EFFICIENT, LOW PRESSURE RATIO PROPULSOR FOR GAS TURBINE ENGINES
A gas turbine engine includes a gear assembly and a bypass flow passage that has an inlet. A fan is arranged within the bypass flow passage. A first turbine is coupled with a first shaft, which is coupled with the fan. A second turbine is coupled with a second shaft. The fan includes a hub and a row of fan blades that extend from the hub. The row includes 12 to 14 (N) of the fan blades, a solidity value (R) at tips of the fan blades that is greater than 0.85 and less than 1.1, and a ratio of N/R that is from 9 to 20.
1 . A gas turbine engine comprising:
a gear assembly;
a bypass flow passage, the bypass flow passage including an inlet and an outlet;
a fan arranged within the bypass flow passage;
a first shaft and a second shaft;
a first turbine coupled with the first shaft, the first shaft coupled with the fan; and
a second turbine coupled with the second shaft;
wherein the fan includes a hub and a row of fan blades that extend from the hub, and the row includes a number (N) of the fan blades that is from 12 to 14, a solidity value (R) at tips of the fan blades that is greater than 0.85 and less than 1.1.
2 . The gas turbine engine as recited in claim 1 , wherein the second turbine is a 2-stage turbine.
3 . The gas turbine engine as recited in claim 2 , wherein the first turbine is a 5-stage turbine.
4 . The gas turbine engine as recited in claim 2 , further comprising a case surrounding the fan, the case including a carbon-fiber reinforced polymer matrix material.
5 . The gas turbine engine as recited in claim 4 , wherein the fan blades include a carbon-fiber reinforced polymer matrix material.
6 . The gas turbine engine as recited in claim 5 , wherein the fan blades further include a three-dimensional fiber structure.
7 . The gas turbine engine as recited in claim 5 , wherein the inlet and the outlet define a design pressure ratio with regard to an inlet pressure at the inlet and an outlet pressure at the outlet at a design rotational speed of the engine, wherein the design pressure ratio is between 1.2 and 1.55.
8 . The gas turbine engine as recited in claim 7 , wherein the carbon-fiber reinforced polymer matrix material of the fan blades and the carbon-fiber reinforced polymer matrix material of the case each include a polymer and a fiber, and the carbon-fiber reinforced polymer matrix material of the fan blades is different from the carbon-fiber reinforced polymer matrix material of the case in one or more of the kinds of polymers of the matrices, or the kinds of fibers.
9 . The gas turbine engine as recited in claim 8 , further comprising a variable area nozzle, wherein the design pressure ratio is achieved in operation with the variable area nozzle fully open.
10 . The gas turbine engine as recited in claim 8 , wherein the fan blades and case are different in composition, and each of the fan blades has first and second distinct regions that are adjacent to each other and that are different in vibrational properties.
11 . A gas turbine engine comprising:
a gear assembly;
a bypass flow passage, the bypass flow passage including an inlet and an outlet;
a fan arranged within the bypass flow passage;
a first shaft and a second shaft;
a first turbine coupled with the first shaft, the first shaft coupled with the fan; and
a second turbine coupled with the second shaft;
wherein the fan includes a hub and a row of fan blades that extend from the hub, and the row includes a number (N) of the fan blades that is 16, a solidity value (R) at tips of the fan blades that is greater than 0.85 and less than 1.1.
12 . The gas turbine engine as recited in claim 11 , wherein the second turbine is a 2-stage turbine.
13 . The gas turbine engine as recited in claim 12 , further comprising a case surrounding the fan, the case including a carbon-fiber reinforced polymer matrix material.
14 . The gas turbine engine as recited in claim 13 , wherein the fan blades and the case include a carbon-fiber reinforced polymer matrix material.
15 . The gas turbine engine as recited in claim 14 , wherein the fan blades further include a three-dimensional fiber structure.
16 . The gas turbine engine as recited in claim 14 , wherein the carbon-fiber reinforced polymer matrix material of the fan blades and the carbon-fiber reinforced polymer matrix material of the case each include a polymer and a fiber, and the carbon-fiber reinforced polymer matrix material of the fan blades is different from the carbon-fiber reinforced polymer matrix material of the case in one or more of the kinds of polymers of the matrices, or the kinds of fibers.
17 . The gas turbine engine as recited in claim 14 , wherein the case further includes glass fiber, aramid fiber, or combinations thereof.
18 . The gas turbine engine as recited in claim 12 , wherein the inlet and the outlet define a design pressure ratio with regard to an inlet pressure at the inlet and an outlet pressure at the outlet at a design rotational speed of the engine, and the design pressure ratio is between 1.2 and 1.55.
19 .- 30 . (canceled)