Patent Application
20160363138
The present disclosure relates generally to fluid flow devices, and more specifically to wave rotors.
Some wave rotors compress gasses with generally unsteady shock or compression waves and allow the gasses to expand by expansion waves. Typical wave rotors include an inlet end plate, an outlet end plate spaced apart from the inlet end plate along a central axis of the wave rotor, and a rotor drum positioned therebetween. The inlet port (or aperture) in the inlet end plate directs a flow of gasses into rotor passages formed in the rotor drum. The rotor drum defines passages that compress the gasses as the rotor drum rotates about the central axis relative to the inlet end plate and the outlet end plate. The outlet port in the exit end plate directs the gasses out of the rotor drum. The compression waves within the rotor passages may cause pressure pulses to travel upstream within the inlet port. The exit gasses may exit the outlet end plate port with high pressure pulses traveling within the exit flow.
The present disclosure may comprise one or more of the following features and combinations thereof.
According to a first aspect of the present disclosure, a wave rotor may include a rotor drum and a first end plate. The rotor drum may be mounted for rotation about a central axis of the wave rotor. The rotor drum may be formed to include a plurality of rotor passages that extend along the central axis. The first end plate may be aligned axially with the rotor drum and formed to include a port aperture extending axially through the first end plate along an arc around the central axis and aligned radially with the rotor passages.
In illustrative embodiments, the wave rotor may include a first cancelling resonator. The first canceling resonator may include a body and a neck that cooperate to define a cavity. The neck may be narrower than the body and is formed to include a mouth positioned adjacent to the port aperture.
In illustrative embodiments, the first end plate may include a leading edge wall and a trailing edge wall spaced apart circumferentially from the leading edge wall to form portions of the port aperture. The rotor passages may be configured to rotate in a direction from the leading edge wall to the trailing edge wall. The mouth may be positioned adjacent to the leading edge wall. The first canceling resonator may extend circumferentially away from the port aperture.
In illustrative embodiments, the wave rotor may include a second canceling resonator. A mouth of the second canceling resonator may be positioned adjacent to the trailing edge wall. The second canceling resonator may extend circumferentially away from the port aperture and the first canceling resonator.
In illustrative embodiments, the first end plate may include a leading edge wall, a trailing edge wall spaced apart circumferentially from the leading edge wall, a radial outer wall interconnecting the leading edge wall and the trailing edge wall, and a radial inner wall radially spaced apart from the radial outer wall and interconnecting the leading edge wall and the trailing edge wall to form the port aperture. The mouth may be positioned adjacent to one of the radial outer wall and the radial inner wall. The first canceling resonator may extend radially away from the port aperture.
In illustrative embodiments, the wave rotor may include a second end plate axially spaced apart from the first end plate and a second canceling resonator. The first end plate may positioned at an outlet end of the rotor drum. The second end plate may be positioned at an inlet end of the rotor drum. A mouth of the second canceling resonator may be positioned adjacent to a second port aperture formed in the second end plate.
In illustrative embodiments, the first canceling resonator may have a tuned frequency that is about equal to a frequency of pressure pulsations produced as the rotor passages pass the port aperture when the rotor drum is rotated.
In illustrative embodiments, the first canceling resonator may further include a frequency adjuster configured to vary a volume of the body to vary a tuned frequency of the first canceling resonator. The tuned frequency may be about equal to a frequency of the rotor passages passing the port aperture when the rotor drum is rotated.
In illustrative embodiments, the first canceling resonator may include an orifice plate covering the mouth of the first canceling resonator and may be formed to include a plurality of orifices extending through the orifice plate.
According to another aspect of the present disclosure, a wave rotor may include a rotor drum and an outlet plate. The rotor drum may be mounted for rotation about a central axis of the wave rotor. The rotor drum may be formed to include a plurality of rotor passages that extend along the central axis. The outlet end plate may be aligned axially with the rotor drum and may be formed to include an outlet port aperture extending axially through the outlet end plate along an arc around the central axis and aligned radially with the rotor passages. The outlet end plate may include a leading edge wall and a trailing edge wall spaced apart circumferentially from the leading edge wall to define a portion of the outlet port aperture. The rotor passages may be configured to rotate in a direction from the leading edge wall to the trailing edge wall.
In illustrative embodiments, the wave rotor may include a first canceling resonator including a body and a neck that cooperate to define a cavity. The neck may be narrower than the body and may be formed to include a mouth positioned adjacent to the leading edge wall.
In illustrative embodiments, the first canceling resonator may extend circumferentially away from the outlet port aperture. The wave rotor may include a second canceling resonator and a mouth of the second canceling resonator may be positioned adjacent to the trailing edge wall. The second canceling resonator may extend circumferentially away from the outlet port aperture and the first canceling resonator.
In illustrative embodiments, the outlet end plate may further include a radial outer wall interconnecting the leading edge wall and the trailing edge wall and a radial inner wall radially spaced apart from the radial outer wall and interconnecting the leading edge wall and the trailing edge wall to form the port aperture. The mouth may be positioned adjacent to one of the radial outer wall and the radial inner wall. The first canceling resonator may extend radially away from the outlet port aperture.
In illustrative embodiments, the wave rotor may include a second canceling resonator and an inlet end plate axially spaced apart from the outlet end plate. A mouth of the second canceling resonator may be positioned adjacent to an inlet port aperture formed in the inlet end plate.
In illustrative embodiments, the first canceling resonator may have a tuned frequency about equal to a frequency of pressure pulses produced as the rotor passages pass the port aperture when the rotor drum is rotated. The tuned frequency may be about equal to a frequency of the rotor passages passing the port aperture when the rotor drum is rotated.
In illustrative embodiments, the first canceling resonator further includes a frequency adjuster configured to vary a volume of the body to vary the tuned frequency of the first canceling resonator.
In illustrative embodiments, the first canceling resonator may include an orifice plate covering the mouth of the first canceling resonator and formed to include a plurality of orifices extending through the orifice plate.
According to another aspect of the present disclosure, a method of canceling pressure pulses produced by a wave rotor is taught. The method may include operating a wave rotor to produce high pressure pulses of gasses at a port aperture of the wave rotor, forcing a portion of the high pressure pulses of gasses into a cavity to increase a pressure inside the cavity, and releasing the gasses inside the cavity during intervals between the high pressure pulses of gasses to decrease the pressure inside the cavity.
In illustrative embodiments, the method may include tuning the cavity to a frequency of the high pressure pulses
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 wave rotor 10 in accordance with the present disclosure is shown in
The illustrative wave rotor 10 is configured to receive fluids such as, for example, gasses including combustible gas mixtures and use transient internal fluid flow including, but not limited to, combustion to compress the fluids. In the illustrative embodiment, the wave rotor 10 includes an inlet end plate 12, a rotor drum 14, an outlet end plate 16, and a canceling resonator 18 as shown in
The rotor drum 14 is formed to include a plurality of rotor passages 26 that extend along the central axis 20 as shown in
The wave rotor 10 produces unsteady flow such as the pulses of high pressure gasses, for example, at the outlet port aperture 24 as each rotor passage 26 aligns with the outlet port aperture 24. Similarly, pressure pulses may be produced at the inlet port aperture 22 as each rotor passage 26 aligns with the inlet port aperture 22. A number of factors may contribute to the production of pressure pulses, including the finite number of rotor passages 26, the gradual opening process of the rotor passages 26 into the port apertures 22, 24, and the arrival of pressure waves within each rotor passage 26 due to design constraints on the internal temporal cycle in the wave rotor 10. The unsteadiness may degrade the performance and life of components upstream and downstream of the wave rotor 10. The canceling resonators 18 are located adjacent to the port apertures 22, 24 and are configured to cancel pressure pulsations produced as the rotor passages 26 pass the port apertures 22, 24 when the rotor drum 14 is rotated.
The inlet end plate 12 includes a leading edge wall 40, a trailing edge wall 42, a radial outer wall 44, and a radial inner wall 46 that cooperate to form the inlet port aperture 22 as shown in
The outlet end plate 16 includes a leading edge wall 50, a trailing edge wall 52, a radial outer wall 54, and a radial inner wall 56 that cooperate to form the outlet port aperture 24 as shown in
In the illustrative embodiment, the rotor passages 26 rotate about the central axis 20 in a direction from the leading edge wall 40, 50 toward the trailing edge wall 42, 52. In some embodiments, the inlet end plate 12 includes a single inlet port aperture 22 and the outlet end plate 16 includes a single outlet port aperture 24 as shown in
The canceling resonator 18 includes a body 30 and a neck 32 as shown in
The mouth 36 is positioned adjacent to a port 22, 24 so that a portion of the high pressure pulses of gasses expelled from the wave rotor 10 are forced into the cavity 34 to increase a pressure inside the cavity 34. Between intervals of high pressure pulses, the gasses inside the cavity 34 are released and the pressure inside the cavity 34 is decreased. The decreased pressure in the cavity 34 draws gasses back into the cavity 34 and the magnitude of the pressure changes decreases for each iteration.
The canceling resonator 18 has a tuned frequency. The canceling resonator 18 is more effective for frequencies that are within a range of the tuned frequency. In some embodiments, the tuned frequency is about equal to a frequency of the pressure pulsations produced as the rotor passages 26 pass the port aperture 22, 24 when the rotor drum 14 is rotated. In the illustrative embodiment, the tuned frequency is about equal to a frequency of the rotor passages 26 passing the port aperture 22, 24 when the rotor drum 14 is rotated. In some embodiments, the canceling resonator 18 further includes a frequency adjuster 270 configured to vary a volume of the body 30 to vary the tuned frequency of the canceling resonator as shown in
The mouth 36 of the canceling resonators 18 may be positioned in one of a plurality of locations adjacent to the port apertures 22, 24. The canceling resonators 18 may be positioned adjacent to the port apertures 22, 24 along any of the leading edge wall 40, 50, trailing edge wall 42, 52, radial outer wall 44, 54, and radial inner wall 46, 56. The canceling resonators 18 may be oriented to extend in one of a plurality of orientations. As an example, each canceling resonator 18 may extend radially, axially, circumferentially, or any combination thereof relative to the port apertures 22, 24.
The illustrative wave rotor 10 shown in
The mouth 36 of the inlet canceling resonator 18 is positioned adjacent to the radial outer wall 44 of the inlet port aperture 22 as shown in
The mouth 36A of the outlet canceling resonator 18A is positioned adjacent to the leading edge wall 50 of the outlet port aperture 24 as shown in
In another illustrative embodiment, the wave rotor 10 includes the first outlet canceling resonator 18A and a second outlet canceling resonator 18B as shown in
The mouth 36B of the second outlet canceling resonator 18B is positioned adjacent to the trailing edge wall 52 of the outlet port aperture 24 as shown in
A method of canceling pressure pulses produced by the wave rotor 10 may include a number of steps. The method may include operating the wave rotor 10 to produce high pressure pulses of gasses at a port aperture 22, 24 of the wave rotor 10, forcing a portion of the high pressure pulses of gasses into the cavity 34 to increase a pressure inside the cavity 34, and releasing the gasses inside the cavity 34 during intervals between the high pressure pulses of gasses to decrease the pressure inside the cavity 34. The method may further include tuning the cavity 34 to a frequency of the high pressure pulses.
Another illustrative wave rotor 110 is shown in
The wave rotor 110 includes an inlet end plate, a rotor drum, and an outlet end plate 116 as shown in
The wave rotor 110 includes a first outlet canceling resonator 118A and a second outlet canceling resonator 118B. A mouth 136A of the first outlet canceling resonator 118A is positioned adjacent to the leading edge wall 150 of the first outlet port aperture 124 as shown in
Another illustrative canceling resonator 218 is shown in
The canceling resonator 218 includes a body 230 and a neck 232 as shown in
The canceling resonator 218 includes a frequency adjuster 270 configured to vary a tuned frequency of the canceling resonator 218 as shown in
As shown in
The canceling resonator 218 includes an orifice plate 278 as shown in
Referring to
The rotor drum 14 includes an outer tube 86, an inner tube 88, and a plurality of webs 90 as shown in
The outer tube 86 extends around the central axis 20 to form a radially outer portion of the rotor passages 26. The inner tube 88 extends around the central axis 20 and is positioned radially between the central axis 20 and the outer tube 86 to form a radially inner portion of the rotor passages 26. The plurality of webs 90 are spaced apart circumferentially and extend between and interconnect the outer tube 86 and the inner tube 88 to separate the plurality of rotor passages 26.
In the illustrative embodiment, the rotor passages 26 are generally parallel with the central axis 20 and the rotor drum 14 is rotated by a drive shaft 84. In other embodiments, the rotor passages 26 extend axially along and circumferentially around the central axis 20. In some embodiments, the rotor passages 26 are arranged to cause the rotor drum 14 to rotate as a result of the shape of the rotor passages 26 and/or a combustion process that may occur within the rotor passages 26.
As one example, the wave rotor 10 may be included in a gas turbine engine to power a turbine included in the gas turbine engine. The engine includes a compressor, the wave rotor 10, and the turbine. The compressor is configured to compress and deliver air to the wave rotor 10. The turbine extracts work from the combusted gasses (sometimes called hot high-pressure products or exhaust gasses) to drive the compressor and a fan assembly. The fan assembly pushes air through and around the engine to provide thrust for an aircraft. The wave rotor 10 is configured to use transient internal fluid flow to compress fuel and air prior to combustion and to confine the volume of the gas as combustion takes place for the purpose of improving the available amount of work that can be produced by the exit flow of the combustor.
During operation of the wave rotor 10, fuel and compressed air, produced by the compressor, is drawn axially into each rotor passage 26 through the inlet port aperture 22 formed in the inlet end plate 12. As each rotor passage 26 rotates about the central axis 20, the compressed air and fuel are mixed together and are then ignited to produce hot high-pressure products. The hot high-pressure products are blocked from escaping the rotor passage 26 by the inlet end plate 12 and an outlet end plate 16 until the rotor passage 26 aligns with the outlet port aperture 24 formed in the outlet end plate 16. The hot high-pressure products exit the rotor passage 26 through the outlet port aperture 24 into the turbine.
Pressure pulses may be observed in the inlet and exit flow of wave rotors 10 including, for example, combustors, pressure exchangers, flow dividers, flow combiners, etc. A cancelling resonator (sometimes called a Helmholtz resonator) may be used to achieve a degree of cancelation of pressure pulsations of a defined frequency. As one example, a canceling resonator 18 may be positioned adjacent to the location where a pressure pulse is propagating out of the rotor passages 26 of the wave rotor 10 and into the port of the wave rotor 10. The canceling resonator 18 may include an opening and a cavity adjacent to the opening in the form of a branch.
The tuned frequency of the canceling resonator 18 may be designed into the device and selected such that the frequency of the arriving series of pressure pulses matches that of the canceling resonator 18. In some embodiments, the tuned frequency is about equal to the passage passing frequency of the wave rotor 10.
The canceling pulses generated within the resonator 18 propagate into a duct connecting the wave rotor 10 and adjacent flow components. In some embodiments, the canceling resonator 18 opening is located on the outer wall of the port duct at the rotor end plate. In some embodiments, the canceling resonator opening is located on the inner wall of the port duct at the rotor end plate. In some embodiments, the canceling resonator opening is located on the leading edge of the port duct at the rotor end plate. In some embodiments, the canceling resonator opening is located on the trailing edge of the port duct at the rotor end plate. The location is selected based on the area of the canceling resonator 18 being adjacent to the area within the port where the pressure pulsation emanates from the rotor passages 26.
In some embodiments, the wave rotor ports form partial annulus ducts and the canceling resonator 18 is located in a region between the partial annulus ducts. In other embodiments, the canceling resonator 18 is located radially inward relative to the port. In other embodiments, the canceling resonator is located outward relative to the port. Some wave rotors 10 do not have axial passage orientation and, in such embodiments, the canceling resonator 18 may be located in alternative available positions.
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.
This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62/173,171, filed 9 Jun. 2015, the disclosure of which is now expressly incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62173171 | Jun 2015 | US |
