阅读说明：本技术 一种低压涡轮叶片锯齿冠结构设计方法 (A kind of low-pressure turbine blade sawtooth hat construction design method ) 是由 石伟 朱培模 娄春娟 褚云会 蒋竞升 吴锦华 梁湘华 林垲 李义平 栗尼娜 靳福 于 2019-08-02 设计创作，主要内容包括：本发明属叶轮机械技术领域,涉及一种低压涡轮叶片锯齿冠结构设计方法,主要针对高负荷低压涡轮转子叶片。确定锯齿冠结构特征的步骤如下：建立全局坐标系XYZ和叶冠坐标系X<Sub>1</Sub>Y<Sub>1</Sub>Z<Sub>1</Sub>；根据气动设计的要求给定低压涡轮叶片锯齿冠啮合面所在直径高度D,以满足发动机性能要求；确定低压涡轮叶片锯齿冠啮合面与Y轴的夹角α；确定低压涡轮叶片预扭角△β；根据夹角α、预扭角△β和直径高度D,确定低压涡轮叶片锯齿冠啮合面弦宽b。本设计方法实现了低压涡轮叶片啮合面上的扭矩和因旋转后低压涡轮叶片叶身的恢复力矩平衡；与此同时,通过低压涡轮叶片锯齿冠啮合面之间相互约束,达到减少叶片振幅的目的。(The invention belongs to impeller machinery technical fields, are related to a kind of low-pressure turbine blade sawtooth hat construction design method, mainly for high load capacity Low Pressure Turbine Rotor blade.It determines that the step of sawtooth is preced with structure feature is as follows: establishing global coordinate system XYZ and integral shroud coordinate system X 1 Y 1 Z 1 ；Diameter height D where giving the low-pressure turbine blade sawtooth hat field of conjugate action according to the requirement of pneumatic design, to meet engine performance requirement；Determine the angle α of low-pressure turbine blade sawtooth the hat field of conjugate action and Y-axis；Determine the pre- torsional angle △ β of low-pressure turbine blade；According to angle α, pre- torsional angle △ β and diameter height D, determine that low-pressure turbine blade sawtooth is preced with field of conjugate action chord width b.The design method realizes the torque on the low-pressure turbine blade field of conjugate action and the righting moment balance because of low-pressure turbine blade blade after rotation；At the same time, it is preced between the field of conjugate action by low-pressure turbine blade sawtooth and is mutually constrained, achieve the purpose that reduce blade amplitude.)

1. a kind of low-pressure turbine blade sawtooth is preced with construction design method, which is characterized in that the design method comprises the following steps that

The first step establishes global coordinate system XYZ and integral shroud coordinate system X₁Y₁Z₁；

Second step determines the hat engagement of cold conditions Low Pressure Turbine Rotor blade sawtooth according to the hot runner height that pneumatic design gives Diameter D where any given point Q in face；

Third step determines the angle α of low-pressure turbine blade sawtooth the hat field of conjugate action and Y-axis；

4th step determines the pre- torsional angle △ β of low-pressure turbine blade；

5th step determines that low-pressure turbine blade sawtooth is preced with field of conjugate action chord width b according to angle α, pre- torsional angle △ β and diameter height D；

6th step determines the non-field of conjugate action；Because complete envelope blade tip is vented side, adjacent low-pressure turbine blade two is non-to be nibbled the non-field of conjugate action Conjunction face does not contact, and guarantees that there are small―gap sutures when working condition；

7th step determines that sawtooth is preced with position of centre of gravity.

2. low-pressure turbine blade sawtooth according to claim 1 is preced with construction design method, which is characterized in that the global seat Mark system XYZ: using blade centre of gyration line direction as X-axis, to pass through blade tenon center, and normal orientation is the flat of X-direction The intersection point of face and X-axis is coordinate origin, and being directed toward blade exhaust edge direction is positive direction, to cross origin and perpendicular to the straight line of X-axis For Y-axis, positive direction is directed toward blade basin to Z axis is determined according to the right-hand rule.

3. low-pressure turbine blade sawtooth according to claim 1 is preced with construction design method, which is characterized in that the integral shroud is sat Mark system X₁Y₁Z₁: centered on global coordinate system XYZ origin, using global coordinate system Z axis negative direction as axis, rotation △ β angle is obtained The coordinate system arrived.

4. low-pressure turbine blade sawtooth according to claim 1 is preced with construction design method, which is characterized in that the fixed point Q In field of conjugate action intermediate region.

5. low-pressure turbine blade sawtooth according to claim 1 is preced with construction design method, which is characterized in that in third step, The method for determining the angle α of the low-pressure turbine blade sawtooth hat field of conjugate action and Y-axis is as follows: when α is greater than angle [alpha] 2, tightness is small, Acutely, there is gap in the integral shroud unstable working condition even field of conjugate action for normal pressure variation between the field of conjugate action；Meanwhile the public affairs of vane manufacturing Poor objective reality, field of conjugate action pressure oscillating amount caused by chord width slightly changes is big, and enchancement factor influences big；When α is less than angle [alpha] 1 When, for the positive pressure force request for guaranteeing the field of conjugate action, biggish pretwist △ β, changing of the relative positions wear block are needed, while being introduced by pretwist △ β Additional stress is big, and blade exhaust side is easy to appear crackle；It is preced with use experience according to sawtooth, α angle OK range is α₁< α < α₂；

Wherein, α 2, α 1 are empirical value.

6. low-pressure turbine blade sawtooth according to claim 1 is preced with construction design method, which is characterized in that in the 4th step, Determine pre- torsional angle △ β method are as follows: low-pressure turbine blade bears the centrifugal force introduced by rotation, to guarantee low-pressure turbine blade in work The reliability for making blade working when state, should not be too big by the shearing force that sawtooth hat pretwist introduces, when preventing blade working state, The lesser exhaust side trailing edge of size is cracked because being sheared nearby, designs a model and analyzes to obtain by software.

7. low-pressure turbine blade sawtooth according to claim 1 is preced with construction design method, which is characterized in that the 5th step determines Sawtooth hat field of conjugate action chord width b: chord width b diameter height D, field of conjugate action angle α and pre- torsional angle △ β where blade quantity, point Q is comprehensive It determines, with Y-direction angle in design desired value when guaranteeing sawtooth hat field of conjugate action work.

8. low-pressure turbine blade sawtooth according to claim 7 is preced with construction design method, which is characterized in that blade quantity by Pneumatic design is given.

9. according to claim 1, low-pressure turbine blade sawtooth described in 5 or 6 is preced with construction design method, which is characterized in that angle α, pre- torsional angle △ β analyze to obtain its optimal angle value by Ansys software.

Technical field

The invention belongs to impeller machinery technical fields, are related to a kind of Turbine Sawtooth Shroud design method, negative mainly for height Lotus Low Pressure Turbine Rotor blade.

Background technique

Core component one of of the low-pressure turbine blade as aviation gas turbine Duct-Burning Turbofan key is stablized, is reliable Work influence aviation gas turbine Duct-Burning Turbofan using safe.

As aeropropulsion system develops to the direction of high thrust ratio, compressor pressure ratio, turbine inlet temperature and efficiency are wanted It asks higher and higher, under identical front face area, higher want is proposed using temperature, revolving speed and efficiency to low-pressure turbine blade It asks.Consider from aspect of performance, in low-pressure turbine blade blade tip location arrangements integral shroud, can effectively reduce at blade tip position Stream, can effectively improve low-pressure turbine efficiency；Consider from configuration aspects, it is low due to the elongated feature of low-pressure turbine blade Pressure turbo blade needs to arrange integral shroud to limit blade amplitude, to achieve the purpose that reduce blade root vibration stress, guarantees low pressure The safety of turbo blade work, reliability.Existing integral shroud design is usually common imitated or goes to set according to the experience of designer Meter, the integral shroud homogeneity designed are very poor.

Summary of the invention

The purpose of the present invention: a kind of design method of low-pressure turbine blade sawtooth hat is proposed, in the high-revolving work of high temperature Under state, low-pressure turbine blade blade tip location arrangements sawtooth be preced with, reach improve turbo blade working efficiency, job security and The purpose of reliability.

Technical solution of the invention: a kind of low-pressure turbine blade sawtooth hat construction design method, it is negative mainly for height Lotus Low Pressure Turbine Rotor blade.It determines that the step of sawtooth is preced with structure feature is as follows: establishing global coordinate system XYZ and integral shroud coordinate system X₁Y₁Z₁；Diameter height D where giving the low-pressure turbine blade sawtooth hat field of conjugate action according to the requirement of pneumatic design, is started with meeting Machine performance requirement；Determine the angle α of low-pressure turbine blade sawtooth the hat field of conjugate action and Y-axis；Determine the pre- torsional angle △ of low-pressure turbine blade β；According to angle α, pre- torsional angle △ β and diameter height D, determine that low-pressure turbine blade sawtooth is preced with field of conjugate action chord width b；Determine non-engagement Face；The non-field of conjugate action is in integral shroud coordinate system Y₁Chord width on direction is designed according to the theoretical value after low-pressure turbine blade pretwist, most Final value is that theoretical value subtracts reserved gap；Determine that sawtooth is preced with position of centre of gravity: after completing above content, analysis blade tip section is used Property, relative position of the sawtooth hat center of gravity at blade tip is checked, under conditions of guaranteeing above-mentioned chord width, by whole translation adjustment come really Sawtooth hat will not add biggish moment of flexure when protecting work.

Advantageous effects: when design low-pressure turbine blade sawtooth hat, by the reality between two fields of conjugate action in the Y direction Chord width is designed as being greater than the value of theoretical chord width, and when assembling low-pressure turbine blade, due to chord width interference, sawtooth hat can revolve counterclockwise Turn to eliminate interference and form the domain, to realize torque on the low-pressure turbine blade field of conjugate action and because of low-pressure turbine blade after rotation The righting moment of blade balances.Above-mentioned design is preced between the field of conjugate action by low-pressure turbine blade sawtooth and is mutually constrained, and reduction is reached The purpose of blade amplitude.

Detailed description of the invention

Fig. 1 is zigzag integral shroud design parameter schematic diagram,

Fig. 2 is zigzag integral shroud position view in blade.

Specific embodiment

The present invention is described in further details below.

The construction design method of low-pressure turbine blade sawtooth hat, the main relevant parameters being related to have: defining following parameter；Saw Diameter height D, the sawtooth hat field of conjugate action and Y-direction angle α where any given point Q of the crown field of conjugate action, the pre- torsional angle △ β of sawtooth hat and Sawtooth is preced with field of conjugate action chord width b, the specific steps are as follows:

1, global coordinate system XYZ: using blade centre of gyration line direction as X-axis, to pass through blade tenon center, and normal direction side Intersection point to plane and X-axis for X-direction is coordinate origin, and being directed toward blade exhaust edge direction is positive direction, to cross origin simultaneously Straight line perpendicular to X-axis is Y-axis, and positive direction is directed toward blade basin to Z axis is determined according to the right-hand rule；

2, integral shroud coordinate system X₁Y₁Z₁: centered on global coordinate system origin, using global coordinate system Z axis negative direction as axis, The coordinate system that rotation △ β angle obtains；

3, the hot runner height given according to pneumatic design determines that cold conditions Low Pressure Turbine Rotor blade sawtooth is preced with the field of conjugate action Diameter D where set point Q；

4, the sawtooth hat field of conjugate action and Y-direction angle α OK range are determined: when α is greater than angle [alpha]₂When, tightness is small, the field of conjugate action Between normal pressure variation acutely, integral shroud unstable working condition even the field of conjugate action there is gap；Meanwhile the tolerance of vane manufacturing is objective In the presence of field of conjugate action pressure oscillating amount caused by chord width slightly changes is big, and enchancement factor influences big；When α is less than angle [alpha]₁When, to protect The positive pressure force request for demonstrate,proving the field of conjugate action, needs biggish pretwist △ β, changing of the relative positions wear block, while the additional stress introduced by pretwist △ β Greatly, blade exhaust side is easy to appear crackle；

Wherein, α₂、α₁It is empirical value.

5, determine pre- torsional angle △ β: low-pressure turbine blade bears the very big centrifugal force introduced by rotation, to guarantee low-pressure turbine The reliability of blade blade working in working condition, should not be too big by the shearing force that sawtooth hat pretwist introduces, and prevents blade work When making state, the lesser exhaust side trailing edge of size is cracked because being sheared nearby.

6, determine that sawtooth is preced with field of conjugate action chord width b: the angle to guarantee that sawtooth is preced with field of conjugate action working condition and Y-axis is (α+△ β) angle needs to give specific chord width b, guarantees designing desired value with Y-direction angle when sawtooth hat field of conjugate action work.

7, determine the non-field of conjugate action 1: for the non-field of conjugate action 1 because complete envelope blade tip is vented side, adjacent low-pressure turbine blade two is non- The field of conjugate action does not contact, and there are small―gap sutures when working condition；

8, determine that sawtooth is preced with position of centre of gravity: sawtooth hat center of gravity present position will not generate excessive additional bending moment, Yi Mianzeng Add working stress at low-pressure turbine blade blade back lateral lobe point middle part or leaf basin lateral lobe point inlet and outlet side.

In step 5, the determination method of pre- torsional angle △ β is realized by following steps: passing through the sunykatuib analysis of ANSYS software first The normal pressure and trailing edge equivalent stress of a series of corresponding field of conjugate action of pre- torsional angle △ β is calculated, then according to the lasting of blade Life requirements and positive pressure force request choose suitable pre- torsional angle △ β.

The set point Q is in field of conjugate action intermediate region；The positive pressure force request is 10-20MPa；The diameter height D It is given by pneumatic design.The angle α, pre- torsional angle △ β analyze to obtain its optimal angle value by Ansys software.