A fuel cell assembly comprising an enclosure having a fuel cell stack mounted therein, and an inlet opening into the enclosure. The fuel cell stack having an inlet face for receiving coolant/oxidant fluid. The fuel cell assembly further comprises a delivery gallery extending from the inlet in the enclosure to the inlet face of the fuel cell stack, the delivery gallery having a first region and a second region separated by an aperture. The delivery gallery and aperture are configured such that, in use, coolant/oxidant fluid within the first region of the delivery gallery is turbulent, and coolant/oxidant fluid within the second region of the delivery gallery has a generally uniform pressure.