Method for setting a gear ratio of a fan drive gear system of a gas turbine engine
AssigneeUnited Technologies Corporation
InventorsWilliam G. Sheridan, Karl L. Hasel
Life of this patent
Estimating the term…
Abstract
A gas turbine engine has a fan section including a fan rotatable about an axis. A speed reduction device is in communication with the fan. The speed reduction device includes a planetary fan drive gear system with a planet gear ratio of at least 2.6. A fan blade tip speed of the fan is less than 1400 fps. A low pressure turbine section is in communication with the speed reduction device. The low pressure turbine section includes three or four stages. A bypass ratio is between 11.0 and about 22.0. A method of improving performance of a gas turbine engine comprising
Claims21
A gas turbine engine comprising:
- a fan section including a fan rotatable about an axis;
- a speed reduction device in communication with the fan, wherein the speed reduction device includes an epicyclic gear system with a gear ratio of at least 2.6, wherein a fan blade tip speed of the fan is less than 1400 fps;
- and
- a low pressure turbine section in communication with the speed reduction device, wherein the low pressure turbine section includes three or four stages;
- and a bypass ratio that is between 11.0 and about 22.0.
A method of improving performance of a gas turbine engine comprising:
- determining fan tip speed boundary conditions for at least one fan blade of a fan section;
- determining rotor boundary conditions for a rotor of a low pressure turbine;
- and
- utilizing stress level constraints in the rotor of the low pressure turbine and the at least one fan blade to determine if the rotary speed of the fan section and the low pressure turbine will meet a desired number of operating cycles;
- and
- wherein a bypass ratio is greater than about 6.0.
A gas turbine engine comprising:
- a fan section including a fan rotatable about an axis;
- a speed reduction device in communication with the fan, wherein the speed reduction device includes an epicyclic gear system with a gear ratio of at least 2.6;
- and
- a bypass ratio that is between about 11.0 and about 22.0, wherein a fan blade tip speed of the fan is less than 1400 fps.
Dependencies are inferred from the claim text.