical power? How to make the carbon footprint of an electric vehicle battery not be an ecological disaster? How to ensure that recycling a battery is not an ecological disaster? How to find enough rare raw material to make the cells and chemistry of the...
  11. Jean - Claude

    Sparrowhawk rotorhead

    It seems you were very lucky that the pivot did not come out My question would be rather: "Why and how the elastic limit is exceeded on this plate?"
  12. Jean - Claude

    Rotor Blade Length

    Why maintain the same coning angle? Because increased undersling increase also the vibrations 2/rev. This problem would not exist with the articulated three bladed rotors. Those have low vibrations 3/rev and allows a larger chord.
  13. Jean - Claude

    xxxxx

    On sait que accélération = Vitesse / tempsou en abrégé : a = V/t La distance x parcourue, quand l’accélération a est constante, est donnée par la formule x = ½ a . t2 D’où on tire que t = √(2x /a) En remplaçant cette valeur dans l’équation a = V/t, on trouve : a = V / (√(2x /a) De là, on...
  14. Jean - Claude

    Thrust as a function of horizontal velocity

    Do not forget that the moments of flapping also have to remain balanced, despite the differences of air speed on each side. This means that a longitudinal flapping angle (called a1) appears, which decreases the A.o.A of the advancing blade and increases the A.o.A of the retreating blade (hence...
  15. Jean - Claude

    Thrust as a function of horizontal velocity

    Flight level keep by the pilot despite the increase in forward speed has no movement upward, by definition Just he A.o.A disc is reduced with the stick.accordingly and this reduces the rotor drag. Reduced rotor drag as the forward speed increases requires about the same power. But the...
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