An optimization design method for the guide vane of a low-vibration and low-flow-resistance axial-flow pump

Abstract

The present invention discloses an optimized design method for the guide vane of a low-vibration and low-flow-resistance axial-flow pump. This method improves the traditional axial-flow pump blade profile design, and designs the guide vane airfoil that simultaneously meets the vibration performance and self-flow performance through the low-vibration design principle and the low-flow-resistance design principle; conducts curve research point design on the installation angle in the flow direction of the guide vane middle flow surface airfoil, and targets the vibration performance and self-flow performance positioning control at different flow positions, so that the airfoil design of the guide vane simultaneously meets the coordinated control of low vibration and low flow resistance; verifies the vibration performance and self-flow performance for the model to obtain the guide vane model of the low-vibration and low-flow-resistance axial-flow pump. The design method of the present invention can effectively improve the vibration performance and self-flow performance of the axial-flow pump, and achieve the efficient synchronous coordinated design of dual working conditions.

Description

Technical Field

[0001] The present invention relates to the field of optimization design of fluid machinery blades, and provides an optimization design method for the guide vane of an axial flow pump with low vibration and low flow resistance. Background Art

[0002] The quality of the gravity flow performance of the cooling system has an important impact on the safe operation of ships and submarines. The gravity flow cooling system utilizes the kinetic energy of the submarine during navigation to increase the head of the inlet cooling water, and uses the negative pressure formed by the forward movement of the submarine to reduce the back pressure of the cooling water drainage. When sailing at high speed, seawater flows into the inlet pipe at a very high relative speed, and part of the kinetic energy is converted into positive static pressure head therein, enabling the seawater to flow through the pipeline resistance by itself. Under the cruise speed condition, the cooling system does not require pump power, and allows the seawater to flow through the circulation pump and cooling equipment by itself; at low speed, high speed and reverse navigation, the circulation pump is used to supply cooling water. Therefore, higher requirements are put forward for the flow resistance characteristics and vibration noise of the circulation pump, and low flow resistance and low vibration have become the development trend of the circulation pump for the new generation of ships and nuclear-powered submarines.

[0003] Due to the complex operating conditions of the circulation pump, it brings great difficulties to the suppression of the flow-induced vibration and gravity flow resistance of the circulation pump. Most of the existing analyses and researches are only based on the single-condition analysis of the rated pump condition or the gravity flow condition. At present, the technical focus is respectively concentrated on the vibration reduction and noise reduction in the rated pump condition and the rough estimation of the gravity flow resistance in the gravity flow condition, and the performance requirements of the two conditions are not considered synchronously. With the rapid development of application requirements and pump technology, the problem of low flow resistance and low vibration of the circulation pump has gradually become the main bottleneck restricting the further application of pump technology. The vibration reduction design principle and the low flow resistance design principle have different requirements for the angle of the dynamic and static interference area, which causes great difficulties in vibration reduction and resistance reduction of the pump, and the synchronous coordinated control of low flow resistance and low vibration has become a major difficulty. Summary of the Invention

[0004] The object of the present invention is to overcome the deficiencies of the above background art, and provides an optimization design method for the guide vane of an axial flow pump with low vibration and low flow resistance. By using the low vibration design principle and the low flow resistance design principle, the fitting curve point design method is adopted for the middle flow surface airfoil of the guide vane of the axial flow pump, and the vibration performance and gravity flow performance are targeted for positioning control at different flow positions of the guide vane, effectively reducing the vibration force level and gravity flow resistance coefficient of the axial flow pump. The vibration performance and gravity flow performance of the axial flow pump optimized according to the present invention are effectively improved, and the synchronous coordinated control of low vibration and low flow resistance is realized.

[0005] The present invention is realized through the following technical solutions:

[0006] An optimization design method for the guide vane of an axial flow pump with low vibration and low flow resistance, comprising the following steps:

[0007] Step 1: Select four evenly distributed design points on the blade airfoil of the intermediate flow surface of the guide vane. These four design points are located at the inlet of the guide vane, the outlet of the guide vane, and in the middle between the inlet and outlet of the guide vane respectively; the blade installation angles of the four design points are β1, β2, β3, and β4 in sequence, which are used to control the blade airfoil angle;

[0008] Step 2: Considering the low vibration performance of the pump body, according to the low vibration design relationship of α0 + β1 = 180° satisfied by the liquid flow angle α0 at the outlet of the impeller and the installation angle β1 at the inlet of the guide vane, calculate the installation angle β1 at the inlet of the guide vane;

[0009] Step 3: Subtract 35 - 45° from the installation angle β1 at the inlet of the guide vane to obtain the installation angle β4 at the outlet of the guide vane; then, based on the installation angle β1 at the inlet of the guide vane and the installation angle β4 at the outlet of the guide vane, perform a linear fitting on the blade airfoil of the guide vane to obtain β2 and β3;

[0010] Step 4: Change β1 to adopt the low flow resistance design principle, and the angle design value is in the range of 95 - 115°, satisfying the S - type airfoil design; then, according to the new β1, and β2, β3, β4 obtained in Step 3, adopt the modified Bessel function fitting or cubic spline curve fitting method to perform curve fitting on the blade airfoil of the guide vane to obtain the control line of the blade airfoil of the intermediate flow surface of the guide vane;

[0011] Step 5: Thicken the blade airfoil according to the control line of the blade airfoil of the intermediate flow surface of the guide vane. Take the minimum thickness at the inlet and outlet of the blade airfoil of the intermediate flow surface of the guide vane, and take the maximum thickness at 40% - 50% of the length of the blade airfoil of the intermediate flow surface of the guide vane, and use the spline curve to control the thickness distribution of the airfoil, so as to obtain the blade airfoil of the intermediate flow surface of the guide vane; obtain the guide vane according to the blade airfoil of the intermediate flow surface of the guide vane;

[0012] Step 6: Use the guide vane obtained in Step 5 to perform numerical simulation on the axial - flow pump body, and analyze the axial force vibration performance of the impeller of the pump body. Perform FFT (Fast Fourier Transform) on the time - domain pulsation data of the axial force of the impeller under the pump working condition to obtain the frequency - domain pulsation data of the axial force, and use the following formula to extract the frequency - domain pulsation data of the axial force F of the impeller from 10 to 1000 to obtain the vibration force level L F , and judge whether the vibration force level L F meets the requirements:

[0013] L F = 20lg(F / F0)

[0014] where F0 is the reference value of the vibration force level, and F0 = 1 μN.

[0015] If it does not meet the requirements, return to Step 3 to redesign β2, β3, β4; if it meets the vibration requirements, then perform the verification of the self - flowing resistance coefficient. For the verification of the self - flowing resistance coefficient, calculate the self - flowing loss coefficient C according to the following formulad , determine C d to see if it meets the requirements:

[0016] C d = 2(p1 - p2) / ρv 2

[0017] where p1 and p2 are the static pressures at the inlet and outlet of the pump body respectively, ρ is the medium density, and v is the flow velocity of the circulating pump.

[0018] If the self-flow performance requirements are not met, return to step four and redesign β1; if the self-flow performance requirements are met, complete the guide vane design.

[0019] Advantages of the present invention:

[0020] Based on the requirements of vibration performance and self-flow performance, the present invention uses the low-vibration design principle and the low-flow-resistance design principle to achieve the low-vibration and low-flow-resistance optimization design of the axial-flow pump guide vane airfoil. Aiming at the optimization design of the middle flow surface airfoil of the axial-flow pump guide vane, the flow direction position of the guide vane airfoil is targeted for positioning control, and then the synchronous design of low vibration and low flow resistance of the guide vane is realized, effectively reducing the vibration force level and self-flow resistance coefficient of the axial-flow pump. The optimization design purpose of the axial-flow pump guide vane is clearer, the optimization method is simple and efficient, and the optimization design idea is clear and reliable. Through the optimization design of the present invention, the vibration performance and self-flow performance of the axial-flow pump are effectively improved, and the synchronous coordinated control of the dual working conditions of low vibration and low flow resistance is realized. Description of the drawings

[0021] Figure 1 It is a flow schematic diagram of the design method of the embodiment.

[0022] Figure 2 It is a velocity triangle diagram of the dynamic and static interference area.

[0023] Figure 3 It is a distribution diagram of the middle flow surface airfoil of Model 1.

[0024] Figure 4 It is a distribution diagram of the middle flow surface airfoil of Model 2.

[0025] Figure 5 It is a distribution diagram of the middle flow surface airfoil of Model 3.

[0026] Figure 6 It is an angle design diagram of the airfoils of three groups of models.

[0027] Figure 7 It is a geometric model diagram of three groups of models: a) Model 1, b) Model 2, c) Model 3.

[0028] Figure 8 It is a frequency domain diagram of the axial force pulsation of the impeller of Model 1.

[0029] Figure 9 It is the frequency domain diagram of the axial force pulsation of the impeller of Model 2.

[0030] Figure 10 It is the frequency domain diagram of the axial force pulsation of the impeller of Model 3.

[0031] Figure 11 Contour map of the volume entropy generation rate distribution on the guide vane wall surface: a) Model 1, b) Model 2, c) Model 3.

[0032] Figure 12 Contour map of the volume entropy generation rate distribution on the middle stream surface (0.5 cascade position) of the guide vane inner flow passage: a) Model 1, b) Model 2, c) Model 3. Specific implementation manners

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. The described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] As Figure 1 shown, an optimization design method for the guide vane of a low-vibration and low-flow-resistance axial flow pump of the present invention includes the following steps:

[0035] Step 1: Select four evenly distributed design points on the blade airfoil of the middle stream surface of the guide vane. These four design points are respectively located at the inlet of the guide vane, the outlet of the guide vane, and in the middle of the inlet and outlet of the guide vane; the blade installation angles of the four design points are β1, β2, β3, and β4 in sequence, which are used to control the blade airfoil angle;

[0036] Step 2: Considering the low-vibration performance of the pump body, according to the low-vibration design relationship of α0 + β1 = 180° satisfied by the liquid flow angle α0 at the impeller outlet and the installation angle β1 at the guide vane inlet, calculate the installation angle β1 at the guide vane inlet;

[0037] Step 3: Subtract the angle difference from the installation angle β1 at the guide vane inlet to obtain the installation angle β4 at the guide vane outlet; then, based on the installation angle β1 at the guide vane inlet and the installation angle β4 at the guide vane outlet, linearly fit the guide vane blade airfoil to obtain β2 and β3; preferably, the angle difference is taken as 35 - 45°;

[0038] Step 4: Change β1 to make it adopt the low-flow-resistance design principle to meet the S-shaped airfoil design; then, according to the new β1 and β2, β3, β4 obtained in Step 3, curve-fit the guide vane blade airfoil. The curve-fitting method can select the modified Bessel function fitting or the cubic spline curve fitting method to obtain the control line of the guide vane middle stream surface blade airfoil; preferably, the angle design value is in the range of 95 - 115°;

[0039] Step 5: Thicken the blade airfoil according to the control line of the blade airfoil of the middle flow surface of the guide vane. Take the minimum thickness at the inlet and outlet of the blade airfoil of the middle flow surface of the guide vane, take the maximum thickness at 40%-50% of the length of the blade airfoil of the middle flow surface of the guide vane, and use a spline curve to control the thickness distribution of the airfoil, so as to obtain the blade airfoil of the middle flow surface of the guide vane; obtain the guide vane according to the blade airfoil of the middle flow surface of the guide vane;

[0040] Step 6: Perform numerical simulation on the pump body of the axial flow pump using the guide vane obtained in Step 5, and analyze the axial force vibration performance of the impeller of the pump body. Perform FFT fast Fourier transform on the time-domain pulsation data of the axial force of the impeller under the pump condition to obtain the frequency-domain pulsation data of the axial force. Use the following formula to extract the frequency-domain pulsation data of the axial force F of the impeller from 10 to 1000 to obtain the vibration force level L F , and judge whether the vibration force level L F meets the requirements:

[0041] L F = 20lg(F / F0)

[0042] where F0 is the reference value of the vibration force level, and F0 = 1 μN.

[0043] If the requirements are not met, return to Step 3 and redesign β2, β3, and β4; if the vibration requirements are met, then check the self-flow resistance coefficient. For the check of the self-flow resistance coefficient, calculate the self-flow loss coefficient C according to the following formula d , and judge whether C d meets the requirements:

[0044] C d = 2(p1 - p2) / ρv 2

[0045] where p1 and p2 are the static pressures at the inlet and outlet of the pump body respectively, ρ is the medium density, and is the incoming flow velocity of the circulating pump.

[0046] If the self-flow performance requirements are not met, return to Step 4 and redesign β1; if the self-flow performance requirements are met, the design of the guide vane is completed.

[0047] Taking the design and optimization of a certain axial flow pump model as an example, referring to Figures 2 to 12 , the specific implementation process is as follows:

[0048] For the steady numerical simulation of hydraulic components, the ANSYS BladeGen is used for the airfoil design of the blade hub surface, the middle flow surface, and the shroud surface. The ANSYS TurboGrid is used to draw the blade grid, and ICEM is used to draw the grids of the remaining flow channels. The total number of grids is approximately 4.93 million. The ANSYS CFX software is used for numerical simulation. In the steady numerical simulation, the impeller part is the rotating region, and the other parts are the stationary regions. Each region is connected to each other through the interface surface.

[0049] The design geometric parameters of the axial flow pump are shown in Table 1.

[0050] Table 1 Geometric parameters of the axial flow pump

[0051]

[0052]

[0053] Step 1: The middle flow surface airfoil of the general design guide vane model (i.e., Model 1) is as Figure 3 shown. Four evenly distributed design points of the guide vane middle flow surface blade airfoil are selected. These four design points are located at the guide vane inlet, the guide vane outlet, and the middle of the guide vane inlet and the guide vane outlet respectively. The blade installation angles of the four design points are β1, β2, β3, and β4 in sequence, which are used to control the blade airfoil angle.

[0054] Step 2: Considering the low vibration performance of the pump body, the low vibration performance design of the guide vane is carried out. The outlet installation angle β0 of the impeller is 23.12°. According to the velocity triangle conversion calculation, the outlet liquid flow angle α0 of the impeller is 42.37°. The low vibration design relationship of α0 + β1 = 180° is satisfied between the outlet liquid flow angle α0 of the impeller and the inlet installation angle β1 of the guide vane. The optimal value of the inlet installation angle β1 of the guide vane that satisfies the low vibration performance should be 137.63°, and it is rounded to 138°.

[0055] Step 3: The blade airfoil of the guide vane is controlled by linear fitting. Using β1, β2, β3, and β4 that control the blade airfoil angle, the middle flow surface blade airfoil of the guide vane is optimized. Under the design condition that the inlet installation angle of the guide vane is β1 and satisfies the low vibration design principle, the outlet installation angle β4 of the guide vane differs from the inlet installation angle β1 by 35 - 45°. Based on β1 and β4, the linear fitting of the guide vane blade airfoil is carried out, and the design of β2 and β3 is completed and fine-tuned. The linear fitting formula is shown as the following formula, and the fitting error R 2 = 0.9942, as Figure 6 shown. The blade airfoil of the middle flow surface of the designed Model 2 guide vane is as Figure 4 shown.

[0056] y = -0.3925x + 138.12

[0057] Among them, x represents the flow direction position, and y represents the fitted installation angle.

[0058] Step 4: Adopt the S-shaped blade airfoil design method to optimize the design of the blade airfoil on the intermediate flow surface of the guide vane. The installation angle β1 of the guide vane inlet is designed to meet the low-flow-resistance design principle, and the fluid in the stator-rotor interference area tends to flow in vertically. β1 is set at 110°. The design of the angles of β2, β3, and β4 still meets the low-vibration design principle and the basic principle of guide vane pressure unloading. The cubic spline curve is used to fit the curve of the guide vane blade airfoil to obtain the control line of the blade airfoil on the intermediate flow surface of the guide vane, and an optimized model 3 with low-vibration and low-flow-resistance characteristics is obtained. The optimization design of the S-shaped airfoil on the intermediate flow surface is as Figure 5 shown.

[0059] Step 5: Thicken the blade airfoil according to the control line of the blade airfoil on the intermediate flow surface of the guide vane. Take the minimum thickness at the inlet and outlet of the blade airfoil on the intermediate flow surface of the guide vane, and take the maximum thickness at 40%-50% of the length of the blade airfoil on the intermediate flow surface of the guide vane. Use the spline curve to control the thickness distribution of the airfoil shape, so as to obtain the blade airfoil on the intermediate flow surface of the guide vane; obtain the guide vane according to the blade airfoil on the intermediate flow surface of the guide vane. The comparison of the angle designs of the intermediate flow surface airfoils of the guide vanes of the three groups of models is as Figure 6 shown, and the comparison of the geometric models is as Figure 7 shown.

[0060] Step 6: Check the vibration performance and self-flow performance of the axial-flow pump. Perform FFT fast Fourier transform on the time-domain pulsation data of the axial force under the pump working condition to obtain the frequency-domain pulsation data of the axial force. The shaft frequency is 50, and the first blade passing frequency is 250. Figure 8 This is the axial force vibration frequency spectrum diagram of the impeller of Model 1, in which the amplitude of the second blade passing frequency is the main one, and the amplitudes of the first blade passing frequency and the fourth blade passing frequency are relatively large, indicating that the stator-rotor interference effect is serious, and the low-speed vortex between the blades has a strong impact on the vibration performance. Figure 9 This is the axial force vibration frequency spectrum diagram of the impeller of Model 2, in which the amplitude of the first blade passing frequency is the main one, and the amplitude close to the second blade passing frequency is relatively large. Compared with Model 1, there is a significant improvement, indicating that there are only some low-speed vortices affecting the vibration performance between the blades, and the flow performance in the stator-rotor interference area has been optimized. Figure 10 Shown is the axial force vibration frequency spectrum diagram of the impeller of the optimized Model 3. The amplitude of the first blade passing frequency has been optimized, but the vibration amplitude close to the second blade passing frequency has increased slightly compared with Model 2. Using the vibration force level L F calculation formula, extract the axial force frequency-domain pulsation data from 10 to 1000, and obtain that the vibration force level of Model 1 is 126.92 dB, the vibration force level of Model 2 is 118.42 dB, and the vibration force level of the optimized Model 3 is 117.33 dB.

[0061] Set the threshold of the axial force vibration level from 10 to 1000 to 120 dB. If the vibration level of the optimized model is less than the threshold of the vibration level and meets the optimization conditions, further check the self-flow performance of the pump body under the rated flow rate.

[0062] Use the volume entropy production rate to locate and describe the distribution of the self-flow resistance. The comparison contour maps of the entropy production on the diffuser blade surfaces of the three groups of models are as Figure 11 shown. The optimized design of the airfoil on the middle flow surface causes the evolution of the high entropy production region to show a truncation effect on the middle flow surface, preventing the further development of the high entropy production region, blocking the fusion and superposition of the two entropy production peak regions on the hub surface and the shroud surface, weakening the energy dissipation on the diffuser blade surface, and effectively reducing the flow loss on the diffuser blade surface. The internal flow entropy production of the three groups of models is as Figure 12 shown. By optimizing the installation angle of the diffuser inlet, the scale of the low-speed vortex behind the diffuser head decreases, and the high entropy production region with high energy loss derived from the diffuser head weakens. The separated flow that appears at the diffuser tail is also weakened with the optimization of the diffuser inlet installation angle, and the flow loss at the diffuser tail caused by the separated vortex in the wake decreases.

[0063] According to the calculation formula of the self-flow resistance coefficient, the self-flow resistance of Model 1 is 1.76 m, and the self-flow resistance coefficient is 8.26. The self-flow resistance of Model 2 is 1.34 m, and the self-flow resistance coefficient is 6.28. The self-flow resistance of the optimized Model 3 is 0.93 m, and the self-flow resistance coefficient is 4.38. Set the threshold of the self-flow resistance coefficient to 5. Since the self-flow resistance coefficient of the optimized model is less than the set threshold and meets the optimization conditions, the obtained Model 3 is the optimized model.

[0064] The calculation results of the three groups of models are shown in Table 2. Under the condition of ensuring the basic performance of the head and efficiency, the optimized Model 3 meets the conditions of the vibration level threshold and the self-flow resistance coefficient threshold. Compared with Model 1, the vibration level is optimized by 9.59 dB, and the self-flow resistance coefficient is optimized by 3.88; compared with Model 2, the vibration level is optimized by 1.09 dB, and the self-flow resistance coefficient is optimized by 1.91. The optimization effect is significant. Therefore, the optimized Model 3 is selected as the low-vibration and low-flow-resistance diffuser model.

[0065] Table 2 Comparison of Calculation Results

[0066]

[0067]

[0068] Those of ordinary skill in the art can understand that the above are only preferred examples of the invention and are not used to limit the invention. Although the invention has been described in detail with reference to the foregoing examples, for those skilled in the art, they can still modify the technical solutions described in the foregoing examples or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, etc. made within the spirit and principle of the invention shall be included within the protection scope of the invention.

Claims

1. An optimized design method for the guide vane of an axial-flow pump with low vibration and low flow resistance, characterized in that, It includes the following steps: Step 1: Select four evenly distributed design points on the blade airfoil of the intermediate flow surface of the guide vane. These four design points are located at the inlet of the guide vane, the outlet of the guide vane, and in the middle between the inlet and outlet of the guide vane respectively. The blade installation angles of the four design points are β1, β2, β3, and β4 in sequence, which are used to control the blade airfoil angle; Step 2: Considering the low vibration performance of the pump body, according to the low vibration design relationship of α0 + β1 = 180° satisfied by the liquid flow angle α0 at the impeller outlet and the installation angle β1 at the guide vane inlet, calculate the installation angle β1 at the guide vane inlet; Step 3: Subtract the angle difference from the installation angle β1 at the guide vane inlet to obtain the installation angle β4 at the guide vane outlet; then, based on the installation angle β1 at the guide vane inlet and the installation angle β4 at the guide vane outlet, perform a linear fit on the guide vane blade airfoil to obtain β2 and β3; Step 4: Change β1 to adopt the low flow resistance design principle to meet the S-shaped airfoil design; then, according to the new β1 and β2, β3, β4 obtained in Step 3, perform a curve fit on the guide vane blade airfoil to obtain the control line of the blade airfoil of the intermediate flow surface of the guide vane; Step 5: Thicken the blade airfoil according to the control line of the blade airfoil of the intermediate flow surface of the guide vane to obtain the blade airfoil of the intermediate flow surface of the guide vane; obtain the guide vane according to the blade airfoil of the intermediate flow surface of the guide vane; Step 6: Use the guide vane obtained in Step 5 to perform a numerical simulation on the axial flow pump body, analyze the impeller axial force vibration performance of the pump body. If the requirements are not met, return to Step 3 to redesign β2, β3, β4; if the vibration requirements are met, then perform a check on the self-flow resistance coefficient. If the self-flow performance requirements are not met, return to Step 4 to redesign β1; if the self-flow performance requirements are met, the guide vane design is completed.

2. The optimized design method of the guide vane of the low-vibration and low-flow-resistance axial-flow pump according to claim 1, wherein The angle difference between β1 and β4 in Step 3 is 35 - 45°.

3. The optimized design method of the guide vane of the low-vibration and low-flow-resistance axial-flow pump according to claim 1, characterized in that In Step 4, change β1 to adopt the low flow resistance design principle to meet the S-shaped airfoil design, specifically, make β1 within the range of 95 - 115°.

4. The optimized design method of the guide vane of the low-vibration and low-flow-resistance axial-flow pump according to claim 1, characterized in that, In Step 4, when performing a curve fit on the guide vane blade airfoil, adopt the modified Bessel function fit or the cubic spline curve fit method.

5. The optimized design method of the guide vane of the low-vibration and low-flow-resistance axial-flow pump according to claim 1, characterized in that, In Step 5, when thickening the blade airfoil, specifically: Take the minimum thickness at the inlet and outlet of the blade airfoil of the intermediate flow surface of the guide vane, take the maximum thickness at 40% - 50% of the length of the blade airfoil of the intermediate flow surface of the guide vane, and use a spline curve to control the thickness distribution of the airfoil, so as to obtain the blade airfoil of the intermediate flow surface of the guide vane.

6. The optimized design method of the guide vane of the low-vibration and low-flow-resistance axial-flow pump according to claim 1, wherein Analyze the impeller axial force vibration performance of the pump body, specifically: Perform a fast Fourier transform (FFT) on the time-domain pulsation data of the axial force of the impeller under pump operating conditions to obtain the frequency-domain pulsation data of the axial force. Using the following formula, extract the frequency-domain pulsation data of the axial force F of the impeller in the range of 10 to 1000 Hz to obtain the vibration force level L F , and judge the vibration force level L F to determine whether it meets the requirements: L F = 20 lg (F / F0) Among them, F0 is the reference value of the vibration force level, F0 = 1 μN.

7. The optimized design method of the guide vane of the low-vibration and low-flow-resistance axial-flow pump according to claim 1, characterized in that, In Step 6, when performing a check on the self-flow resistance coefficient, specifically: Calculate the gravity flow loss coefficient C according to the following formula d , and judge C d to see if it meets the requirements: C d = 2(p1 - p2) / ρv 2 Among them, p1 and p2 are the static pressures at the inlet and outlet of the pump body respectively, ρ is the medium density, and v is the incoming flow velocity of the circulating pump.

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