Premixing fuel injector and method of operation

A premixing fuel injector (10) is provided, comprising a centerbody (58) and at least two circumferentially neighboring scrolls (18). Each scroll (18) has a circumferentially leading end (28) and a circumferentially trailing end (34) that terminates at a trailing edge (36). The scrolls (18) collectively circumscribe the centerbody (58) to radially bound a mixing chamber (24). The leading end (28) of each scroll and the trailing end (34) of the neighboring scroll define radially inner and outer extremities of an intake slot (42) for admitting a stream of air into the mixing chamber. The leading end of at least one of the scrolls (18) includes an array of axially distributed fuel injection passages (52) for introducing fuel into the air stream. The injector (10) can be used in both a prescribed state of operation and a degraded state of operation.