A kind of non-rotational symmetry combination processing machine box
Technical field
The present invention relates to a kind of device that improves the air compressor stability margin, refer in particular to a kind of non-rotational symmetry combination processing machine box that can obviously improve the air compressor stability margin and can improve its adiabatic efficiency/adia.eff. simultaneously.
Background technology
Air compressor is used in aero-engine and the commercial production in a large number.But in the designs process of air compressor, the instability of air compressor flows, and as propagating stall, surge etc., has greatly limited the further lifting of air compressor performance.When rotating stall, exist one or more low energy stall group to rotate along gas compressor circumferential, the performance of air compressor can descend suddenly, flow, pressure ratio and efficient all reduce as far as possible, and can produce periodic disturbance force to compressor blade, even cause the generation of surge, very harmful.Therefore people have taked a lot of methods to postpone air compressor and have rotated wild effects such as stall, to enlarge its stable operation nargin.
In order to enlarge the stability margin of air compressor, the worker has done a lot of research both at home and abroad.The steady effect of the expansion of processor box technology is considered to very obvious, and practicality is very strong, thereby has obtained using more widely.The used air compressor of the advanced aero-engine machine of lot of domestic and international has all adopted this technology at present.Fig. 1-Fig. 3 has provided three kinds of representative type processor casing structure forms.
As shown in Figure 1, axial chute processor casing is axially grooved at casing upper edge air compressor, radially form an angle (being generally 60 degree) of its groove depth direction and air compressor.When the groove depth direction aimed at flow path direction, no matter incoming flow was equal uniform flow or the import distortion takes place, and stability margin all has bigger improvement.But the shortcoming of this class processor box is that the improvement of stability margin is a cost with the efficient of loss air compressor.
As shown in Figure 2, tangential chute processor casing is that the groove depth direction can have different angles at the tangential fluting of casing upper edge blade tip primitive.Under the uniform incoming flow situation, the growth of stability margin is only second to axial chute processor casing 3%, and the loss of compressor efficiency is also lacked than axial chute.
As shown in Figure 3, derotation whirlpool shallow slot processor box is direction and the intensity according to known vortex in the blade path, at casing upper edge compressorshaft to the triangular groove of opening no air chamber, when inswept these treatment troughs of blade, in triangular groove, produce and the oppositely directed vorticity in tip leakage whirlpool, and offset with the leakage vortex in blade tip district.This processor box has obvious lifting to the adiabatic efficiency/adia.eff. of air compressor, but little to the recruitment of stability margin.
Sum up traditional processor box technology, have such shortcoming: the stability margin and the adiabatic efficiency/adia.eff. that are difficult to improve simultaneously air compressor.The most of processor box that comprises above-mentioned preceding two kinds of typical structure processor boxes is when enlarging the air compressor stability margin, and having to pay the adiabatic efficiency/adia.eff. that reduces air compressor is cost.This cost is generally about 1%-3%.On aero-engine, the decline of the adiabatic efficiency/adia.eff. of air compressor means that fuel oil consumption can be more.Though it is and above-mentioned derotation whirlpool shallow slot processor box promotes to some extent to the adiabatic efficiency/adia.eff. of air compressor, few to the recruitment of the stability margin of air compressor.
As previously mentioned, when air compressor rotates stall, can produce one or more low energy stall and roll into a ball, the strong air flow pulsation that produces the circumferential variation in edge thus and propagate along rotating in a circumferential direction.The air compressor flow field of this moment is the non-axisymmetric flow field of representative type.And traditional processor box all is the single treatment trough structure that rotational symmetry distributes, and does not consider that the serious nonaxisymmetry in flow field was the big shortcoming of one when air compressor rotated stall.And this non-rotational symmetry characteristic of air compressor has reflected a kind of stronger UNSTEADY FLOW state.
Therefore, how from the nonaxisymmetry in air compressor flow field, in conjunction with the advantage of some casing, the combination casing that is designed to display one's respective advantages and to produce different non-permanent excitations becomes the original intention of work of the present invention.
Summary of the invention
At the shortcoming that above-mentioned conventional process casing technology exists, the invention provides a kind of combination processing machine box of nonaxisymmetric structure, this processor box comprises:
A processing ring that has the non-rotational symmetry distribution of two kinds of version treatment trough combinations;
One or two roll adjustment ring is used to adjust the axial location that above-mentioned processing encircles relative compressor blade.
The described processing ring of this non-rotational symmetry combination processing machine box has the treatment trough of two kinds of versions, is respectively a kind of later-model arc slot structure and derotation whirlpool shallow slot structure.Press the difference of treatment trough version, this can be handled ring and upwards be divided into one or more excitation region in week, one or more buffer zones.Excitation region and buffer zone distribute alternately.Have the arc slot formula treatment trough more than three or three in the excitation region, and the cooresponding treatment trough number of the single rotor passage of air compressor is 3~8, has derotation whirlpool shallow-slot type treatment trough in the buffer zone.The circumferential lengths of excitation region should be greater than the blade tip pitch of a compressor rotor passage.The circumferential lengths of buffer zone also should be greater than the blade tip pitch of a compressor rotor passage.The pairing segment angle sum of all excitation region α is with respect to ratio cc/β=1/5~5 of the pairing segment angle sum of all buffer zones β.
The position of non-rotational symmetry combination processing machine box of the present invention in air compressor is above the compressor rotor blade tip, and relative in the axial direction blade has the front-extending quantity that is equivalent to rotator tip chord length 30%-70%.This processor box has been considered the non-stationarity of air compressor interior flow field in design process, especially designed the processing ring that has the treatment trough that non-rotational symmetry distributes at calm the anger non-axisymmetric flow field when rotating stall of axial flow.
From the non-permanent excitation frequency analysis of processor box to the air compressor flow field, can see that non-rotational symmetry processor box of the present invention is multifrequency to the excitation frequency in air compressor flow field, and traditional axially symmetric structure processor box is a single-frequency to the excitation frequency in air compressor flow field.Therefore, the processor box of the traditional relatively axially symmetric structure of non-rotational symmetry processor box of the present invention has the different non-permanent mechanism of action.
This structure can produce significantly non-permanent incentive action to the blade tip flow field of air compressor, make the flow field become more orderly, thereby can obtain the effect different with the conventional process casing, except the stability margin that can significantly improve air compressor, can also it improve adiabatic efficiency/adia.eff..
Description of drawings
Fig. 1 has the processor box scheme drawing of the axial chute structure of rotational symmetry distribution for representative type;
Fig. 2 has the processor box scheme drawing of the tangential flume structure of rotational symmetry distribution for representative type;
Fig. 3 has the processor box scheme drawing of the derotation whirlpool shallow slot structure of rotational symmetry distribution for representative type;
Fig. 4 is a kind of processor box scheme drawing with arc slot structure of rotational symmetry distribution;
Fig. 5 is the cutaway view of processing ring of the arc slot formula processor box of axially symmetric structure shown in Figure 4;
Fig. 6 is the axle cutaway view of the preferred embodiment of non-rotational symmetry combination processing machine box of the present invention;
Fig. 7 is the cutaway view (two rotor movable vanes of air compressor only are shown) of the vertical axial of the processing ring of the preferred embodiment of non-rotational symmetry combination processing machine box of the present invention;
Fig. 8 is the cutaway view (the rotor movable vane of not shown air compressor) of vertical axial of processing ring of second kind of embodiment of non-rotational symmetry combination processing machine box of the present invention;
Fig. 9 is the cutaway view (the rotor movable vane of not shown air compressor) of vertical axial of processing ring of the third embodiment of non-rotational symmetry combination processing machine box of the present invention;
Figure 10 is the excitation spectrum figure of the arc slot formula processor box of axially symmetric structure shown in Figure 5 to the air compressor flow field;
Figure 11 is the excitation spectrum figure of the preferred embodiment of the described non-rotational symmetry combination processing machine box of Fig. 7 of the present invention to the air compressor flow field.
The specific embodiment
Be clearer description the present invention, describe below in conjunction with several exemplary embodiments of accompanying drawing to non-rotational symmetry combination processing machine box of the present invention.
Fig. 6 is the axle cutaway view of the preferred embodiment of non-rotational symmetry combination processing machine box of the present invention.This non-rotational symmetry combination processing machine box is handled 1 and two roll adjustment ring 2 of ring by one and is formed.Handle ring 1 above compressor rotor blade 3, and the axial location of rotor blade 3 is 50% front-extending quantity of the blade tip position axial length that keeps being equivalent to rotor blade 3 relatively.
Those skilled in the art expect easily, in other embodiments, by adjusting the axial width of roll adjustment ring 2, the axial location of handling ring 1 can move forward or backward with respect to the described axial location of this embodiment, the roll adjustment ring 2 of handling the roll adjustment ring 2 in ring 1 the place ahead or rear can remove wherein any one, changes handling ring 1 front-extending quantity with respect to rotor blade 3 with this.
Handling on the ring 1, the zone that has arc slot formula treatment trough 6 can produce very strong incentive action to the flow field, blade tip district of air compressor, can make the flow field become more orderly, therefore be referred to as excitation region 4, and the zone that has derotation whirlpool shallow-slot type treatment trough 7 is very little to the incentive action in the flow field, blade tip district of air compressor, can produce buffering to the tip leakage stream of air compressor, therefore be referred to as buffer zone 5.
Fig. 7 is the cutaway view of vertical axial of processing ring 1 of the preferred embodiment of non-rotational symmetry combination processing machine box of the present invention.This handles ring 1 and is made up of two excitation region 4 and two buffer zones 5.The circumferential lengths of two excitation region 4 is the same, its pairing fan angle alpha
1And α
2Be 90 degree.Handle ring 1 and respectively have 9 arc slot formula treatment troughs 6 equally spacedly in two excitation region 4, the number of the pairing arc slot formula of the single rotor passage treatment trough 6 of air compressor is 3, and the version of this treatment trough as shown in Figure 4.The circumferential lengths of this excitation region 4 is greater than the blade tip pitch t of the folded passage of two rotor blades 3.Handle the treatment trough 7 that ring 1 inwall at two buffer zones 5 has derotation whirlpool shallow slot form, the version of treatment trough as shown in Figure 3, its pairing segment angle β
1And β
2Be respectively 118 degree and 72 degree.The ratio of described excitation region 4 of this embodiment and buffer zone 5 cooresponding segment angle sums is (α
1+ α
2)/(β
1+ β
2)=1.
Those skilled in the art can be appreciated that, be applied on the different air compressors, the number of the arc slot formula treatment trough 6 in the excitation region 4 of the foregoing description can change any numerical value greater than 2 according to the non-permanent feature in the flow field of different air compressors into, and arc slot formula treatment trough 6 upwards can be that non-equidistance distributes in week.
Fig. 8 is the cutaway view of vertical axial of processing ring of second kind of embodiment of non-rotational symmetry combination processing machine box of the present invention.This handles ring 1 and is made up of an excitation region 4 and a buffer zone 5.Excitation region 4 pairing fan angle alpha are 60 degree.Have 7 arc slot formula treatment troughs 6 in the excitation region 4 equally spacedly, the number of the pairing arc slot formula of the single rotor passage treatment trough 6 of air compressor is 7.The inwall of the processing ring 1 in buffer zone 5 scopes has the treatment trough 7 of derotation whirlpool shallow slot form, and its pairing segment angle β is 300 degree.The ratio of described excitation region 4 of this embodiment and buffer zone 5 cooresponding segment angles is α/β=1/5.
Those skilled in the art can be appreciated that, be applied on the different air compressors, the number of the arc slot formula treatment trough 6 in the excitation region 4 of the foregoing description can change any numerical value greater than 2 according to the non-permanent feature in the flow field of different air compressors into, and arc slot formula treatment trough 6 upwards can be that non-equidistance distributes in week.
Fig. 9 is the cutaway view of vertical axial of processing ring of the third embodiment of non-rotational symmetry combination processing machine box of the present invention.This handles ring 1 and is made up of three excitation region 4 and three buffer zones 5.Three excitation region 4 pairing fan angle alpha
1, α
2And α
3Be 100 degree.Have 10 arc slot formula treatment troughs 6 in the excitation region 4 equally spacedly, the number of the pairing arc slot formula of the single rotor passage treatment trough 6 of air compressor is 4.The inwall of the processing ring 1 in buffer zone 5 scopes has the treatment trough 7 of derotation whirlpool shallow slot form, its pairing segment angle β
1, α
2And β
3Be 20 degree.The ratio of described excitation region 4 of this embodiment and buffer zone 5 cooresponding segment angle sums is (α
1+ α
2+ α
3)/(β
1+ β
2+ β
3)=5.
Those skilled in the art can be appreciated that, be applied on the different air compressors, the number of the arc slot formula treatment trough 6 in the excitation region 4 of the foregoing description can change any numerical value greater than 2 according to the non-permanent feature in the flow field of different air compressors into, and arc slot formula treatment trough 6 upwards can be that non-equidistance distributes in week.
Summing up the non-rotational symmetry combination processing machine box of above-mentioned three kinds of exemplary embodiments can find, non-rotational symmetry combination processing machine box of the present invention is with respect to traditional processor box, and topmost being characterised in that handled the treatment trough that encircles the different structure form that has non-rotational symmetry distribution.
And can see from the angle of excitation spectrum analysis, on Figure 10, show, the arc slot formula processor box of axially symmetric structure is a single-frequency to the non-permanent excitation frequency in air compressor flow field, and this mono-excitation frequency determines by handling the treatment trough that makes progress in ring week rotating speed total and compressor rotor.And the described non-rotational symmetry combination processing machine box of the shown present embodiment of Figure 11 is several values of multi-frequency to the non-permanent excitation frequency in air compressor flow field, except by handling ring week upwards the high-frequency excitation of the number decision of treatment trough, the low frequency incentive action that checker brought when also comprising relative rotor rotation between buffer zone and the excitation region.The difference of the excitation spectrum of these two kinds of relative air compressors of processor box has reflected that the two is different for the non-permanent mechanism of action in air compressor flow field.Therefore, the two action effect for air compressor also is different: the cost that the arc slot formula processor box of axially symmetric structure increases substantially the stability margin of air compressor is a loss air compressor adiabatic efficiency/adia.eff. about 1%, and non-rotational symmetry combination processing machine box of the present invention can improve its adiabatic efficiency/adia.eff. when increasing substantially the stability margin of air compressor.