CN101571144A

CN101571144A - Gas compressor circumferential direction vorticity through-flow design method

Info

Publication number: CN101571144A
Application number: CNA2009101432800A
Authority: CN
Inventors: 李秋实; 李志平; 吴宏; 周盛; 陆亚钧
Original assignee: Beihang University
Current assignee: Beijing Feiqing Technology Co ltd
Priority date: 2008-12-10
Filing date: 2009-05-22
Publication date: 2009-11-04
Anticipated expiration: 2029-05-22
Also published as: CN101571144B

Abstract

The invention relates to a design method for circumferential vortex flow of an aeroengine compressor. Circumferential vorticity distribution has an important influence on the overall performance of the compressor. The circumferential vorticity is used as the key vortex dynamics diagnostic parameter, and the important design parameter circulation distribution is optimized in the flow design stage to pre-control the circumferential vorticity and realize High performance compressor design. According to the optimal distribution criterion that the circumferential vorticity is close to zero in the mainstream area of the meridian plane and its close relationship with the circulation, this method obtains the iterative formula of the circulation optimization from the Crocco equation, and can be conveniently obtained from the initial circulation distribution Carry out automatic optimization of circulation distribution, realize better distribution of circumferential vorticity, improve the pressure ratio and efficiency of the compressor, and guide the aerodynamic design of the compressor.

Description

Design Method of Circumferential Vortex Flow in Compressor

技术领域 technical field

本发明涉及一种航空发动机压气机气动设计方法，尤其涉及一种以周向涡量为诊断参数的压气机通流设计方法。The invention relates to an aerodynamic design method of an aero-engine compressor, in particular to a design method of the flow of the compressor with the circumferential vortex as a diagnosis parameter.

背景技术 Background technique

压气机是航空发动机的三大部件之一，起到对气流压缩作功的作用。压气机内部流动非常复杂，存在各种旋涡结构，如尾涡、叶尖泄漏涡、通道涡等，各种旋涡结构对压气机总性能参数压比、效率等有定量的影响，合理组织涡量场的分布是压气机设计成功的关键。The compressor is one of the three major components of an aero-engine, which performs the work of compressing the airflow. The internal flow of the compressor is very complicated, and there are various vortex structures, such as wake vortex, tip leakage vortex, channel vortex, etc. Various vortex structures have a quantitative impact on the overall performance parameters of the compressor, such as pressure ratio and efficiency. The distribution of the field is the key to the success of the compressor design.

通流设计方法是压气机初步设计的必需步骤。通流设计是在柱坐标系轴对称假设下，进行子午面流动参数的计算，从而得到叶片造型所需的数据。环量分布是通流设计中关键的气动输入参数，环量分布代表的即是加功量分布，给定合理的环量分布形式是压气机设计成功的关键，环量分布形式直接影响到压气机内部涡量场的分布。传统的环量分布往往依靠设计者的经验进行给定，然后再进行三维计算，得到流场和涡量场信息，评价压气机是否符合设计要求，若有不足之处，再返回通流设计修改环量分布或流道、叶片前尾缘曲线，反复进行多次直到得到满意的设计结果。传统通流设计方法对设计者经验要求很高，且尚未从合理组织涡量场角度进行指导环量分布。The through-flow design method is a necessary step in the preliminary design of the compressor. The through-flow design is to calculate the flow parameters of the meridian plane under the assumption of axisymmetric cylindrical coordinate system, so as to obtain the data required for the blade shape. Circulation distribution is the key aerodynamic input parameter in flow design. Circulation distribution represents the distribution of added work. Given a reasonable circulation distribution form is the key to the success of the compressor design, the circulation distribution form directly affects the compressor. The distribution of the vorticity field inside the machine. The traditional circulation distribution is often given by the designer's experience, and then three-dimensional calculation is performed to obtain the flow field and vorticity field information, and evaluate whether the compressor meets the design requirements. If there are deficiencies, then return to the flow design for modification Circulation distribution or flow path, blade leading and trailing edge curves, repeated many times until a satisfactory design result is obtained. The traditional through-flow design method requires high experience of the designer, and has not guided the distribution of circulation from the perspective of rationally organizing the vorticity field.

传统通流设计方法至少可以在以下方面进行补充：The traditional through-flow design method can be supplemented in at least the following aspects:

(1)在通流设计阶段给定合理的环量分布形式预先组织涡量场；(1) Pre-organize the vorticity field with a reasonable circulation distribution form in the flow design stage;

(2)通过关键的涡量分布参数指导并优化环量分布形式的给定。(2) Guide and optimize the given form of circulation distribution through the key vorticity distribution parameters.

发明内容 Contents of the invention

作为压气机传统通流设计方法的补充，本发明提供一种周向涡量优化环量分布的通流设计方法。As a supplement to the traditional through-flow design method of the compressor, the present invention provides a through-flow design method for optimizing the circulation distribution of the circumferential vortex.

由于压气机内部是一个高强度的复杂涡量场，各类旋涡涡量对压气机总性能参数都有其正负、大小贡献，通过研究发现周向涡量这个新型的涡动力学参数对压气机性能如流量、压比、效率有重要影响，当周向涡量正峰值越贴近于机匣表面，负峰值越贴近于轮毂表面时，即正、负峰值不向主流区扩散，压气机加功增压能力越强，流量、压比、效率等指标越高。Since the interior of the compressor is a high-intensity complex vorticity field, all kinds of vortex vortices have their positive and negative contributions to the overall performance parameters of the compressor. Through research, it is found that the circumferential vorticity, a new type of vortex dynamics parameter, has a significant impact on the compressor. Compressor performance such as flow rate, pressure ratio, and efficiency have an important impact. When the positive peak value of the circumferential vorticity is closer to the surface of the casing and the negative peak value is closer to the surface of the hub, that is, the positive and negative peak values do not spread to the mainstream area, and the compressor increases. The stronger the power boosting capability, the higher the flow rate, pressure ratio, efficiency and other indicators.

本发明为了在压气机初步设计阶段能预先有效地控制周向涡量分布，将周向涡量诊断应用于通流设计中。根据理论推导和机理分析，提出周向涡量在通流设计子午面最优的分布准则是：子午面主流区周向涡量接近于零。根据该设计准则，从叶轮机轴对称Crocco方程出发，并利用涡量与环量的密切关系，得到了环量的优化迭代公式。In order to effectively control the distribution of the circumferential vortex in advance in the preliminary design stage of the compressor, the present invention applies the diagnosis of the circumferential vortex to the flow design. According to the theoretical derivation and mechanism analysis, it is proposed that the optimal distribution criterion of the circumferential vorticity in the flow design meridian is that the circumferential vorticity in the main flow area of the meridian is close to zero. According to the design criterion, starting from the axisymmetric Crocco equation of the turbine, and using the close relationship between vorticity and circulation, the optimal iterative formula of circulation is obtained.

轴对称假设下，涡量的各分量如下，且与环量有如下关系：Under the axisymmetric assumption, the components of vorticity are as follows, and have the following relationship with circulation:

${ω ω}_{r r} = = \frac{&PartialD; &PartialD; {V V}_{z z}}{r r &PartialD; &PartialD; θ θ} - - \frac{&PartialD; &PartialD; {V V}_{θ θ}}{&PartialD; &PartialD; z z} = = - - \frac{11}{r r} \frac{&PartialD; &PartialD; Γ Γ}{&PartialD; &PartialD; z z} - - - - - - ((11))$

${ω ω}_{θ θ} = = \frac{&PartialD; &PartialD; {V V}_{r r}}{&PartialD; &PartialD; z z} - - \frac{{&PartialD; &PartialD; V V}_{z z}}{&PartialD; &PartialD; r r} - - - - - - ((22))$

${ω ω}_{z z} = = \frac{11}{r r} \frac{&PartialD; &PartialD; (({V V}_{θ θ} r r))}{&PartialD; &PartialD; r r} - - \frac{11}{r r} \frac{{&PartialD; &PartialD; V V}_{r r}}{&PartialD; &PartialD; θ θ} = = \frac{11}{r r} \frac{&PartialD; &PartialD; Γ Γ}{&PartialD; &PartialD; r r} - - - - - - ((33))$

其中V为绝对速度，ω为涡量，下标(r，θ，z)为柱坐标下各分量。Crocco方程为Where V is the absolute velocity, ω is the vorticity, and the subscripts (r, θ, z) are the components in cylindrical coordinates. The Crocco equation is

$ω ω \times \times V V = = - - &dtri; &dtri; H h + + T T &dtri; &dtri; s the s + + F f - - - - - - ((44))$

其中H是滞止总焓，s为熵，F为体积力包括两部分，叶片力和粘性体积力。在通流设计的轴对称假设前提下，Crocco方程在柱坐标下三个分式为：Where H is the total enthalpy of stagnation, s is the entropy, and F is the body force including two parts, blade force and viscous body force. Under the premise of the axisymmetric assumption of the flow design, the three fractions of the Crocco equation in cylindrical coordinates are:

${V V}_{z z} {ω ω}_{θ θ} = = \frac{11}{{22 r r}^{22}} \frac{&PartialD; &PartialD; (({Γ Γ}^{22}))}{&PartialD; &PartialD; r r} - - \frac{&PartialD; &PartialD; H h}{&PartialD; &PartialD; r r} + + T T \frac{&PartialD; &PartialD; s the s}{&PartialD; &PartialD; r r} + + {F f}_{r r} - - - - - - ((55))$

$V V \cdot &Center Dot; &dtri; &dtri; Γ Γ = = r r {F f}_{θ θ} - - - - - - ((66))$

${V V}_{r r} {ω ω}_{θ θ} = = \frac{11}{{22 r r}^{22}} \frac{&PartialD; &PartialD; (({Γ Γ}^{22}))}{&PartialD; &PartialD; z z} + + \frac{&PartialD; &PartialD; H h}{&PartialD; &PartialD; z z} - - T T \frac{&PartialD; &PartialD; H h}{&PartialD; &PartialD; z z} - - {F f}_{z z} - - - - - - ((77))$

根据子午面主流区周向涡量接近于零的最优分布准则，应满足(5)和(7)式左边项为0，从而得到对应的环量平方的轴向和径向梯度，即According to the optimal distribution criterion that the circumferential vorticity in the mainstream area of the meridian surface is close to zero, the left-hand term of equations (5) and (7) should be 0, so that the corresponding axial and radial gradients of the square of the circulation can be obtained, namely

$\frac{&PartialD; &PartialD; (({Γ Γ}^{22}))}{&PartialD; &PartialD; r r} = = {22 r r}^{22} ((\frac{&PartialD; &PartialD; H h}{&PartialD; &PartialD; r r} - - T T \frac{&PartialD; &PartialD; s the s}{&PartialD; &PartialD; t t} - - {F f}_{r r})) - - - - - - ((88))$

$\frac{&PartialD; &PartialD; (({Γ Γ}^{22}))}{&PartialD; &PartialD; z z} = = {22 r r}^{22} ((- - \frac{&PartialD; &PartialD; H h}{&PartialD; &PartialD; z z} + + T T \frac{&PartialD; &PartialD; s the s}{&PartialD; &PartialD; z z} + + {F f}_{z z})) - - - - - - ((99))$

根据求得的环量两个方向梯度更新环量分布，在通流设计中用来进行环量分布的寻优迭代。The circulation distribution is updated according to the calculated two-direction gradient of the circulation, which is used for optimization iteration of the circulation distribution in the flow design.

本发明的特点在于用周向涡量作为诊断参数，根据周向涡量最优分布准则和涡、环量关系推导通流设计中环量的寻优迭代公式，用于环量分布优化，另外还可以将周向涡量作为诊断参数优化流道曲线及叶片前尾缘曲线等，该周向涡量通流设计方法可以指导压气机设计，且有利于降低对经验性的要求，实现压气机的高性能设计。The feature of the present invention is that the circumferential vorticity is used as the diagnostic parameter, and the optimal iterative formula of the circulation in the flow design is deduced according to the optimal distribution criterion of the circumferential vorticity and the relationship between the vortex and the circulation, which is used for the optimization of the circulation distribution, and in addition The circumferential vorticity can be used as a diagnostic parameter to optimize the flow channel curve and the leading and trailing edge curve of the blade. High performance design.

本发明的内容包括具有周向涡量诊断功能的通流设计方法，以及具有周向涡量优化环量分布的功能的通流设计方法。本发明还包括将周向涡量作为诊断参数优化其他设计参数如流道形式，叶片前尾缘曲线等功能。The content of the invention includes a through-flow design method with the function of diagnosing the circumferential vortex, and a through-flow design method with the function of optimizing the circulation distribution of the circumferential vortex. The invention also includes the function of using the circumferential vortex as a diagnostic parameter to optimize other design parameters such as flow path form, blade leading and trailing edge curves and the like.

附图说明 Description of drawings

图1为本发明的压气机周向涡量通流设计方法流程图；Fig. 1 is the flow chart of design method of compressor circumferential vortex flow of the present invention;

图2为用该设计方法优化前后的跨声转子特性对比Figure 2 is a comparison of the characteristics of the transacoustic rotor before and after optimization with this design method

具体实施方式 Detailed ways

本发明的压气机周向涡量通流设计方法其具体实施方式如图1所示，包括：Its specific implementation method of the compressor circumferential vortex flow design method of the present invention is shown in Figure 1, including:

步骤1、给定通流设计需要的流道曲线、叶片前尾缘曲线等几何数据，生成子午面计算网格，并给定初始的气动设计参数环量分布，包括沿径向和轴向的分布形式，运用通流程序进行子午面流场计算；Step 1. Given the geometric data such as flow channel curves and blade leading and trailing edge curves required by the flow design, generate meridian surface calculation grids, and give the initial aerodynamic design parameter circulation distribution, including radial and axial Distribution form, use the through-flow program to calculate the meridian surface flow field;

步骤2、根据涡量定义由速度场求解涡量场，得到周向涡量在子午面的分布；Step 2. According to the definition of vorticity, the vorticity field is solved by the velocity field, and the distribution of the circumferential vorticity on the meridian plane is obtained;

步骤3、按照周向涡量最优分布准则判断得到的周向涡量分布是否符合要求，即检查在子午面周向涡量正负峰值是否局限于轮毂机匣区域，是否向主流区扩散，若向主流区扩散较严重，需进行环量分布形式的优化，进入步骤4，反之，若周向涡量分布较理想则可以进行叶片造型和三维计算；Step 3. Determine whether the obtained circumferential vorticity distribution meets the requirements according to the optimal distribution criterion of the circumferential vorticity, that is, check whether the positive and negative peaks of the circumferential vorticity on the meridian plane are limited to the hub casing area and whether they diffuse to the main flow area, If the diffusion to the mainstream area is serious, it is necessary to optimize the circulation distribution form and proceed to step 4. On the contrary, if the circumferential vorticity distribution is ideal, the blade shape and three-dimensional calculation can be carried out;

步骤4、利用根据涡量与环量密切关系推导出的环量迭代公式(8)和(9)，进行环量分布的优化，然后再返回步骤1进行通流计算，直至达到满意的结果。Step 4. Use circulation iterative formulas (8) and (9) derived from the close relationship between vorticity and circulation to optimize circulation distribution, and then return to step 1 for flow calculation until a satisfactory result is achieved.

本发明可以从较简单的环量分布形式如线性分布开始进行迭代，进行3～4次迭代后便可得到较优的环量分布形式，相应的周向涡量分布更佳，峰值向主流区扩散变弱。这样可以减弱对设计者经验的要求，借助周向涡量诊断帮助设计者自动寻找到较优的环量分布形式。The present invention can iterate from a relatively simple circulation distribution form such as linear distribution, and after 3 to 4 iterations, a better circulation distribution form can be obtained, and the corresponding circumferential vorticity distribution is better, and the peak is toward the mainstream area. Diffusion becomes weaker. In this way, the requirements for the designer's experience can be weakened, and the designer can automatically find a better circulation distribution form by means of the circumferential vorticity diagnosis.

最终的设计结果将进行三维粘性分析的校验，检验根据优化的环量分布形式设计的压气机的确能获得高性能。The final design results will be verified by three-dimensional viscous analysis to verify that the compressor designed according to the optimized circulation distribution form can indeed obtain high performance.

如图2为运用该新设计方法优化前后的跨声转子三维计算特性曲线对比，左为流量-压比特性曲线，右为流量-效率特性曲线，黑色空心点为优化前特性，红色实心点为优化后特性。可以发现优化后转子压比、效率都大大提高。峰值效率点压比提高了1.9％，效率提高了1.36％。Figure 2 shows the comparison of the three-dimensional calculation characteristic curves of the transacoustic rotor before and after optimization using the new design method. The left is the flow-pressure ratio characteristic curve, and the right is the flow-efficiency characteristic curve. Optimized features. It can be found that the optimized rotor pressure ratio and efficiency are greatly improved. The peak efficiency point-to-pressure ratio has been improved by 1.9%, and the efficiency has been improved by 1.36%.

本发明优点在于抓住了影响压气机总性能的关键涡动力学参数-周向涡量，在压气机初步设计阶段即通流设计中预先控制周向涡量分布；根据周向涡量最优分布设计准则自动优化环量分布，减少了对设计者经验的高要求，提高了设计效率。The present invention has the advantage of grasping the key vortex dynamics parameter—circumferential vorticity, which affects the overall performance of the compressor, and controlling the distribution of circumferential vorticity in advance in the preliminary design stage of the compressor, that is, in the flow design; The distribution design criterion automatically optimizes the circulation distribution, which reduces the high requirement for the designer's experience and improves the design efficiency.

以上所述，仅为本发明较佳的具体实施方式，但本发明的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本发明揭露的技术范围内，可轻易想到的变化或替换，都应涵盖在本发明的保护范围之内。The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of changes or modifications within the technical scope disclosed in the present invention. Replacement should be covered within the protection scope of the present invention.

Claims

1. A design method for circumferential vortex flow of a compressor, characterized in that it comprises steps:

(1) Given the geometric data such as the flow channel curve, the blade front and trailing edge curves and the initial circulation distribution required for the flow design, use the flow program to calculate the flow field on the meridian surface;

(2) Diagnose the circumferential vorticity to obtain the distribution of the circumferential vorticity on the meridian plane;

(3) According to the optimal distribution criterion of the circumferential vorticity, it is judged whether the obtained circumferential vorticity distribution meets the requirements, that is, to check whether the positive and negative peaks of the circumferential vorticity on the meridian plane are limited to the hub casing area and whether they diffuse to the main flow area, If the diffusion to the mainstream area is serious, the circulation distribution form needs to be optimized, and enter step (4); if the circumferential vorticity distribution is ideal, the blade shape and three-dimensional analysis and calculation can be carried out;

(4) According to the circulation iterative formula deduced from the vorticity, circulation relationship and Crocco equation, optimize the circulation distribution; then return to step 1 for flow calculation until a satisfactory result is achieved.

2. The method for designing the circumferential vortex flow of a compressor according to claim 1, wherein the circumferential vortex is used as a diagnostic parameter in the flow design.

3. The method for designing the circumferential vortex flow of a compressor according to claim 1, wherein the optimal distribution of the circumferential vorticity is as follows: the positive peak value is close to the casing, the negative peak value is close to the hub, and the peak value is as far away from the hub as possible. Diffusion in the mainstream area; the optimal distribution criterion for the circumferential vorticity on the meridian surface of the flow design is: the circumferential vorticity in the mainstream area is close to zero.

4. The method for designing the circumferential vortex flow of a compressor as claimed in claim 1, characterized in that, according to the optimal distribution criterion of the circumferential vorticity and its close relationship with the circulation, the optimal circulation is obtained from the Crocco equation The iterative formula is put into the flow design for automatic optimization of the circulation.

5. The design method for circumferential vortex flow of a compressor according to claim 1, characterized in that it also has the function of using the circumferential vortex as a diagnostic parameter to optimize the form of the flow path and the curve of the leading and trailing edges of the blade.