Gearbox assembly with lubricant extraction volume ratio

A gas turbine engine comprising:

• a fan shaft coupled to a fan;
• a combustor positioned in a core air flowpath that combusts compressed air and fuel to generate combustion gases;
• a turbine positioned downstream of the combustor to receive the combustion gases and to rotate the turbine, the turbine having a core shaft being drivingly coupled to the fan shaft to rotate the fan;
• a steam system that extracts water from the combustion gases, vaporizes the water to generate steam, and injects the steam into the core air flowpath, the steam system comprising one or more water storage devices that store the water therein prior to the water vaporizing to generate the steam, the one or more water storage devices including a first state in which the one or more water storage devices increase or maintain a level of the water in the one or more water storage devices as the water flows through the one or more water storage devices, and a second state in which the one or more water storage devices decrease the level of the water in the one or more water storage devices as the water flows through the one or more water storage devices, wherein the first state is during steady state operating conditions of the gas turbine engine and the second state is during transient operating conditions of the gas turbine engine, and the one or more water storage devices include an overflow drain such that the water fills to the overflow drain and drains from the one or more water storage devices through the overflow drain to maintain the level of the water at a maximum water level during the first state of the one or more water storage devices;
• and
• a gearbox assembly comprising:
• a gearbox, the fan shaft being drivingly coupled to the core shaft through the gearbox, the gearbox having a gearbox volume defined by an outer diameter of the gearbox and a gearbox length of the gearbox;
• and
• a gutter for collecting a gearbox lubricant scavenge flow from the gearbox, the gutter having a gutter volume defined by an inner surface of a gutter wall of the gutter and being characterized by a lubricant extraction volume ratio between 0.01 and 0.3, inclusive of the endpoints, for a maximum gearbox power greater than 35 kHP and less than or equal to 90 kHP, and the lubrication extraction volume ratio is between 0.03 to 0.3, inclusive of the endpoints, for a maximum gearbox power less than 35 kHP, the lubricant extraction volume ratio defined by:
• V
• G
• V
• G
• ⁢
• B
• ,
• wherein VG is the gutter volume of the gutter and VGB is the gearbox volume.