TWO-FLOW GAS TURBINE JET ENGINE

1,180,524. Gas turbine by-pass type jet engines. SOC. NATIONALE D'ETUDE ET DE CONSTRUCTION DE MOTEURS D'AVIATION. Jan. 22, 1968 [Jan. 23, 1967], No.3300/68. Headings F1J and F1L. The invention relates to a gas turbine jet engine of the by-pass type in which reheat combustion equipment is disposed downstream of the turbine, the wall which separates the flow of turbine exhaust gases and by-pass air being formed at its downstream end to provide an annular pilot combustion chamber for the reheat equipment, the pilot chamber being open at its upstream and downstream ends. In Fig. 1 part of the wall which separates the turbine exhaust gas passage 13 from the by-pass duct 14 is indicated at 12 and comprises inner wall 16, outer wall 17 and end wall 18, the turbine exhaust cone being indicated at 112 and a support strut therefor at 113. The outer wall of the by-pass duct is indicated at 11. The wall 12 is extended downstream by inner and outer annular walls 20, 19 which define an annular pilot combustion chamber 15 which is open at its upstream end 22 for inflow of turbine exhaust gases from the passage 13, and open at its downstream end at 19a, 20a for discharge of hot combustion gases which ignite the mixtures of exhaust gases and fuel and by-pass air and fuel in the reheat combustion equipment, the reheat fuel injectors being indicated at 73, 74, 61, 62, 53 and 52. The inner wall 20 of the pilot chamber extends forwardly within the annular wall 16 to define the inlet 22. The outer wall 19 of the pilot chamber is secured to the end of the wall 16 and is formed with openings 75 for inflow of by-pass air from the duct 14 into the pilot chamber. A wall 41 is secured to the outer wall 19 and defines a chamber 48 therewith, the chamber being open at its upstream end 44 for inflow of by-pass air. A wall 37 is disposed within the pilot chamber adjacent the inner wall 20 and defines therewith a passage 40 to which cooling air is supplied from the chamber 48 through ducts 45 which extend across the pilot chamber. A pilot fuel annular manifold 33 is located within the chamber 15 and fuel is discharged therefrom in an upstream direction on to an impingement plate 34. An annular flameholder 35 is disposed downstream of the manifold 33. Alternative or additional locations for the fuel manifold are indicated at 33a and 33b. A spark device 36 projects into the chamber 15. Alternative arrangements for cooling the inner wall 20 are described. In Fig. 5 the outlet 19a of the pilo