Method and device for bending counter-rotating fan blades, counter-rotating fan and vehicle

Abstract

The application discloses a kind of to the curved method of cross-flow fan blade, device, cross-flow fan and vehicle.The method comprises the following steps: the accumulation line of the blade of the fan blade on the cross-flow fan is set as a modeling control curve, and a plurality of radial curve control points on the modeling control curve are determined;For each blade, based on the accumulation line modeling requirement, the blade top phase angle of the curve control point located at the top of the blade is adjusted and the blade top is reversed, the blade root phase angle of the curve control point located at the root of the blade is adjusted based on the preset control condition, and the preset control condition is the linear relationship between the blade root phase angle and the blade top phase angle.The application realizes the accumulation line modeling of eliminating noise by setting the blade top reverse bending, and since the blade top phase angle and the blade root phase angle are only limited by the linear relationship, the number of control points required to be adjusted is greatly reduced, and the design difficulty of the accumulation line when eliminating noise is greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fan, and in particular to a method and device for bending blades of a contra-rotating fan, an electronic device, a storage medium, a computer program product, a contra-rotating fan and a vehicle. BACKGROUND

[0002] Compared with an ordinary axial fan, a contra-rotating fan produces discrete noise caused by rotation interference, and the noise is related to the rotation speeds of front and rear fan blades. In a use scenario, the contra-rotating fan often needs a high rotation speed to achieve the demand for large air volume and large air pressure. In the scenario of high rotation speed and large air volume, a particularly obvious "buzzer" screeching noise is extremely easy to occur, and the frequency of the noise is usually related to the rotation speed of the fan blades, which is called order noise of the fan. This phenomenon is usually caused by the fact that the decibel value of noise at one or more frequencies is much higher than the average decibel value of noise at other frequencies, so it produces a feeling that is easy to be perceived and uncomfortable, which affects the psychological comfort of a person after hearing the noise, and this is one of the important reasons for limiting the widespread use of the contra-rotating fan.

[0003] In order to eliminate the noise of the contra-rotating fan, the prior art proposes to adjust the stacking line of the blade, and to eliminate the noise by a special stacking line.

[0004] However, the stacking line used in the prior art is relatively complex, which is generally a quadratic curve. The adjustment of the quadratic curve is relatively complex, which makes it very difficult to adjust the stacking line, and the design cycle is too long. SUMMARY

[0005] Therefore, it is necessary to provide a method and device for bending blades of a contra-rotating fan, an electronic device, a storage medium, a computer program product, a contra-rotating fan and a vehicle to solve the technical problem of difficulty in adjusting the stacking line when eliminating noise of the contra-rotating fan in the prior art.

[0006] The present application provides a method for bending blades of a contra-rotating fan, comprising:

[0007] The stacking line of the blade of the upper fan blade of the contra-rotating fan is set as a modeling control curve, and a plurality of radial curve control points on the modeling control curve are determined. The phase angle of each curve control point is the included angle between the line connecting the curve control point and the center and the vertical direction.

[0008] For each blade, the blade top phase angle of the curve control point located at the top of the blade is adjusted based on the stacking line modeling requirement and the blade top is reversed, and the blade root phase angle of the curve control point located at the root of the blade is adjusted based on a preset control condition, and the preset control condition is a linear relationship between the blade root phase angle and the blade top phase angle.

[0009] Further, the adjusting the blade tip phase angle of the curve control point located at the top of the blade and making the blade tip reverse bending comprises:

[0010] Setting the blade tip phase angle of the curve control point located at the top of the blade to be greater than the phase angle of the adjacent curve control point.

[0011] Further, the adjusting the blade root phase angle of the curve control point located at the root of the blade based on the preset control condition comprises:

[0012] Adjusting the blade root phase angle of the curve control point located at the root of the blade based on the preset control condition to make the blade root reverse bending.

[0013] Further, the preset control condition is that the blade root phase angle is set to be the product of the blade tip phase angle and a preset ratio, and the blade tip phase angle is a positive value and the blade root phase angle is a negative value, wherein the positive value represents that the phase angle is the same as the rotation direction of the fan blade, and the negative value represents that the phase angle is opposite to the rotation direction of the fan blade.

[0014] Further, the modeling control curve comprises five curve control points, and the five curve control points in the direction from the blade root to the blade tip are a first curve control point, a second curve control point, a third curve control point, a fourth curve control point and a fifth curve control point in sequence, and the adjusting the blade tip phase angle of the curve control point located at the top of the blade and making the blade tip reverse bending based on the stacking line modeling requirement, and the adjusting the blade root phase angle of the curve control point located at the root of the blade based on the preset control condition comprises:

[0015] Setting the phase angles of the first curve control point, the third curve control point and the fourth curve control point to be 0;

[0016] Setting the phase angle of the fifth curve control point to be a positive value;

[0017] Adjusting the phase angle of the fifth curve control point and the phase angle of the second curve control point according to the stacking line modeling requirement based on the preset control condition, the phase angle of the fifth curve control point being the blade tip phase angle, the phase angle of the second curve control point being the blade root phase angle, and the preset control condition being:

[0018] θ2=-θ5 / N, wherein θ2 is the blade root phase angle, θ5 is the blade tip phase angle, and N is a positive integer.

[0019] Further, the blade of the front fan blade of the counter-rotating fan is a front blade, and the blade of the rear fan blade of the counter-rotating fan is a rear blade, and the setting the blade tip phase angle of the curve control point located at the top of the blade to be greater than the phase angle of the adjacent curve control point comprises:

[0020] The phase angle of the curve control point at the top of the front blade is greater than the phase angle of the adjacent curve control point, and the phase angle of the front blade is less than 180° / N f wherein N f is the number of front blades;

[0021] The phase angle of the curve control point at the top of the rear blade is greater than the phase angle of the adjacent curve control point, and the phase angle of the rear blade is less than 180° / N r wherein N r is the number of rear blades.

[0022] Further, the blades of the front fan of the counter-rotating fan are front blades, and the blades of the rear fan of the counter-rotating fan are rear blades, and the method further comprises:

[0023] The number of front blades is greater than the number of rear blades, and both the number of front blades and the number of rear blades are odd numbers.

[0024] Further, the blades of the front fan of the counter-rotating fan are front blades, and the blades of the rear fan of the counter-rotating fan are rear blades, and the method further comprises:

[0025] After the accumulation of the line modeling is achieved, the phase angle of all the curve control points of the front blade is taken as a front blade bending angle, the phase angle of all the curve control points of the rear blade is taken as a rear blade bending angle, the front blade bending angle and the rear blade bending angle are taken as a bending angle group, and the order noise of the superimposed noise of all the front blades and all the rear blades is calculated based on different bending angle groups.

[0026] The bending angle group when the order noise is optimal is selected as an optimal bending angle group and output.

[0027] Further, the calculation of the order noise of the superimposed noise of all the front blades and all the rear blades comprises:

[0028] The time-domain superposition waveform of the superimposed noise and time relationship is calculated.

[0029] The time-domain superposition waveform is transformed into a frequency-domain waveform.

[0030] The order noise is extracted from the frequency-domain waveform.

[0031] Further, the calculation of the time-domain superposition waveform of the superimposed noise and time relationship comprises:

[0032] cutting the front blades into a plurality of front blade surfaces in a radial direction and cutting the rear blades into a plurality of rear blade surfaces in a radial direction, generating a front blade noise basic two-dimensional phase waveform of the noise generated by all the front blade surfaces of all the front blades with respect to the circumferential phase angle and a rear blade noise basic two-dimensional phase waveform of the noise generated by all the rear blade surfaces of all the rear blades with respect to the circumferential phase angle;

[0033] at a plurality of sampling time points, determining a front blade rotation angle of the front blades according to the front blade rotation speed, determining a rear blade rotation angle of the rear blades according to the rear blade rotation speed, moving the front blade noise basic two-dimensional phase waveform to the waveform after the front blade rotation angle in the rotation direction, as a front blade noise sampling time point two-dimensional phase waveform, and moving the rear blade noise basic two-dimensional phase waveform to the waveform after the rear blade rotation angle in the rotation direction, as a rear blade noise sampling time point two-dimensional phase waveform;

[0034] discretizing the front blade noise sampling time point two-dimensional phase waveform to obtain a front blade noise column vector, discretizing the rear blade noise sampling time point two-dimensional phase waveform to obtain a rear blade noise column vector, and taking the dot product of the front blade noise column vector and the rear blade noise column vector as the superimposed noise at the sampling time point;

[0035] generating a time domain superposition waveform of the superimposed noise with respect to the time according to the superimposed noise corresponding to all the sampling time points.

[0036] The application provides a bending device for a contra-rotating fan blade, comprising:

[0037] a control point determination module configured to set an accumulation line of the blades of the upper fan blades of the contra-rotating fan as a modeling control curve, and determine a plurality of radial curve control points on the modeling control curve, wherein the phase angle of each curve control point is the included angle between the line connecting the curve control point and the center of the circle and the vertical direction;

[0038] an accumulation line control module configured to, for each blade, adjust the blade tip phase angle of the curve control point located at the top of the blade based on the accumulation line modeling requirement and make the blade tip reverse bending, and adjust the blade root phase angle of the curve control point located at the root of the blade based on a preset control condition, wherein the preset control condition is the linear relationship between the blade root phase angle and the blade tip phase angle.

[0039] The application provides an electronic device, comprising:

[0040] at least one processor; and,

[0041] a memory connected in communication with the at least one processor; wherein,

[0042] The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method for bending the blade of the cyclone fan as described above.

[0043] The present application provides a storage medium storing computer instructions for performing all steps of the method for bending the blade of the cyclone fan as described above when the computer executes the computer instructions.

[0044] The present application provides a computer program product comprising computer program / instructions for implementing the method for bending the blade of the cyclone fan as described above when the computer program / instructions are executed by a processor.

[0045] The present application provides a cyclone fan comprising a fan and a blade arranged along a circumferential direction of the fan, wherein the stacking line of the blade is shaped by the method for bending the blade of the cyclone fan as described above.

[0046] The present application provides a vehicle comprising the cyclone fan as described above.

[0047] The present application sets the stacking line by shaping the control curve, adjusts the tip phase angle of the control point at the top of the blade and makes the tip reverse bending based on the stacking line shaping requirement when setting the control point, and adjusts the root phase angle of the control point at the root of the blade based on the preset control condition of the linear relationship, and eliminates the stacking line shaping of the noise by setting the tip reverse bending, and greatly reduces the number of control points to be adjusted because the tip phase angle and the root phase angle are only limited by the linear relationship, and greatly reduces the design difficulty of the stacking line when eliminating the noise. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 A work flow chart of the method for bending the blade of the cyclone fan according to an embodiment of the present application;

[0049] Figure 2 A work flow chart of the method for bending the blade of the cyclone fan according to another embodiment of the present application;

[0050] Figure 3 A schematic diagram for defining the positive and reverse bending of the blade;

[0051] Figure 4 A stacking line schematic diagram of an example of the present application;

[0052] Figure 5 A FFT result schematic diagram of the interference between the front and rear blades;

[0053] Figure 6 A work flow chart of the method for bending the blade of the cyclone fan according to the best embodiment of the present application;

[0054] Figure 7 The working flow chart of the noise simulation of the curved blade of the axial counter-rotating fan according to the best embodiment of the application;

[0055] Figure 8 The schematic diagram of the blade bending device of the counter-rotating fan according to an embodiment of the application;

[0056] Figure 9 The schematic diagram of the hardware structure of the electronic device according to the application. DETAILED DESCRIPTION

[0057] The specific embodiments of the application are further described below with reference to the accompanying drawings. The same reference signs are used for the same components throughout the drawings. It should be noted that the words "front", "back", "left", "right", "up" and "down" used in the following description refer to the directions in the drawings, and the words "inner" and "outer" refer to the directions towards or away from the geometric center of a particular component.

[0058] As Figure 1 The working flow chart of the blade bending method of the counter-rotating fan according to an embodiment of the application is shown, which comprises:

[0059] Step S101, setting the stacking line of the blade of the upper fan blade of the counter-rotating fan as a modeling control curve, determining a plurality of radial curve control points on the modeling control curve, and the phase angle of each curve control point being the included angle between the line connecting the curve control point and the center and the vertical direction.

[0060] Step S102, for each blade, adjusting the blade tip phase angle of the curve control point located at the top of the blade based on the stacking line modeling requirement and making the blade tip reverse bending, adjusting the blade root phase angle of the curve control point located at the root of the blade based on a preset control condition, and the preset control condition being the linear relationship between the blade root phase angle and the blade tip phase angle.

[0061] Specifically, the application can be applied to electronic devices with processing capabilities, such as computers.

[0062] The blade bending method of the counter-rotating fan, the electronic device first performs step S101, sets the stacking line of the blade in the circumferential direction of the counter-rotating fan as a modeling control curve, determines a plurality of radial curve control points on the modeling control curve, and the phase angle of each curve control point being the included angle between the line connecting the curve control point and the center and the vertical direction. Wherein, the radial curve control point is also called the spanwise curve control point.

[0063] Wherein, the stacking line is used for designing the blade. In some embodiments, the stacking line is the center of gravity of the blade profile with the same diameter.

[0064] The profile control curve is a curve used to achieve the profile requirement of the stacking line. By adjusting the position of the curve control point on the profile control curve, the shape of the whole profile control curve can be adjusted by using the existing setting method of the profile control curve. The adjusted profile control curve is taken as the stacking line to complete the design of the blade.

[0065] In some embodiments, the profile control curve is a Bezier curve.

[0066] In some embodiments, the radial distance between each adjacent curve control point is equal.

[0067] Figure 4 The stacking line schematic diagram of the blade bending implementation method is given. The blade bending method of the front and rear fan blades of the cyclone is consistent. The stacking line 41 of the blade is composed of five spanwise curve control points, including the first curve control point 1, the second curve control point 2, the third curve control point 3, the fourth curve control point 4, and the fifth curve control point 5. The radial distance between each adjacent curve control point is equal. The phase angle θ of each curve control point is the included angle between the line connecting each curve control point and the center and the vertical direction. The θ value in the same direction of rotation is positive, otherwise it is negative.

[0068] Then, step S102 is performed. For each blade, the tip phase angle of the curve control point located at the top of the blade is adjusted based on the profile requirement of the stacking line and the tip is reversed. The root phase angle of the curve control point located at the root of the blade is adjusted based on a preset control condition, which is the linear relationship between the root phase angle and the tip phase angle.

[0069] Specifically, for each blade, the tip phase angle of the curve control point located at the top of the blade is adjusted based on the profile requirement of the stacking line and the tip is reversed to achieve the noise-eliminating stacking line profile. Meanwhile, the tip phase angle of the curve control point located at the top of the blade and the root phase angle of the curve control point located at the root of the blade are adjusted based on a preset control condition, which is the linear relationship between the root phase angle and the tip phase angle.

[0070] For all blades on the same fan, the same stacking line profile is used. Therefore, the profile of all blades on the fan can be completed by controlling one stacking line.

[0071] To achieve the noise-eliminating stacking line profile, the tip phase angle of the curve control point located at the top of the blade can be set to be greater than the phase angle of the adjacent curve control point, thereby ensuring the tip reversal.

[0072] As Figure 4As shown, θ5>θ4 can be set, wherein θ5 is the phase angle of the fifth curve control point 5, and θ4 is the phase angle of the fourth curve control point 4.

[0073] By adopting the appropriate reverse bending design at the blade top, the pressure gradient of the blade top flow field can be improved, and then the separation zone size of the blade suction surface angle area is reduced, and the source of the blade noise is reduced.

[0074] Meanwhile, the blade top phase angle and the blade root phase angle are adjusted based on a preset control condition. The control condition is a linear relationship between the blade root phase angle and the blade top phase angle. When designing, only the blade top phase angle needs to be adjusted based on the stacking line modeling requirement, and the blade root phase angle is directly adjusted according to the preset control condition. Since the control condition is a linear relationship, the blade root phase angle can be quickly obtained.

[0075] The blade top is the blade top of the blade, and the blade root is the blade root of the blade.

[0076] After the curve control points are determined, based on the existing setting method of the modeling control curve, the shape of the modeling control curve can be uniquely limited, so that the determined stacking line shape is obtained, and the blade modeling is completed. For example, when a Bezier curve is used as the modeling control curve, after each curve control point (when a Bezier curve is used, the curve control point is also called a Bezier curve control point) is determined, based on the existing setting method of the Bezier curve, the shape of the Bezier curve can be uniquely limited.

[0077] In one embodiment, the linear relationship is that the blade root phase angle is the product of the blade top phase angle and a preset constant, and the constant is a negative number.

[0078] The present application sets the stacking line through the modeling control curve. When setting the control points, the blade top phase angle of the curve control point located at the blade top is adjusted based on the stacking line modeling requirement and the blade top reverse bending is realized, and the blade root phase angle of the curve control point located at the blade root is adjusted based on the preset control condition of the linear relationship. The stacking line modeling for eliminating noise is realized through the setting of the blade top reverse bending. Since the blade top phase angle and the blade root phase angle are only limited by the linear relationship, the number of control points that need to be adjusted is greatly reduced, and the design difficulty of the stacking line for eliminating noise is greatly reduced.

[0079] As shown in the figure, Figure 2 The working flowchart of the blade bending method of the counter-rotating fan in another embodiment of the present application is shown in the figure, which comprises:

[0080] In step S201, the stacking line of the blade of the upper fan blade of the counter-rotating fan is set as a modeling control curve, and a plurality of radial curve control points on the modeling control curve are determined. The phase angle of each curve control point is the included angle between the line connecting the curve control point and the center and the vertical direction.

[0081] In step S202, for each blade, based on the stacking line shaping requirement, the blade tip phase angle of the curve control point located at the top of the blade is set to be greater than the phase angle of the adjacent curve control point, and the blade root phase angle of the curve control point located at the root of the blade is adjusted based on a preset control condition to make the blade root reverse bending, and the preset control condition is the linear relationship between the blade root phase angle and the blade tip phase angle.

[0082] Specifically, first, step S201 is performed to set the stacking line of the blade in the circumferential direction of the counter-rotating fan as a shaping control curve, and a plurality of radial curve control points on the shaping control curve are determined.

[0083] Then, step S202 is performed, for each blade, based on the stacking line shaping requirement, the blade tip phase angle of the curve control point located at the top of the blade is set to be greater than the phase angle of the adjacent curve control point, and the blade root phase angle of the curve control point located at the root of the blade is adjusted based on a preset control condition to make the blade root reverse bending, and the preset control condition is the linear relationship between the blade root phase angle and the blade tip phase angle.

[0084] Figure 3 A schematic diagram of the definition of blade positive and reverse bending is given. PS represents the pressure surface (Pressure Surface, PS) of the blade 31, SS represents the suction surface (Suction Surface, SS) of the blade 31, and the black thick line represents the stacking line of the three-dimensional blade in the spanwise direction. The blade 31 adopts the barycentric stacking. When the angle α between the tangent direction of the pressure surface PS and the end wall 32 (related to the rotation direction) is greater than 90°, the blade 31 is reverse bending at this time. Similarly, when α < 90°, the blade 31 is positive bending at this time.

[0085] Therefore, the blade tip phase angle of the curve control point located at the top of the blade is set to be greater than the phase angle of the adjacent curve control point, so as to ensure the reverse bending of the blade tip.

[0086] As shown in Figure 4 θ5> θ4 can be set. Wherein θ5 is the phase angle of the fifth curve control point 5, and θ4 is the phase angle of the fourth curve control point 4.

[0087] By adopting appropriate reverse bending design at the blade tip, the pressure gradient of the flow field at the top of the blade can be improved, and then the separation zone size of the blade suction surface angle area is reduced, and the source of blade noise is reduced.

[0088] Finally, based on a preset control condition, the blade root phase angle of the curve control point located at the root of the blade is adjusted according to the blade tip phase angle to make the blade root reverse bending, and the preset control condition is the linear relationship between the blade root phase angle and the blade tip phase angle.

[0089] By designing the reverse bending of the blade root, the pressure gradient of the blade suction surface is adjusted, the velocity and pressure gradient of the fluid are adjusted, the fluid separation (one of the sources of broadband noise) is reduced, and the purpose of noise reduction is achieved.

[0090] In the embodiment, the phase angle of the curve control point at the blade tip is greater than the phase angle of the adjacent curve control point, the phase angle of the curve control point at the blade root is adjusted based on the preset control condition to make the blade root reverse bending, the reverse bending is realized at the blade tip and root, the source of blade noise is reduced, the noise elimination profile is quickly realized, and the noise reduction effect is improved.

[0091] In one of the embodiments, the preset control condition is that the phase angle of the blade root is set as the product of the phase angle of the blade tip and a preset ratio, and the phase angle of the blade tip is positive, and the phase angle of the blade root is negative, wherein the positive value indicates that the phase angle is the same as the rotation direction of the fan blade, and the negative value indicates that the phase angle is opposite to the rotation direction of the fan blade.

[0092] Specifically, the phase angle of the curve control point at the blade tip is greater than the phase angle of the adjacent curve control point to ensure the reverse bending of the blade tip. By adopting appropriate reverse bending design at the blade tip, the pressure gradient of the flow field at the blade tip can be improved, the size of the separation zone at the blade suction surface corner area is reduced, and the source of blade noise is reduced. The phase angle of the blade root is set to be negative to ensure the reverse bending of the blade root. By designing the reverse bending of the blade root, the pressure gradient of the blade suction surface is adjusted, the velocity and pressure gradient of the fluid are adjusted, the fluid separation (one of the sources of broadband noise) is reduced, and the purpose of noise reduction is achieved.

[0093] In the embodiment, the phase angle of the curve control point at the blade tip is greater than the phase angle of the adjacent curve control point to ensure the reverse bending of the blade tip. By adopting appropriate reverse bending design at the blade tip, the pressure gradient of the flow field at the blade tip can be improved, the size of the separation zone at the blade suction surface corner area is reduced, and the source of blade noise is reduced. The phase angle of the blade root is set to be negative to ensure the reverse bending of the blade root. By designing the reverse bending of the blade root, the pressure gradient of the blade suction surface is adjusted, the velocity and pressure gradient of the fluid are adjusted, the fluid separation (one of the sources of broadband noise) is reduced, and the purpose of noise reduction is achieved.

[0094] In one of the embodiments, the profile control curve includes five curve control points, and the five curve control points in the direction from the blade root to the blade tip are a first curve control point, a second curve control point, a third curve control point, a fourth curve control point, and a fifth curve control point in sequence. The phase angle of the curve control point at the blade tip is adjusted based on the profile modeling requirement to make the blade tip reverse bending, and the phase angle of the curve control point at the blade root is adjusted based on the preset control condition.

[0095] The phase angles of the first curve control point, the third curve control point, and the fourth curve control point are all set to 0.

[0096] The phase angle of the fifth curve control point is set to be positive.

[0097] Based on preset control conditions, the phase angles of the fifth curve control point and the second curve control point are adjusted according to the requirements of the stacked line shape. The phase angle of the fifth curve control point is the blade tip phase angle, and the phase angle of the second curve control point is the blade root phase angle. The preset control conditions are:

[0098] θ2 = -θ5 / N, where θ2 is the leaf root phase angle, θ5 is the leaf tip phase angle, and N is a positive integer.

[0099] Specifically, to ensure the smoothness and curvature of the stacked lines, the first curve control point 1, the third curve control point 3, and the fourth curve control point 4 are fixed, so that the phase angle θ1 of the first curve control point 1, the phase angle θ3 of the third curve control point 3, and the phase angle θ4 of the fourth curve control point 4 are all 0. The stacked line shape is achieved by adjusting the θ values ​​of the second curve control point 2 and the fifth curve control point 5.

[0100] like Figure 4 As shown, to ensure tip curvature, the phase angle of the fifth curve control point on the accumulation line must be greater than the phase angle of the fourth curve control point, i.e., θ5 > θ4. Here, θ5 is the phase angle of the fifth curve control point 5, and θ4 is the phase angle of the fourth curve control point 4.

[0101] Since θ4 is set to 0, we only need to set θ5>0 to ensure that θ5>θ4 and that the blade tip bends in reverse.

[0102] Then, based on preset control conditions, the phase angle of the second curve control point is adjusted according to the phase angle of the fifth curve control point to achieve the stacked line shape. The preset control conditions are:

[0103] θ2 = -θ5 / N, where θ2 is the leaf root phase angle, i.e., the phase angle of the second curve control point 2, θ5 is the leaf tip phase angle, i.e., the phase angle of the fifth curve control point 5, and N is a positive integer.

[0104] Since θ5 > 0, θ2 < 0, thus ensuring that the leaf root bends in reverse.

[0105] The stacking line can be shaped by adjusting the second curve control point and the fifth curve control point to achieve the stacking line shape of the blade. By setting θ2 = -θ5 / N, the input variables can be reduced while meeting the requirements. The stacking line shape can be completed by controlling either θ5 or θ2.

[0106] In some embodiments, θ2 = -θ5 / 4.

[0107] The embodiment fixes the phase angles of the first curve control point, the third curve control point and the fourth curve control point, thereby ensuring the smoothness of the stacking line and the bending angle. Meanwhile, the phase angle of the fifth curve control point is adjusted to be greater than 0, thereby ensuring the reverse bending of the blade tip, realizing noise reduction, the phase angle of the second curve control point is controlled by setting a control condition, thereby ensuring the reverse bending of the blade root and further realizing noise reduction. By setting the control point association condition, the input variable is reduced under the premise of meeting the requirements, and the stacking line modeling can be completed only by controlling θ5 or θ2, thereby improving the design efficiency.

[0108] In one of the embodiments, the blade of the front fan blade of the counter-rotating fan is a front blade, the blade of the rear fan blade of the counter-rotating fan is a rear blade, the top phase angle of the curve control point located at the top of the blade is greater than the phase angle of the adjacent curve control point, and the top phase angle of the front blade is less than 180° / N

[0109] The top phase angle of the curve control point located at the top of the front blade is greater than the phase angle of the adjacent curve control point, and the top phase angle of the front blade is less than 180° / N f , wherein N f is the number of the front blades;

[0110] The top phase angle of the curve control point located at the top of the rear blade is greater than the phase angle of the adjacent curve control point, and the top phase angle of the rear blade is less than 180° / N r , wherein N r is the number of the rear blades.

[0111] Specifically, the counter-rotating fan includes coaxial and counter-rotating front and rear fan blades, the blade of the front fan blade is a front blade, and the blade of the rear fan blade is a rear blade.

[0112] The main target of controlling the bending of the front and rear fan blades is to reduce the interference order noise generated by the front and rear fan blades when rotating. When the top phase angle is greater than 180° / N, the stacking line of the front and rear fan blades will overlap, and the bending angle of the blade cannot be further increased to obtain additional benefits, but will adversely affect the air volume and air pressure performance. Therefore, the top phase angle is set to be less than 180° / N in the embodiment. Wherein N is the number of the blades of the front and rear fan blades, and therefore:

[0113] The top phase angle of the curve control point located at the top of the front blade is greater than the phase angle of the adjacent curve control point, and the top phase angle of the front blade is less than 180° / N f , wherein N f is the number of the front blades of the front fan blade;

[0114] the phase angle of the curve control point located at the top of the trailing edge of the trailing blade is greater than the phase angle of the adjacent curve control point, and the phase angle of the trailing edge of the trailing blade is less than 180° / N r wherein N r is the number of trailing blades of the trailing fan.

[0115] In some embodiments, the profile control curve includes five curve control points, and the phase angle of the curve control point located at the top of the trailing edge of the trailing blade is greater than the phase angle of the adjacent curve control point, and the phase angle of the trailing edge of the trailing blade is less than 180° / N

[0116] In the adjustment of the profile of the front blade by adjusting the curve control points, the phase angle of the fifth curve control point is adjusted to be greater than the phase angle of the fourth curve control point, and the phase angle of the fifth curve control point is adjusted to be less than 180° / N f wherein N f is the number of front blades of the front fan;

[0117] In the adjustment of the profile of the trailing blade by adjusting the curve control points, the phase angle of the fifth curve control point is adjusted to be greater than the phase angle of the fourth curve control point, and the phase angle of the fifth curve control point is adjusted to be less than 180° / N r wherein N r is the number of trailing blades of the trailing fan.

[0118] In practical applications, the greater the phase angle of the trailing edge, the more obvious the improvement of the counter-rotating fan order noise under the influence of the wake. However, increasing the phase angle of the trailing edge will reduce the air volume and pressure performance of the counter-rotating fan. Therefore, it is necessary to balance the air volume and pressure performance and noise performance of the counter-rotating fan within a proper range, and therefore the phase angle of the trailing edge should be ensured to be within 5°-180° / N.

[0119] Since the rotation directions of the front and trailing fan blades are opposite, the design of the present embodiment can reduce the obvious and regular noise caused by the impact of non-mainstream flow such as blade wake and downstream structure, and disperse the noise caused by factors such as blade wake at different times, thereby improving the noise, vibration, and harshness (Noise, Vibration, and Harshness, NVH) performance of the counter-rotating fan.

[0120] In one embodiment, the blades of the front fan of the counter-rotating fan are front blades, and the blades of the trailing fan of the counter-rotating fan are trailing blades, and the method further comprises:

[0121] The number of the front vanes is greater than the number of the rear vanes, and both the number of the front vanes and the number of the rear vanes are odd numbers.

[0122] Specifically, to reduce the noise generated by resonance between the front and rear fan blades of the axial flow counter-rotating fan, the number of vanes N f and N r of the front and rear fan blades should be unequal, and N f >N r , wherein N f is the number of front vanes of the front fan blade, N r is the number of rear vanes of the rear fan blade. Meanwhile, N f and N r should be odd numbers.

[0123] The embodiment limits the number of vanes of the front and rear fan blades to reduce the noise generated by resonance between the front and rear fan blades of the axial flow counter-rotating fan.

[0124] In one embodiment, the vanes of the front fan blade of the counter-rotating fan are front vanes, the vanes of the rear fan blade of the counter-rotating fan are rear vanes, and the method further comprises:

[0125] After the accumulation of the lines is shaped, the phase angle of all the curve control points of the front vanes is taken as the front vane bending angle, the phase angle of all the curve control points of the rear vanes is taken as the rear vane bending angle, the front vane bending angle and the rear vane bending angle are taken as a bending angle group, and the order noise of the superimposed noise of all the front vanes and all the rear vanes is calculated based on different bending angle groups.

[0126] The bending angle group when the order noise is optimal is selected as the optimal bending angle group and outputted.

[0127] Specifically, the counter-rotating fan comprises coaxial and counter-rotating front and rear fan blades, the vanes of the front fan blade are front vanes, and the vanes of the rear fan blade are rear vanes.

[0128] The method of the embodiment further comprises front and rear vane optimal bending optimization, and noise simulation is performed on the bent vanes.

[0129] Specifically, steps S101 to S102 or steps S201 to S202 are performed, the front vanes and the rear vanes are respectively bent based on different bending angle groups, the accumulation of the lines is shaped, and the order noise of the superimposed noise of the noise generated by all the front vanes and the noise generated by all the rear vanes is calculated for each bending angle group.

[0130] Then, the bending angle group when the order noise is optimal is selected as the optimal bending angle group.

[0131] an optimal bending angle group, wherein the front blade bending angle in the optimal bending angle group is used to perform the stacking line modeling of the stacking line of the front blade, and the rear blade bending angle in the optimal bending angle group is used to perform the stacking line modeling of the stacking line of the rear blade.

[0132] In the method, a plurality of different bending angle groups can be set, the order noise of each bending angle group is calculated, and the bending angle group with the optimal order noise is selected as the optimal bending angle group.

[0133] The order noise optimization step can be performed multiple times. In each order noise optimization step, the front blade and the rear blade are respectively bent based on different bending angle groups to perform the stacking line modeling. For each bending angle group, the order noise of the superimposed noise of the noise generated by all the front blades and the noise generated by all the rear blades is calculated. If the order noise is the minimum, the bending angle group of the current order noise optimization step is selected as the optimal bending angle group. Otherwise, the bending angle group is modified, and the order noise optimization step is performed again.

[0134] When the data is less, a design of experiments (DOE) strategy is used, the bending angle group with the minimum order noise is output as the optimal bending angle group. When the data is more, a Pareto optimal strategy is used, the bending angle group with the smaller order noise is output as the optimal bending angle group.

[0135] The bending angle group includes a front blade bending angle and a rear blade bending angle. The front blade bending angle is the phase angle of each curve control point on the stacking line of the front blade after the stacking line modeling is performed. The rear blade bending angle is the phase angle of each curve control point on the stacking line of the rear blade after the stacking line modeling is performed.

[0136] In some embodiments, the front blade bending angle is the phase angle of the fifth curve control point on the stacking line of the front blade after the stacking line modeling is performed. The rear blade bending angle is the phase angle of the fifth curve control point on the stacking line of the rear blade after the stacking line modeling is performed. The phase angles of the first curve control point, the third curve control point and the fourth curve control point on the stacking lines of the front blade and the rear blade are all 0. The phase angle of the second curve control point is θ2=-θ5 / 4.

[0137] As shown in FIG. 1, the method comprises the following steps. Figure 6 As shown in FIG. 1, the method comprises the following steps.

[0138] In step S601, the front blade bending angle is determined, and the stacking line of the front blade is completed based on the front blade bending angle to perform the stacking line modeling of the front blade.

[0139] In step S602, the bending angle of the rear blade is determined, and the stacking line of the front blade is determined based on the bending angle of the rear blade to complete the stacking line modeling of the rear blade.

[0140] In step S603, the order noise of the superimposed noise of the noise generated by all the front blades and the noise generated by all the rear blades is calculated. If the order noise is Pareto optimal, step S604 is executed, otherwise steps S601 and S602 are executed again.

[0141] In step S604, the front and rear blade bending strategy is output.

[0142] The output of the front and rear blade bending strategy is the output of the optimal bending angle group.

[0143] The embodiment realizes the optimization strategy for the bending of the cyclone fan blade, and maximizes the reduction of the order noise of the cyclone fan.

[0144] In one embodiment, the calculation of the order noise of the superimposed noise of all the front blades and all the rear blades includes:

[0145] The time-domain superposition waveform of the relationship between the superimposed noise and time is calculated.

[0146] The time-domain superposition waveform is transformed into a frequency domain waveform.

[0147] The order noise is extracted from the frequency domain waveform.

[0148] Specifically, the calculation of the order noise of the superimposed noise of the noise generated by all the front blades and the noise generated by all the rear blades includes:

[0149] Steps S101 to S102, or steps S201 to S202 are executed to bend the front blades and the rear blades based on different bending angle groups, realize stacking line modeling, and for each bending angle group, the phases of the front blades of the front fan blades on the circumference and the phases of the rear blades of the rear fan blades on the circumference are generated according to the uniform distribution of the blades.

[0150] Based on the phases of the front blades on the circumference and the phases of the rear blades on the circumference, the time-domain superposition waveform of the relationship between the superimposed noise of the noise generated by all the front blades and the noise generated by all the rear blades and time is calculated.

[0151] The time-domain superimposed waveform is converted into a frequency-domain waveform (a frequency-domain signal) by fast Fourier transform (FFT), and the key attention order is extracted, such as for a seven-leaf fan, the seventh-order noise is the largest, and the key attention order is the seventh order, and for a nine-leaf fan, the ninth-order noise is the largest, and the key attention order is the ninth order. The order noise result is recorded, such as Figure 5 is the FFT result of the front and rear fan blades interference, and the corresponding peak frequency is the order frequency, and the amplitude corresponding to the peak is the modulus energy value of the order noise.

[0152] The minimum order noise is the minimum amplitude of the key attention order, and the smaller order noise is the smaller amplitude of the key attention order.

[0153] The embodiment accurately extracts the order noise by frequency domain transformation on the time-domain superimposed waveform.

[0154] In one of the embodiments, the time-domain superimposed waveform of the superimposed noise and time relationship comprises:

[0155] The front blade is radially divided into a plurality of front blade surfaces, and the rear blade is radially divided into a plurality of rear blade surfaces, and the front blade noise basic two-dimensional phase waveform about the noise generated by all the front blade surfaces and the circular phase angle relationship of all the rear blade surfaces and the noise generated by all the rear blade surfaces and the circular phase angle relationship are generated;

[0156] At a plurality of sampling time points, the front blade rotation angle of the front blade is determined according to the front blade rotation speed, the rear blade rotation angle of the rear blade is determined according to the rear blade rotation speed, the waveform of the front blade noise basic two-dimensional phase waveform after moving in the rotation direction by the front blade rotation angle is taken as the front blade noise sampling time two-dimensional phase waveform, and the waveform of the rear blade noise basic two-dimensional phase waveform after moving in the rotation direction by the rear blade rotation angle is taken as the rear blade noise sampling time two-dimensional phase waveform;

[0157] The front blade noise sampling time two-dimensional phase waveform is discretized to obtain a front blade noise column vector, the rear blade noise sampling time two-dimensional phase waveform is discretized to obtain a rear blade noise column vector, and the dot product of the front blade noise column vector and the rear blade noise column vector is taken as the superimposed noise at the sampling time.

[0158] The time-domain superimposed waveform about the superimposed noise and the time relationship is generated according to the superimposed noise corresponding to all the sampling time points, and the superimposed noise is the superposition of the noise generated by all the front blades and the noise generated by all the rear blades.

[0159] Specifically, first, the front blades are radially divided into a plurality of front blade faces, and the rear blades are radially divided into a plurality of rear blade faces, respectively generating a front blade noise basic two-dimensional phase waveform about the relationship between the noise generated by all the front blade faces of all the front blades and the circumferential phase angle and a rear blade noise basic two-dimensional phase waveform about the relationship between the noise generated by all the rear blade faces of all the rear blades and the circumferential phase angle.

[0160] Since the blades are three-dimensional, each blade can be radially divided at different radial heights to obtain a plurality of blade faces of each blade. Since the blades are curved, the circumferential phase angle of each blade face of the same blade on the circumference is not exactly the same. The circumferential phase angle of the blade face is the angle between the selected reference point on the blade face and the center line. The reference points of all blades are consistent.

[0161] In some embodiments, the center of gravity in the selected blade is selected as the reference point.

[0162] In some embodiments, the radially dividing the front blades into a plurality of front blade faces and the radially dividing the rear blades into a plurality of rear blade faces, respectively generating a front blade noise basic two-dimensional phase waveform about the relationship between the noise generated by all the front blade faces of all the front blades and the circumferential phase angle and a rear blade noise basic two-dimensional phase waveform about the relationship between the noise generated by all the rear blade faces of all the rear blades and the circumferential phase angle, comprises:

[0163] radially dividing the front blades into a plurality of front blade faces and radially dividing the rear blades into a plurality of rear blade faces;

[0164] For each radial height, generating a front blade noise basic one-dimensional phase waveform about the relationship between the noise generated by all the front blade faces and the circumferential phase angle at the radial height, and combining the front blade noise basic one-dimensional phase waveforms of all the radial heights into a front blade noise basic two-dimensional phase waveform;

[0165] For each radial height, generating a rear blade noise basic one-dimensional phase waveform about the relationship between the noise generated by all the rear blade faces and the circumferential phase angle at the radial height, and combining the rear blade noise basic one-dimensional phase waveforms of all the radial heights into a rear blade noise basic two-dimensional phase waveform.

[0166] Wherein the abscissa of the front blade noise basic one-dimensional phase waveform and the rear blade noise basic one-dimensional phase waveform is the circumferential phase angle, and the ordinate is the noise contribution degree.

[0167] The front blade noise basis one-dimensional phase waveform of the noise generated by all the front blade surfaces of the same radial height in relation to the circumferential phase angle is obtained, and then the front blade noise basis one-dimensional phase waveforms of all the radial heights are arranged along the radial height direction to obtain the front blade noise basis two-dimensional phase waveform.

[0168] The rear blade noise basis one-dimensional phase waveform of the noise generated by all the rear blade surfaces of the same radial height in relation to the circumferential phase angle is obtained, and then the rear blade noise basis one-dimensional phase waveforms of all the radial heights are arranged along the radial height direction to obtain the rear blade noise basis two-dimensional phase waveform.

[0169] In some embodiments, the generating, for each radial height, the front blade noise basis one-dimensional phase waveform of the noise generated by all the front blade surfaces of the radial height in relation to the circumferential phase angle comprises:

[0170] For each radial height, the noise contribution amplitude of the circumferential phase angle position of each front blade surface is set as A, the noise contribution amplitude of the remaining positions is set as B, and A is greater than B. A gradual transition region is set with the circumferential phase angle position of each front blade surface as the center to generate the front blade surface noise basis one-dimensional phase waveform in relation to the noise generated by all the front blade surfaces and the phase.

[0171] In some embodiments, the generating, for each radial height, the rear blade noise basis one-dimensional phase waveform of the noise generated by all the rear blade surfaces of the radial height in relation to the circumferential phase angle comprises:

[0172] For each radial height, the noise contribution amplitude of the circumferential phase angle position of each rear blade surface is set as A, the noise contribution amplitude of the remaining positions is set as B, and A is greater than B. A gradual transition region is set with the circumferential phase angle position of each rear blade surface as the center to generate the rear blade surface noise basis one-dimensional phase waveform in relation to the noise generated by all the rear blade surfaces and the phase.

[0173] Specifically, according to the uniform or unequal distribution of the blades, the circumferential phase angle of each blade of the fan blade is generated, the blades are divided into a plurality of blade surfaces in the radial direction, for each radial height, the noise contribution degree amplitude is set to 1 at the circumferential phase angle of the blade surface, and the noise contribution degree amplitude is set to 0.1 at the circumferential phase angle of the non-blade surface. In order to ensure continuity, a sine gradual transition region with a range of 360° / N*0.25 is set at the center of the circumferential phase angle of the blade surface, and the low-speed area formed by the blade wake is simulated. Through the above strategy, a one-dimensional waveform of the simulated noise is formed, which is the noise simulation form of the fan blade at a certain radial height. In the one-dimensional waveform, the abscissa is the circumferential phase angle, and the ordinate is the noise contribution degree. In the radial direction, according to the blade bending strategy, a respective one-dimensional noise simulation waveform is formed in the direction of the blade radial height, and the waveforms are superimposed in the radial and circumferential directions to form a two-dimensional waveform.

[0174] Then, at a plurality of sampling time points, the front blade rotation angle rotated by the front blade is determined according to the front fan speed, the rear blade rotation angle rotated by the rear blade is determined according to the rear fan speed, the waveform of the front blade noise basic two-dimensional phase after moving the front blade noise basic two-dimensional phase in the rotation direction by the front blade rotation angle is taken as the front blade noise sampling time two-dimensional phase waveform, and the waveform of the rear blade noise basic two-dimensional phase after moving the rear blade noise basic two-dimensional phase in the rotation direction by the rear blade rotation angle is taken as the rear blade noise sampling time two-dimensional phase waveform.

[0175] Specifically, the generated front blade noise basic two-dimensional phase waveform and the rear blade noise basic two-dimensional phase waveform are superimposed with the front and rear fan speeds respectively to generate the change of the waveform with time, and the process of the sound wave acting on a single point is simulated.

[0176] Wherein, the front fan speed and the rear fan speed can be the same or different, and are determined according to the design requirement. Since all the front blades in the front fan rotate at the same time, and all the rear blades in the rear fan rotate at the same time, the front fan speed and the rear fan speed represent the rotation angle of the blade per unit time, therefore, at each sampling time point, the front blade rotation angle rotated by the front blade since the starting time can be calculated according to the front fan speed, the front blade noise basic two-dimensional phase is moved in the rotation direction by the front blade rotation angle, so as to obtain the waveform at the sampling time point, as the front blade noise sampling time two-dimensional phase waveform. Similarly, at each sampling time point, the rear blade rotation angle rotated by the rear blade since the starting time can be calculated according to the rear fan speed, the rear blade noise basic two-dimensional phase is moved in the rotation direction by the rear blade rotation angle, so as to obtain the waveform at the sampling time point, as the rear blade noise sampling time two-dimensional phase waveform.

[0177] Then, the front blade noise sampling time two-dimensional phase waveform is discretized to obtain a front blade noise column vector, the rear blade noise sampling time two-dimensional phase waveform is discretized to obtain a rear blade noise column vector, and the dot product of the front blade noise column vector and the rear blade noise column vector is calculated as the superimposed noise at the sampling time.

[0178] Specifically, the front blade noise column vector and the rear blade noise column vector are respectively:

[0179] [Sf 11 ,Sf 12 ,...,Sf 1M ,...Sf i1 ,Sf i2 ,...,Sf iM ,...,Sf L1 ,Sf L2 ,...Sf LM ] T ;

[0180] [Sr 11 ,Sr 12 ,...,Sr 1M ,...Sr i1 ,Sr i2 ,...,Sr iM ,...,Sr L1 ,Sr L2 ,...Sr LM ] T 。

[0181] Wherein, Sf 11 ,Sf 12 ,...,Sf 1M are M discrete values of the front blade face at the 1st radial height in the front blade noise sampling time two-dimensional phase waveform, Sf i1 ,Sf i2 ,...,Sf iM are M discrete values of the front blade face at the i-th radial height in the front blade noise sampling time two-dimensional phase waveform, Sf L1 ,Sf L2 ,...Sf LM are M discrete values of the front blade face at the L-th radial height in the front blade noise sampling time two-dimensional phase waveform, Sr 11 ,Sr 12 ,...,Sr 1M are M discrete values of the rear blade face at the 1st radial height in the rear blade noise sampling time two-dimensional phase waveform, Sr i1 ,Sr i2 ,...,Sr iMM is the number of discrete values of the back blade surface at the i-th radial height in the two-dimensional phase waveform of the back blade noise sampling moment, L1 M is the number of discrete values of the back blade surface at the i-th radial height in the two-dimensional phase waveform of the back blade noise sampling moment, L2 M is the number of discrete values of the back blade surface at the i-th radial height in the two-dimensional phase waveform of the back blade noise sampling moment, LM M is the number of discrete values of the back blade surface at the i-th radial height in the two-dimensional phase waveform of the back blade noise sampling moment,

[0182] Specifically, the two-dimensional phase waveform of the front blade noise sampling moment is continuous, a certain number of discrete values are selected, 360° is discretized into a discrete number of discrete circumferential phase angles, and the noise contribution amplitude corresponding to all discrete circumferential phase angles in each radial height in the two-dimensional phase waveform of the front blade noise sampling moment is combined into a front blade noise column vector. Similarly, the two-dimensional phase waveform of the back blade noise sampling moment is continuous, the same number of discrete values as the two-dimensional phase waveform of the front blade noise sampling moment is selected, 360° is discretized into a discrete number of discrete circumferential phase angles, and the noise contribution amplitude corresponding to all discrete circumferential phase angles in each radial height in the two-dimensional phase waveform of the back blade noise sampling moment is combined into a back blade noise column vector.

[0183] Then the dot product of the front blade noise column vector and the back blade noise column vector is calculated as the superimposed noise at the sampling moment, specifically, the front blade noise column vector is transposed and multiplied with the back blade noise column vector, and the resulting scalar is taken as the superimposed noise at the sampling moment.

[0184] The superimposed noises of multiple sampling moments are combined together to obtain a time-domain superposition waveform of the superimposed noise and time relationship.

[0185] The embodiment realizes the interference simulation of the front and back blades, and optimizes the blade bending strategy of the counter-rotating fan through a simplified two-dimensional order noise prediction model.

[0186] As shown in Figure 7 The working flowchart of the bending blade noise simulation of the axial counter-rotating fan of the best embodiment of the application comprises:

[0187] Step S701, a front blade noise two-dimensional waveform generator module is adopted, a front blade bending angle of a bending angle group is adopted, and a blade bending strategy is adopted to generate a front blade noise basic two-dimensional phase waveform;

[0188] Step S702, a back blade noise two-dimensional waveform generator module is adopted, a back blade bending angle of a bending angle group is adopted, and a blade bending strategy is adopted to generate a back blade noise basic two-dimensional phase waveform;

[0189] Step S703, the front fan blade speed is obtained;

[0190] Step S704, the back fan blade speed is obtained;

[0191] Step S705, the front blade, rear blade, front and rear blade interference order noise statistics superposition;

[0192] Step S706, if the order noise is Pareto optimal, step S707 is executed, otherwise step S701 and step S702 are executed again;

[0193] Step S707, the front and rear blade bending strategy output.

[0194] Specifically, according to the different blade bending angles of the front and rear fan blades, the blade stacking curves of the front and rear fan blades are obtained. The noise contribution of each order is obtained by FFT transformation of the simulated noise energy of the front and rear blades and their mutual involvement. The highest order noise contribution to the sound pressure level is taken as the target, the front and rear blade bending angles are taken as variables, and the Pareto optimal algorithm is used for optimization to obtain the optimal bending strategy of the front and rear blades. Figure 7 The flow of python programming code simulates the simulated noise energy of the front and rear blades and their mutual involvement, and obtains the contribution of each order noise energy to the sound pressure level after FFT transformation. The highest order noise contribution to the sound pressure level is taken as the target, the front and rear blade bending angles are taken as variables, and the Pareto optimal algorithm is used for optimization to obtain the optimal bending strategy of the front and rear blades.

[0195] The order noise Pareto optimality is evaluated by self-programming code, and the basic judgment process of the code is as follows:

[0196] 1. Generate the noise waveform generated by the front and rear fan blades:

[0197] According to the uniform distribution of the blades, the phases of the blades on the circumference are generated. The blades are divided into multiple blade surfaces along the radial direction. For each radial height, the noise contribution degree amplitude is set to 1 at the phase angle of the blade surface on the circumference, and the noise contribution degree amplitude is set to 0.1 at the phase angle of the non-blade surface on the circumference. In order to ensure continuity, a sinusoidal transition region with a range of 360° / N*0.25 is set around the phase angle of the blade surface on the circumference. The low-speed area formed by the blade wake is simulated. Through the above strategy, a one-dimensional waveform of the simulated noise is formed, which is the noise simulation form of the fan blade at a certain radial height. According to the blade bending strategy, a one-dimensional noise simulation waveform is formed at different blade radial heights in the radial direction. The waveforms are superimposed in the radial and circumferential directions to form a two-dimensional waveform.

[0198] 2. Superimpose the generated front and rear blade waveforms on the front and rear blade rotating speeds respectively to generate the change of the waveforms with time, simulate the sound wave effect on a single point;

[0199] 3. Superimpose the two waveforms in the form of dot product to solve the simulated noise size. With the rotation of the fan blade, the two waveforms change respectively to form a simulated noise change curve with time. The simulated noise time domain signal is converted into a frequency domain signal by fast Fourier transform FFT, and the key order is extracted, such as seven order noise for seven-blade fan, nine order noise for nine-blade fan, and the order noise result is recorded, such as Figure 5The FFT results of the front and rear fan blades interference, wherein the corresponding peak frequencies are the respective order frequencies, and the amplitude values corresponding to the peaks are the mode energy values of the order noise;

[0200] 4. When the data is less, a DOE strategy is adopted to select the bending angle of the front and rear fan blades with the minimum order noise; when the data is more, a Pareto optimal strategy is adopted to extract the bending angle of the front and rear fan blades with the smaller order noise.

[0201] The embodiment optimizes the blade bending strategy of the contra-rotating fan through a simplified two-dimensional order noise prediction model.

[0202] Based on the same inventive concept, as Figure 8 Fig. 1 is a schematic diagram of a blade bending device for a contra-rotating fan according to an embodiment of the present application, which comprises:

[0203] The control point determination module 801 is configured to set the stacking line of the blade of the upper fan blade of the contra-rotating fan as a modeling control curve, and determine a plurality of radial curve control points on the modeling control curve, wherein the phase angle of each curve control point is the included angle between the line connecting the curve control point and the center and the vertical direction.

[0204] The stacking line control module 802 is configured to, for each blade, adjust the blade tip phase angle of the curve control point located at the top of the blade based on the stacking line modeling requirement and make the blade tip reverse bending, and adjust the blade root phase angle of the curve control point located at the root of the blade based on a preset control condition, wherein the preset control condition is the linear relationship between the blade root phase angle and the blade tip phase angle.

[0205] The present application sets the stacking line through the modeling control curve, adjusts the blade tip phase angle of the curve control point located at the top of the blade based on the stacking line modeling requirement and makes the blade tip reverse bending when setting the control point, and adjusts the blade root phase angle of the curve control point located at the root of the blade based on the preset control condition of the linear relationship, thereby realizing the stacking line modeling for eliminating the noise by setting the blade tip reverse bending, and greatly reducing the number of control points to be adjusted due to the linear relationship between the blade tip phase angle and the blade root phase angle, thereby greatly reducing the design difficulty of the stacking line for eliminating the noise.

[0206] In one embodiment, the adjustment of the blade tip phase angle of the curve control point located at the top of the blade and the making of the blade tip reverse bending comprises:

[0207] The blade tip phase angle of the curve control point located at the top of the blade is set to be greater than the phase angle of the adjacent curve control point.

[0208] In one embodiment, the adjustment of the blade root phase angle of the curve control point located at the root of the blade based on the preset control condition comprises:

[0209] adjusting a blade root phase angle of the curve control point located at the blade root based on a preset control condition to make the blade root of the blade reverse.

[0210] In one of the embodiments, the preset control condition is that the blade root phase angle is set as a product of the blade tip phase angle and a preset ratio, and the blade tip phase angle is positive, and the blade root phase angle is negative, wherein the positive value means that the phase angle is the same as the rotating direction of the fan blade, and the negative value means that the phase angle is opposite to the rotating direction of the fan blade.

[0211] In one of the embodiments, the modeling control curve includes five curve control points, and the five curve control points in the direction from the blade root to the blade tip are a first curve control point, a second curve control point, a third curve control point, a fourth curve control point and a fifth curve control point in sequence, and the adjusting of the blade tip phase angle of the curve control point located at the blade tip based on the stacking line modeling requirement and the making of the blade tip reverse, and the adjusting of the blade root phase angle of the curve control point located at the blade root based on the preset control condition, include:

[0212] setting the phase angles of the first curve control point, the third curve control point and the fourth curve control point as 0;

[0213] setting the phase angle of the fifth curve control point as a positive value;

[0214] adjusting the phase angle of the fifth curve control point and the phase angle of the second curve control point based on the preset control condition and the stacking line modeling requirement, the phase angle of the fifth curve control point is the blade tip phase angle, the phase angle of the second curve control point is the blade root phase angle, and the preset control condition is:

[0215] θ2=-θ5 / N, wherein θ2 is the blade root phase angle, θ5 is the blade tip phase angle, and N is a positive integer.

[0216] In one of the embodiments, the blade of the front fan blade of the counter-rotating fan is a front blade, and the blade of the rear fan blade of the counter-rotating fan is a rear blade, and the setting of the blade tip phase angle of the curve control point located at the blade tip of the front blade to be greater than the phase angle of the adjacent curve control point includes:

[0217] setting the blade tip phase angle of the curve control point located at the blade tip of the front blade to be greater than the phase angle of the adjacent curve control point, and the blade tip phase angle of the front blade is less than 180° / N f , wherein N f is the number of the front blades;

[0218] The phase angle of the top of the curve control point of the rear blade at the top of the rear blade is greater than the phase angle of the adjacent curve control point, and the phase angle of the top of the rear blade is less than 180° / N r wherein N r is the number of the rear blades.

[0219] In one of the embodiments, the blades of the front fan of the counter-rotating fan are front blades, the blades of the rear fan of the counter-rotating fan are rear blades, and the device further comprises a blade number setting module for:

[0220] setting the number of the front blades to be greater than the number of the rear blades, and both the number of the front blades and the number of the rear blades are odd numbers.

[0221] In one of the embodiments, the blades of the front fan of the counter-rotating fan are front blades, the blades of the rear fan of the counter-rotating fan are rear blades, and the device further comprises an optimization strategy module for:

[0222] after the implementation of the accumulation line modeling, taking the phase angle of all the curve control points of the front blades as the front blade bending angle, taking the phase angle of all the curve control points of the rear blades as the rear blade bending angle, taking the front blade bending angle and the rear blade bending angle as a bending angle group, calculating the order noise of the superimposed noise of all the front blades and all the rear blades based on different bending angle groups.

[0223] selecting the bending angle group when the order noise is optimal as the optimal bending angle group and outputting.

[0224] In one of the embodiments, the calculation of the order noise of the superimposed noise of all the front blades and all the rear blades comprises:

[0225] calculating the time domain superimposed waveform of the superimposed noise and time relationship;

[0226] transforming the time domain superimposed waveform into a frequency domain waveform;

[0227] extracting the order noise from the frequency domain waveform.

[0228] In one of the embodiments, the calculation of the time domain superimposed waveform of the superimposed noise and time relationship comprises:

[0229] dividing the front blades into a plurality of front blade surfaces along the radial direction, dividing the rear blades into a plurality of rear blade surfaces along the radial direction, respectively generating the front blade noise basic two-dimensional phase waveform about the noise generated by all the front blade surfaces of all the front blades and the circumferential phase angle relationship, and the rear blade noise basic two-dimensional phase waveform about the noise generated by all the rear blade surfaces of all the rear blades and the circumferential phase angle relationship.

[0230] At the plurality of sampling instants, the front vane rotation angle turned by the front vane is determined according to the front vane rotation speed, the rear vane rotation angle turned by the rear vane is determined according to the rear vane rotation speed, the waveform of the front vane noise basic two-dimensional phase waveform is moved in the rotation direction by the front vane rotation angle, and the waveform after the movement is taken as the front vane noise sampling instant two-dimensional phase waveform; the waveform of the rear vane noise basic two-dimensional phase waveform is moved in the rotation direction by the rear vane rotation angle, and the waveform after the movement is taken as the rear vane noise sampling instant two-dimensional phase waveform;

[0231] The front vane noise sampling instant two-dimensional phase waveform is discretized to obtain a front vane noise column vector, the rear vane noise sampling instant two-dimensional phase waveform is discretized to obtain a rear vane noise column vector, and the dot product of the front vane noise column vector and the rear vane noise column vector is taken as the superimposed noise of the sampling instant.

[0232] The time-domain superimposed waveform about the superimposed noise and time relationship is generated according to the superimposed noises corresponding to all the sampling instants.

[0233] As to the device in the above embodiment, the specific manner in which each module performs the operation has been described in detail in the embodiment about the method, and will not be described in detail here.

[0234] As Figure 9 Fig. 1 shows a hardware structure schematic diagram of an electronic device according to the present application, which comprises:

[0235] at least one processor 901; and

[0236] a memory 902 in communication connection with the at least one processor 901; wherein

[0237] The memory 902 stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method for bending the cyclone fan vane as described above.

[0238] Figure 9 The processor 901 is taken as an example.

[0239] The electronic device can further comprise an input device 903 and a display device 904.

[0240] The processor 901, the memory 902, the input device 903 and the display device 904 can be connected through a bus or other means, and the connection through the bus is taken as an example in the figure.

[0241] The memory 902, as a non-volatile computer readable storage medium, can be used to store non-volatile software programs, non-volatile computer executable programs and modules, such as the program instructions / modules corresponding to the method for bending the blade of a counter-rotating fan in the embodiments of the present application, for example, the method flow shown in FIG. 8. Figure 1 , Figure 2 The processor 901 performs various function applications and data processing by running the non-volatile software programs, instructions and modules stored in the memory 902, that is, implements the method for bending the blade of a counter-rotating fan in the above embodiments.

[0242] The memory 902 can include a program storage area and a data storage area, wherein the program storage area can store an operating system and application programs required by at least one function; the data storage area can store data created according to the use of the method for bending the blade of a counter-rotating fan, etc. In addition, the memory 902 can include a high-speed random access memory, and can also include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state memory device. In some embodiments, the memory 902 can optionally include a memory disposed remotely with respect to the processor 901, and these remote memories can be connected to the device performing the method for bending the blade of a counter-rotating fan through a network. Examples of the above network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0243] The input device 903 can receive input user clicks and generate signal inputs related to user settings and function controls of the method for bending the blade of a counter-rotating fan. The display device 904 can include a display screen and the like display equipment.

[0244] When the one or more modules are stored in the memory 902 and are run by the one or more processors 901, the method for bending the blade of a counter-rotating fan in any of the above method embodiments is executed.

[0245] The present application sets the stacking line by controlling the curve, when setting the control point, adjusts the blade tip phase angle of the curve control point located at the top of the blade based on the stacking line modeling requirement and makes the blade tip reverse bending, and adjusts the blade root phase angle of the curve control point located at the root of the blade based on the preset control condition of the linear relationship, realizes the stacking line modeling of eliminating noise by setting the blade tip reverse bending, and since the blade tip phase angle and the blade root phase angle are only limited by the linear relationship, the number of control points required to be adjusted is greatly reduced, and the design difficulty of the stacking line when eliminating noise is greatly reduced.

[0246] An embodiment of the present application provides a storage medium, which stores computer instructions, when a computer executes the computer instructions, all steps of the method for bending the blade of a counter-rotating fan as described above are executed.

[0247] In the context of the present disclosure, the storage medium can be a tangible medium which can contain or store the program for use by or in connection with the instruction execution system, apparatus, or device. The storage medium can be a machine-readable signal medium or a machine-readable storage medium. Optionally, the storage medium can be a non-transitory computer-readable storage medium, for example, the non-transitory computer-readable storage medium can be a ROM, a random access memory (RAM), a compact disc read-only memory (CD-ROM), a magnetic tape, a floppy disk, and an optical data storage device, etc.

[0248] An embodiment of the present application provides a computer program product comprising computer programs / instructions which, when executed by a processor, implement the method for bending the blade of a counter-rotating fan as described above.

[0249] An embodiment of the present application provides a counter-rotating fan, comprising a fan and a blade arranged along the circumferential direction of the fan, wherein the blade is subjected to the blade stacking line modeling of the blade stacking line of the blade by using the method for bending the blade of a counter-rotating fan as described above.

[0250] An embodiment of the present application provides a vehicle comprising the counter-rotating fan as described above.

[0251] The above-described embodiments only express several embodiments of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of protection of the present application. Therefore, the scope of protection of the patent of the present application should be subject to the appended claims.

Claims

1. A method of bending a contra-rotating fan blade, characterized by, The method comprises the following steps: setting a stacking line of a blade of a blade of a counter-rotating fan as a shaping control curve, determining a plurality of radial curve control points on the shaping control curve, and setting a phase angle of each of the curve control points as an included angle between a line connecting the curve control point and a center of the curve control point and a vertical direction; for each of the blades, adjusting a blade tip phase angle of the curve control point located at a top of the blade based on a stacking line shaping requirement and making the blade tip reverse, and adjusting a blade root phase angle of the curve control point located at a root of the blade based on a preset control condition, the preset control condition being a linear relationship between the blade root phase angle and the blade tip phase angle.

2. The contra-rotating fan blade bending method of claim 1, wherein, The adjusting of the blade tip phase angle of the curve control point located at the top of the blade and the making of the blade tip reverse comprises: setting the blade tip phase angle of the curve control point located at the top of the blade to be greater than a phase angle of an adjacent curve control point.

3. The contra-rotating fan blade bending method of claim 1, wherein, The adjusting of the blade root phase angle of the curve control point located at the root of the blade based on the preset control condition comprises: adjusting the blade root phase angle of the curve control point located at the root of the blade based on the preset control condition to make the blade root reverse.

4. The contra-rotating fan blade bending method of claim 3, wherein, The preset control condition is that the blade root phase angle is set as a product of the blade tip phase angle and a preset ratio, and the blade tip phase angle is a positive value and the blade root phase angle is a negative value, wherein the positive value indicates that the phase angle is the same as a rotating direction of the blade, and the negative value indicates that the phase angle is opposite to the rotating direction of the blade.

5. The contra-rotating fan blade bending method of claim 4, wherein, The shaping control curve comprises five curve control points, and the five curve control points in a direction from the blade root to the blade tip are a first curve control point, a second curve control point, a third curve control point, a fourth curve control point and a fifth curve control point in sequence, and the adjusting of the blade tip phase angle of the curve control point located at the top of the blade based on the stacking line shaping requirement and the making of the blade tip reverse and the adjusting of the blade root phase angle of the curve control point located at the root of the blade based on the preset control condition comprise: setting phase angles of the first curve control point, the third curve control point and the fourth curve control point to be 0; setting a phase angle of the fifth curve control point to be a positive value; adjusting the phase angle of the fifth curve control point and a phase angle of the second curve control point based on a preset control condition according to the stacking line shaping requirement, the phase angle of the fifth curve control point being the blade tip phase angle, the phase angle of the second curve control point being the blade root phase angle, and the preset control condition being: θ2=-θ5 / N, wherein θ2 is the blade root phase angle, θ5 is the blade tip phase angle, and N is a positive integer.

6. The contra-rotating fan blade bending method of claim 2, wherein, The blade of the front blade of the counter-rotating fan is a front blade, and the blade of the rear blade of the counter-rotating fan is a rear blade, and the setting of the blade tip phase angle of the curve control point located at the top of the blade to be greater than the phase angle of the adjacent curve control point comprises: The phase angle of the top of the curve control point of the front blade at the top of the front blade is greater than the phase angle of the adjacent curve control point, and the phase angle of the top of the front blade is less than 180° / N f wherein N f is the number of the front blades; The setting of the top phase angle of the curve control point at the top of the rear blade is greater than the phase angle of the adjacent curve control point, and the top phase angle of the rear blade is less than 180° / N r where N r is the number of the rear blades.

7. The method of bending contra-rotating fan blades according to any one of claims 1-6, wherein, The blade of the front blade of the counter-rotating fan is a front blade, and the blade of the rear blade of the counter-rotating fan is a rear blade, and the method further comprises: setting a number of the front blades to be greater than a number of the rear blades, and the number of the front blades and the number of the rear blades are both odd numbers.

8. The contra-rotating fan blade bending method of claim 7, wherein, The blade of the front fan blade of the counter-rotating fan is a front blade, the blade of the rear fan blade of the counter-rotating fan is a rear blade, and the method further comprises: After the implementation of the accumulation line modeling, the phase angle of all the curve control points of the front blade is taken as a front blade bending angle, the phase angle of all the curve control points of the rear blade is taken as a rear blade bending angle, the front blade bending angle and the rear blade bending angle are taken as a bending angle group, the order noise of the superimposed noise of all the front blades and all the rear blades is calculated based on different bending angle groups; The bending angle group when the order noise is optimal is selected as an optimal bending angle group and output.

9. The contra-rotating fan blade bending method of claim 8, wherein, The calculation of the order noise of the superimposed noise of all the front blades and all the rear blades comprises: Calculating a time-domain superimposed waveform of the superimposed noise and time relationship; Transforming the time-domain superimposed waveform into a frequency-domain waveform; Extracting the order noise from the frequency-domain waveform.

10. The contra-rotating fan blade bending method of claim 9, wherein, The calculation of the time-domain superimposed waveform of the superimposed noise and time relationship comprises: The front blade is divided into a plurality of front blade surfaces along the radial direction, the rear blade is divided into a plurality of rear blade surfaces along the radial direction, a front blade noise basic two-dimensional phase waveform about the noise generated by all the front blade surfaces of all the front blades and a circumferential phase angle relationship and a rear blade noise basic two-dimensional phase waveform about the noise generated by all the rear blade surfaces of all the rear blades and a circumferential phase angle relationship are respectively generated; At a plurality of sampling time points, the front blade rotation angle through which the front blade rotates is determined according to the front fan blade rotation speed, the rear blade rotation angle through which the rear blade rotates is determined according to the rear fan blade rotation speed, the waveform of the front blade noise basic two-dimensional phase waveform after being moved in the rotation direction by the front blade rotation angle is taken as a front blade noise sampling time point two-dimensional phase waveform, and the waveform of the rear blade noise basic two-dimensional phase waveform after being moved in the rotation direction by the rear blade rotation angle is taken as a rear blade noise sampling time point two-dimensional phase waveform; The front blade noise sampling time point two-dimensional phase waveform is discretized to obtain a front blade noise column vector, the rear blade noise sampling time point two-dimensional phase waveform is discretized to obtain a rear blade noise column vector, and the dot product of the front blade noise column vector and the rear blade noise column vector is taken as the superimposed noise at the sampling time point; A time-domain superimposed waveform about the superimposed noise and time relationship is generated according to the superimposed noise corresponding to all the sampling time points.

11. A contra-rotating fan blade bending apparatus characterized by, Comprise: A control point determination module is configured to set an accumulation line of a blade of a fan blade of a counter-rotating fan as a modeling control curve, determine a plurality of radial curve control points on the modeling control curve, and set a phase angle of each curve control point as an included angle between a line connecting the curve control point and a center and a vertical direction; An accumulation line control module is configured to, for each blade, adjust a blade tip phase angle of the curve control point located at a top of the blade based on accumulation line modeling requirements and make the blade tip reverse bending, and adjust a blade root phase angle of the curve control point located at a root of the blade based on a preset control condition, the preset control condition being a linear relationship between the blade root phase angle and the blade tip phase angle.

12. An electronic device, comprising: Comprise: At least one processor; And a memory in communication connection to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions, when executed by the at least one processor, enable the at least one processor to perform the method for bending a contra-rotating fan blade according to any one of claims 1 to 10.

13. A storage medium, characterized by The storage medium stores computer instructions for performing all the steps of the method for bending a contra-rotating fan blade according to any one of claims 1 to 10 when the computer executes the computer instructions.

14. A computer program product comprising computer programs / instructions, characterized in that, The computer program / instructions, when executed by the processor, implement the method for bending a contra-rotating fan blade according to any one of claims 1 to 10.

15. A contra-rotating fan characterised in that, A fan comprising a fan and a blade arranged along a circumferential direction of the fan, and the blade is profiled according to the method for bending a contra-rotating fan blade according to any one of claims 1 to 10.

16. A vehicle characterized by comprising: A contra-rotating fan according to claim 15.

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