GB727136A - Improvements in or relating to ram jet engines and methods of operating the same - Google Patents

Abstract

727,136. Jet-propulsion plant. SWEET, D. H. May 16, 1952 [July 11, 1951], No. 16481/51. Class 110 (3). [Also in Group XII] A method of starting or operating a ram jet engine comprises creating in an expansion chamber thereof an air stream to flow in the direction of thrust, segregating the air stream into a major and a minor portion, accelerating the minor portion by combustion therein and merging the accelerated minor portion into the major portion to exert an aspiratory impulse to produce an acceleration of the major portion in the direction of thrust. A ram jet engine comprises an air intake cone 68 and a bulbous portion 70 interconnected by a cylindrical portion. Segregators 64, 66 are mounted in the cylindrical and bulbous portions respectively by struts 78, 80. The strut 78 constitutes a fuel supply duct which has discharge ports 86 and is controlled by a valve C. Compressed air and exhaust gases is fed through a valvecontrolled manifold 60 and jets 28 into the annular space between the segregator 64 and the cylindrical portion of the engine; fuel being burnt in the jets 28. The engine is also provided with valve controlled fuel lines 74, 40 arranged as shown. In a modification, Fig. 2 (not shown), the segregator 66 and the bulbous portion 70 are dispensed with; the fuel line 74 being disposed in a continuation of the cylindrical portion of the engine. In a modification, Fig. 4, of the ram jet engine described with reference to Fig. 2, the air intake is provided with a downwardly directed neck portion 88 which merges into the cylindrical portion 20 of the engine; the latter portion being provided with a jacket 94 through which air from a compressor is circulated prior to entering the manifold 60. About 10-20 per cent of the air in the jacket is fed directly into the cylindrical portion of the engine through a series of perforations. The perforations are arranged in quincunx formation and are about an eighth of an inch in diameter and spaced about an inch apart: The engine may-be faired into the wing of an aircraft, left exposed to the air stream or housed in a fuel tank. A pitot tube may be disposed in the small end of the entrance cone for operating a bellows to control the supply of fuel in accordance with the function of the air stream available. The aircraft, Fig. 1 (not shown), incorporates a ram jet engine in each wing together with a single booster unit for supplying compressed air thereto. The booster unit is closed down or maintained at one quarter load when the ram jet engine is operating.