Abstract: A fuel system for a hydrogen fueled aircraft propulsion system comprises a fuel tank configured to store hydrogen fuel, a main fuel conduit configured to provide fuel to a combustor of a gas turbine engine, a fuel heater comprising a catalytic combustor configured to catalytically combust a portion of the hydrogen fuel prior to delivery to the combustor and a heat exchanger configured to exchange heat between exhaust gases from the fuel heater and hydrogen fuel in the fuel conduit.

Abstract: A fuel system for a hydrogen fuelled aircraft propulsion system comprises a fuel tank configured to store hydrogen fuel, a main fuel conduit configured to provide fuel to a combustor of a gas turbine engine, a fuel heater comprising a catalytic combustor configured to catalytically combust a portion of the hydrogen fuel prior to delivery to the combustor and a heat exchanger configured to exchange heat between exhaust gases from the fuel heater and hydrogen fuel in the fuel conduit.

Abstract: A bladed disc for a rotating machine comprising a central disc that rotates about a central axis, the central disc having a series of blades arranged around its periphery; the blades have dovetail roots which engage with slots on the central disc; the bladed disc being configured so that there is a pre-loading force between the blades and the central disc such that each blade is forced away from the central axis of the bladed disc; and wherein the pre-loading force is equal or greater than 40% of the maximum centrifugal force applied to the blade during a flight cycle.

Abstract: A battery or fuel cell module comprising a plurality of battery cells or fuel cells and metal foam bus bars that electrically connect together at least some of the battery cells or fuel cells is described. The battery or fuel cell module may further include a cooling system arranged to provide a flow of cooling fluid through the metal foam bus bars to remove heat from the bus bars. In some examples, the cooling system comprises one or more forced air devices. In other examples, the metal foam bus bars are encased in a fluid-impermeable skin so that the bus bars form fluid-tight pipes with a metal foam interior, and the cooling system is arranged to provide the flow of cooling fluid through the metal foam interior of the fluid-tight pipes.

Abstract: A method of producing an oxide dispersion strengthened nickel-base superalloy, comprising introducing an oxide dispersoid material into a plasma gun of a plasma spray apparatus, where it is sublimed and turned to vapour; and introducing a nickel-base superalloy material into the plasma spray apparatus at a cooler location, downstream of the plasma gun, such that the oxide dispersoid material condenses on the superalloy material to produce the oxide dispersion strengthened nickel-base superalloy.