GB439805A - Improvements in jet propulsion apparatus for aircraft, projectiles and turbine apparatus - Google Patents

Abstract

439,805. Aircraft; jet-reaction apparatus. LEDUC, R., 3, Avenue Gabriel Dupont, Le Vesinet, Seine-et-Oise, France. June 6, 1934, Nos. 16861 and 18140. Convention dates, June 7, 1933 and Jan. 2, 1934. [Classes 4 and 114] [See also Groups XXI and XXVI] Jet - propulsion apparatus for aircraft, projectiles, and turbines comprises a nozzle of varying section and provided with a heat source so as to produce a cyclical variation of temperature and velocity of the fluid passing through it without mechanical means, the nozzle having a rearwardly divergent section immediately upstream from the source of heat and convergent directly afterwards, and to prevent separation of the streams of fluid from the nozzle walls, passages are formed in the walls between zones of different pressures. Fig. 3 shows the simplest form of nozzle wherein cold air entering at 0 is compressed by reason of the divergence of the nozzles from 0 to 1 and is then heated in its passage from 1 to 2 and finally expanded by reason of the convergence of the nozzle and the consequent fall of pressure until the air is discharged at 3. Fig. 1 shows a nozzle in which heat is applied in a divergent section from 0 to 1 and the fluid expanded in the section 1 to 2 cooled during its passage from 2 to 3 and finally compressed in the section 3 to 4 before discharge. A nozzle combining these two forms also is described. To prevent separation of the fluid stream from the nozzle walls in the divergent sections fluid is conveyed from ducts 8, Fig. 7, where the pressure is high to annular nozzles 10 and discharged tangentially in the direction of the main stream. Alternatively air may be drawn through rearwardly convergent passages through the nozzle walls from outside or the boundary layer within the nozzle may be sucked off through rearwardly divergent passages to the outside. Fig. 10 shows an aeroplane, having planes 7<a>, driven by a nozzle 1<a> surrounding the rear end of an enclosed nacelle 2a kept at a normal pressure inside. The hot source consists of burners 3a supplied with fuel vapourized in a radiator 4a which acts as the cold source. An annular guide vane 9a is provided near the entrance to the nozzle. For starting, a turbine or motor-driven propeller may be provided in front of the hot source and stopped during normal flight. The planes also may be fitted with nozzles as shown in Fig. 12 which also indicates the application to a projectile. The fluid enters at 29, and a hot source 28 and passages through the nozzle walls are provided. Fig. 13 shows a turbine in which air enters radially divergent passages 33 separated by blades, burners 34 being provided in the passages and supplied with fuel through a hollow shaft 36 and radial conduits 35. The fuel may be preheated in a radiator 37 swept by the exhaust gases. Alternatively the nozzles and burners may be stationary and the gases discharged at the peripheral speed of a bladed wheel. The temperature in the combustion chamber is kept below 500‹ C. The Specification as open to inspection under Sect. 91 comprises also the following subjectmatter. Where the nozzles are combined with a turbine, loose discs may be provided on each side of the turbine discs to reduce air friction. A projectile 15, Fig. 12 (Cancelled), is provided in front with a nozzle 16 to prevent the formation of an impact wave. The nozzle has passages 20 in its walls and may have a hot source 17. Fig. 13 (Cancelled), shows aprojectile provided with a casing 22 having holes 23 near its front end through which air is sucked and discharged at the rear end 24. A cap 25 obstructs the opening 24 during the firing of the gun. This subject-matter does not appear in the Specification as accepted.