IPC분류정보
국가/구분 |
United States(US) Patent
등록
|
국제특허분류(IPC7판) |
|
출원번호 |
US-0379204
(2009-02-17)
|
등록번호 |
US-8262351
(2012-09-11)
|
우선권정보 |
DE-10 2008 009 604 (2008-02-15) |
발명자
/ 주소 |
- Clemen, Carsten
- Schrapp, Henner
|
출원인 / 주소 |
- Rolls-Royce Deutschland Ltd Co KG
|
대리인 / 주소 |
|
인용정보 |
피인용 횟수 :
2 인용 특허 :
9 |
초록
▼
A casing (2) includes at least one casing structure (casing treatment) for stabilizing a flow in an area of blade tips of rotor blades (4) in a fluid-flow machine, with the casing structure (casing treatment) being provided in at least one stage on an inner circumference of the casing (2). To provid
A casing (2) includes at least one casing structure (casing treatment) for stabilizing a flow in an area of blade tips of rotor blades (4) in a fluid-flow machine, with the casing structure (casing treatment) being provided in at least one stage on an inner circumference of the casing (2). To provide a casing which improves compressor stability, is simply designed, features low weight and operates reliably without heating-up fluid in the fluid-flow machine, the casing structure is designed as a duct (20) which includes a first end (21) and a second end (22), with the first end (21) issuing into the interior of the casing (2) in the area of the blade tips of a rotor blade row and with the second end (22) being closed.
대표청구항
▼
1. A fluid-flow machine casing, comprising: at least one casing structure for stabilizing flow in an area of blade tips of rotor blades of the fluid-flow machine, the casing structure being provided in at least one stage on an inner circumference of the casing, wherein the casing structure is config
1. A fluid-flow machine casing, comprising: at least one casing structure for stabilizing flow in an area of blade tips of rotor blades of the fluid-flow machine, the casing structure being provided in at least one stage on an inner circumference of the casing, wherein the casing structure is configured as a duct, which includes a first end and a second end, the first end issuing into an interior of the casing in the area of the blade tips of a rotor blade row and the second end being closed;a mechanism for speed-dependable adjusting a length l of the duct at the second end in a continuous range between a minimum length lmin and a maximum length lmax. 2. The casing of claim 1, wherein the duct is arranged essentially radially to the inner circumference of the casing. 3. The casing of claim 1, wherein the duct is rectilinear at least in the range between lmin and lmax and has a constant cross-section in this range, and further comprising a piston which is movably positioned in the duct in the range between lmin and lmax. 4. The casing of claim 3, and further comprising at least one of an electric, hydraulic and pneumatic drive for controlling the position of the piston. 5. The casing of claim 4, wherein the duct includes a constriction at the first end. 6. The casing of claim 1, wherein the duct is arranged angularly to a longitudinal axis of the casing. 7. The casing of claim 1, wherein the duct is curvilinear outside of the range between lmin and lmax. 8. The casing of claim 1, wherein the duct is curvilinear in an area of the first end and parallel to a longitudinal axis of the casing in the range between lmin and lmax. 9. The casing of claim 1, wherein the position of the first end of the duct is between a trailing edge of the rotor blade and a distance measured from the trailing edge of the rotor blade which is 1.3 times an axial chord length lax of the rotor blade at the blade tip. 10. The casing of claim 1, wherein the casing is for a compressor of a gas turbine. 11. A method for stabilizing flow in an area of blade tips of rotor blades in a fluid-flow machine, comprising: providing a duct in a casing of the fluid-flow machine, the duct having a first end issuing from an inner circumference of the casing into an interior of the casing in the area of the blade tips of a rotor blade row and a second end being closed;moving a static pressure field forming on each rotor blade into the first end of the duct during rotation of the rotor blade and exciting vibrations of a fluid column in the duct;producing a standing wave in the duct to form a pulsating mass flow at the first end of the duct;adjusting a natural frequency of the fluid column to be speed-dependent by adjusting a length l of the duct. 12. The method of claim 11, and further comprising: producing the standing wave in the natural frequency of the fluid column and matching that to a blade passing frequency such that the natural frequency of the fluid column concurs with a multiple of a blade passing frequency of the rotor blades. 13. The method of claim 12, and further comprising calculating the length l of the duct using the formula l(n)=(12k+14)κRnz,with l being the length of the duct,k any natural number,□ an isentropic exponent,R a specific gas constant,n an aerodynamic speed of a compressor rotor, andz a number of blades of the rotor blade row. 14. The method of claim 13, and further comprising calculating a minimum length lmin of the duct using the formula lmin=(12kmin+14)κRnmaxzwithkmin≤k,and with lmin being the minimum length of the duct,kmin any natural number,□ the isentropic exponent,R the specific gas constant,nmax the maximum aerodynamic speed of the compressor rotor, andz the number of blades of the rotor blade row. 15. The method of claim 13, and further comprising calculating a maximum length lmax of the duct using the formula lmax=(12k+14)κRnminz,with lmax being the maximum length of the duct,k any natural number,□ the isentropic exponent,R the specific gas constant,nmin the minimum aerodynamic speed of the compressor rotor, andz the number of blades of the rotor blade row. 16. The method of claim 11, and further comprising calculating the length l of the duct using the formula l(n)=(12k+14)κRnz,with l being the length of the duct,k any natural number,□ an isentropic exponent,R a specific gas constant,n an aerodynamic speed of a compressor rotor, andz a number of blades of the rotor blade row. 17. The method of claim 16, and further comprising calculating a minimum length lmin of the duct using the formula lmin=(12kmin+14)κRnmaxzwithkmin≤k,and with lmin being the minimum length of the duct,kmin any natural number,□ the isentropic exponent,R the specific gas constant,nmax the maximum aerodynamic speed of the compressor rotor, andz the number of blades of the rotor blade row. 18. The method of claim 16, and further comprising calculating a maximum length lmax of the duct using the formula lmax=(12k+14)κRnminz,with lmax being the maximum length of the duct,k any natural number,□ the isentropic exponent,R the specific gas constant,nmin the minimum aerodynamic speed of the compressor rotor, andz the number of blades of the rotor blade row.
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