Gearbox assembly with lubricant extraction volume ratio

A gas turbine engine comprising:

• a fan having a fan shaft;
• a turbo-engine including a compressor section, a combustion section, and a turbine section, the turbine section having a low-pressure shaft drivingly coupled to the compressor section;
• a turbo-engine including a compressor section, a turbine section having a low-pressure shaft drivingly coupled to the compressor section, and a combustion section in fluid communication with the compressor section and the turbine section;
• a gearbox assembly, the fan shaft coupled to the low-pressure shaft through the gearbox assembly, wherein the gearbox assembly comprises:
• a 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
• GB
• ,
• wherein VG is the gutter volume of the gutter and VGB is the gearbox volume;
• a fuel delivery system comprising:
• a fuel tank that stores fuel therein;
• a fuel supply line in fluid communication with the fuel tank and the combustion section;
• and
• one or more fuel pumps for delivering the fuel from the fuel tank to the combustion section through the fuel supply line;
• a lubrication system comprising:
• a lubricant tank that stores lubricant therein;
• a lubricant supply line in fluid communication with the lubricant tank and the gearbox assembly;
• and
• one or more lubricant pumps for delivering the lubricant from the lubricant tank to the gearbox assembly through the lubricant supply line;
• and
• a thermal management system comprising:
• a fuel-lubricant heat exchanger in fluid communication with the fuel supply line and the lubricant supply line, the fuel-lubricant heat exchanger cooling the lubricant with the fuel as the lubricant and the fuel flows through the fuel-lubricant heat exchanger;
• one or more fuel bypass lines in fluid communication with the fuel supply line for bypassing the fuel around the fuel-lubricant heat exchanger;
• and
• one or more lubricant bypass lines in fluid communication with the lubricant supply line for bypass the lubricant around the fuel-lubricant heat exchanger;
• and
• a controller that controls the thermal management system to selectively direct at least one of the fuel through the one or more fuel bypass lines or the lubricant through the one or more lubricant bypass lines based on at least one of a fuel temperature of the fuel or a lubricant temperature of the lubricant.