GB888265A - Improvements relating to jet propulsion engines with afterburners - Google Patents

Abstract

888,265. Generating combustion products under pressure. GENERAL MOTORS CORPORATION. Oct. 6, 1960 [Oct. 7, 1959], No. 34247/60. Class 51 (1). [Also in Group XXVI] A jet-propulsion engine comprises an exhaust duct which is divided by an annular wall into inner and outer annular passages, a reheat combustion chamber being disposed within the annular wall and arranged to receive gases flowing in the inner passage, fuel spray bars being distributed circumferentially of the combustion chamber and spaced apart so as to form inlets for the entry of gas into the combustoin chamber from the inner passage. The invention is shown applied in the case of a gas turbine jet engine the exhaust duct 28 of which contains an annular frusto-conical wall 98 which affords an outer annular passage 94 of constant crosssectional area, and an inner passage 96 which increases in cross-sectional area so as to constitute a diffuser through which gases pass to the reheat combustion chamber 18 disposed within the wall 98. The chamber 18 comprises an upstream dome portion 42, a series of circumferentially spaced, axially extending fuel spray bars 64, a series of overlapping frustoconical ring members 38 which are spaced apart where they overlap by means of corrugated ring members, and a downstream cylindrical portion 34. The spray bars are spaced apart so as to form gas inlet passages 92 therebetween. The spray bars each comprise a pair of nested U- section members 70, 72 which together form a fuel supply passage 74, the flanges 76 of the outer member 70 being formed with corrugations which co-operate with the sides of the inner member 72 to form fuel outlet ducts 90 disposed along both sides of the spray bar. The spray bars are connected at their upstream ends to an annular supply manifold 50 which is connected to a tubular fuel supply duct 52 which in turn is connected to a supply conduit 54 which receives fuel through its inlet 62. The supply conduit 54 is formed by a strut 30 which with other similar struts affords a support for the wall 98 and by means of the frusto-conical wall 44 for the combustion chamber 18. Fairing members 104 are disposed around the struts 30 where they extend across the outer and inner annular passages 94, 96. A heat shield 27 is disposed between the upstream end wall 42 of the combustion chamber 18 and the turbine rear bearing 26. The propulsion nozzle is of the convergent-divergent type.