Turbine combustion chamber

A combustion chamber for a gas or liquid fuelled turbine, has a central fuel injector module (13) surrounded by other fuel injector modules (5) and projecting downstream of them and their associated flame zone (2). The central module (13) comprises a radial jet fuel nozzle (18) the radial jets passing into an axial flow air chamber (16) where it is diverted to a secondary flame zone (14) downstream of the central module. The central nozzle (18) and chamber (16) are contained by tubes (27 and 37) which between them form an annular duct (10) which is fed with air and controllable fuel to feed in turn the secondary zone (14). This dispersed feeding of the secondary zone (14) is desirable during the transition from primary zone operation to secondary zone operation with increase in load. The fuel can be distributed to the injector modules so that (a) 100% passes to the outer modules, (b) a major portion passes to the outer modules with all modules individually ignited and (c) a major portion passes to the outer modules with a single flame zone fed by all the modules but centered on and downstream of the central module. The transition between conditions (b) and (c) is achieved by feeding 100% fuel to the central module to extinguish the outer modules and then reducing the proportion to the central module while increasing the proportions of the outer modules without igniting them individually.