A few safety features include a built-in redundancy on ducted fan
capacity, stall speeds, a ballistic parachute for emergency landing, and a triple redundancy on flight control system.
Hamel, "Position control of a ducted fan
VTOL UAV in crosswind," International Journal of Control, vol.
UAV Modeling and Simulation in Preliminary Design", AIAA Modeling and Simulation Technologies Conference and Exhibit, South Carolina,
Whether we are using fan total pressure for a ducted fan
selection, or fan static pressure for an unducted fan selection, it is important that the fan data used by the selection tool are appropriate for those configurations.
An open rotor engine generates most of the thrust from two counter-rotating propellers instead of a ducted fan
. This enables a larger engine diameter and thus a higher propulsive efficiency, without resulting in excessively large and heavy engine nacelle.
Metropolitan Vickers collaborated with the RAE from 1937 and tested the first British axial-flow jet engine in 1941 (two were later installed in a Gloster Meteor) and the first ducted fan
engine in 1943.
The four primary technologies that currently provide VTOL capability include (1) airships, (2) rotor wing, (3) tilt-rotor, and (4) ducted fan
. (2) This paper does not discuss airships, since they currently are unable to attain the required forward velocities (and arguably the required maneuverability and lift).
It has two ducted fan
UAVs capable of vertical take off and landing and a two-seat aircraft that can be either piloted or unpiloted.
The rotors provide the lift for handling loads, while the ducted fan
at the bow and stern provides propulsion and directional control.
Deliveries of Russia[sup.1]s NK-93 ducted fan
could begin in 2009 Two test flights of Russia's NK-93 ducted fan
prototype engine have been completed on board an Ilyushin Il-76 flying test bed.
The new kitchen, in hand-painted tulip wood by Greenheart, has a Leisure Rangemaster 110 fourring electric hob, twin ovens, ducted fan
, fridge/freezer, dishwasher and polished granite worktops.
Instead of wheels it has four large ducted fan
thrusters at each of its corners.