JP2009236121A - Diffuser for diagonal flow compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the performance of a diagonal flow compressor using a diffuser by blowing a flow along a main flow (blade) into a separation region to reduce the separation region without generating disturbance in the flow. <P>SOLUTION: The diffuser 1 for a wind powered machine is mounted on a rotor of the diagonal flow compressor, and comprises a first blade 2 located on the upstream side with reference to the flowing direction of fluid, and a second blade 3 located on the downstream side. The downstream end of the first blade 2 is located on the downstream side of the upstream end of the second blade 3, and a narrow flow path S is formed between the first blade 2 and the second blade 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a diffuser for a mixed flow compressor.

  A diffuser is provided with blades in a fluid flow channel, and the flow is guided along an arbitrary bending direction by bending the blades and flowing the flow along the blades, or compared with an inlet channel formed by a plurality of blades. Used to slow down the flow by enlarging the path. In addition, the diffuser is provided on the outer periphery of a fluid introduction path, a discharge path, or a rotating rotor or an impeller facing the flow path of a wind machine such as a compressor, a pump, a gas blower, etc., to improve wind performance. . Further, in a diffuser in which the inflow velocity distribution is transonic and a three-dimensional flow distortion is large, such as a mixed flow compressor, when a diffuser vane is arranged, a local cross section having a large vane (blade) load due to the flow distortion. As a result, the boundary layer was enlarged and a low speed region or a separation region was formed on the downstream side. This increased pressure loss, which was a cause of reduced compressor performance and surge margin.

  In the case of a conventional diffuser when exposed to a fluid flow, a flow separation region (a region where the fluid flow is turbulent and a loss is large) inevitably occurs at the rear end of the blade, resulting in performance degradation. In order to reduce this peeling area, a diffuser shown in FIG. 14 has been proposed. This diffuser is provided with a first blade 20 on the upstream side of the air flow A and a second blade 30 on the downstream side, and the first blade 20 and the second blade A gap is provided between the blades 30. This diffuser has a certain effect by blowing the fluid flow B2 at a certain angle into the separation zone C1 in order to reduce the separation zone C1 generated at the rear end of the first blade 20. On the other hand, since the flow B2 having a high speed is blown into the peeling area C1 having a low speed, there is a problem that the disturbance is promoted. Further, since the flow B2 flows at a certain angle rather than parallel to the main air flow A, the flow is disturbed and a new separation region C2 is generated in the second blade 30 on the downstream side. (See Patent Document 1). In addition, there is a type in which the circumferential overlap between the front and rear blades of the diffuser of the centrifugal blower is 9% of the blade pitch angle (2Π / number of blades) (see Non-Patent Document 1).

JP-A-6-241197 Transactions of the Japan Society of Mechanical Engineers (B) 49, 439, published in March 1983

  In view of the above-mentioned conventional problems, the present invention blows a flow along the main flow (blade) to the location where the separation area is generated, so that the flow is not disturbed, the separation area is reduced, and a wind machine using a diffuser It is proposed to improve the performance of the mixed flow compressor.

  In order to solve the above problems, the present invention employs the following means (1) to (15).

  (1) The diffuser of the mixed flow compressor according to the first means is a diffuser attached to a rotor of the mixed flow compressor, and the diffuser is located on the upstream side with respect to the flow direction of the fluid. And a second blade located on the downstream side, the second blade extending to the first blade, and between the first blade and the second blade A narrow flow path is formed. According to this means, a part of the main flow flows in substantially the same direction along the main flow (blade) at a flow velocity decelerated from the narrow flow path of the upstream and downstream blades.

  (2) The diffuser of the mixed flow compressor according to the second means is a diffuser attached to the rotor of the mixed flow compressor, and the diffuser is located on the upstream side with respect to the direction in which the fluid flows. And a second blade located on the downstream side, wherein the downstream end of the first blade is located downstream of the upstream end of the second blade, and the first blade A narrow flow path is formed between the second blades. According to this means, a part of the main flow flows in substantially the same direction along the main flow (blade) at a flow velocity decelerated from the narrow flow path constituted by the upstream and downstream blades.

  (3) The diffuser of the mixed flow compressor according to the third means is the diffuser of the mixed flow compressor described in (1) or (2) above, wherein the narrow flow path is a downstream side root of the first blade. It is formed by a part of the end or the upstream end of the second blade.

  (4) The diffuser of the mixed flow compressor according to the fourth means is the diffuser of the mixed flow compressor described in the above (1) or (2), wherein the second flow from the outer peripheral end of the first blade. The distance to the end on the outer peripheral side of the blade is longer than the distance from the root-side end of the first blade to the root-side end of the second blade. The root side is the rotor side on which the blades are attached, and the outer peripheral side is the outer peripheral direction side of the rotor, which is the opposite direction.

  (5) The diffuser of the mixed flow compressor according to the fifth means is the diffuser of the mixed flow compressor described in the above (1) or (2), and a high pressure surface side at a downstream end of the first blade. The second blade is provided so as to face the low pressure surface at the upstream end.

  (6) The diffuser of the mixed flow compressor according to the sixth means is the diffuser of the mixed flow compressor according to any one of (1) to (5), wherein the first blade or the second blade is used. However, it is extended over the largest diameter part of a mixed flow compressor, It is characterized by the above-mentioned. There is a phenomenon in which the largest diameter portion has the smallest curvature and separation starts therefrom, and it is effective to provide upstream and downstream blades across the position.

  (7) A diffuser of a mixed flow compressor according to a seventh means is the diffuser of the mixed flow compressor according to any one of (1) to (6), wherein the narrow flow path is a cross flow compressor. It is located in the maximum diameter part. There is a phenomenon in which the largest diameter portion has the smallest curvature and separation starts therefrom, and it is effective to provide a narrow flow path at that position.

  (8) The diffuser of the mixed flow compressor according to the eighth means is the diffuser of the mixed flow compressor according to any one of (1) to (7), wherein the length of the narrow flow path in the fluid flow direction is the same. The cord length of the first blade is 1% or more and 50% or less. If the narrow flow path is too long, the distance that the flow comes into contact with the blades becomes long, which increases the frictional resistance, which is not preferable. On the other hand, if the narrow flow path is too short, the distance over which the flow can be controlled is shortened, so that the flow deceleration effect cannot be obtained, which is not preferable. The blade cord length is the length of the blade in the fluid flow direction.

  (9) The diffuser of the mixed flow compressor according to the ninth means is the diffuser of the mixed flow compressor according to any one of (1) to (8), wherein the gap in the narrow flow path is set to the first flow passage. The gap between the blades is 5% or more and 50% or less. If it is 50% or more, the gap is too small, the amount of air entering the adjacent passage is reduced, and the intended effect of guiding air with less flow to the adjacent passage cannot be obtained.

  (10) The diffuser of the mixed flow compressor according to the tenth means is the junction surface in the direction in which the rotor crosses the narrow flow path in the diffuser of the mixed flow compressor described in (1) or (2). The end portion of at least one of the first and second blades extends from the joint surface of the rotor so as to protrude in the fluid flow direction.

  (11) The diffuser of the mixed flow compressor according to the eleventh means is a diffuser attached to the rotor of the mixed flow compressor, and the diffuser is located on the upstream side with respect to the direction in which the fluid flows. Between the downstream end of the first blade and the upstream end of the second blade, the first and second blades And a vane provided on the low pressure surface side.

  (12) The diffuser of the mixed flow compressor according to the twelfth means is the diffuser of the mixed flow compressor described in (1) or (2), wherein the upstream blades and / or the downstream blades are provided. The angle with respect to the flow is variable. Since the upstream side has a higher flow velocity than the downstream side, if the upstream blades can be made variable compared to the downstream side, the response is accelerated.

  (13) A mixed flow compressor according to a thirteenth means includes a rotor that is rotationally driven in a casing, first upstream blades that are erected at regular intervals in the outer circumferential direction of the rotor, And a second compressor provided on the downstream side of the first blade, wherein the downstream end of the first blade is located downstream of the upstream end of the second blade, A narrow flow path is formed between the first blade and the second blade. According to this means, a part of the main flow flows from the narrow channel at a decelerated flow velocity along the main flow (blade) in substantially the same direction, and is generated on the downstream end side of the first blade. The peeling area to be reduced can be reduced.

  (14) A jet engine according to a fourteenth means includes a cylindrical casing, a turbine stored in the casing and driven to rotate by an expansion gas, and a mixed flow compressor. A jet engine to which a rotor of a flow compressor is connected, and is provided on the downstream side of the first blade and the upstream first blade that is erected at regular intervals in the outer circumferential direction of the rotor And a downstream end of the first blade is located downstream of an upstream end of the second blade, and the first blade and the second blade A narrow flow path is formed between the blades. Since the mixed flow compressor of this means has a high rectification effect and high compression efficiency, the size of the jet engine can be reduced.

  (15) In the mixed flow compressor rotor manufacturing method according to the fifteenth aspect, a plurality of upstream-side blades that guide the flow are provided around the outer periphery of the mixed flow compressor at intervals in the circumferential direction. In a manufacturing method of a mixed flow compressor rotor having a diffuser in which a rear end portion and a front end portion of a blade on the downstream side overlap to form a narrow flow path, a joining surface is provided at a position crossing the flow path The upstream or downstream blades and their end portions are extended from the joint surface on the outer periphery of the plurality of divided rotors and integrally cut and molded, and the plurality of divided rotors are connected to each other at the joint surfaces. Thus, a mixed flow compressor rotor is manufactured.

  The diffuser of the mixed flow compressor according to claim 1, comprising the first means, is a diffuser attached to a rotor of the mixed flow compressor, and the diffuser is positioned upstream with respect to a direction in which the fluid flows. And a second blade located on the downstream side, the second blade extending to the first blade, the first blade and the second blade Since a narrow flow path is formed between the two, a part of the main flow of the fluid becomes a slower flow than the narrow flow path of the upstream and downstream blades and flows in almost equal to the main flow, Turbulence does not occur, the separation zone is reduced, and the performance of the mixed flow compressor is improved.

  The diffuser of the mixed flow compressor according to claim 2, comprising the second means, is a diffuser attached to a rotor of the mixed flow compressor, and the diffuser is positioned on the upstream side with respect to the direction in which the fluid flows. And a second blade located on the downstream side, wherein a downstream end of the first blade is located downstream of an upstream end of the second blade, and the first blade Since a narrow flow path is formed between one blade and the second blade, a part of the main flow of the fluid is slower than the narrow flow path formed by the upstream and downstream blades. Thus, the turbulent flow does not occur by flowing at a speed substantially equal to that of the main flow, the separation zone is reduced, and the performance of the mixed flow compressor is improved.

  The diffuser of the mixed flow compressor according to claim 3, wherein the diffuser of the mixed flow compressor according to claim 1 or 2 is a downstream of the first blade. Since it is formed by the side root end portion or a part of the upstream root end portion of the second blade, the flow is locally narrowed in a part of the narrow flow path, and local disturbance is caused. There is a flow prevention effect.

  The diffuser of the mixed flow compressor according to claim 4, which comprises the fourth means, is the diffuser of the mixed flow compressor according to claim 1 or 2, wherein the diffuser of the mixed flow compressor according to claim 1 or 2 extends from an outer peripheral end of the first blade. The distance to the end on the outer peripheral side of the second blade is longer than the distance from the root-side end of the first blade to the root-side end of the second blade. In the case of a mixed flow compressor, there is a phenomenon in which the flow distribution is not uniform in the direction of the outer periphery of the rotor of the blade, and the boundary layer is thicker on the base side (base end side), so a low speed region is more likely to develop. There is a situation. Therefore, if the interval between the blades is reduced, the flow velocity in the span direction of the narrow flow path formed by the upstream and downstream blades is averaged, and the difference in velocity from the low speed region is sufficient. The flow straightening effect can be improved by blowing closer and through the narrow flow path, and the performance of the mixed flow compressor is improved.

  The diffuser for a mixed flow compressor according to claim 5, comprising the fifth means, wherein the downstream end of the first blade is the diffuser for the mixed flow compressor according to claim 1. The high pressure surface side of the second blade and the low pressure surface side of the upstream end of the second blade are provided so as to face each other. Can be reduced.

  The diffuser of the mixed flow compressor according to claim 6, comprising the sixth means, wherein the first blade or the second diffuser of the mixed flow compressor according to any one of the above claims 1 to 5. Since the second blade extends across the maximum diameter portion of the mixed flow compressor, the effect of preventing the occurrence of turbulent flow and the effect of reducing the separation region are increased.

  The diffuser of a mixed flow compressor according to claim 7 comprising the seventh means, the diffuser of the mixed flow compressor according to any one of claims 1 to 6, wherein the narrow flow path is mixed flow. Since it is located at the maximum diameter portion of the compressor, the effect of preventing the occurrence of turbulent flow and the effect of reducing the separation zone are maximized.

  The diffuser of a mixed flow compressor according to claim 8 comprising the eighth means, wherein the diffuser of the mixed flow compressor according to any one of claims 1 to 7 is a fluid flow direction of the narrow channel. Since the length is not less than 1% and not more than 50% with respect to the cord length of the first blade, the above-described effect can be achieved and the rectifying function of the downstream second blade can be impaired. As a result, the flow from the narrow flow path flows in a direction substantially equal to the main flow, so that no turbulent flow is generated, the separation zone is reduced, and the performance of the mixed flow compressor is improved.

  The diffuser for a mixed flow compressor according to claim 9, comprising the ninth means, in the diffuser for a mixed flow compressor according to any one of the above claims 1 to 8, Since the gap between the first blades is 5% or more and 50% or less, the above-described effects are achieved, and the flow straightening function of the downstream blades is not impaired. As a result, the turbulent flow is not generated, the separation zone is reduced, and the performance of the mixed flow compressor is improved.

  The diffuser of the mixed flow compressor according to claim 10, which comprises tenth means, is the diffuser of the mixed flow compressor according to claim 1 or 2, wherein the rotor crosses the narrow flow path. Since the end of at least one of the first and second blades extends in the direction of fluid flow from the joint surface of the rotor, If the joint surfaces of the rotor are matched, a narrow passage for the blades can be formed. In particular, when the gap between the narrow channels is narrow, an effect that can be easily formed is great.

  The diffuser of the mixed flow compressor according to claim 11, comprising the eleventh means, is a diffuser attached to a rotor of the mixed flow compressor, and the diffuser is positioned on the upstream side with respect to the direction in which the fluid flows. Between the first blade and the second blade located on the downstream side, the downstream end of the first blade and the upstream end of the second blade, Since the vane is provided on the low pressure surface side of the two blades, the vane suppresses the flow rate from the gap between the first blade on the upstream side and the second blade on the downstream side, and the first blade and There is an effect of reducing the separation area generated in the second blade.

  The diffuser of the mixed flow compressor according to claim 12, comprising the twelfth means, the diffuser of the mixed flow compressor according to claim 1 or 2, wherein the upstream blades and / or the downstream side. Since the angle of the blades can be changed with respect to the flow, the width of the narrow flow passage can be increased or decreased by adjusting the blade angle according to the operating state, that is, when the flow pressure increases The flow path width is narrowed, and the flow path width is adjusted to increase when the flow pressure decreases.

  The mixed flow compressor according to claim 13, which comprises thirteenth means, includes a rotor that is rotationally driven in the casing, and first upstream blades that are erected at regular intervals in the outer circumferential direction of the rotor. A mixed flow compressor having a second blade provided downstream of the first blade, wherein the downstream end of the first blade is downstream of the upstream end of the second blade. Since a narrow flow path is formed between the first blade and the second blade, a part of the main flow is decelerated from the narrow flow channel along the main flow (blade). Therefore, the separation zone generated on the downstream end side of the first blade can be reduced, the rectifying effect and the compression efficiency of the mixed flow compressor can be improved, and the mixed flow compression is achieved. Miniaturization of the machine can be achieved.

  15. The jet engine according to claim 14, comprising fourteenth means, comprising a cylindrical casing, a turbine stored in the casing and driven to rotate by an expansion gas, and a mixed flow compressor. Engine and a rotor of the mixed flow compressor, wherein the first blades on the upstream side standing at regular intervals in the outer circumferential direction of the rotor, and the downstream of the first blades A diffuser comprising a second blade provided on the side, wherein the downstream end of the first blade is located downstream of the upstream end of the second blade, and the first blade and the Since the narrow flow path is formed between the second blades, the mixed flow compressor can be reduced in size, and the front area of the jet engine, the engine length can be reduced, and the weight can be reduced.

  16. The mixed flow compressor rotor manufacturing method according to claim 15, comprising a fifteenth means, wherein a plurality of circumferentially spaced outer rotor rotors of the mixed flow compressor are provided in the circumferential direction to guide the flow. In a method of manufacturing a mixed flow compressor rotor having a diffuser in which a rear end portion of a blade and a front end portion of a downstream blade overlap to form a narrow flow path, the rotor blade is joined at a position crossing the flow path. The upstream or downstream blades and their ends are extended from the joint surface and integrally molded around the outer periphery of the plurality of split rotors having surfaces, and the plurality of split rotors are joined together. Since the mixed flow compressor rotor is manufactured by connecting the surfaces, the narrow flow path constituted by the upstream and downstream blades can be easily manufactured at once. Regardless of this method, when it is intended to form a narrow channel integrally from the beginning without dividing the rotor as in the prior art, it is very difficult to cut the narrow channel.

FIG. 1 is a plan view of a diffuser according to a first embodiment of the present invention. FIG. 2 is a plan view for explaining the overlapping length of the blades of the diffuser according to the first embodiment of the present invention. FIG. 3 is an explanatory view illustrating the distance between the diffuser blades according to the first embodiment of the present invention. FIG. 4 is a perspective view of the mixed flow compressor rotor according to the first embodiment of the present invention. FIG. 5 is a cross-sectional view of the diffuser according to the first embodiment of the present invention. FIG. 6 is a perspective view for explaining a state before the joining portion of FIG. 5 is connected. FIG. 7 is a front view showing a diagonal flow path of the mixed flow compressor according to the first embodiment of the present invention. FIG. 8 is a front view for explaining the overlapping portion of the diffuser blades according to the second embodiment of the present invention. FIG. 9 is a perspective view of a diffuser according to a third embodiment of the present invention. FIG. 10 is a plan view of a diffuser according to a fourth embodiment of the present invention. FIG. 11 is a plan view of a diffuser according to a fifth embodiment of the present invention. FIG. 12 is an explanatory diagram of a jet engine according to Embodiment 6 of the present invention. FIG. 13 is an external view when a jet engine according to Embodiment 6 of the present invention is mounted on a jet aircraft. FIG. 14 is a plan view showing a conventional diffuser.

  The best mode for carrying out the present invention will be described based on Examples 1, 2, 3, 4, 5, and 6 shown in FIGS. 1 is a plan view of the diffuser on the outer periphery of the mixed flow compressor rotor, FIG. 2 is a plan view for explaining the overlapping length of the diffuser blades, FIG. 3 is an explanatory diagram for explaining the distance between the diffuser blades, and FIG. FIG. 5 is a cross-sectional view of a mixed flow compressor diffuser, FIG. 6 is a perspective view illustrating a state before connection of the joint portion in FIG. 5, and FIG. 7 is a cross flow diagram of the mixed flow compressor. It is a front view. 8 is a front view for explaining a blade overlapping portion of the second embodiment, FIG. 9 is a perspective view of the diffuser of the third embodiment, FIG. 10 is a plan view of the diffuser of the fourth embodiment, and FIG. 11 is a diffuser of the fifth embodiment. FIG. FIG. 12 is an explanatory diagram of a jet engine according to the sixth embodiment, and FIG. 13 is an external view of a jet aircraft equipped with the jet engine according to the sixth embodiment.

  FIG. 1 is a plan view showing a part of a diffuser provided on the entire outer periphery of a mixed flow compressor rotor. In the figure, reference numeral 2 denotes a first blade (vane) that is arranged in parallel on the outer periphery of the rotor of the mixed flow compressor at a predetermined interval and is located on the upstream side with respect to the flowing direction of the fluid (air). Similarly, reference numeral 3 denotes a second blade (vane) which is arranged in parallel at regular intervals and is located on the downstream side of the first blade 2. 2a is a low pressure surface (convex surface) of the first blade 2; 2b is a high pressure surface (concave surface) of the first blade 2; 3a is a low pressure surface (convex surface) of the second blade 3; The high pressure surface (concave surface) of the blade 3, the arrow A indicates the air flow (main flow) direction, the arrow F indicates the rotation axis direction of the rotor, and the arrow G indicates the rotation direction of the rotor. A narrow flow path S is formed by the overlapping portion D arranged in parallel so that the front end portion of the second blade 3 overlaps the rear end portion of the first blade 2. Further, the first blade 2 is provided on the high pressure surface 2b side so that the low pressure surface 3a side of the second blade 3 faces.

  Thus, when the air flow A flows into the diffuser 1, a part of the flow A becomes the flow B from the narrow flow path S of the overlapping portion D and flows along the low pressure surface 3 a of the second blade 3. It will be. Since the flow B passes through the narrow flow path S of the overlapping portion D, the velocity thereof decreases, and the flow B flows downstream at an angle substantially equal to that of the flow A (main flow), and the separation zone C has a minimum size. And no turbulence occurs. That is, since the flow speed flowing along the high pressure surface 2b side of the first blade 2 is faster than the flow speed flowing along the low pressure surface 2a side, the flow speed is reduced by passing through the narrow flow path S. As a result, the flow speed of the flow B is made substantially the same as the flow speed on the low pressure surface 2a side, and the separation area C is decreased by discharging the flow B to the separation area generation location. Further, by causing a part of the flow A to pass through the narrow flow path S and ejecting it as the flow B at a direction angle substantially equal to that of the flow A, generation of turbulent flow is prevented. The flow speed is mainly determined by the gap dimension of the narrow flow path S, and the flow direction angle can be determined mainly by the flow path length dimension of the narrow flow path S. By appropriately setting the discharge flow speed and the discharge direction angle of the flow B, it is possible to reduce the separation area C and prevent the generation of turbulent flow due to the discharge of the flow B to the separation area C. The setting value is described below.

  As shown in FIG. 2, the length in the fluid flow direction (length of the overlapping portion D) L1 of the narrow flow path S1 between the first blade 2 on the upstream side and the second blade 3 on the downstream side is the upstream side. The cord length L of the first blade 2 may be 1% to 50%. If the length is the same range, the flow discharged from the narrow flow path S formed by the first blade 2 and the second blade 3 without impairing the rectifying function of the second blade 3 on the downstream side, By flowing in almost the same direction as the main flow, no turbulent flow is generated, the separation zone is reduced, and the performance of the mixed flow compressor is improved. In addition, when the length of the narrow flow path S is too large, the distance that the flow comes into contact with the blades becomes long. On the other hand, if the length of the narrow flow path S is too small, the distance that can control the flow becomes short, so the effect of the narrow flow path S cannot be obtained, which is not preferable. If the length L1 of the narrow flow path S is 5% or more and 30% or less with respect to the cord length L of the first blade 2 on the upstream side, more preferable results can be obtained with respect to the above-described effects. Further, when the length L1 of the narrow flow path S is set to 5% or more and 15% or less with respect to the cord length L of the first blade 2 on the upstream side, more preferable results can be obtained with respect to the above-described effects.

  As shown in FIG. 3, the gap P <b> 1 of the narrow flow path S (overlapping portion D) between the first blade 2 on the upstream side and the second blade 3 on the downstream side is different from that on the first blade 2 on the upstream side. If the distance P is set to 5% or more and 50% or less with respect to the interval P with respect to 21, the flow velocity flowing out from the gap becomes appropriate, and the occurrence of turbulence can be prevented. Further, if the gap P1 is set to a gap within 5% to 30% of the gap P, the flow speed flowing out of the gap becomes more appropriate, and the occurrence of turbulence can be prevented. Further, if the gap P1 is a gap between 5% and 20% of the gap P, the flow speed flowing out of the gap becomes the most appropriate, and the generation of turbulence can be further prevented. If the gap is narrower than the lower limit, the amount of air entering the adjacent flow path is too small, and it is difficult to obtain the intended effect of guiding less disturbed air to the adjacent flow path. Conversely, if the gap is made wider than the upper limit, the flow of air entering the adjacent flow path is disturbed, and it is difficult to obtain a predetermined effect. In FIG. 3, for the sake of convenience, the thicknesses of the first blade 2, the second blade 3, and the adjacent first blade 21 are illustrated and described for explaining the gap P <b> 1 and the interval P. However, for example, the blade thickness of a mixed flow compressor or a gas compressor for aircraft use is 1 mm or less, and in the case of the same use, it does not look as shown in the figure.

  Further, as shown in FIGS. 4 to 6, the rotor of the mixed flow compressor is a direction crossing the narrow flow path S formed by the overlapping portion D having the length L1, and is a straight line perpendicular to the rotor axis. The first blade 2 on the upstream side is integrated with one rotor 4 and the second blade 3 on the downstream side is integrated with the other rotor 5 by machining. It is machined and molded. Further, the rear end portion of the first blade 2 is extended from the joint surface T of the rotor 4 so as to project the E dimension length, and the tip portion of the second blade 3 is similarly E dimension length from the joint surface T of the rotor 5. It protrudes and extends. According to this structure, if the joint surfaces T of the rotors 4 and 5 are made to coincide with each other and connected by a bolt structure or welding, the narrow flow path S (overlapping portion D) of the first blades 2 and 3 is provided. A rotor with a diffuser can be easily manufactured at once. In particular, when the gap of the narrow flow path S is set to be small, there are many cases where the cutting tool does not enter the gap and the machining cannot be performed. However, in this embodiment, the narrow flow path (S) can be easily formed. There is.

  The joining surface T is a zigzag joining surface along the rear edge of the first blade 2 and the front edge of the second blade 3 from a position along the gap of the narrow flow path S formed by the overlapping portion D. T can be considered, but in the present embodiment, since it is in a straight line, the first blade 2 and the second blade 2 are connected by connecting the rotors 4 and 5 and rotating one of the rotors along the joint surface T. The gap between the blades 3 can be easily adjusted. In the present embodiment, the E dimension lengths of the upstream side and the downstream side are the same, but they may be different from each other. Further, the blades (2) may be provided only from one rotor (4 or 5) side. Alternatively, 3) may be extended, and even in that case, the narrow flow path S can be formed.

  Moreover, the length dimension L1 of the narrow flow path S (overlapping portion D) with respect to the cord length L of the first blade 2 on the upstream side shown in FIG. 5 may be half or less. Further, the ratio of the cord length of the first blade 2 on the upstream side and the cord length of the second blade 3 on the downstream side may be about 3 to 7 or 4 to 6. By shortening the upstream first blade 2 in such a manner, it is possible to reduce the generation range of the separation area on the low pressure surface 2a side of the rear end portion of the upstream first blade 2, , When viewed from the direction perpendicular to the rotor axis, the second blade 3 is overlapped to the downstream end of the first blade 2 so as to close the space between the first blade 2 and the second blade 3. By extending the upstream end portion adjacent to each other, the peeling area can be further reduced.

  FIG. 7 illustrates the first blade 2 and the second blade 3 provided on the outer periphery of the rotor facing the oblique flow path H of the mixed flow compressor. The second blade 3 on the downstream side extends across the maximum diameter portion R of the rotor. Further, a narrow flow path formed by the overlapping portion D of the first blade 2 and the second blade 3 on the upstream side and the downstream side is provided so as to be located at the maximum diameter portion R of the rotor, The effect of preventing flow generation and the effect of reducing the separation area are maximized.

  In this embodiment, the overlapping portion is formed over the entire length in the outer circumferential direction (rotor outer circumferential direction) of the blades 2 and 3 in the first embodiment, but only a part thereof is used as the overlapping portion D. The diffuser of the mixed flow compressor shown in FIG. 8 has a shape in which the leading edge of the second blade 3 on the downstream side is inclined in the downstream direction (flow A direction), and the overlapping portion D is located on the upstream side. By arranging the root portion (base end portion) of the first blade 2 and the second blade 3 on the downstream side in the length L1 dimension in a superimposed state, only the root portions of the blades 2 and 3 are arranged. A narrow flow path is formed. According to the present embodiment, in the narrow flow path formed by a part of the overlapping portions D, the flow of the root portions of the blades 2 and 3 is narrowed, and there is an effect of preventing local turbulence. Contrary to the above, only a part of the downstream end portion of the first blade 2 on the upstream side may be extended in the downstream direction, and only a part thereof may be overlapped. In addition, when it is necessary to provide a narrow flow path only on the outer peripheral direction side of the blades 2 and 3, the above inclination is reversed, that is, for example, the outer peripheral side of the upstream end portion of the second blade 3 on the downstream side. It is sufficient to extend only in the upstream direction and to provide a narrow channel only on the outer peripheral side of the blades 2 and 3.

  This embodiment is the same as that of the first embodiment, and further adopts the configuration shown in FIG. 9. The diffuser of the mixed flow compressor shown in FIG. Or, since the situation of the flow A is different depending on the position up to M), it is adapted to the situation. That is, in the case of a mixed flow compressor, there is a phenomenon in which the flow distribution is not uniform on the outer peripheral side M of the first blade 2 and the second blade 3 provided in the rotor, and the root side (base end side) is Since the boundary layer is thicker, the low speed region is more likely to develop. Therefore, the second blade 3 on the downstream side is inclined with respect to the first blade 2 on the upstream side in the circumferential direction of the rotor so that the interval J on the outer peripheral side M is larger than the interval K on the root side. It is provided. In this way, the flow speed on the outer peripheral side M of the narrow flow path formed by the first blade 2 and the second blade 3 is averaged, and the difference in speed from the low speed region is sufficiently close. Then, the flow straightening effect of the flow A <b> 1 is increased by blowing into the low pressure surface side of the second blade 3. Further, depending on the device to which the diffuser is applied, there may be a situation opposite to the above, in which case the second blade 3 may be tilted in the opposite direction.

  In this embodiment, the configuration shown in FIG. 10 is further adopted in the embodiment 1, and the diffuser of the mixed flow compressor shown in FIG. 10 includes the first blade 2 on the upstream side and the second blade on the downstream side. The blade 3 can change the angle with respect to the flow in the directions of the arrows 2d and 3d around the rotation axes 2c and 3c. The supply of the high-energy fluid from the narrow flow path (S) formed by the first blade 2 and the second blade 3 is variably adjusted according to the operating condition of the engine. For example, when the flow pressure becomes high, the clearance is narrowed to reduce the speed, and conversely, when the flow pressure becomes low, the speed increase is adjusted so that the clearance becomes wide. What is necessary is just to vary according to the operating conditions (pressure and number of rotations) of the upstream turbine and engine, etc. When the engine is low in output, it is only necessary to overlap the blades (narrow the gap). The operating state may be detected by a pressure or rotation sensor provided in the upstream flow path of the first blade 2, and the blade angle may be controlled based on the sensor signal. In addition, since the flow speed on the upstream side is faster than that on the downstream side, the first blade 2 on the upstream side may be variably adjusted for quick control with a slight movement. Further, only the upstream or downstream blades may be varied. The means for changing the blades may use a known technique such as a variable impeller pump, and the description thereof is omitted.

  The diffuser of the mixed flow compressor shown in FIG. 11 is provided with a plurality of first blades on the upstream side for guiding the flow A provided around the outer periphery of the rotor of the mixed flow channel of the mixed flow compressor at intervals in the circumferential direction. 2 and the downstream blade 41, and a gap S1 is provided between the first blade 2 and the second blade 41 as in the prior art. The narrow flow path S is formed between the low pressure surfaces 2a and 4a of the first blade 2 and the second blade 41 between the clearance S1 from the downstream end of the blade 2 to the upstream end of the second blade 41. A vane (blade) 51 is additionally provided so as to form a circle. Reference numeral 5a denotes a low pressure surface of the vane 51, F denotes a rotor axial direction, and G denotes a rotation direction of the rotor. The thing of this Example suppresses the high energy fluid B1 from the clearance gap S1 between the 1st blade | wing 2 and the blade | wing 41 with the vane 51, and the low pressure surface 2a of the 1st blade | wing 2 and the blade | wing 41, The peeled area generated on the 4a side is reduced.

  FIG. 12 is a diagram illustrating an example in which the mixed flow compressor having the mixed flow compressor rotor of the first embodiment is applied to a jet engine, and FIG. 13 is an external view showing a case where the jet engine N of FIG. is there. The mixed flow compressor 10 includes a first blade 2 of the diffuser, a second blade 3 of the diffuser, a rotor 6, an impeller blade 7, an air intake port 8, and a cylindrical casing 9. On the downstream outer periphery of the impeller blades 7, a first blade 2 and a second blade 3 are erected at regular intervals to constitute a diffuser. In the drawing, for convenience, the rotor 6 is shown in a cross section, and only a part of the diffuser is shown. The downstream end of the first blade 2 is located downstream of the upstream end of the second blade 3, and a narrow flow path (S) is formed between the first blade 2 and the second blade 3. The configuration is the same as that of the first embodiment. The rotor 6 of the mixed flow compressor 10 is connected to the turbine 12 by a connecting shaft 11, and the mixed flow compressor 10 is rotated by rotating the turbine 12 using the expansion force of the gas generated in the combustor 14. To compress the air. The combustion gas after passing through the turbine 12 is accelerated by the exhaust duct 13 to generate a thrust by ejecting a jet. In the figure, 15 is a fuel pipe, 16 is a fuel injection hole, 17 is a bearing, 18 is a gas duct, and 19 is an air flow path. The present embodiment uses the mixed flow compressor of the first embodiment which has high compression efficiency and can reduce the axial length and the outer diameter, so that the front area of the jet engine and the engine length can be reduced. , Has a weight reduction effect.

  Each of the above embodiments has been described using a diffuser for mixed flow compressors as an example. However, the present invention can also be applied to a diffuser of a wind machine such as a centrifugal or axial compressor, a pump, a blower, or a general-purpose diffuser. . In addition, since the compressor to which the present invention is applied has a high compression efficiency η, a compressor having the same performance can be designed in a small size, the weight can be reduced as well as the cross-sectional area can be reduced, and it is particularly suitable for an aero engine. .

  The present invention is not limited to the above-described embodiments, and can be appropriately modified as necessary. In addition, each component in the embodiment includes those that can be easily assumed by those skilled in the art and those that are substantially the same.

1 Diffuser 2 First blade 3 Second blade S Narrow flow path

Claims (15)

  A diffuser attached to a rotor of a mixed flow compressor, the diffuser including a first blade located on the upstream side and a second blade located on the downstream side with respect to the direction of fluid flow The mixed flow compressor is characterized in that the second blade extends to the first blade, and a narrow flow path is formed between the first blade and the second blade. Diffuser.   A diffuser attached to a rotor of a mixed flow compressor, the diffuser including a first blade located on the upstream side and a second blade located on the downstream side with respect to the direction of fluid flow The downstream end of the first blade is located downstream of the upstream end of the second blade, and a narrow flow path is formed between the first blade and the second blade. This is a mixed flow compressor diffuser.   The narrow channel is formed by a part of a downstream root end of the first blade or a part of an upstream root end of the second blade. Diffuser for mixed flow compressor.   The distance from the outer peripheral end of the first blade to the outer peripheral end of the second blade is the distance from the root end of the first blade to the root end of the second blade The diffuser of the mixed flow compressor according to claim 1 or 2, wherein the diffuser is longer.   The high pressure surface side at the downstream end of the first blade and the low pressure surface side at the upstream end of the second blade are provided so as to face each other. The diffuser of the mixed flow compressor in any one of 4.   The mixed flow compression according to any one of claims 1 to 5, wherein the first blade or the second blade extends across a maximum diameter portion of the mixed flow compressor. Machine diffuser.   The diffuser of a mixed flow compressor according to any one of claims 1 to 6, wherein the narrow flow path is located at a maximum diameter portion of the mixed flow compressor.   The fluid flow direction length of the narrow channel is 1% or more and 50% or less with respect to the cord length of the first blades, according to any one of claims 1 to 7. Diffuser for mixed flow compressor.   The mixed flow according to any one of claims 1 to 8, wherein a gap between the narrow flow paths is a gap of 5% or more to 50% or less with respect to the interval between the first blades. Compressor diffuser.   The rotor has a divided structure having a joint surface in a direction crossing the narrow flow path, and an end portion of at least one of the first or second blades protrudes in a fluid flow direction from the joint surface of the rotor. The diffuser for a mixed flow compressor according to claim 1 or 2, wherein the diffuser is extended.   A diffuser attached to a rotor of a mixed flow compressor, wherein the diffuser is a first blade located on the upstream side with respect to the direction of fluid flow, a second blade located on the downstream side, and A mixed flow comprising a vane provided between the downstream end portion of the first blade and the upstream end portion of the second blade and provided on the low pressure surface side of the first and second blades. Compressor diffuser.   The diffuser of the mixed flow compressor according to claim 1 or 2, wherein the upstream blade and / or the downstream blade are variable in angle with respect to a flow.   A rotor that is rotationally driven in the casing, a first blade on the upstream side that is erected at regular intervals in the outer circumferential direction of the rotor, and a second blade that is provided on the downstream side of the first blade The downstream end of the first blade is located downstream of the upstream end of the second blade, and is narrower between the first blade and the second blade. A mixed flow compressor characterized in that a flow path is formed.   A jet engine including a cylindrical casing, a turbine that is rotationally driven by an expansion gas, and a mixed flow compressor, and is connected to the turbine and the rotor of the mixed flow compressor. And having a diffuser comprising a first blade on the upstream side standing at regular intervals in the outer circumferential direction of the rotor and a second blade provided on the downstream side of the first blade. The downstream end of the first blade is positioned downstream of the upstream end of the second blade, and a narrow flow path is formed between the first blade and the second blade. A jet engine characterized by   A plurality of circumferentially spaced rotors around the rotor of the mixed flow compressor, with a narrow flow path where the rear end of the upstream blade that guides the flow overlaps the front end of the downstream blade In the method of manufacturing a mixed flow compressor rotor having a diffuser that forms the above-mentioned upstream or downstream blades and the periphery thereof, on the outer periphery of a plurality of split rotors having joint surfaces at positions crossing the flow path The mixed flow compressor rotor is manufactured by extending the end portion from the joint surface, integrally cutting and forming each of the divided rotors, and connecting the plurality of divided rotors with the joint surface. A method of manufacturing a machine rotor.

Images