A turbine engine system includes aircraft systems including at least one hydrogen fuel tank, engine systems comprising a compressor section, a combustor section having a burner, and a turbine section, and a hydrogen fuel flow supply line configured to supply hydrogen fuel from the at least one hydrogen fuel tank into the burner for combustion. The turbine engine system has a bypass ratio between 5 to 20.

A turbine engine system includes aircraft systems including at least one hydrogen fuel tank, engine systems comprising a compressor section, a combustor section having a burner, and a turbine section, and a hydrogen fuel flow supply line configured to supply hydrogen fuel from the at least one hydrogen fuel tank into the burner for combustion. The turbine engine system has a bypass ratio between 5 to 20.

A chassis includes top rails extending along a top side of the chassis, bottom rails extending along a bottom side of the chassis, a fluid inlet connected to the chassis that is configured to receive a thermal transfer fluid, and a fluid outlet connected to the chassis that is configured to discharge the thermal transfer fluid. The chassis further includes a thermal transfer fluid path extending between and fluidly coupled to the fluid inlet and the fluid outlet, wherein the thermal transfer fluid is configured to flow through the thermal transfer fluid path, and wherein the thermal transfer fluid path extends in a serpentine pattern through at least one of the top rails and through at least one of the bottom rails.

A chassis includes top rails extending along a top side of the chassis, bottom rails extending along a bottom side of the chassis, a fluid inlet connected to the chassis that is configured to receive a thermal transfer fluid, and a fluid outlet connected to the chassis that is configured to discharge the thermal transfer fluid. The chassis further includes a thermal transfer fluid path extending between and fluidly coupled to the fluid inlet and the fluid outlet, wherein the thermal transfer fluid is configured to flow through the thermal transfer fluid path, and wherein the thermal transfer fluid path extends in a serpentine pattern through at least one of the top rails and through at least one of the bottom rails.

A thermal management system adapted to vent a two-phase working fluid into an environment having a higher pressure than a vapor pressure of a working fluid corresponding to a set point of the system including a secondary vessel containing a secondary species. The system includes a primary vessel containing the working fluid and the secondary species, and at least one valve to selectively control venting of a mixture of the working fluid and the secondary species from the primary vessel to the environment. The system includes at least one valve connected between the primary vessel and the secondary vessel to selectively control charging of the secondary species into the primary vessel.

In accordance with at least one aspect of this disclosure, there is provided a system for an aircraft engine. In embodiments, the system includes an accessory box and a fuel accessory located in an interior space within the accessory box, where a vent is defined through a wall of the accessory box. In embodiments, the vent includes a plurality of holes or slots in an outer wall of the accessory box for passage of gaseous fuel from the interior space. In embodiments, the vent is configured for passive ventilation of the interior space.

In accordance with at least one aspect of this disclosure, there is provided a system for an aircraft engine. In embodiments, the system includes an accessory box and a fuel accessory located in an interior space within the accessory box, where a vent is defined through a wall of the accessory box. In embodiments, the vent includes a plurality of holes or slots in an outer wall of the accessory box for passage of gaseous fuel from the interior space. In embodiments, the vent is configured for passive ventilation of the interior space.

In accordance with at least one aspect of this disclosure, there is provided a system for an aircraft engine. In embodiments, the system includes an accessory box and a fuel accessory located in an interior space within the accessory box, where a vent is defined through a wall of the accessory box. In embodiments, the vent includes a plurality of holes or slots in an outer wall of the accessory box for passage of gaseous fuel from the interior space. In embodiments, the vent is configured for passive ventilation of the interior space.

In accordance with at least one aspect of this disclosure, there is provided a system for an aircraft engine. In embodiments, the system includes an accessory box and a fuel accessory located in an interior space within the accessory box, where a vent is defined through a wall of the accessory box. In embodiments, the vent includes a plurality of holes or slots in an outer wall of the accessory box for passage of gaseous fuel from the interior space. In embodiments, the vent is configured for passive ventilation of the interior space.

A propulsion system is provided and includes a solid hydride storage unit from which gaseous hydrogen fuel is drawn, an engine comprising a combustion chamber and a piping system to draw the gaseous hydrogen fuel from the solid hydride storage unit, the piping system being interposed between the solid hydride storage unit and the combustion chamber. The combustion chamber is receptive of the gaseous hydrogen fuel drawn from the solid hydride storage unit by the piping system and is configured to combust the gaseous hydrogen fuel to drive an operation of the engine.