CN112648240B - Plane blade grid blade of transonic compressor with bulge and concave seam structure and design method thereof - Google Patents
Plane blade grid blade of transonic compressor with bulge and concave seam structure and design method thereof Download PDFInfo
- Publication number
- CN112648240B CN112648240B CN202110070706.5A CN202110070706A CN112648240B CN 112648240 B CN112648240 B CN 112648240B CN 202110070706 A CN202110070706 A CN 202110070706A CN 112648240 B CN112648240 B CN 112648240B
- Authority
- CN
- China
- Prior art keywords
- bulge
- concave
- blade
- length
- concave seam
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 42
- 238000013461 design Methods 0.000 title claims abstract description 27
- 230000035939 shock Effects 0.000 claims abstract description 37
- 238000000926 separation method Methods 0.000 claims abstract description 30
- 230000000694 effects Effects 0.000 claims abstract description 16
- 238000004088 simulation Methods 0.000 claims abstract description 11
- 238000004458 analytical method Methods 0.000 claims abstract description 5
- 239000010410 layer Substances 0.000 claims description 15
- 238000005452 bending Methods 0.000 claims description 6
- 230000014509 gene expression Effects 0.000 claims description 5
- 238000009434 installation Methods 0.000 claims description 5
- 238000005516 engineering process Methods 0.000 claims description 4
- 238000012545 processing Methods 0.000 claims description 4
- 239000002344 surface layer Substances 0.000 claims description 4
- 241000764238 Isis Species 0.000 claims description 3
- 230000006872 improvement Effects 0.000 description 4
- 230000008859 change Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/40—Casings; Connections of working fluid
- F04D29/52—Casings; Connections of working fluid for axial pumps
- F04D29/54—Fluid-guiding means, e.g. diffusers
- F04D29/541—Specially adapted for elastic fluid pumps
- F04D29/542—Bladed diffusers
- F04D29/544—Blade shapes
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
- F04D29/661—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps
- F04D29/667—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps by influencing the flow pattern, e.g. suppression of turbulence
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Geometry (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
Abstract
The invention provides a plane blade grid blade of a transonic compressor with a bulge and concave seam structure and a design method thereof, comprising the following steps: step one, confirming the positions of bulges and concave joints through numerical simulation analysis; substituting different geometric parameters into modeling formulas of the bulges and the concave joints respectively, determining initial positions and lengths of the bulges and the concave joints to form different bulge and concave joint combined structure schemes, and performing two-dimensional numerical simulation by using numerical simulation software to obtain a bulge and joint combined structure scheme with good effect; and thirdly, according to the obtained combined structural scheme with good effect, utilizing three-dimensional modeling software to obtain a suction surface with bulges and concave joints, and combining the new suction surface with the original pressure surface to obtain the planar blade grid blade with the bulges and concave joints with good effect. The invention can control shock wave and separation by adding the bulge and concave seam structure to weaken flow loss caused by strong shock wave and separation, thereby improving the performance of the air compressor.
Description
Technical Field
The invention relates to the technical field of impeller machinery, in particular to a plane blade grid blade of a transonic compressor with a bulge and concave seam structure and a design method thereof.
Background
The study of planar cascades has taken a very important role in compressor design and research. As compressor load increases, transonic compressors have been greatly developed and used. In the process that the internal flow of the compressor is gradually changed from subsonic velocity to transonic velocity, stronger shock waves can occur, and the strong shock waves not only can cause the increase of the reverse pressure gradient and shock wave loss, but also can induce the separation of boundary layers to increase the separation loss. Thus, control of the shock wave and its associated losses is necessary for the performance enhancement of transonic compressors.
Any method for reducing shock wave intensity, improving the wave train structure, and reducing separation losses may improve performance of a transonic compressor. The existing flow control methods comprise active control methods such as boundary layer suction, plasma excitation, synthetic jet flow, blade tip jet and the like, and also comprise passive control methods such as shock wave control bulge, blade profile optimization, blade sweep design, cavity and porous medium surfaces, casing treatment, vortex generators and the like. Although the active control method can well control shock wave and separate flow loss, it needs to add additional devices and energy sources, which not only consumes additional energy, but also causes increased design difficulty. The passive control method can cause a large-amplitude blade profile change under the condition of large logarithm, such as the cavity and the surface of the porous medium, so that the workload is increased. The shock wave loss can be effectively reduced by adding the shock wave control bulge, but the improvement effect of the flow separation is not obvious. The bulge and recess structure can control shock waves and reduce flow separation, and ensure that the quality of the blade is basically unchanged.
Disclosure of Invention
Although shock wave and separation flow loss can be well controlled according to the active control method, additional devices and energy sources are required to be added, so that not only is additional energy consumed, but also design difficulty is increased; the passive control method can cause a large-amplitude blade profile change under the condition of large logarithm, such as the surfaces of a cavity and a porous medium, so that the workload is increased; the shock wave control bulge is added to effectively reduce shock wave loss, but the improvement effect on flow separation is less obvious, so that the plane blade grid blade of the transonic compressor with the bulge and concave seam structure and the design method thereof are provided. The plane blade grid structure with the bulges and the concave joints is obtained mainly by adjusting the modeling mode and the arrangement positions of the bulges and the concave joints, so that the reduction of shock wave strength, the reduction of separation loss and the improvement of blade grid expansion capacity are realized.
The invention adopts the following technical means:
A design method of a plane blade grid blade of a transonic compressor with a bulge and concave seam structure comprises the following steps:
Step one, confirming positions of bulges and concave joints: performing numerical simulation on the original compressor plane blade cascade by using numerical simulation software, and obtaining the position of shock waves on a suction surface through result analysis, thereby determining the arrangement position range of the bulge, including the initial installation position of the bulge and the end position of the bulge; determining the arrangement position range of the concave seam through the separation position of the auxiliary surface layer, wherein the arrangement position range comprises the starting position of the concave seam and the ending position of the concave seam;
Substituting different geometric parameters of the bulge into a modeling formula of the bulge, determining the initial position and length of the bulge, and determining the initial position and length of the recess according to the separation position of the boundary layer;
Substituting different geometric parameters of the concave seam into a modeling formula of the concave seam; different bulge height and length, recess depth and length and bulge and recess arrangement spacing are mutually matched to form different bulge and recess combined structure schemes, and point data of the different bulge and recess combined structure schemes are obtained; combining point data, performing two-dimensional numerical simulation on different combined structure schemes by using numerical simulation software to obtain a bulge and seam combined structure scheme with good effect;
And thirdly, according to the obtained combined structural scheme with good effect, utilizing three-dimensional modeling software such as UG and the like to carry out modification reconstruction on the original suction surface to obtain the suction surface with bulges and concave seams, and combining the new suction surface with the original pressure surface to obtain the planar blade grid blade with the bulges and concave seams with good effect.
Further, in the second step, the different geometric parameters of the bulge include a starting position of the bulge, a height of the bulge and a length of the bulge; the ending position of the bulge is determined by the starting position of the bulge and the bulge length;
The different geometric parameters of the concave seam comprise the starting position of the concave seam, the depth of the concave seam and the length of the concave seam; the end position of the concave seam is determined by the start position of the concave seam and the length of the concave seam;
the starting position of the concave seam can be adjusted within the range of 0-0.15 times of the chord length of the bulge ending position.
Further, in the second step, the modeling formula of the bulge adopts a CST parameterization, polynomial interpolation function, B spline curve, cubic C-Cardinal spline curve or p-nary subdivision curve modeling mode;
the modeling formula of the concave seam adopts a CST parameterization, polynomial interpolation function, B spline curve, cubic C-Cardinal spline curve or p-nary subdivision curve modeling mode;
The parameters related to the modeling of the concave seam comprise the depth H2 and the length L2 of the concave seam, which correspond to the height H1 and the length L1 of the bulge respectively.
Further, the depth H2 and the length L2 of the recess corresponding to the height H1 and the length L1 of the bulge respectively means that in the related formula, when the height of the bulge is m, the depth of the recess is also m, and the directions are opposite, where m >0; the length of the bulge is n, the length of the concave seam is also n, the directions are the same, and n is more than 0.
Further, the expression of the CST parameterized shape function S (x) satisfies the following formula:
In the formula, Is Bernstein polynomial, i isIs n is an index ofIs the order of (2); is the number of combinations; b i is an introduced weighting factor, i=0, 1, …, n; x=x/b, b is the blade chord length, X is the X-axis coordinate;
The polynomial interpolation function y satisfies the following formula:
y＝f(x)(1-x)0.5x0.5±g(x)(1-x)1.5x0.5
Wherein f (x) and g (x) are polynomial interpolation functions, X is a node vector; a i、Bi is a polynomial coefficient, and can be obtained by fitting the original blade data through a least square method; the bending degree of the arc curve can be changed by changing the coefficient and the order of the polynomial in f (x), so that the bending degree of the bulge is changed; changing the coefficient and the order of the polynomial in g (x), and changing the thickness of the bulge;
The B spline curve is defined by adopting a control vertex, the B spline basis function is a basis function which can describe complex shapes and has globally special characteristics, and a curve equation P (u) of the B spline curve meets the following formula:
Wherein d j is a control vertex, j= (i-k, i-k+1, …, i), N i,k (u) is a k-degree canonical B-spline basis function, i represents a sequence number, i=0, 1,2,3 … N, k is a basis function number, u represents a parameter, and the interval is [ u i,ui+k+1 ]; the basis function of the B spline curve is a polynomial spline, and is related to not only times, but also node intervals where parameters are located, so that the flexibility and diversity of the B spline regulation and control curve are improved;
The mathematical definition formula of the cubic C-Cardinal spline curve meets the following formula:
0≤t≤α，i＝0,1,2,…,n-3
Wherein, the point b i is a given model value point, i=0, 1,2,3 … n, j is 0-3, b i+j is contained in b i, ω j,a (t) is a spline basis function, t is a node value, the value of t in spline curve drawing determines the precision of the drawn curve, the parameter α can perform fine tuning on the spline curve without affecting the continuity of the curve, which is also called a fine tuning factor, α is greater than 0, and the curve P (t) formed by the curve segment P i (t) is called a cubic C-cartonal spline curve;
The p-nary subdivision curve satisfies the following formula:
given an initial set of ordered control vertices J 0 is a finite set of subscripts for the initial ordered control vertex; is provided withFor the k-th sub-divided ordered control vertex set, J k is the corresponding limited subscript set; wherein α= { α j } is a real coefficient sequence, and only a limited number of components are not zero, called mask, which is a shape parameter; the uniform and stable p-nary subdivision curve modeling method actually comprises p subdivision rules defining new ordered control points under the curve condition:
In the formula, Represents the jth ordered control vertex after the K+1th subdivision, P i k represents the ith ordered control vertex after the K th subdivision, Z represents an integer set, i represents the integer number of times, i is given to be smaller than j, j is an initial given value, alpha j-pi represents j-pi real coefficient parameters, P represents the integer number of subdivisions, and P is greater than or equal to 1; beta = j-i, beta being greater than 0;
if p=1, then the subdivision rule is:
if p=2, then the subdivision rule is:
And
If p=3, the subdivision rule is 3, and so on.
Further, the modeling formula of the concave seam can also be constructed in a circular arc modeling mode or a square modeling mode.
Further, constructing an arc-shaped concave seam in an arc modeling mode, wherein the arc diameter D of the arc-shaped concave seam is used for controlling the length L2 and the depth H2, the length L2 is 0.05b-0.2b, b is the chord length of the blade, and the depth H2 is not more than 50% of the thickness of the blade at the position;
the curvature and shape of the concave seam are controlled by changing the diameter of the circular arc, the length of the concave seam and the depth of the concave seam, so that the circular arc-shaped concave seam with different characteristics is realized.
Further, a square modeling mode is adopted to construct and obtain a rectangular concave seam, the length L2 of the rectangular concave seam is 0.05b-0.2b, b is the chord length of the blade, and the depth H2 is not more than 50% of the thickness of the blade at the position;
The flow loss of the suction surface is restrained by changing the length-depth ratio of the concave seam and controlling the size of the flow direction vortex generated by the concave seam; simultaneously, the bottom of the concave seam can be processed and manufactured by using an arc chamfer or a linear chamfer according to the processing technology requirements of a specific rotor.
Further, in the second step, the modeling formula of the bulge is the same as or different from the modeling formula of the concave seam;
According to different blade grid structures, the positions of the bulges and the concave seams relative to the chord direction of the blade can be adjusted according to specific conditions, and the influence of the modified blade grid blade on the flow field structure and the aerodynamic parameters is further realized through the combination of the modeling modes of the different bulges and the concave seams.
The invention also provides a plane blade grid blade of the transonic compressor with the bulge and concave seam structure, which is obtained by the design method and comprises a plane blade grid plate, blades, bulges and concave seams, wherein the blades are fixedly connected with the plane blade grid plate through blade-shaped grooves arranged on the plane blade grid plate, and the bulges and the concave seams are arranged on the blades.
Compared with the prior art, the invention has the following advantages:
1. According to the plane blade grid blade of the transonic compressor with the bulge and concave seam structure and the design method thereof, provided by the invention, the influence caused by shock wave loss and separation loss in the transonic compressor is considered, and the shock wave and separation can be controlled by adding the bulge and concave seam structure to weaken the flow loss caused by strong shock wave and separation, so that the performance of the compressor is improved.
2. According to the plane blade grid blade of the transonic compressor with the bulge and concave seam structure and the design method thereof, provided by the invention, shock waves and separation can be controlled under the condition that the blade is changed slightly without adding an auxiliary device, and the design difficulty of redesigning a novel blade is saved by changing the modeling mode of the bulge and concave seam on the basis of the existing blade profile.
3. Compared with other control technologies, the transonic compressor plane blade grid blade with the bulge and concave seam structure and the design method thereof provided by the invention have the advantages that the quality of the blade is basically unchanged by changing the local structure, the structure is simple, the processing difficulty is relatively low, the reliability is higher, and the like.
In summary, the technical scheme of the invention can solve the problems that the active control method in the prior art can well control shock waves and separate flow losses, but needs to add additional devices and energy sources, which not only consumes additional energy, but also causes increased design difficulty; the passive control method can cause a large-amplitude blade profile change under the condition of large logarithm, such as the surfaces of a cavity and a porous medium, so that the workload is increased; the shock wave loss can be effectively reduced by adding the shock wave control bulge, but the improvement effect on the flow separation is less obvious.
Based on the reasons, the method can be widely popularized in the fields of transonic compressor plane blade grid shock wave control and the like.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings may be obtained according to the drawings without inventive effort to a person skilled in the art.
Fig. 1 is a schematic view of a transonic compressor cascade structure with bulges and concave seams in accordance with the present invention.
Fig. 2 is a two-dimensional schematic of a transonic compressor cascade with bulges and concave seams in accordance with the present invention.
FIG. 3 is a diagram of bulge and recess parameters of a transonic compressor cascade of the present invention.
Fig. 4 is a schematic diagram of the bulge and circular arc shaped concave seam structure and parameters of the transonic compressor cascade of the present invention.
FIG. 5 is a diagram showing the bulge and square concave seam structure and parameters of the transonic compressor cascade of the present invention
FIG. 6 is a schematic view of the bottom chamfer of the rectangular recess of the present invention.
Fig. 7 is a pressure contour plot of an original cascade of a transonic compressor of the invention.
Fig. 8 is a pressure contour plot of a transonic compressor of the present invention with a bulge and a slot cascade.
Fig. 9 is a cloud plot of the total pressure loss coefficient of the original cascade of the transonic compressor of the invention.
Fig. 10 is a cloud plot of the total pressure loss coefficient of a transonic compressor of the present invention with a bulge and a pocket vane cascade.
In the figure: 1. planar leaf grating plates; 2. a blade; 3. a bulge; 4. concave joints; 5. chamfering linearly; 6. and (5) arc chamfering.
Detailed Description
It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other. The invention will be described in detail below with reference to the drawings in connection with embodiments.
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present invention. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.
The relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless it is specifically stated otherwise. Meanwhile, it should be clear that the dimensions of the respective parts shown in the drawings are not drawn in actual scale for convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.
Example 1
The invention provides a design method of a plane blade grid blade of a transonic compressor with a bulge and concave seam structure, which comprises the following steps:
step one, confirming positions of bulges and concave joints: performing numerical simulation on the original compressor plane blade cascade by using numerical simulation software, and obtaining the position of shock waves on a suction surface through result analysis, thereby determining the arrangement position range of the bulge, including the initial installation position of the bulge and the end position of the bulge; determining the arrangement position range of the concave seam through the separation position of the auxiliary surface layer, wherein the arrangement position range comprises the starting position of the concave seam and the ending position of the concave seam; wherein; the shock wave can interact with the boundary layer to cause the separation of the boundary layer, and the added bulge can delay the position of the shock wave incident to the suction surface of the blade, so that the separation position of the boundary layer is delayed; the concave seam can reduce the separation of the boundary layer, so the arrangement position of the concave seam is determined according to the separation position of the boundary layer;
Substituting different geometric parameters of the bulge into a modeling formula of the bulge, determining the initial position and length of the bulge, and determining the initial position and length of the recess according to the separation position of the boundary layer;
Substituting different geometric parameters of the concave seam into a modeling formula of the concave seam; different bulge height and length, recess depth and length and bulge and recess arrangement spacing are mutually matched to form different bulge and recess combined structure schemes, and point data of the different bulge and recess combined structure schemes are obtained; combining point data, performing two-dimensional numerical simulation on different combined structure schemes by using numerical simulation software to obtain a bulge and seam combined structure scheme with good effect;
And thirdly, according to the obtained combined structural scheme with good effect, utilizing three-dimensional modeling software such as UG and the like to carry out modification reconstruction on the original suction surface to obtain the suction surface with bulges and concave seams, and combining the new suction surface with the original pressure surface to obtain the planar blade grid blade with the bulges and concave seams with good effect.
Preferably, in the second step, the different geometric parameters of the bulge include a starting position of the bulge, a height of the bulge and a length of the bulge; the ending position of the bulge is determined by the starting position of the bulge and the bulge length;
The different geometric parameters of the concave seam comprise the starting position of the concave seam, the depth of the concave seam and the length of the concave seam; the end position of the concave seam is determined by the start position of the concave seam and the length of the concave seam;
the starting position of the concave seam can be adjusted within the range of 0-0.15 times of the chord length of the bulge ending position.
Preferably, in the second step, the modeling formula of the bulge adopts a CST parameterization, polynomial interpolation function, B spline curve, cubic C-Cardinal spline curve or p-nary subdivision curve modeling mode;
the modeling formula of the concave seam adopts a CST parameterization, polynomial interpolation function, B spline curve, cubic C-Cardinal spline curve or p-nary subdivision curve modeling mode;
The parameters related to the modeling of the concave seam comprise the depth H2 and the length L2 of the concave seam, which correspond to the height H1 and the length L1 of the bulge respectively.
Preferably, the depth H2 and the length L2 of the recess corresponding to the height H1 and the length L1 of the bulge respectively means that in the related formula, when the height of the bulge is m, the depth of the recess is also m, and the directions are opposite, where m >0; the length of the bulge is n, the length of the concave seam is also n, the directions are the same, and n is more than 0.
Preferably, the expression of the CST parameterized shape function S (x) satisfies the following formula:
In the formula, Is Bernstein polynomial, i isIs n is an index ofIs the order of (2); is the number of combinations; b i is an introduced weighting factor, i=0, 1, …, n; x=x/b, b is the blade chord length, X is the X-axis coordinate;
The polynomial interpolation function y satisfies the following formula:
y＝f(x)(1-x)0.5x0.5±g(x)(1-x)1.5x0.5
Wherein f (x) and g (x) are polynomial interpolation functions, X is a node vector; a i、Bi is a polynomial coefficient, and can be obtained by fitting the original blade data through a least square method; the bending degree of the arc curve can be changed by changing the coefficient and the order of the polynomial in f (x), so that the bending degree of the bulge is changed; changing the coefficient and the order of the polynomial in g (x), and changing the thickness of the bulge;
The B spline curve is defined by adopting a control vertex, the B spline basis function is a basis function which can describe complex shapes and has globally special characteristics, and a curve equation P (u) of the B spline curve meets the following formula:
Wherein d j is a control vertex, j= (i-k, i-k+1, …, i), N i,k (u) is a k-degree canonical B-spline basis function, i represents a sequence number, i=0, 1,2,3 … N, k is a basis function number, u represents a parameter, and the interval is [ u i,ui+k+1 ]; the basis function of the B spline curve is a polynomial spline, and is related to not only times, but also node intervals where parameters are located, so that the flexibility and diversity of the B spline regulation and control curve are improved;
The mathematical definition formula of the cubic C-Cardinal spline curve meets the following formula:
0≤t≤α，i＝0,1,2,…,n-3
Wherein, the point b i is a given model value point, i=0, 1,2,3 … n, j is 0-3, b i+j is contained in b i, ω j,a (t) is a spline basis function, t is a node value, the value of t in spline curve drawing determines the precision of the drawn curve, the parameter α can perform fine tuning on the spline curve without affecting the continuity of the curve, which is also called a fine tuning factor, α is greater than 0, and the curve P (t) formed by the curve segment P i (t) is called a cubic C-cartonal spline curve;
The p-nary subdivision curve satisfies the following formula:
given an initial set of ordered control vertices J 0 is a finite set of subscripts for the initial ordered control vertex; is provided withFor the k-th sub-divided ordered control vertex set, J k is the corresponding limited subscript set; wherein α= { α j } is a real coefficient sequence, and only a limited number of components are not zero, called mask, which is a shape parameter; the uniform and stable p-nary subdivision curve modeling method actually comprises p subdivision rules defining new ordered control points under the curve condition:
In the formula, Represents the jth ordered control vertex after the K+1th subdivision, P i k represents the ith ordered control vertex after the K th subdivision, Z represents an integer set, i represents the integer number of times, i is given to be smaller than j, j is an initial given value, alpha j-pi represents j-pi real coefficient parameters, P represents the integer number of subdivisions, and P is greater than or equal to 1; beta = j-i, beta being greater than 0;
if p=1, then the subdivision rule is:
if p=2, then the subdivision rule is:
And
If p=3, the subdivision rule is 3, and so on.
Preferably, the modeling formula of the concave seam can also be constructed in a circular arc modeling mode or a square modeling mode.
Preferably, an arc-shaped concave seam is formed in an arc modeling mode, the arc diameter D of the arc-shaped concave seam is used for controlling the length L2 and the depth H2, the length L2 is 0.05b-0.2b, b is the chord length of the blade, and the depth H2 is not more than 50% of the thickness of the blade at the position;
the curvature and shape of the concave seam are controlled by changing the diameter of the circular arc, the length of the concave seam and the depth of the concave seam, so that the circular arc-shaped concave seam with different characteristics is realized.
Preferably, a square modeling mode is adopted to construct and obtain a rectangular concave seam, the length L2 of the rectangular concave seam is 0.05b-0.2b, b is the chord length of the blade, and the depth H2 is not more than 50% of the thickness of the blade at the position;
the flow loss of the suction surface is restrained by changing the length-depth ratio of the concave seam and controlling the size of the flow direction vortex generated by the concave seam; meanwhile, the bottom of the concave seam can be manufactured by using an arc chamfer 6 or a linear chamfer 5 according to the processing technology requirements of a specific rotor.
Preferably, in the second step, the modeling formula of the bulge is the same as or different from the modeling formula of the concave seam;
According to different blade grid structures, the positions of the bulges and the concave seams relative to the chord direction of the blade can be adjusted according to specific conditions, and the influence of the modified blade grid blade on the flow field structure and the aerodynamic parameters is further realized through the combination of the modeling modes of the different bulges and the concave seams.
Example 2
As shown in fig. 1-6, the present invention further provides a plane blade grid blade of a transonic compressor with a bulge and a concave seam structure, which is obtained by the design method in the embodiment, and the plane blade grid blade comprises a plane blade grid plate 1, a blade 2, a bulge 3 and a concave seam 4, wherein the blade 2 is fixedly connected with the plane blade grid plate 1 through a blade profile groove arranged on the plane blade grid plate 1, and the bulge 3 and the concave seam 4 are arranged on the blade 2. As shown in fig. 3-5, C1 is the position from the leading edge point of the blade to the highest point of the bulge, C2 is the position from the leading edge point of the blade to the deepest point of the recess, and C0 is the chord length of the blade, i.e. the parameter b.
Example 3
A design method of a plane blade grid blade of a transonic compressor with a bulge and concave seam structure comprises the following steps:
Step one, selecting a 70% leaf height plane cascade of a transonic rotor, wherein specific parameters of the cascade are shown in table 1:
TABLE 1 phyllosphere parameters
And secondly, performing numerical simulation on the original compressor plane blade grid by using numerical simulation software, and obtaining a strong shock wave position and an boundary layer separation position by analyzing a numerical simulation result. And determining a bulge installation range according to the strong shock wave position, and determining a recess joint installation range according to the boundary layer separation position.
Step three, adopting a polynomial interpolation function method for the bulge modeling in the step, wherein the equation expression is as follows:
y＝f(x)(1-x)0.5x0.5±g(x)(1-x)1.5x0.5
The initial position of the bulge is preliminarily determined to be at the length of 0.5 times of chord according to the position of the strong shock wave; preliminarily determining that the bulge height is 0.4 times of chord length according to the thickness of the boundary layer of the main flow area; f (x) =0.4×5.7×0.1; g (x) =0.4×5.7×1.
And fourthly, determining the chord length of the concave seam starting position which is 0.01 times after the bulge ending position according to the separation position of the boundary layer of the main flow area through numerical simulation analysis. The concave seam modeling in the step is constructed by adopting a circular arc method, the concave seam length is initially selected to be 0.05 times of chord length, and the concave seam depth is 0.02 times of chord length.
Fifthly, modifying the suction surface by utilizing UG software according to the bulge point data and the recess point data obtained in the steps, and determining the positions and the shapes of the bulge and the recess on the suction surface to obtain a new suction surface. The newly obtained suction surface and the original pressure surface are combined, so that the plane blade grid blade with bulges and concave seams with good effect can be obtained.
Step six, performing numerical calculation on the prototype blade cascade, the bulge blade cascade and the bulge and concave seam blade cascade by using Numeca numerical simulation software respectively to obtain the results shown in the table 2 and the table 3:
TABLE 2 Total pressure loss and flow variation of prototype cascades and bulges and concave cascades
As shown in Table 2, according to the results, the bulges and the concave slot blade cascades can effectively reduce loss and improve the performance of the air compressor on the premise of not changing the flow basically. Compared with the original blade grating, the bulge and concave seam blade grating has the advantages that the total pressure loss coefficient is reduced by 1.78% and the flow is reduced by 0.38% under the design working condition.
TABLE 3 total pressure loss and flow variation for the bulge and pocket cascades
According to the data in Table 3, the bulge cell cascade also resulted in a reduction in the total pressure coefficient under design conditions as compared to the prototype cell cascade. But the bulge and the concave seam blade grid can reduce the total pressure loss coefficient by 0.67 percent and the flow by 0.01 percent on the basis. The bulge and pocket cascades can more effectively reduce losses.
As can be seen from the pressure contour map of the original blade row in FIG. 7 and the pressure contour map of the bulge and concave seam blade row in FIG. 8, in the black square frame area, the bulge and concave seam structure can effectively reduce the intensity of shock waves in the flow channel, and the position of the shock waves incident on the suction surface is moved backwards, and after the bulge and concave seam structure controls the separation position of the boundary layer, the flow loss is reduced.
As can be seen from the total pressure loss coefficient cloud of the original cascade of fig. 9 and the total pressure loss coefficient cloud of the bulge and the concave slot cascade of fig. 10, in the black rectangular region, the flow field high-loss region of the bulge and the concave slot cascade is significantly smaller than that of the original cascade. The bulge and concave seam structure changes the shock wave system structure, improves the pressure gradient of the suction surface, and is favorable for reducing the separation loss of the surface layer.
The bulge and concave seam structure can reduce shock wave intensity, reduce shock wave loss, reduce flow loss and improve the performance of the air compressor.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.
Claims (7)
1. The design method of the plane blade grid blade of the transonic compressor with the bulge and concave seam structure is characterized by comprising the following steps of:
Step one, confirming positions of bulges and concave joints: performing numerical simulation on the original compressor plane blade cascade by using numerical simulation software, and obtaining the position of shock waves on a suction surface through result analysis, thereby determining the arrangement position range of the bulge, including the initial installation position of the bulge and the end position of the bulge; determining the arrangement position range of the concave seam through the separation position of the auxiliary surface layer, wherein the arrangement position range comprises the starting position of the concave seam and the ending position of the concave seam;
Substituting different geometric parameters of the bulge into a modeling formula of the bulge, determining the initial position and length of the bulge, and determining the initial position and length of the recess according to the separation position of the boundary layer;
Substituting different geometric parameters of the concave seam into a modeling formula of the concave seam; different bulge height and length, recess depth and length and bulge and recess arrangement spacing are mutually matched to form different bulge and recess combined structure schemes, and point data of the different bulge and recess combined structure schemes are obtained; combining point data, performing two-dimensional numerical simulation on different combined structure schemes by using numerical simulation software to obtain a bulge and seam combined structure scheme with good effect;
Thirdly, according to the obtained combined structural scheme with good effect, the original suction surface is remodelled and reconstructed by utilizing three-dimensional modeling software to obtain the suction surface with bulges and concave joints, and the new suction surface is combined with the original pressure surface to obtain the planar blade grid blade with the bulges and concave joints with good effect;
in the second step, the modeling formula of the bulge adopts CST parameterization, a polynomial interpolation function, a B spline curve, a cubic C-Cardinal spline curve or a p-nary subdivision curve modeling mode;
the modeling formula of the concave seam adopts a CST parameterization, polynomial interpolation function, B spline curve, cubic C-Cardinal spline curve or p-nary subdivision curve modeling mode;
Parameters related to the modeling of the concave seam comprise the depth H2 and the length L2 of the concave seam, which correspond to the height H1 and the length L1 of the bulge respectively;
The expression of the CST parameterized shape function S (x) satisfies the following formula:
In the formula, Is Bernstein polynomial, i isIs n is an index ofIs the order of (2); is the number of combinations; b i is an introduced weighting factor, i=0, 1, …, n; x=x/b, b is the blade chord length, X is the X-axis coordinate;
The polynomial interpolation function y satisfies the following formula:
y＝f(x)(1-x)0.5x0.5±g(x)(1-x)1.5x0.5
Wherein f (x) and g (x) are polynomial interpolation functions, X is a node vector; a i、Bi is a polynomial coefficient, and can be obtained by fitting the original blade data through a least square method; the bending degree of the arc curve can be changed by changing the coefficient and the order of the polynomial in f (x), so that the bending degree of the bulge is changed; changing the coefficient and the order of the polynomial in g (x), and changing the thickness of the bulge;
The B spline curve is defined by adopting a control vertex, the B spline basis function is a basis function which can describe complex shapes and has globally special characteristics, and a curve equation P (u) of the B spline curve meets the following formula:
Wherein d j is a control vertex, j= (i-k, i-k+1, …, i), N i,k (u) is a k-degree canonical B-spline basis function, i represents a sequence number, i=0, 1,2,3 … N, k is a basis function number, u represents a parameter, and the interval is [ u i,ui+k+1 ]; the basis function of the B spline curve is a polynomial spline, and is related to not only times, but also node intervals where parameters are located, so that the flexibility and diversity of the B spline regulation and control curve are improved;
The mathematical definition formula of the cubic C-Cardinal spline curve meets the following formula:
0≤t≤α，i＝0,1,2,…,n-3
Wherein, the point b i is a given model value point, i=0, 1,2,3 … n, j is 0-3, b i+j is contained in b i, ω j,a (t) is a spline basis function, t is a node value, the value of t in spline curve drawing determines the precision of the drawn curve, the parameter α can perform fine tuning on the spline curve without affecting the continuity of the curve, which is also called a fine tuning factor, α is greater than 0, and the curve P (t) formed by the curve segment P i (t) is called a cubic C-cartonal spline curve;
The p-nary subdivision curve satisfies the following formula:
given an initial set of ordered control vertices J 0 is a finite set of subscripts for the initial ordered control vertex; is provided withFor the k-th sub-divided ordered control vertex set, J k is the corresponding limited subscript set; wherein α= { α j } is a real coefficient sequence, and only a limited number of components are not zero, called mask, which is a shape parameter; the uniform and stable p-nary subdivision curve modeling method actually comprises p subdivision rules defining new ordered control points under the curve condition:
In the formula, Represents the jth ordered control vertex after the K+1th subdivision, P i k represents the ith ordered control vertex after the K th subdivision, Z represents an integer set, i represents the integer number of times, i is given to be smaller than j, j is an initial given value, alpha j-pi represents j-pi real coefficient parameters, P represents the integer number of subdivisions, and P is greater than or equal to 1; beta = j-i, beta being greater than 0;
if p=1, then the subdivision rule is:
if p=2, then the subdivision rule is:
if p=3, the subdivision rule is 3, and so on.
2. The method according to claim 1, wherein in the second step, the different geometric parameters of the bulge include a starting position of the bulge, a height of the bulge and a length of the bulge; the ending position of the bulge is determined by the starting position of the bulge and the bulge length;
The different geometric parameters of the concave seam comprise the starting position of the concave seam, the depth of the concave seam and the length of the concave seam; the end position of the concave seam is determined by the start position of the concave seam and the length of the concave seam;
the starting position of the concave seam can be adjusted within the range of 0-0.15 times of the chord length of the bulge ending position.
3. The design method according to claim 1, wherein the depth H2 and the length L2 of the recess corresponding to the height H1 and the length L1 of the bulge, respectively, means that in the formula concerned, when the height of the bulge is m, the recess depth is m, and the directions are opposite, m >0; the length of the bulge is n, the length of the concave seam is also n, the directions are the same, and n is more than 0.
4. The design method according to claim 1, wherein the modeling formula of the recess is further constructed in a circular arc modeling manner or a square modeling manner.
5. The design method according to claim 4, wherein the arc-shaped concave seam is formed by adopting an arc modeling mode, the arc diameter D of the arc-shaped concave seam is used for controlling the length L2 and the depth H2, the length L2 is 0.05b-0.2b, b is the chord length of the blade, and the depth H2 is not more than 50% of the thickness of the blade at the position;
the curvature and shape of the concave seam are controlled by changing the diameter of the circular arc, the length of the concave seam and the depth of the concave seam, so that the circular arc-shaped concave seam with different characteristics is realized.
6. The design method according to claim 4, wherein a square modeling mode is adopted to construct a rectangular concave seam, the length L2 of the rectangular concave seam is 0.05b-0.2b, b is the chord length of the blade, and the depth H2 is not more than 50% of the thickness of the blade at the position;
The flow loss of the suction surface is restrained by changing the length-depth ratio of the concave seam and controlling the size of the flow direction vortex generated by the concave seam; simultaneously, the bottom of the concave seam is processed and manufactured by using an arc chamfer or a linear chamfer according to the processing technology requirement of a specific rotor.
7. The design method according to claim 1 or 4, wherein in the second step, different blade cascade structures adjust positions of the bulges and the concave joints relative to the chord direction of the blade according to specific conditions, and the influence of the modified blade cascade blade on the flow field structure and the aerodynamic parameters is further realized through the combination of the modeling modes of the different bulges and the concave joints.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110070706.5A CN112648240B (en) | 2021-01-19 | 2021-01-19 | Plane blade grid blade of transonic compressor with bulge and concave seam structure and design method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110070706.5A CN112648240B (en) | 2021-01-19 | 2021-01-19 | Plane blade grid blade of transonic compressor with bulge and concave seam structure and design method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112648240A CN112648240A (en) | 2021-04-13 |
| CN112648240B true CN112648240B (en) | 2024-11-08 |
Family
ID=75370669
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110070706.5A Active CN112648240B (en) | 2021-01-19 | 2021-01-19 | Plane blade grid blade of transonic compressor with bulge and concave seam structure and design method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112648240B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105298912A (en) * | 2015-11-10 | 2016-02-03 | 南京航空航天大学 | Bump front edge inlet guider blade |
| CN106250652A (en) * | 2016-08-16 | 2016-12-21 | 深圳友铂科技有限公司 | The construction method of a kind of compressor blade blade profile and compressor blade |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108829970A (en) * | 2018-06-12 | 2018-11-16 | 深圳森蓝忠信科技有限公司 | Axial fan blade optimum design method and optimization system based on vortex dynamics |
| CN110287647B (en) * | 2019-07-18 | 2022-10-21 | 大连海事大学 | Design method for plane cascade shock wave control of transonic compressor |
| RU2727223C1 (en) * | 2019-12-11 | 2020-07-21 | федеральное государственное бюджетное образовательное учреждение высшего образования "Национальный исследовательский университет "МЭИ" (ФГБОУ ВО "НИУ "МЭИ") | Method of profiling the elements of the flowing part of the blade machine |
-
2021
- 2021-01-19 CN CN202110070706.5A patent/CN112648240B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105298912A (en) * | 2015-11-10 | 2016-02-03 | 南京航空航天大学 | Bump front edge inlet guider blade |
| CN106250652A (en) * | 2016-08-16 | 2016-12-21 | 深圳友铂科技有限公司 | The construction method of a kind of compressor blade blade profile and compressor blade |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112648240A (en) | 2021-04-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102996511B (en) | CAD (Computer-Aided Design) aided design method of controllable diffused blade profile with curvature continuity | |
| CN110727995A (en) | Blade shape construction method, blade, and computer device | |
| KR102616901B1 (en) | Aerodynamic layout design method and system for wide-speed-range hypersonic aircraft | |
| CN107480392B (en) | Blade modeling method based on elliptical non-uniform deformation | |
| CN111400834A (en) | Aerodynamic optimization design method, model and device for wind generating set blade airfoil | |
| CN112115558A (en) | Steam turbine blade grid profile parameterization reconstruction method based on crowd search algorithm | |
| CN112685852A (en) | Axial flow compressor load customized pneumatic optimization method capable of keeping continuity of through-flow structure | |
| CN214247795U (en) | Transonic compressor rotor blade with bulge and concave seam structure | |
| CN112648240B (en) | Plane blade grid blade of transonic compressor with bulge and concave seam structure and design method thereof | |
| Cheng et al. | A phased aerodynamic optimization method for compressors based on multi-degrees-of-freedom surface parameterization | |
| CN111079326A (en) | Two-dimensional anisotropic grid unit measurement tensor field smoothing method | |
| CN110287647A (en) | A kind of design method of transonic compressor plane cascade shock wave control | |
| Li et al. | Multidisciplinary design optimization based on parameterized free-form deformation for single turbine | |
| CN108664742B (en) | Multi-objective optimization method for nacelle parametric design | |
| Zhaoyun et al. | Optimization of tandem blade based on improved particle swarm algorithm | |
| CN102108883B (en) | Semi-rotation speed nuclear turbine final stage moving blade | |
| CN113090580A (en) | Centrifugal impeller blade with S-shaped front edge and modeling method thereof | |
| CN214247804U (en) | Transonic compressor plane cascade blade with bulge and concave joint structure | |
| CN112648235B (en) | Transonic compressor rotor blade with bulge and concave seam structure | |
| Sanz | Improved design of subcritical and supercritical cascades using complex characteristics and boundary-layer correction | |
| CN113221483B (en) | Binary free-form air inlet channel optimization design method and system based on class shape function | |
| CN112177777B (en) | Noise reduction blade profile leading edge design method for high-freedom controllable theoretical sound velocity point | |
| CN116720268A (en) | Periodically described global fairing reconstruction method for blade profile | |
| CN117386663A (en) | Rotor blade of axial flow compressor and method for obtaining stacking line of rotor blade | |
| CN116090091A (en) | Design method for tail profile of tail pushing layout aircraft |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant |