The present disclosure relates generally to engines with rotating detonation combustion, and more specifically to actively cooled systems within the engines.
Gas turbine engines are used to power aircraft, watercraft, power generators, and the like. Gas turbine engines typically include a compressor, a combustor, and a turbine. The compressor compresses air drawn into the engine and delivers high pressure air to the combustor. In the combustor, fuel is mixed with the high pressure air and is ignited. Products of the combustion reaction in the combustor are directed into the turbine where work is extracted to drive the compressor and, sometimes, an output shaft. Left-over products of the combustion are exhausted out of the turbine and may provide thrust in some applications.
Rotating detonation combustors and other pressure-gain combustors designed for use in gas turbine engines can offer increased fuel efficiency and more compact systems over conventional deflagration-based combustors. Part of the gain in efficiency is due to a pressure rise occurring across the combustor rather than a pressure drop. From a fundamental cycle thermodynamics perspective, the pressure rise is desirable, but it presents a problem for turbines that receive products of the combustion reaction to extract mechanical energy.
Modern turbines operate at temperatures above their melting point by using cooling air that is fed through the blades and vanes of the turbine system. The cooling air is taken from the compressor, typically prior to discharge into the combustor. The cooling air is able to be driven through the blades and vanes of the turbine system because the pressure drop across typical combustors lowers pressure in the flow path of the turbine system. If the pressure increases across the combustor, as can be the case in rotating detonation combustors, the cooling air can no longer be forced through the turbine blades and vanes due to an adverse pressure gradient.
The present disclosure may comprise one or more of the following features and combinations thereof.
A gas turbine engine may comprise a compressor, a rotating detonation combustor, and a turbine system. The compressor may include at least one compressor rotor with a compressor blade configured to compress air drawn into the engine upon rotation of the compressor rotor. The rotating detonation combustor may be arranged around a reference axis. The rotating detonation combustor may include a combustion chamber and an inlet splitter. The inlet splitter may be fluidly coupled to the compressor to receive compressed air from the compressor and to the combustion chamber. The rotating detonation combustor may be configured to mix fuel with the compressed air in the combustion chamber, ignite the mixed fuel and the compressed air in the combustion chamber, and to discharge products of the combustion reaction between the mixed fuel and the compressed air at a discharge pressure greater than an inlet pressure of the compressed air received from the compressor.
In some embodiments, the turbine system may define a flow path across which static vanes and rotating blades extend. The flow path may be fluidly coupled to the rotating detonation combustor so as to receive products of the combustion reaction from the rotating detonation combustor. The static vanes and rotating blades may be formed to include cooling air passageways shaped to carry cooling air therethrough to lower the temperature of the associated static vanes and rotating blades.
In some embodiments, the inlet splitter of the rotating detonation combustor may be shaped to include a combustion passageway and a bypass passageway. The combustion passageway may fluidly couple the compressor with the combustion chamber. The bypass passageway may be separated from the combustion chamber and may fluidly couple the compressor with the cooling air passageways formed in the static vanes and rotating blades.
In some embodiments, the inlet splitter may include an annular ring separating the combustion passageway from the bypass passageway. The inlet splitter may include combustion airfoils arranged across the combustion passageway and bypass airfoils arranged across the bypass passageway. The number of combustion airfoils may be different from the number of bypass airfoils. The bypass airfoils may be shaped to increase static pressure downstream of the inlet splitter more than the combustion airfoils.
In some embodiments, the bypass passageway may include (i) a radially-inner portion that is shaped to fluidly couple the compressor with radially-inwardly facing openings into the cooling air passageways formed in at least one of the static vanes and rotating blades, and (ii) a radially-outer portion that is shaped to interconnect the compressor with radially-outwardly facing openings into the cooling air passageways formed in at least one of the static vanes and rotating blades. The inlet splitter may include an inner ring that separates the combustion passageway from the radially-inner portion of the bypass passageway and an outer ring that separates the combustion passageway from the radially-outer portion of the bypass passageway.
In some embodiments, the compressor may include a compressor airfoil upstream of the inlet splitter of the rotating detonation combustor. The compressor airfoil may have a combustor portion upstream of the combustor passageway shaped to compress air directed to the combustor passageway and a bypass portion shaped to compress air directed to the bypass passageway. The bypass portion of the compressor airfoil may be shaped to increase pressure of compressed air directed to the bypass passageway more than the combustor portion of the compressor airfoil.
In some embodiments, the combustor passageway of the inlet splitter included in the rotating detonation combustor may be annular. The bypass passageway of the inlet splitter included in the rotating detonation combustor may be annular. The bypass passageway may be radially separated from the combustor passageway.
In some embodiments, the bypass passageway of the inlet splitter may be radially inward of the combustor passageway. The bypass passageway of the inlet splitter may be radially outward of the combustor passageway.
According to another aspect of the present disclosure, a gas turbine engine may comprise a compressor, a turbine system, and a pressure-gain combustor. The compressor may be configured to compress air drawn into the engine. The turbine system may include static vanes and rotating blades formed to include cooling air passageways. The pressure-gain combustor may be fluidly coupled between the compressor and the turbine system. The pressure-gain combustor may include a combustion chamber and an inlet splitter. The inlet splitter of the pressure-gain combustor may be shaped to include a combustion passageway and a bypass passageway. The combustion passageway may fluidly couple the compressor with the combustion chamber. The bypass passageway may fluidly couple the compressor with the cooling air passageways formed in the static vanes and rotating blades included in the turbine system.
In some embodiments, the inlet splitter of the pressure-gain combustor may include a wall that separates the combustion passageway from the bypass passageway. The wall may comprise an annular ring separating the combustion passageway from the bypass passageway.
In some embodiments, the inlet splitter may include combustion airfoils arranged across the combustion passageway and bypass airfoils arranged across the bypass passageway. The number of combustion airfoils may be different from the number of bypass airfoils. The bypass airfoils may be shaped to increase static pressure downstream of the inlet splitter more than the combustion airfoils.
According to another aspect of the present disclosure, a pressure-gain combustor configured to discharge products of a combustion reaction therein at a pressure greater than that of compressed air supplied to the combustion reaction may comprise a combustion chamber and an inlet splitter. The inlet splitter may be shaped to include a combustion passageway in fluid communication with the combustion chamber and a bypass passageway in fluid communication with a bypass space around the combustion chamber.
In some embodiments, the inlet splitter may include an annular ring separating the combustion passageway from the bypass passageway. The inlet splitter may include combustion airfoils arranged across the combustion passageway and bypass airfoils arranged across the bypass passageway. The bypass airfoils may be shaped to increase static pressure downstream of the inlet splitter more than the combustion airfoils.
These and other features of the present disclosure will become more apparent from the following description of the illustrative embodiments.
For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to a number of illustrative embodiments illustrated in the drawings and specific language will be used to describe the same.
An illustrative gas turbine engine 10 includes a fan 12, a compressor 14, a combustor 16 located downstream of the compressor 14, and a turbine system 18 located downstream of the rotating detonation pressure-gain combustor 16 as shown in
In the illustrative embodiment, the combustor 16 is a rotating detonation combustor that drives a pressure gain from its inlet having a first pressure P1 to its outlet having a second pressure P2 as suggested in
The compressor 14 includes at least one compressor rotor having compressor blades 20 coupled with the compressor rotor as shown in
The rotating detonation pressure-gain combustor 16 is arranged around the axis 11 and coupled axially between the compressor 14 and the turbine system 18 as shown in
In traditional designs, a combustor included in a gas turbine engine may experience a pressure drop across the combustor. Due to the pressure drop, cooling air can be forced into a flow path of the turbine system downstream of the combustor to cool components of the turbine system. However, the rotating detonation pressure-gain combustor 16 experiences a pressure gain across the combustor 16. Because of the pressure gain across the rotating detonation pressure-gain combustor 16, cooling air may not be forced into the flow path of the turbine system 18 due to the adverse pressure gradient.
As such, to deliver cooling air to the turbine system 18, the rotating detonation pressure-gain combustor 16 includes an inlet splitter 22 configured to divide the compressed air from the compressor 14 into a first stream 24 that enters the combustor 16 and a second stream 26 that bypasses the combustor 16 as shown in
Though shown and described illustratively as a rotating detonation pressure-gain combustor 16, the combustor 16 may be any combustor configured to have a pressure gain across the combustor. For example, wave rotor combustors, ram jet combustors, pulsed detonation combustors, resonant pulse combustors, and other suitable combustors can discharge combustion products at pressures greater than the combustor inlet pressure. Such other pressure gain combustors, or even other traditional non-pressure gain combustors, may be implemented in place of the illustrated combustor 16 while remaining within the spirit of this disclosure.
Turning back to the illustrative compressor 14, the compressor blades 20 are arranged upstream of the inlet splitter 22 of the combustor 16 as shown in
The pressure of the second stream 26 that bypasses the combustor 16 is higher than the first pressure P1 of the first stream 24 that enters the combustor 16. Thus, there is a higher compressor ratio at the bypass portion 30 of the compressor blade 20 compared to the compressor ratio at the combustor portion 28 of the compressor blade 20. The differing compressor ratios may be achieved through twist and camber distribution of the compressor blade 20. In the illustrative embodiment, the compressor blade 20 is arranged in the most axially aft rotor stage of the compressor 14.
The rotating detonation pressure-gain combustor 16 includes the inlet splitter 22 arranged downstream of the compressor blade 20, a combustor outer shell 31, and a combustion chamber 32 located downstream of the inlet splitter 22 as shown in
The rotating detonation wave 34 is constrained within the combustion chamber 32 such that the wave 34 propagates circumferentially around the combustion chamber 32. The products of the combustion reaction in the combustion chamber 32 are discharged from the combustion chamber 32 at the second pressure P2, which is greater than the first pressure P1. The pressure gain across the combustion chamber 32 is a result of the detonation process.
Because the inlet splitter 22 divides the compressed air into the first stream 24 and the second stream 26, only the first stream 24 is subject to the combustion reaction in the combustion chamber 32. Thus, the second stream 26 that bypasses the combustor 16 has a lower temperature than that of the first stream 24. As such, the second stream 26 provides cooling to components of the turbine system 18 as the first stream 24 may heat the components of the turbine system 18.
The inlet splitter 22 includes annular rings 36 arranged circumferentially around the central axis 11 as shown in
The annular rings 36 of the inlet splitter 22 include a first annular ring 36A, a second annular ring 36B, and a third annular ring 36C as shown in
The first stream 24 flows radially between the first annular ring 36A and the second annular ring 36B as shown in
The second stream 26 flows radially between the second annular ring 36B and the third annular ring 36C as shown in
The second annular ring 36B separates the combustor passageway 38 and the bypass passageway 40 from one another such that the first stream 24 flows radially outward of the second annular ring 36B and the second stream 26 flows radially inward of the second annular ring 36B as shown in
The combustor passageway 38 fluidly couples the compressor 14 with the combustion chamber 32 as shown in
The combustor passageway 38 is arranged radially outward of the bypass passageway 40 as shown in
In some embodiments, the combustor outer shell 31 is formed, for example, in the radially-inward portion 311 of the combustor outer shell 31, to include combustor liner cooling passages 51 extending therethrough as shown in
The illustrative inlet splitter of the combustor 16 includes combustion vanes 42 and bypass vanes as shown in
In the illustrative embodiment, a number of combustion vanes 42 is different than a number of bypass vanes 44. In some embodiments, the number of combustion vanes 42 is greater than the number of bypass vanes 44. In some embodiments, the number of combustion vanes 42 is less than the number of bypass vanes 44. In some embodiments, the number of combustion vanes 42 may be the same as the number of bypass vanes 44.
A shape of the bypass vanes 44 is different than a shape of the combustion vanes 42 such that a static pressure downstream of the inlet splitter 22 in the bypass passageway 40 is increased more than a static pressure downstream of the inlet splitter 22 in the combustor passageway 38. In some embodiments, the shape of the bypass vanes 44 may be the same as the shape of the combustion vanes 42.
The bypass vanes 44 are configured to convert extra energy added by the bypass portion 30 of the compressor blade 20 into a higher static pressure than the combustion vanes 42. The bypass portion 30 of the compressor blade 20 and the bypass vanes 44 cause a greater pressure gain in the second stream 26 than that in the first stream 24. Thus, a pressure of the second stream 26 downstream of the bypass vanes 44 may be greater than the second pressure P2 of the first stream 24 exiting the combustor 16.
The turbine system 18 is coupled with the combustor 16 downstream of the combustor 16 as shown in
The combustion chamber 32 is fluidly coupled with the turbine flow path 50 to deliver the first stream 24 that underwent the combustion reaction to the turbine flow path 50. The hot, high-pressure products of the combustion reaction included in the first stream 24 rotate the rotating blades 48 about the axis 11 to extract work to drive the compressor 14. The hot, high-pressure products of the combustion reaction increase a temperature of the static vanes 46 and rotating blades 48.
The static vanes 46 and the rotating blades 48 are both formed to include cooling air passageways 52 with radially-inwardly facing openings as suggested in
In some embodiments, both the static vanes 46 and the rotating blades are formed to include cooling air passageways 52. In some embodiments, at least one of the static vanes 46 and the rotating blades are formed to include cooling air passageways 52.
As discussed, the gas turbine engine 10 in accordance with the disclosure is configured such that the last compressor rotor stage prior to the combustor 16 has a higher compressor ratio at the root 30 of the compressor blade 20 and a lower pressure ratio at the tip 28 of the compressor blade 20 via twist and camber distribution. The last compressor rotor stage is followed by a final compressor stator vane, illustratively considered part of the combustor 16 that is configured with an inlet splitter 22 and different vanes 42, 44 above and below the inlet splitter 22.
The vanes 44 of the inlet splitter 22 are configured to convert the extra energy added at the root 30 of the compressor blade 20 into higher static pressure than the vanes 42 above the inlet splitter 22. The lower vanes 44 feed the cooling air circuit while the upper vanes 42 feed the main combustor flow. The vanes 44 below the inlet splitter 22 may be of a different design than those above the inlet splitter 22 and may also have a different vane count. In this way, the compressor 14 adds extra work to the cooling flow such that its pressure rise is greater than the pressure rise from the tip 28 of the last compressor stage plus the pressure rise from the combustor 16.
Another embodiment of a gas turbine engine 210 including a rotating detonation pressure-gain combustor 216 in accordance with the present disclosure is shown in
The gas turbine engine 210 includes a compressor 214, the rotating detonation pressure-gain combustor 216 located downstream of the compressor 214, and a turbine system 218 located downstream of the rotating detonation pressure-gain combustor 216 as shown in
The combustor portion 228 of the compressor blade 220 is radially inward of the bypass portion 230 of the compressor blade 220 as shown in
The rotating detonation pressure-gain combustor 216 includes an inlet splitter 222 arranged downstream of the compressor blade 220, a combustor outer shell 231, and a combustion chamber 232 located downstream of the inlet splitter 222 as shown in
The inlet splitter 222 includes annular rings 236 arranged circumferentially around a central axis of the gas turbine engine 210 as shown in
The annular rings 236 of the inlet splitter 222 include a first annular ring 236A, a second annular ring 236B, and a third annular ring 236C as shown in
The first stream 224 flows radially between the second annular ring 236B and the third annular ring 236C as shown in
The second stream 226 flows radially between the first annular ring 236A and the second annular ring 236B as shown in
The second annular ring 236B separates the combustor passageway 238 and the bypass passageway 240 from one another such that the first stream 224 flows radially inward of the second annular ring 236B and the second stream 226 flows radially outward of the second annular ring 236B as shown in
The combustor passageway 238 fluidly couples the compressor 214 with the combustion chamber 232 as shown in
The combustor passageway 238 is arranged radially inward of the bypass passageway 240 as shown in
In some embodiments, the combustor outer shell 231 is formed, for example, in the radially-outward portion 231O of the combustor outer shell 231, to include combustor liner cooling passages 251 extending therethrough as shown in
The combustor 216 includes combustion vanes 242 arranged across the combustor passageway 238 and bypass vanes 244 arranged across the bypass passageway 240 as shown in
The turbine system 218 is coupled with the combustor 216 downstream of the combustor 216 as shown in
The static vanes 246 and the rotating blades 248 are both formed to include cooling air passageways 252 with radially-outwardly facing openings as suggested in
In the alternative embodiment of the gas turbine engine 210, the high pressure ratio feeding the cooling air passageways 252 is done at the tip 230 of the blades 220 with the low pressure ratio near the hub 228 as suggested in
Another embodiment of a gas turbine engine 310 including a rotating detonation pressure-gain combustor 316 in accordance with the present disclosure is shown in
The gas turbine engine 310 includes a compressor 314, the rotating detonation pressure-gain combustor 316 located downstream of the compressor 314, and a turbine system 318 located downstream of the rotating detonation pressure-gain combustor 316 as shown in
The rotating detonation pressure-gain combustor 316 includes an inlet splitter 322 arranged downstream of the compressor blade 320, a combustor outer shell 331, and a combustion chamber 332 located downstream of the inlet splitter 322 as shown in
The inlet splitter 322 includes annular rings 336 arranged circumferentially around a central axis of the gas turbine engine 310 as shown in
The annular rings 336 of the inlet splitter 322 include a first annular ring 336A, a second annular ring 336B, a third annular ring 336C, and a fourth annular ring 336D as shown in
The second stream 326A flows radially between the first annular ring 336A and the second annular ring 336B as shown in
The first stream 324 flows radially between the second annular ring 336B and the third annular ring 336C as shown in
The third stream 326B flows radially between the third annular ring 336C and the fourth annular ring 336D as shown in
The second annular ring 336B separates the first bypass passageway 340A and the combustor passageway 338 from one another such that the first stream 324 flows radially inward of the second annular ring 336B and the second stream 326A flows radially outward of the second annular ring 336B as shown in
The combustor passageway 338 fluidly couples the compressor 314 with the combustion chamber 332 as shown in
The first bypass passageway 340A fluidly couples the compressor 314 with the turbine system 318 to deliver the second stream 326A to the turbine system 318 for cooling of components in the turbine system 318 as suggested in
The second stream 326A passes over the bypass portion 330A of the compressor blade 320, between the first annular ring 336A and the second annular ring 336B, through the first bypass passageway 340A, and into the turbine system 318 as suggested in
The combustor passageway 338 is arranged radially between the first and second bypass passageways 340A, 340B as shown in
In some embodiments, the combustor outer shell 331 is formed, for example, in the radially-outward portion 331O and the radially-inward portion 331I of the combustor outer shell 331, to include combustor liner cooling passages 351 extending therethrough as shown in
The combustor 316 includes combustion vanes 342 arranged across the combustor passageway 338 and bypass vanes 344A, 344B arranged across the first and second bypass passageways 340A, 340B as suggested in
The turbine system 318 is coupled with the combustor 316 downstream of the combustor 316 as shown in
The static vanes 346 and the rotating blades 348 are both formed to include cooling air passageways 352 with radially-outwardly facing openings and radially-inwardly facing openings as suggested in
Because some turbine static vane 346 arrangements have cooling air delivered both from the tip and the hub, the gas turbine engine 310 includes an additional annular ring 336D as shown in
While the disclosure has been illustrated and described in detail in the foregoing drawings and description, the same is to be considered as exemplary and not restrictive in character, it being understood that only illustrative embodiments thereof have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected.
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Entry |
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Fundamentals of Heat Exchanger Design, Ramesh K. Shah and Dusan P. Sekulic, 2003, pp. 848-852. |