GB708343A - Improvements in or relating to ram jets - Google Patents

Abstract

708,343. Jet propulsion plant. SOC. D'ETUDE DE LA PROPULSION PAR REACTION. May 1, 1951 [May 11, 19SO], No. 10237/51. Class 110(3) [Also in Group XII] A ram jet has a deformable ring-like member supported from it at a predetermined distance from, and co-axial with, the jet nozzle and means for deforming the profile of the member so as vary the effective area of the jet. The ram jet 1, Fig. 1 carries a ring-like member 2 by means of struts 22. The external diameter of the ring is smaller than the maximum internal diameter of the ram jet. The effective area of the propulsion nozzle may be varied from r to r<SP>1</SP> as shown in the two halves of the figure by altering the shape of the member 2 which modifies the air now 3 through the gap 4. The shape of the member 2 may be varied by making the trailing or leading edges 2a, 2b, Fig. 4 or both of a flexible material such as natural or synthetic rubber which may be deformed by a fluid under pressure supplied to a cavity 5. In a modification,. the ring 2 is made of metal and certain parts are made thin so that they may be deformed by fluid under pressure. In a further modification, flaps are pivoted on the ring 2 to vary its shape. The effective area of the jet may be controlled in conjunction with the fuel supply. As shown in Fig. 8, the pressure drop across the fuel control valve 10 is applied to a piston 17 connected to a further piston 19 mounted in a cylinder 20 connected by a conduit 21 to the hollow spaces in the ring 2. In a modification, the throttle 12 also operates a two-way valve which connects to the fuel supply conduit to the ring 2 or connects the ring 2 to the burners. The combustion chamber has a continuously operating burner 27 Fig. 10 and two annular burners 29, 30 which are supplied with fuel in sequence as the thrust is increased.