A fan drive gear system for a gas turbine engine includes a gear system that provides a speed reduction between a fan drive turbine and a fan and a mount flexibly supporting portions of the gear system. A lubrication system supporting the fan drive gear system provides lubricant to the gear system and removes thermal energy produced by the gear system. The lubrication system includes a capacity for removing thermal energy equal to less than about 2% of power input into the gear system.

A gas turbine engine includes a gear system that transfers power input from a fan drive turbine to a fan through a gear system with a gear reduction ratio greater than 2.3. A flexible mount supports the gear system and accommodates movement of the gear system relative to an engine static structure. A lubrication system provides lubricant flow to a plurality of rotating components including bearing systems and the gear system and has a maximum capacity for removing thermal energy less than or equal to no more than 2% of power input into the gear system.

A fan drive gear system for a gas turbine engine includes a gear system that provides a speed reduction between a fan drive turbine and a fan and a mount flexibly supporting portions of the gear system. A lubrication system supporting the fan drive gear system provides lubricant to the gear system and removes thermal energy produced by the gear system. The lubrication system includes a capacity for removing thermal energy equal to less than about 2% of power input into the gear system.

A fan drive gear system for a gas turbine engine includes a gear system that provides a speed reduction between a fan drive turbine and a fan and a mount flexibly supporting portions of the gear system. A lubrication system supporting the fan drive gear system provides lubricant to the gear system and removes thermal energy produced by the gear system. The lubrication system includes a capacity for removing thermal energy equal to less than about 2% of power input into the gear system.

A fan drive gear system for a gas turbine engine includes a gear system that provides a speed reduction between a fan drive turbine and a fan and a mount flexibly supporting portions of the gear system. A lubrication system supporting the fan drive gear system provides lubricant to the gear system and removes thermal energy produced by the gear system. The lubrication system includes a capacity for removing thermal energy equal to less than about 2% of power input into the gear system.

A cooling structure for a radial turbine is equipped with a partition wall arranged between a compressor and the radial turbine, and a through hole formed in the partition wall supplying a part of air compressed by the compressor to the rear surface of the radial turbine as cooling air. The through hole is inclined in a rotational direction of the radial turbine in the range of 40 to 80 with respect to a rotation axis of the radial turbine.