Patent GB-1102572-A (GB)
Title: Jet propulsion engines
Inventor: SHARP JAMES WALLER
IPC: F23R3/00
Filed: 1964-06-06
Abstract: 1,102,572. Jet propulsion engine combustion systems. BRISTOL SIDDELEY ENGINES Ltd. June 3, 1965 [June 6, 1964], No. 18870/64. Headings F1J and F1L. Combustion apparatus for aircraft jet propulsion engines comprises a duct for the flow of combustion-supporting gas and means for dispersing fluid fuel into the duct at alternative positions along the duct which are selected in response to changes in the pre-combustion temperature of the gas. The combustion apparatus shown in Fig. 1 comprises a duct 1 to which air is supplied in the direction 2 from a ram air intake not shown. The air flow may be assisted up to flight speeds of about Mach 3 by a turbine driven fan or compressor. The combustion section comprises a first part 4 which is provided with a flame tube built up of overlapping sections 5 and defines cooling air passages 6 and 7. Fuel injectors 15 and flame holding stabilizers 16 are provided at the upstream end of the part 4, and at flight speeds up to about Mach 4 when the pre-combustion temperature of the air is below 600C., combustion takes place in the part 4. The second part 8 of the combustion chamber has a wall formed of refractory ceramic elements 9 mounted on pipes 10 through which fuel is passed from inlet 11 to the valve 13 from which it passes either to the injectors 15 or to injectors 14 at the downstream end of the part 4. The combustion duct terminates in an adjustable area propulsion nozzle 3 the walls of which are formed of refractory material. The length of the part 8 is such that when the pre-combustion air temperature is above 600C., combustion of fuel from injectors 14 may be completed in it; also when the pre-combustion air temperature is above this value, stable combustion may be effected without the use of flame holding baffle systems. The operation of the fuel changeover valve 13 may be controlled by a temperature responsive device 12, Fig. 3 (not shown). The valve 13 comprises a vane 47 which is movable by means of a piston 45 acting against a spring. The piston is acted upon by ram air pressure in duct 43 the outlet from which is controlled by a pivoted valve 41 in dependence on temperature of the air in duct 1 sensed by the device 12. Alternatively a Machmeter Fig. 4 (not shown) may be used to control the pivoted valve 41a and so the position of the fuel valve 13. In Fig. 2, a single fuel supply device 20 is provided being movable between the position indicated in full lines at the upstream end of combustion section 4 when the temperature of the incoming air is below a predetermined value and the position indicated in broken lines at the downstream end of the combustion section 4 when the temperature of the air is above the predetermined value. The fuel supply device 20 is movable axially within cylinder 24 by means of a piston 28 secured thereto, the space 30 above the piston containing a substance which when the air temperature reaches the predetermined value vaporizes and exerts pressure on the piston which moves against the force of the control spring to move the fuel supply device 20 to the downstream position.