Design method and system for auxiliary guide vane of variable air inlet guide vane of air compressor

Abstract

The invention discloses an auxiliary guide vane design method and system for a variable air inlet guide vane of a gas compressor, and is applied to the technical field of fluid machinery. The method comprises the steps of performing CFD numerical simulation on a main guide blade under an existing large-deflection-angle working condition to obtain a separation point position of the main guide blade; determining an initial design parameter combination of the auxiliary guide vane; cFD numerical simulation is carried out on the main guide vane and the auxiliary guide vane, and the minimization of the separation area and the total pressure loss coefficient are taken as optimization targets; solving the optimization target to obtain an optimal auxiliary guide vane design parameter combination; the optimization effect of the optimal auxiliary guide vane design parameter combination is verified through experiments, and the auxiliary guide vane design parameter combination is corrected. According to the invention, one auxiliary guide vane is specifically designed on the basis of the existing main guide vane, so that the loss caused by vane back separation flow under a large deflection angle is reduced, and the main guide vane does not need to be redesigned.

Description

Technical Field

[0001] The present invention relates to the technical field of fluid machinery, and more particularly to a design method and system for a secondary guide vane for a variable inlet guide vane of a compressor. Background Art

[0002] In the field of aeroengines, a compressor compresses air through rotating blades and sends it into a combustion chamber. The guide vane is located at the inlet of the compressor. A variable inlet guide vane (VIGV) is an adjustable guide vane that can change the pre-whirl of the air flow by changing the installation angle of the inlet guide vane of the impeller. Adjusting the guide vane angle can adjust the air flow angle at low speeds, avoid excessive incidence angles between the air flow and the rotating blades, which may cause separation or stall, thereby avoiding surging. At the same time, it can also optimize the inlet conditions and improve the efficiency of the compressor. However, when the existing guide vane is in a large deflection angle condition, separated flow is likely to occur on the back of the guide vane, which will lead to a large flow loss and reduce the aerodynamic area of the guide vane passage. For a vector exhaust device, the former will result in a smaller total pressure recovery coefficient, and the latter will lead to a smaller outlet area coefficient. In addition, the unsteady characteristics of the separated flow may also cause problems such as vibration, structure, and noise. By adding a secondary guide vane, the above losses can be reduced, but the existing technology of the secondary guide vane does not design the secondary guide vane according to the actual working conditions of the main guide vane, resulting in an unsatisfactory effect of the secondary guide vane. Therefore, how to provide a design method and system for a secondary guide vane for a variable inlet guide vane of a compressor is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0003] In view of this, the present invention provides a design method and system for a secondary guide vane for a variable inlet guide vane of a compressor, which performs CFD numerical simulation based on the actual working conditions of the existing main guide vane, designs the secondary guide vane, and simulates and optimizes the design parameters of the secondary guide vane.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A design method for a secondary guide vane for a variable inlet guide vane of a compressor, comprising the following steps:

[0006] S1. Perform CFD numerical simulation on the existing main guide vane under large deflection angle conditions to obtain the separation point position of the main guide vane;

[0007] S2. Determine the initial design parameter combination of the secondary guide vane according to the separation point position of the main guide vane;

[0008] S3. Perform CFD numerical simulation on the main guide vane and the secondary guide vane, and use minimizing the separation zone area and the total pressure loss coefficient as the optimization objectives;

[0009] S4. Solve the optimization objective to obtain the optimal combination of secondary guide vane design parameters;

[0010] S5. Verify the optimization effect of the optimal combination of secondary guide vane design parameters through experiments and correct the combination of secondary guide vane design parameters.

[0011] Optionally, the combination of design parameters in S2 includes: the position, angle, chord length, thickness, leading edge angle, trailing edge angle, leading edge small circle radius, and trailing edge small circle radius of the secondary guide vane.

[0012] Optionally, S2 is specifically: The secondary guide vane is arranged on the lower side of the suction surface of the primary guide vane. Determine the position of the secondary guide vane to be spaced 0.2 - 0.4 times the chord length of the primary guide vane according to the chord length of the primary guide vane; determine the installation deviation angle of the secondary guide vane according to the deviation angle of the primary guide vane; determine the chord length of the secondary guide vane to be 0.1 - 0.2 times the chord length of the primary guide vane according to the chord length of the primary guide vane; determine the thickness of the secondary guide vane to be 0.1 - 0.15 times the chord length of the secondary guide vane according to the chord length of the secondary guide vane.

[0013] Optionally, S3 is specifically:

[0014] S31. Determine the numerical range of the combination of secondary guide vane design parameters and establish a three-dimensional model of the primary guide vane and the secondary guide vane;

[0015] S32. Divide the grid, set the solver and boundary conditions;

[0016] S33. Establish an objective function to minimize the separation zone area and the total pressure loss coefficient, and fit the relationship between the objective function and the secondary guide vane design parameters through the response surface algorithm.

[0017] Optionally, the calculation of the separation zone area is specifically:

[0018] Judge the peak position of the adverse pressure gradient of the primary guide vane, determine the separation region, and calculate the sum of the areas of all grid cells belonging to the separation region:

[0019]

[0020] In the formula, S is the separation zone area, N is the total number of grid cells belonging to the separation region, and s i represents the area of the i-th grid cell in the separation region, i ∈ [1, N];

[0021] The calculation of the total pressure loss coefficient is specifically:

[0022]

[0023] In the formula, w is the total pressure loss coefficient, P1 is the total pressure at the inlet of the guide vane, P2 is the total pressure at the outlet of the guide vane, ρ is the fluid density, and V1 is the flow velocity at the inlet of the guide vane.

[0024] Optionally, S4 is specifically as follows:

[0025] S41. Initialize the iteration count, set the maximum number of iterations, generate n individuals, and randomly set the secondary guide vane design parameters of each individual;

[0026] S42. Calculate the fitness of all individuals, and perform random selection, parameter mixing, and parameter random mutation operations on all individuals in sequence;

[0027] S43. Calculate the fitness of all individuals, and repeat the random selection, parameter mixing, and parameter random mutation operations in S42;

[0028] S44. When the maximum number of iterations is reached or the iteration stop condition is met, enter S45;

[0029] S45. Recalculate the fitness of all individuals, and select the secondary guide vane design parameter combination of the individual with the highest fitness as the optimal solution.

[0030] Optionally, S5 is specifically as follows: Conduct experiments based on the existing primary guide vane and the secondary guide vane designed according to the optimal design parameter combination, collect data during the experiment, compare the separation zone area and total pressure loss coefficient of the experimental results with the CFD simulation results. If the difference between the two is greater than the set threshold, fine-tune the secondary guide vane design parameters according to the experimental results.

[0031] A secondary guide vane design system for a compressor variable inlet guide vane, which executes the above-mentioned secondary guide vane design method for a compressor variable inlet guide vane, includes:

[0032] A CFD numerical simulation module for performing CFD numerical simulation on the primary guide vane and the secondary guide vane with different design parameter combinations;

[0033] A design parameter generation module for generating an initial design parameter combination of the secondary guide vane according to the situation of the primary guide vane and preset rules;

[0034] A design parameter optimization module for optimizing the design parameter combination of the secondary guide vane and calculating the optimal solution;

[0035] An experimental comparison and correction module for experimentally verifying the optimal secondary guide vane design parameter combination.

[0036] As can be seen from the above technical solutions, compared with the prior art, the present invention provides a method and system for designing a secondary guide vane for a variable inlet guide vane of a compressor, having the following beneficial effects: Based on the actual operating conditions of the existing primary guide vane, the present invention performs CFD numerical simulation, designs the secondary guide vane, simulates and optimizes the design parameters of the secondary guide vane, reduces the losses caused by the separated flow on the suction side at large deflection angles, without the need to redesign the primary guide vane, and at the same time can effectively reduce the size and structural weight of the device and improve the performance of the entire power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0038] Figure 1 It is a flowchart of the method for designing the secondary guide vane of the present invention;

[0039] Figure 2 It is a flowchart of the algorithm for solving the optimal combination of design parameters of the secondary guide vane of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0041] The embodiments of the present invention disclose a method for designing a secondary guide vane for a variable inlet guide vane of a compressor, as Figure 1 shown, including the following steps:

[0042] S1. Perform CFD numerical simulation on the existing primary guide vane under large deflection angle conditions to obtain the separation point position of the primary guide vane;

[0043] S2. Determine the initial design parameter combination of the secondary guide vane according to the separation point position of the primary guide vane;

[0044] S3. Perform CFD numerical simulation on the primary guide vane and the secondary guide vane, with minimizing the separation zone area and the total pressure loss coefficient as the optimization objectives;

[0045] S4. Solve the optimization objectives to obtain the optimal design parameter combination of the secondary guide vane;

[0046] S5. Verify the optimization effect of the optimal secondary guide vane design parameter combination through experiments, and correct the secondary guide vane design parameter combination.

[0047] Further, the design parameter combination in S2 includes: the position, angle, chord length, thickness, leading edge angle, trailing edge angle, leading edge small circle radius, and trailing edge small circle radius of the secondary guide vane.

[0048] Further, S2 is specifically: the secondary guide vane is arranged on the lower side of the blade back of the primary guide vane. The position of the secondary guide vane is determined to be 0.2 - 0.4 times the chord length of the primary guide vane at intervals according to the chord length of the primary guide vane; the installation deflection angle of the secondary guide vane is determined according to the deflection angle of the primary guide vane; the chord length of the secondary guide vane is determined to be 0.1 - 0.2 times the chord length of the primary guide vane according to the chord length of the primary guide vane; the thickness of the secondary guide vane is determined to be 0.1 - 0.15 times the chord length of the secondary guide vane according to the chord length of the secondary guide vane.

[0049] In the embodiment of the present invention, the leading edge angle, trailing edge angle, leading edge small circle radius, and trailing edge small circle radius can be determined based on the conventional guide vane. The installation deflection angle is set as β = kα + c, where α is the deflection angle of the primary guide vane, and k and c are preset coefficients. After setting the value ranges of k and c, they are used for subsequent optimization.

[0050] Further, S3 is specifically:

[0051] S31. Determine the numerical range of the secondary guide vane design parameter combination, and establish a three-dimensional model of the primary guide vane and the secondary guide vane;

[0052] In the embodiment of the present invention, if the chord length of the primary guide vane is l, then the numerical range of the position of the secondary guide vane is 0.2 - 0.4l, the numerical range of the chord length of the secondary guide vane is 0.1 - 0.2l, and the thickness range of the secondary guide vane is 0.1 - 0.15 times the chord length of the secondary guide vane. Specifically, the thickness is different at different positions of the secondary guide vane, but the maximum thickness and the minimum thickness are both within the numerical range.

[0053] S32. Divide the grid, and set the solver and boundary conditions;

[0054] S33. Establish an objective function for minimizing the separation zone area and the total pressure loss coefficient, and fit the relationship between the objective function and the secondary guide vane design parameters through the response surface algorithm.

[0055] Further, the calculation of the separation zone area is specifically:

[0056] Judge the position of the peak of the adverse pressure gradient of the primary guide vane, determine the separation region, and calculate the sum of the areas of all grid cells belonging to the separation region:

[0057]

[0058] In the formula, S is the separation zone area, N is the total number of grid cells belonging to the separation region, si represents the area of the grid cell in the \(i\)-th separation region, where \(i\in[1,N]\);

[0059] The calculation of the total pressure loss coefficient is specifically as follows:

[0060]

[0061] In the formula, \(w\) is the total pressure loss coefficient, \(P1\) is the total pressure at the inlet of the guide vane, \(P2\) is the total pressure at the outlet of the guide vane, \(\rho\) is the fluid density, and \(V1\) is the flow velocity at the inlet of the guide vane.

[0062] In the embodiment of the present invention, before optimization, the design parameters are screened, and the parameters that have a greater impact on the optimization result are retained for optimal solution. The influence of each parameter on the separation zone area and the total pressure loss coefficient is calculated respectively, that is, fixing other parameters, optimizing a single parameter and calculating the changes in the separation zone area and the total pressure loss coefficient when the optimized parameter changes through CFD numerical simulation, and screening the parameters through the multi-factor variance analysis method.

[0063] Further, as Figure 2 shown, S4 is specifically as follows:

[0064] S41. Initialize the iteration count, set the maximum number of iterations, generate \(n\) individuals, and randomly set the design parameters of the secondary guide vanes for each individual;

[0065] S42. Calculate the fitness of all individuals, and perform random selection, parameter mixing, and parameter random mutation operations on all individuals in turn;

[0066] S43. Calculate the fitness of all individuals, and repeat the random selection, parameter mixing, and parameter random mutation operations in S42;

[0067] S44. When the maximum number of iterations is reached or the iteration stop condition is met, enter S45;

[0068] S45. Recalculate the fitness of all individuals, and select the combination of the design parameters of the secondary guide vanes of the individual with the highest fitness as the optimal solution.

[0069] In the embodiment of the present invention, S42 is specifically as follows:

[0070] Assign selection probabilities to all individuals according to the fitness calculation results. The higher the fitness of an individual, the higher the probability of being selected. Then randomly select and retain individuals, and then mix the parameters. For example, for a certain continuous variable \(x\), the variable \(x3\) of the offspring is:

[0071] \(x3 = \lambda x1+(1 - \lambda)x2\)

[0072] In the formula, x1 and x2 are the variables of the first parent and the second parent respectively, and λ ∈ (0, 1] is the mixing coefficient; for discrete variables, randomly inherit the value of one of the parents; after parameter mixing, perform a mutation operation, and reset the variable to other values within the variable value range with a certain probability. In the embodiment of the present invention, the mutation probability is 5%. After completing the above operations, a new generation of individuals is obtained, and the individuals with the top fitness rankings in the new generation are retained for the next iteration calculation until the iteration stop condition is met.

[0073] Further, S5 is specifically: conduct experiments based on the existing main guide vane and the secondary guide vane designed according to the optimal design parameter combination, collect the data during the experiment, compare the separation area and the total pressure loss coefficient of the experimental results with the CFD simulation results. If the difference between the two is greater than the set threshold, fine-tune the design parameters of the secondary guide vane according to the experimental results.

[0074] In the embodiment of the present invention, if the difference in the separation area between the experimental result and the CFD simulation result exceeds 10%, fine-tuning optimization can be performed by slightly increasing or decreasing parameters such as the angle and chord length.

[0075] And Figure 1 Corresponding to the method described above, the embodiment of the present invention also discloses a design system for the secondary guide vane of a compressor variable inlet guide vane, which executes the above-mentioned design method for the secondary guide vane of a compressor variable inlet guide vane, including:

[0076] A CFD numerical simulation module for performing CFD numerical simulation on the main guide vane and the secondary guide vanes with different design parameter combinations;

[0077] A design parameter generation module for generating an initial design parameter combination of the secondary guide vane according to the situation of the main guide vane and the preset rules;

[0078] A design parameter optimization module for optimizing the design parameter combination of the secondary guide vane and calculating the optimal solution;

[0079] An experimental comparison and correction module for experimentally verifying the optimal secondary guide vane design parameter combination.

[0080] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0081] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A design method for the auxiliary guide vane of a compressor variable inlet guide vane, characterized in that, It includes the following steps: S1. Conduct a CFD numerical simulation on the leading vane under the existing large deflection angle condition to obtain the separation point position of the leading vane; S2. Determine the initial design parameter combination of the secondary vane according to the separation point position of the leading vane; S3. Conduct a CFD numerical simulation on the leading vane and the secondary vane, with minimizing the separation zone area and the total pressure loss coefficient as the optimization objectives; S4. Solve the optimization objective to obtain the optimal design parameter combination of the secondary vane; S5. Verify the optimization effect of the optimal secondary vane design parameter combination through experiments and correct the secondary vane design parameter combination.

2. A design method for a secondary guide vane of a compressor variable inlet guide vane according to claim 1, characterized in that The design parameter combination in S2 includes: the position, angle, chord length, thickness, leading edge angle, trailing edge angle, leading edge small circle radius, and trailing edge small circle radius of the secondary vane.

3. A design method for a secondary guide vane of a variable inlet guide vane of a compressor according to claim 2, characterized in that, Specifically, S2 is as follows: The secondary vane is arranged on the lower side of the suction surface of the leading vane. According to the chord length of the leading vane, the position of the secondary vane is determined to be spaced 0.2 - 0.4 times the chord length of the leading vane; according to the deflection angle of the leading vane, the installation deflection angle of the secondary vane is determined; according to the chord length of the leading vane, the chord length of the secondary vane is determined to be 0.1 - 0.2 times the chord length of the leading vane; according to the chord length of the secondary vane, the thickness of the secondary vane is determined to be 0.1 - 0.15 times the chord length of the secondary vane.

4. A secondary guide vane design method for a variable inlet guide vane of a compressor according to claim 1, characterized in that Specifically, S3 is as follows: S31. Determine the numerical range of the secondary vane design parameter combination and establish a three-dimensional model of the leading vane and the secondary vane; S32. Divide the grid, set the solver and boundary conditions; S33. Establish an objective function for minimizing the separation zone area and the total pressure loss coefficient, and fit the relationship between the objective function and the secondary vane design parameters through the response surface algorithm.

5. A design method for the auxiliary guide vane of a compressor variable inlet guide vane according to claim 4, characterized in that The calculation of the separation zone area is specifically as follows: Judge the position of the peak value of the adverse pressure gradient of the leading vane, determine the separation region, and calculate the sum of the areas of all grid cells belonging to the separation region: Where S is the area of the separation zone, N is the total number of grid cells belonging to the separation zone, and s i represents the area of the i-th grid cell in the separation zone, where i ∈ [1, N]; The calculation of the total pressure loss coefficient is specifically as follows: In the formula, w is the total pressure loss coefficient, P1 is the total pressure at the inlet of the vane, P2 is the total pressure at the outlet of the vane, ρ is the fluid density, and V1 is the flow velocity at the inlet of the vane.

6. A design method for a secondary guide vane of a variable inlet guide vane of a compressor according to claim 1, characterized in that, Specifically, S4 is as follows: S41. Initialize the iteration count, set the maximum number of iterations, generate n individuals, and randomly set the design parameters of the secondary vane for each individual; S42. Calculate the fitness of all individuals, and perform random selection, parameter mixing, and parameter random mutation operations on all individuals in turn; S43. Calculate the fitness of all individuals, and repeat the random selection, parameter mixing, and parameter random mutation operations in S42; S44. When the maximum number of iterations is reached or the iteration stop condition is met, enter S45; S45. Recalculate the fitness of all individuals, and select the design parameter combination of the individual with the highest fitness as the optimal solution.

7. A design method for the auxiliary guide vane of a compressor variable inlet guide vane according to claim 1, characterized in that, Specifically, S5 is as follows: Conduct experiments based on the existing leading vane and the secondary vane designed according to the optimal design parameter combination, collect data during the experiment, compare the separation zone area and the total pressure loss coefficient of the experimental results with the CFD simulation results. If the difference between the two is greater than the set threshold, fine-tune the secondary vane design parameters according to the experimental results.

8. A secondary guide vane design system for a compressor variable inlet guide vane, characterized in that, Implementing a method for designing a secondary vane for a compressor variable inlet guide vane according to any one of claims 1 - 7, includes: CFD numerical simulation module, used to perform CFD numerical simulation on the main guide vane and the auxiliary guide vanes with different combinations of design parameters; Design parameter generation module, which generates the initial design parameter combinations of the auxiliary guide vanes according to the situation of the main guide vane and the preset rules; Design parameter optimization module, used to optimize the design parameter combinations of the auxiliary guide vanes and calculate the optimal solution; Experimental comparison and correction module, used to conduct experimental verification on the optimal design parameter combinations of the auxiliary guide vanes.

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