COMPREACTIVE PROPELLER (AIRSCREW). Compreactive blades. Compreactive turbine.
It is suggested to use the internal space (internal channel) of a rotating blade as a centrifugal flow pump delivering pressurized air in a jet engine located on the blade tip.
The internal cavity of a rotating propeller
blade, in essence, is a workpiece of a radial flow compressor. If
to open it from both ends, then, under action of centrifugal force, air
will move along the blade. It is necessary to turn only leaving stream at
right angle and to direct it into combustion chamber of a jet engine mounted
on the blade tip. As a whole, the propeller with such blades is suggested
to name a compreactive propeller, and such blade a compreactive blade.
Earlier, as a basis of jet drive of a propeller it was offered to use a ramjet engine. However, the ramjet engine extremely is not effective on subsonic speeds because of impossibility to receive a necessary preliminary compression. The suggested design allows to overcome this lack. We receive a capability to master unique advantages of a jet drive. Any superfluous transformations. Any reduction gearboxes. Thrust of a high-speed jet engine is directly transmitted to a blade tip…
This scheme with reference to a rotor of the helicopter is rather pertinent. The compreactive rotor gives exclusive elegance of a helicopter design.
Thus it will be possible to estimate to the full grace - "refinement" of a helicopter rotor - its blades which keep horizontally on a centrifugal tie rod, as against an aircraft wing - a volumetric, rather "friable" structure resisting to flexion moment in statics.
The idea of compreactive blades can be used and it is simple for obtaining torque - «the compreactive turbine». Its advantage that there are no load-bearing elements driving in hot stream gas flows, namely, - blades of the classical gas turbines. Therefore it is possible to raise temperature in the combustion chamber and by that to increase efficiency of whole design. Here is natural a multiblade construction "passing" in an integral disk design, with expansion to the center. And all this in a snail-like cover.
A possibility of practical realization of the concept of compreactive blades is determined by capabilities of obtaining of necessary flow discharge and power characteristics, that in turn, depends on geometrical ratios - cross sections, radial velocities of this or that version of realization of this idea. For the benefit of a capability of satisfaction of necessary characteristic ratio speaks that fact, that the single-stage centrifugal compressor of a turbojet (for example, of MiG-15) at a diameter of 1-1.5 meter, basically, provides necessary compression. Besides existing versions of the installation ramjet engines on the ends of blades of a carrying helicopter rotor display that sizes of the necessary combustion chamber, its strength properties, its weight "are entered" in frameworks of requirements of the installation on the tip of a rotating blade.
By way of possible improvements it is possible to suggest the following. Blades extending at the butts. To dispose intakes further from a rotation centert if it is required to reduce a compression. To suck away the boundary turbulent layer through a longitudinal slot. To use ejective ("sucking") nozzles on an jet outlets for increasing of jet mass. To dispose dividing lattices in the exhaust flow for noise reduction.
Rather interesting, in the plan of "compreactivization", modern propellers with broad thick scimitar-like blades are assumed. It is possible to recollect also such exotic version as tractor propellers on the tips of a helicopter rotor.
To connect lateral faces of a blade with ribs for increasing of rigidness of the structure (that can be necessary for reduction of vortex generation too). To reel on blade skeletons with automatic devices such as stocking ones, fixing layers with composite material.