Patent Description:
Turbine engine manufacturers continually seek improvements to engine performance including improvements to thermal, transfer and propulsive efficiencies.

<CIT> and <CIT> disclose prior art engines.

From a first aspect, there is provided a turbine engine as recited in claim <NUM>.

Disclosed gas turbine engines integrate electric generators and motors into a hybrid electro-aero-thermal turbine engine. In the example turbine engines, fuel and electricity are converted to mechanical power to increase kinetic energy of flows through the engine. Conversion of fuel to mechanical power is accomplished by combining the fuel with high pressure air and igniting the mixture to produce a high energy gas flow. The high energy gas flow is converted to mechanical energy as it expands through the turbine section. An electro-chemical potential of energy stored in a battery is converted to mechanical power by electric motors to increase kinetic energy of engine flows. Conversion of fuel to mechanical power is not as efficient as the conversion of electro-chemical potential to mechanical power. The disclosed example engines integrate fuel and electro-chemical power to improve overall engine efficiencies.

Referring to <FIG>, disclosed integrated engine architectures are schematically indicated at 20A and 20B. The engine 20A is a turboprop engine with an open fan rotor architecture that operates a fan section 22A outside of any enclosure. The engine 20B is a ducted fan architecture with a fan section 22B directing airflow through a bypass flow path B defined through a nacelle <NUM>. Each of the engines 20A, 20B include common elements described utilizing common reference numerals differentiated by a letter corresponding with a letter in the corresponding <FIG>.

Both engines 20A, 20B include a fan section 22A, 22B with a corresponding plurality of fan blades 42A, 42B. A compressor section 24A, 24B compresses air that is then directed to a combustor section 26A, 26B. In the combustor section 26A, 26B, fuel is mixed with the compressed air and ignited to generate a high energy exhaust gas flow that expands through a turbine section 28A, 28B. The turbine section 28A, 28B is coupled to drive the compressor section 24A, 24B and the fan section 22A, 22B. In the disclosed engine embodiments, a geared architecture 48A, 48B is driven by a portion of the turbine section 28A, 28B provides for rotation of both the fan section 22A, 22B and turbine section 28A, 28B at closer to optimal speeds.

The engines 20A, 20B include integrated electric machines in the compressor section 24A, 24B and the turbine section 28A, 28B to supplement power produced from fuel with electric power. The example compressor section 24A, 24B includes a compressor electric motor 74A, 74B that is coupled to a compressor generator 76A, 76B. The example turbine section 28A, 28B includes a turbine electric motor 94A, 94B that is coupled to the geared architecture 48A, 48B to supplement power driving the fan section 22A, 22B. A turbine generator 96A, 96B provides electric power to the turbine electric motor 94A, 94B.

<FIG> is an engine example that corresponds with each of the engines 20A, 20B and includes reference numerals that refer to like features shown in <FIG>, but without the alphabet designation to indicate application in either of the disclosed engines 20A, 20B.

The example engine <NUM> illustrated in <FIG>, includes integrated electric drive systems augmenting operation of turbine and compressor sections. The example gas turbine engine <NUM> includes the fan section <NUM>, the turbine section <NUM>, the combustor section <NUM> and the compressor section <NUM> disposed serially along an engine longitudinal axis A. The propulsor section <NUM> includes a plurality of fan blades <NUM> rotatable about the axis A. The compressor section <NUM> supplies compressed air to the combustor section <NUM>. Fuel is combined with compressed air from the compressor section <NUM> and ignited in the combustor section <NUM> to generate a high energy exhaust gas flow <NUM>. The high energy exhaust gas flow <NUM> expands through the turbine section <NUM> to generate rotation of the turbine section <NUM>. The geared architecture <NUM> is coupled between the turbine section <NUM> and the propulsor section <NUM> to provide rotation at different speeds. A low pressure compressor section <NUM> is disposed axially forward of the turbine section <NUM> and is coupled to the fan section <NUM>. The low pressure compressor section <NUM> and the plurality of fan blades <NUM> rotate at a common speed.

Inlet airflow <NUM> flows axially through the plurality of fan blades <NUM> and the low pressure compressor <NUM> and into an intake passage <NUM>. The intake passage communicates inlet airflow <NUM> axially aft of the turbine section <NUM>, around the combustor section <NUM> and to the compressor section <NUM>. In this disclosed example, the inlet airflow <NUM> is initially compressed by the low pressure compressor <NUM> and communicated into the intake passages <NUM>. The intake passage <NUM> communicates airflow directly to the example the compressor section <NUM> disposed axially aft of the turbine section <NUM> along the axis A.

The disclosed turbine section <NUM> includes a high pressure turbine <NUM>, an intermediate pressure turbine <NUM> and a low pressure turbine <NUM>. The turbines <NUM>, <NUM> and <NUM> are serially arranged from the combustor section <NUM> forward toward the fan section <NUM>. The high energy exhaust gas flow <NUM> is directed axially forward through the turbine sections <NUM>, <NUM> and <NUM> and finally exhausted through an exhaust manifold <NUM> into a bypass airflow <NUM>. In this example, the exhaust manifold <NUM> reverses the flow of the high energy exhaust gas flow <NUM> to combine with a bypass flow <NUM> generated by the fan section <NUM>.

The disclosed example engine is arranged to include a first spool <NUM> that includes the high pressure turbine <NUM>, a first high pressure compressor section <NUM> and the compressor generator <NUM>. A second spool <NUM> includes the intermediate turbine <NUM> that is coupled to the fan section <NUM>, turbine generator <NUM> and a portion of the geared architecture <NUM>. A third spool <NUM> includes the low pressure turbine <NUM> that is coupled to the turbine motor <NUM> and another portion of the geared architecture <NUM>.

Accordingly, the intermediate pressure turbine <NUM> and the low pressure turbine <NUM> are both coupled to the geared architecture <NUM> that drives the fan section <NUM> at a speed different than either of the low pressure turbine <NUM> and the intermediate pressure turbine <NUM>. In this example, the intermediate pressure turbine <NUM> is coupled to both the geared architecture <NUM> and a turbine generator <NUM>. Electric power produced by the turbine generator <NUM> powers a turbine motor <NUM>. The turbine motor <NUM> is coupled through the geared architecture <NUM> to supplement power to drive the fan section <NUM>.

Referring to <FIG>, with continued reference to <FIG>, the geared architecture <NUM>, the intermediate pressure turbine <NUM>, the low pressure turbine <NUM>, the turbine motor <NUM> and the turbine generator <NUM> define portions of a fan drive gear system <NUM>. The disclosed geared architecture <NUM> is an epicyclic gear system with a sun gear <NUM> intermeshed with intermediate gears <NUM>. The intermediate gears <NUM> are supported by a carrier <NUM>. A ring gear <NUM> is engaged to the intermediate gears <NUM>.

The intermediate pressure turbine <NUM> is coupled to the shaft <NUM> that is coupled to the turbine generator <NUM>. The shaft <NUM> extends through a hollow interior <NUM> of the sun gear <NUM>. The shaft <NUM> is not coupled to the sun gear <NUM> in this example embodiment. The shaft <NUM> is coupled to the ring gear <NUM> and to the fan section <NUM>. The low pressure turbine <NUM> is coupled to the turbine motor <NUM> by way of shaft <NUM>. The shaft <NUM> extends through the turbine motor <NUM> and drives the sun gear <NUM>. The carrier <NUM> is not coupled to either the low pressure turbine <NUM> or the intermediate pressure turbine <NUM>. The carrier <NUM> may be grounded to an engine static structure <NUM> through a selectively actuated clutch <NUM>. It should be appreciated that other portions of the geared architecture <NUM> may be selectively grounded to the engine static structure <NUM> and are within the contemplation of this disclosure.

The intermediate pressure turbine <NUM> is coupled to the output of the geared architecture <NUM> that drives the fan section <NUM>. In this disclosed example, the ring gear <NUM> provides the output to the fan section <NUM>. The intermediate pressure turbine <NUM> also drives the turbine generator <NUM>. The turbine generator <NUM> is electrically coupled to power the turbine motor <NUM>. The turbine motor <NUM> may also be powered by battery systems of the aircraft. The turbine motor <NUM> reduces loads on the intermediate pressure turbine <NUM> and the low pressure turbine <NUM> and thereby the amount of fuel required to power rotation of the fan section <NUM>.

Referring to <FIG> with continued reference to <FIG>, the disclosed compressor section <NUM> includes the first compressor section <NUM> and a second compressor section <NUM> that operate independent of each other to provide compressed airflow to the combustor <NUM>. The first compressor section <NUM> is coupled to the high pressure turbine <NUM> by shaft <NUM>. The second compressor section <NUM> is coupled to a compressor electric motor <NUM> by a shaft <NUM>. Accordingly, the first compressor section <NUM> and the second compressor section <NUM> may operate and rotate independent of each other. The high pressure turbine <NUM> drives a compressor generator <NUM> that is coupled to the shaft <NUM>. The compressor generator <NUM> creates electric power that is utilized to drive the compressor motor <NUM>.

The example compressor section <NUM> supplies compressed airflow from both the first compressor section <NUM> and the second compressor section <NUM> to the combustor <NUM> through a diffuser <NUM> that crosses over an inlet scroll <NUM>. In the combustor <NUM>, the compressed airflow is mixed with fuel and ignited to produce the high energy exhaust gas flow <NUM>.

In this example, the first compressor section <NUM> and the second compressor section <NUM> are identically configured such that they provide an airflow at a common pressure and volume to the combustor section <NUM>. The compressor electric motor <NUM> drives the second compressor section <NUM> to match operation of the first compressor section <NUM> that is driven by the high pressure turbine <NUM>. Accordingly, the second compressor section <NUM> does not induce a load on the high pressure turbine section <NUM>, but provides a portion of the compressed air utilized in the combustor <NUM> to generate the high energy gas flow <NUM>.

Referring to <FIG>, with continued reference to <FIG>, the inlet scroll <NUM>, (<FIG>) includes an inlet <NUM> that is disposed axially between the first compressor section <NUM> and the second compressor section <NUM>. The inlet scroll <NUM> is configured to provide equal amounts of inlet airflow <NUM> flow to each of the first compressor section <NUM> and the second compressor section <NUM>. The example inlet scroll <NUM> includes a single common inlet <NUM> that communicates airflow into an annular portion <NUM> disposed about the axis A. The annular portion <NUM> is open on both axial sides to communicate airflow to each of the compressor sections <NUM>, <NUM>. Inlets <NUM> and <NUM> for the first compressor section <NUM> and the second compressor section <NUM> are identically configured to provide an equal airflow to each compressor section <NUM>, <NUM>. The example inlets <NUM>, <NUM> may include a vane configuration to reduce circumferential velocity components of the airflow to direct airflow axially. It should be appreciated that although a single inlet <NUM> is illustrated by way of example, additional inlets <NUM> could be utilized to aid in distributing flow between the two compressor sections <NUM>, <NUM>.

In this disclosed example, the inlet scroll <NUM> is disposed axially between the first compressor section <NUM> and the second compressor section <NUM>. The compressor generator <NUM> is also disposed substantially between the first compressor section <NUM> and the second compressor section <NUM>. The compressor generator <NUM> may be arranged in other regions within the compressor section <NUM> within the scope and contemplation of this disclosure.

Referring to <FIG>, with continued reference to <FIG> and <FIG>, an example diffuser section <NUM> is shown that communicates airflow from the compressor sections <NUM>, <NUM> to the combustor <NUM>. The example diffuser section <NUM> includes first conduits <NUM> with first outlets <NUM> that communicate airflow from the first compressor section <NUM> to the combustor <NUM>. The diffuser <NUM> includes second conduits <NUM> with second outlets <NUM> that communicate airflow from the second compressor section <NUM> to the combustor <NUM>. The first and second conduits <NUM>, <NUM> extend forward around the inlet <NUM> of the inlet scroll <NUM>. The first outlets <NUM> and the second outlets <NUM> are spaced circumferentially about the combustor <NUM>. In this disclosed example, the first outlets <NUM> alternate circumferentially with the second outlets <NUM> about the combustor <NUM> to provide a uniform distribution of airflow from respective compressor sections <NUM>, <NUM>. In one disclosed embodiment, the number of first conduits <NUM> and second conduits <NUM> are the same.

The axial orientation of the first compressor <NUM> and the second compressor section <NUM> relative to the combustor <NUM> results in the second compressor section <NUM> being spaced axially further from the combustor <NUM> than the first compressor <NUM>. Accordingly, the second conduits <NUM> are axially longer than the first conduits <NUM>. The difference in axial length between the first conduits <NUM> and the second conduits <NUM> may result in differences in airflow characteristics at respective outlets <NUM>, <NUM>. Accordingly, in another disclosed embodiment, the number and flow areas of the first conduits <NUM> and the second conduits <NUM> may be different to accommodate differences in airflow characteristics caused by the different axial distance. Moreover, although the disclosed outlets <NUM>, <NUM> are disclosed as being substantially round, other shapes could be utilized and are within the contemplation of this disclosure.

In one disclosed embodiment, a first airflow <NUM> through a first outlet <NUM> from the first compressor section <NUM> is substantially equal to a second airflow <NUM> through a second outlet <NUM> from the second compressor section <NUM>. Because the second compressor section <NUM> is powered by the compressor electric motor <NUM>, the second compressor section <NUM> does not induce a load on the high pressure turbine <NUM>. Reducing a load on the high pressure turbine <NUM> provides structural changes that can improve engine efficiency. The reduced load on the high pressure turbine <NUM> can improve reaction changes between engine operating conditions. Accordingly, the high pressure turbine <NUM> may react faster to changes in throttle positions to provide different engine thrust levels.

Additionally, a lower capacity high pressure turbine <NUM> may be utilized due to the reduction in load requirements. Alternatively, the high pressure turbine <NUM> may be sized to accommodate loads for operating conditions that occur most often during an engine operating cycle. For example, the high pressure turbine <NUM> could be sized and configured to operate the first compressor section <NUM> to accommodate cruise thrust conditions. The second compressor section <NUM> could be operated at a reduced capacity, or not at all in the cruise conditions and engaged during increased thrust demand conditions, such as during takeoff conditions.

Alternatively, according to another example embodiment, the compressor electric motor <NUM> may drive the second compressor section <NUM> at a speed different than that of the first compressor section <NUM>. The different speed may be faster or slower than the first compressor section <NUM> to provide a variable amount of compressed airflow to the combustor <NUM> to accommodate different engine thrust levels.

Referring to <FIG>, with continued reference to <FIG>, the example gas turbine engine <NUM> is shown schematically to show the electrical system that couples each of the generators <NUM>, <NUM> to the corresponding motors <NUM>, <NUM>. In this disclosed embodiment, the turbine generator <NUM> is electrically coupled to the turbine motor <NUM> through a drive control T <NUM>. The drive control T <NUM> is in communication with the engine FADEC <NUM> and also an aircraft computer <NUM>. In this example, the turbine generator <NUM> is electrically coupled to the turbine motor <NUM> to provide matched operation. Electric power to operate the turbine motor <NUM> may be supplemented by a propulsion battery <NUM>. In this example, the turbine generator <NUM> is driven by the intermediate turbine <NUM> through a shaft <NUM>. However, the turbine generator <NUM> may be driven by other turbine sections or combinations of turbine sections. Power input by the turbine motor <NUM> reduces the power load on the intermediate pressure turbine <NUM> and low pressure turbine <NUM>. The turbine control T <NUM> matches and adjusts speeds of the low pressure turbine <NUM>, intermediate pressure turbine <NUM> and the turbine motor <NUM> to drive the fan section <NUM> at a predefined speed.

In one disclosed example embodiment, the compressor generator <NUM> and compressor motor <NUM> are coupled electrically to provide substantially matched operation of the first compressor section <NUM> and the second compressor section <NUM>. A drive control C <NUM> controls operation of the compressor generator <NUM> and the compressor motor <NUM> to match operation to accommodate engine operation. The drive control C <NUM> may draw electric power from the propulsion battery <NUM> to power the compressor electric motor <NUM>. The electric power from the battery <NUM> may supplement electric power provided by the generator <NUM>. The battery <NUM> may also provide all the power to the compressor motor <NUM>.

Referring to <FIG>, a diagram is schematically shown and indicated at <NUM> to illustrate an example mode for controlling power flow of the disclosed compressor section <NUM>. In this example, power generated by the burning of fuel illustrated as fuel power <NUM> is utilized to drive the high pressure turbine <NUM>. As discussed above, fuel mixed with compressed air is ignited to generate the high energy exhaust gas flow that expands through the high pressure turbine <NUM>. The high pressure turbine <NUM> converts the gas flow to mechanical power used to drive the first compressor section <NUM>. In the illustrated example, the mechanical power generated from the fuel is split between driving the first compressor section <NUM> and driving the compressor generator <NUM>. The power to the compressor generator <NUM> is in turn used to power the compressor motor <NUM> and ultimately the second compressor section <NUM>. Power from the high pressure turbine <NUM> directly drives the first compressor section <NUM>. The remaining power, less losses due to the conversion to electric power, is used to drive the compressor electric motor <NUM>. The chart <NUM> illustrates how the input power to the high pressure turbine <NUM> flows to the compressor electric motor <NUM>.

In this example, the battery <NUM> is not utilized to drive the compressor motor <NUM>. As is shown in graphs <NUM>, <NUM>, the compressor sections <NUM>, <NUM> are operated with a flow that is derived from the power input from the high pressure turbine <NUM>.

Referring to <FIG>, another diagram is schematically shown and indicated at <NUM> to illustrate another mode of power flow to the disclosed compressor sections <NUM>, <NUM> when the battery <NUM> is utilized to supplement power to the compressor electric motor <NUM>. In this example, power input from the battery <NUM> reduces the demand for power from the high pressure turbine <NUM> induced by the compressor generator <NUM>. Accordingly, a greater percentage of power from the high pressure turbine <NUM> can be used to drive the first compressor section <NUM> as is shown by graph <NUM>. Battery power is provided to the compressor electric motor <NUM> such that a reduced load is placed on the compressor generator <NUM> and thereby the high pressure turbine <NUM>. The reduced load on the high pressure turbine <NUM> in combination with the supplemental power input from the battery <NUM> provides an overall net increase in compressor operation for both the first compressor section <NUM> indicated by graph <NUM> and the second compressor section <NUM> indicated by graph <NUM>. The chart <NUM> indicates the power distribution across for this example mode of operation.

Referring to <FIG>, another diagram is schematically shown and indicated at <NUM> that illustrates another example mode of operation where a reduced amount of fuel power <NUM> is utilized such that the power generated by the high pressure turbine <NUM> is substantially reduced. Such a reduction of power derived from fuel provides significant fuel savings. Power to drive the second compressor section <NUM> is supplemented with power from the battery <NUM> to provide operation at levels substantially the same as those shown in <FIG> utilizing a higher level of power from fuel.

Accordingly, supplementing operation of the compressor sections <NUM>, <NUM> by operating the second compressor section <NUM> with power from a battery <NUM> can provide significant fuel savings. As is shown by graphs <NUM> and <NUM> as compared to graphs <NUM> and <NUM> in <FIG>, substantial equal operation of the compressor sections <NUM>, <NUM> is provided with half as much power derived from fuel. As is further shown in chart <NUM>, a reduction in power for each of the high pressure turbine <NUM> and compressor electric generator <NUM> is provided by drawing power from the battery <NUM> to supplement compressor operation.

Accordingly, operating a portion of the high pressure compressor section <NUM> by way of an electric motor <NUM> reduces loads on the high pressure turbine to provide different operating modes and significant reductions in fuel. Additionally, the example gas turbine engine <NUM> provides a compressor section <NUM> that is split such that it may supply the gas generator airflow for significantly greater engine efficiencies.

Claim 1:
A turbine engine (<NUM>; 20A; 20B) comprising:
a fan section (<NUM>; 22A; 22B) containing a fan rotatable about an engine longitudinal axis (A);
a fan drive system (<NUM>) configured to drive the fan, the fan drive system (<NUM>) including a turbine section (<NUM>; 28A; 28B), a turbine generator (<NUM>; 96A; 96B) electrically coupled to a turbine motor (<NUM>; 94A; 94B) and a geared architecture (<NUM>; 48A; 48B), wherein the turbine section (<NUM>; 28A; 28B) and the turbine motor (<NUM>; 94A; 94B) are coupled to drive portions of the geared architecture (<NUM>; 48A; 48B);
a high pressure turbine (<NUM>) coupled to drive a compressor generator (<NUM>; 76A; 76B);
a high pressure compressor section (<NUM>; 24A; 24B) including a first compressor section (<NUM>) and a second compressor section (<NUM>), the first compressor section (<NUM>) driven by the high pressure turbine (<NUM>) and the second compressor section (<NUM>) driven by a compressor motor (<NUM>; 74A; 74B) electrically coupled to the compressor generator (<NUM>; 76A; 76B); and
a combustor (<NUM>) in flow communication with the high pressure compressor section (<NUM>; 24A; 24B),
wherein
the turbine engine includes a diffuser (<NUM>) configured to communicate airflow from the first compressor section (<NUM>) and the second compressor section (<NUM>) separately to the combustor (<NUM>).