CN114673686B - Fan design method and corresponding fan - Google Patents
Fan design method and corresponding fan Download PDFInfo
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- CN114673686B CN114673686B CN202210396080.1A CN202210396080A CN114673686B CN 114673686 B CN114673686 B CN 114673686B CN 202210396080 A CN202210396080 A CN 202210396080A CN 114673686 B CN114673686 B CN 114673686B
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- 238000013461 design Methods 0.000 title claims abstract description 35
- 238000000034 method Methods 0.000 title claims abstract description 32
- 238000000926 separation method Methods 0.000 claims abstract description 54
- 238000004088 simulation Methods 0.000 claims abstract description 23
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- 238000004364 calculation method Methods 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 230000017525 heat dissipation Effects 0.000 description 3
- 230000002401 inhibitory effect Effects 0.000 description 3
- 230000002441 reversible effect Effects 0.000 description 3
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/26—Rotors specially for elastic fluids
- F04D29/32—Rotors specially for elastic fluids for axial flow pumps
- F04D29/38—Blades
- F04D29/388—Blades characterised by construction
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
- F04D29/661—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps
- F04D29/666—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps by means of rotor construction or layout, e.g. unequal distribution of blades or vanes
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
- F04D29/661—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps
- F04D29/667—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps by influencing the flow pattern, e.g. suppression of turbulence
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K7/00—Constructional details common to different types of electric apparatus
- H05K7/20—Modifications to facilitate cooling, ventilating, or heating
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
Abstract
The invention discloses a design method of a fan, which comprises the following steps: obtaining a plurality of blade high sections with different preset heights of the fan blade, and respectively carrying out pneumatic simulation on the blade profiles of the blade high sections; determining a corresponding separation point at each preset height according to a resistance coefficient curve obtained by pneumatic simulation, and determining the position of a first row of grooves on the suction surface according to the corresponding separation point at each preset height; determining the position of the last row of grooves according to the thickness of the tail edge of the blade and the depth of the grooves; the positions of the intermediate grooves of the columns are determined based on the positions of the grooves of the first column and the positions of the grooves of the last column. The invention also discloses a fan. According to the scheme provided by the invention, the groove design structure is adopted on the suction surface of the fan blade, so that the flow separation on the surface of the fan blade can be restrained, the stall phenomenon can be delayed or even avoided on the premise of ensuring the load of the fan blade, and the resistance in the gas flow process can be effectively reduced.
Description
Technical Field
The invention relates to the field of fans, in particular to a design method of a fan and a corresponding fan.
Background
The axial flow fan is used as one of the main components of the server air cooling heat dissipation system, so as to continuously improve the air quantity and the air pressure to meet the higher and higher heat dissipation requirements of the system, and meanwhile, the limitation of the server on the noise and the power consumption of the fan is considered, and researchers are always exploring the limit of the fan performance in a limited space. The electronic cooling fan for server belongs to the category of high-pressure axial-flow fan, and its action mechanism is that the fan blade rotates to apply work to the air flow, and the mechanical energy of the fan blade is converted into the kinetic energy and pressure energy of the air flow, so as to realize higher air quantity and air pressure, the fan blade design of the electronic fan is continuously developed towards the high-load direction. However, for the axial flow fan, the inherent reverse pressure gradient in the axial flow fan is very easy to separate the boundary layer fluid, and stall phenomenon can occur along with further increase of the reverse pressure gradient, the resistance of air flow can also be increased sharply, the fan blade channel is blocked, the aerodynamic performance of the fan is seriously affected, the efficient working range of the fan is narrowed, the air quantity and the air pressure brought by the fan are reduced, the power consumption is increased, and the eddy noise part is also increased. The above problems become more serious based on the current demand of further increasing the load of the electronic fan to provide a larger air volume and a higher air pressure.
In the field of electronic radiator fan design, mainly two modes of traditional blade profile modeling optimization method and blade profile load distribution adjustment are adopted to inhibit flow separation and delay stall phenomenon of the blade surface, but some novel methods for inhibiting flow separation are proposed in researches in recent two years, for example, in a patent CN 113757170A, the blade load is increased by increasing the blade profile folding angle, the blade load can increase the functional capacity of the blade on air flow so as to increase air quantity and air pressure, but flow separation is increased, pneumatic efficiency is reduced and pneumatic noise is increased, so that on this basis, a perforation design from one side of a pressure surface to one side of a suction surface is provided, namely perforation is carried out on the blade, the perforation can penetrate the pressure surface and the suction surface of the blade, and the perforation can effectively inhibit flow separation, thereby achieving the purposes of reducing noise and reducing power consumption. In addition, the diameter, angle and position distribution of the holes are related in the design process of the holes, because the effect of the parameters corresponding to the holes is very important, but in the design process of the geometric parameters of the holes, parametric research is also needed, different fan blade flow conditions need to be iterated repeatedly, so that the design period is longer, and meanwhile, due to the fact that the thickness of the fan blade is thinner, the strength of the fan blade is easily reduced due to perforation design.
Therefore, how to effectively control the separation of the airflow on the surface of the fan blade on the premise of ensuring the load of the fan blade, delay or even avoid the occurrence of stall phenomenon, thereby widening the effective working range of the fan, and being the problem to be solved in the prior art for improving the blade shape and the aerodynamic performance of the fan blade.
Disclosure of Invention
In view of this, in order to overcome at least one aspect of the above-mentioned problems, an embodiment of the present invention provides a design method of a fan, including the following steps:
obtaining a plurality of blade high sections with different preset heights of the fan blade, and respectively carrying out pneumatic simulation on the blade profiles of the blade high sections;
determining a corresponding separation point at each preset height according to a resistance coefficient curve obtained by pneumatic simulation, and determining the position of a first row of grooves on the suction surface according to the corresponding separation point at each preset height;
determining the position of the last row of grooves according to the thickness of the tail edge of the blade and the depth of the grooves;
the positions of the intermediate grooves of the columns are determined based on the positions of the grooves of the first column and the positions of the grooves of the last column.
In some embodiments, determining the corresponding separation point at each preset height according to the resistance coefficient curve obtained by the pneumatic simulation and determining the position of the first column of grooves according to the corresponding separation point at each preset height further comprises:
and determining the chord length position of the first row of grooves on the blade according to the axial chord length position of the corresponding separation point at each preset height in the blade profile of the blade high section and the blade profile installation angle.
In some embodiments, determining the positions of the columns of intermediate grooves based on the positions of the first column of grooves and the last column of grooves further comprises:
equally dividing the positions of the axial chord lengths corresponding to the first grooves and the positions of the axial chord lengths corresponding to the last row of grooves along the axial chord length direction;
and determining the chord length positions of the columns of intermediate grooves on the blade according to the blade profile mounting angle and the position of each cutting point on the axial chord length.
In some embodiments, obtaining a plurality of blade height sections of the fan blade at different preset heights and performing aerodynamic simulation on the blade profile of the blade height section respectively, further comprises:
and acquiring sections of the first preset blade height, the second preset blade height and the third preset blade height of the fan blade, and respectively carrying out pneumatic simulation on the blade profile of the blade height section.
In some embodiments, determining the corresponding separation point at each preset height according to the resistance coefficient curve obtained by the pneumatic simulation and determining the position of the first column of grooves according to the corresponding separation point at each preset height further comprises:
determining chord length positions of three grooves in the first row of grooves according to the obtained separation points corresponding to the three preset heights of the fan blades;
and interpolating based on chord length positions of the three grooves to obtain chord length positions of other grooves in the first row of grooves.
In some embodiments, further comprising:
each row of grooves is designed to be uniformly distributed within the range of 10% -90% of the leaf height.
In some embodiments, further comprising:
the grooves of each row are designed to be staggered along the height of the leaf.
In some embodiments, further comprising:
the grooves are designed to be semi-circular.
In some embodiments, further comprising:
the depth of each groove is designed to be 0.2mm-0.5mm, and the diameter is designed to be 3-5 times of the depth.
According to another aspect of the present invention, there is provided a fan comprising a plurality of blades, each blade having a suction surface provided with a plurality of rows of grooves, wherein the position of each row of grooves on the blade is obtained by a method as described in any of the above embodiments.
The invention has one of the following beneficial technical effects: according to the scheme provided by the invention, the groove design structure is adopted on the suction surface of the fan blade, so that the flow separation of the surface of the fan blade can be restrained, the stall phenomenon can be delayed or even avoided on the premise of ensuring the load of the fan blade, and the resistance in the air flow process is effectively reduced, so that the purposes of improving the air quantity and the air pressure of the fan, reducing the broadband pneumatic noise and reducing the power consumption are achieved. Meanwhile, the groove design method provided by the patent can obtain a groove scheme with a forward flow control effect in a higher efficiency and a shorter time.
Drawings
In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are necessary for the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention and that other embodiments may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a flow chart of a design method of a fan according to an embodiment of the invention;
FIG. 2 is a schematic diagram of coverage area of operating points of different configurations of 2U server system impedance on a fan P-Q curve according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of the principle of groove action and groove parameters on the suction side of a fan blade;
FIG. 4 shows the drag coefficient C of a profile blade profile at 50% of the blade profile high section f Along axial chord length C ax A plot of direction;
FIG. 5 is a schematic view of a first row of grooves on the suction side at different blade height sections;
FIG. 6 is a schematic view showing the definition of the depth h and the diameter d of the spherical recess;
fig. 7 is a schematic structural diagram of a fan according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the following embodiments of the present invention will be described in further detail with reference to the accompanying drawings.
It should be noted that, in the embodiments of the present invention, all the expressions "first" and "second" are used to distinguish two entities with the same name but different entities or different parameters, and it is noted that the "first" and "second" are only used for convenience of expression, and should not be construed as limiting the embodiments of the present invention, and the following embodiments are not described one by one.
According to an aspect of the present invention, an embodiment of the present invention proposes a design method of a fan, as shown in fig. 1, which may include the steps of:
s1, obtaining a plurality of blade high sections with different preset heights of a fan blade, and respectively carrying out pneumatic simulation on the blade profiles of the blade high sections;
s2, determining a corresponding separation point at each preset height according to a resistance coefficient curve obtained by pneumatic simulation and determining the position of a first row of grooves on the suction surface according to the corresponding separation point at each preset height;
s3, determining the position of the last row of grooves according to the thickness of the tail edge of the blade and the depth of the grooves;
s4, determining the positions of a plurality of columns of middle grooves based on the positions of the grooves of the first column and the positions of the grooves of the last column.
According to the scheme provided by the invention, the groove design structure is adopted on the suction surface of the fan blade, so that the flow separation of the surface of the fan blade can be restrained, the stall phenomenon can be delayed or even avoided on the premise of ensuring the load of the fan blade, and the resistance in the air flow process is effectively reduced, so that the purposes of improving the air quantity and the air pressure of the fan, reducing the broadband pneumatic noise and reducing the power consumption are achieved. Meanwhile, the groove design method provided by the patent can obtain a groove scheme with a forward flow control effect in a higher efficiency and a shorter time.
In some embodiments, as shown in fig. 2, the lower curve is a typical dimensionless P-Q schematic diagram of an electronic fan used in the present stage, taking its application on a 2U rack server as an example, for different configurations of the server, the position of the intersection point between the system windage and the P-Q is approximately located in the rectangular range shown in the figure, it can be seen that the system windage is approximately located in the middle air volume and middle air pressure area, the marked part in the figure is the fan stall area, and it can be obviously seen that, along with the change of the flow, the air pressure remains unchanged basically, which indicates that large-scale flow separation occurs on the suction surface of the fan blade, so that the air flow loses the diffusion capability, and therefore, the fan stall is caused; if the stall phenomenon can be delayed and even avoided by adopting some methods for inhibiting flow separation, the air quantity and the air pressure can be effectively improved, the change trend of the stall phenomenon is shown in an upper curve in fig. 2, the intersection point of the impedance and the P-Q can also move like a position with higher air quantity and higher air pressure for a server, the heat dissipation and the noise performance can be obviously improved, the fan blade can overcome lower resistance under the condition of applying the same work to the air flow, and the power consumption of the fan blade can be reduced.
In view of the fact that the suction surface of the fan is easier to generate flow separation phenomenon and needs to be controlled to improve the flow condition, the invention provides an electronic fan blade design structure with a groove structure on the suction surface, which can effectively inhibit flow separation and delay stall phenomenon, and the specific action mechanism mainly comprises the following two points: (1) As shown in fig. 3, considering that the grooves mainly reduce the loss of the blade profile, the two-dimensional blade profile is illustrated, and a vortex is generated when the airflow passes through the grooves on the Suction Surface (SS) in the process of flowing from the front edge (LE) to the Tail Edge (TE) of the blade, and the vortex can act like a rolling bearing, and can strengthen the mixing of the fluid in the boundary layer and the main stream fluid, so that the boundary layer fluid obtains momentum from the fluid in the main stream area, the kinetic energy is improved, the capability of resisting the counter-pressure gradient is stronger, and the boundary layer separation condition is improved; (2) The existence of the grooves can generate a disturbance source for the airflow, and the disturbance source can induce the boundary layer to generate transition in advance, so that the laminar boundary layer is transited into a turbulent boundary layer in advance, and the turbulent boundary layer is not easy to separate, so that the separation of the boundary layer can be restrained, and the stall phenomenon can be delayed. It can be seen that the geometric parameters corresponding to the grooves include the depth h, the width s and the position array arrangement thereof, and the selection of these parameters determines the effect of the grooves, so that it is important to reasonably design the geometric and position parameters of the grooves if a better flow control effect is desired and in combination with the manufacturability.
Therefore, further, the invention provides a novel groove design method with higher efficiency based on the essential action principle of the groove. The essential reason for creating a boundary layer as the gas/fluid flows over the solid surface is that the boundary layer separates as the drag increases further. When the air flows over the fan blade surfaces, the resistance acting on the air is divided into frictional resistance and differential pressure resistance. Blade-shaped resistance is friction resistance when flowingForce is dominant and drag coefficient C f The pressure gradient gradually increases along with the increase of the reverse pressure gradient; once the backflow phenomenon occurs in the boundary layer, the blade type resistance is mainly the pressure difference resistance and the resistance coefficient C f Abrupt changes occur, the value of which becomes negative, which also means that the fan experiences flow separation and even stall phenomena. Therefore, the distribution of the drag coefficient curve of the blade surface can be used as the most visual and effective parameter for measuring the flow state condition of the blade surface, the starting position of flow separation/stall can be directly obtained according to the change rule of the drag coefficient curve, and the purpose of the groove design is considered to restrain flow separation and reduce drag, so that the groove design is arranged at the position at the upstream of the separation starting point to be optimal. Therefore, the invention provides a design method for determining the arrangement of the groove array based on the distribution rule of the two-dimensional blade profile surface resistance coefficient curve, which has the advantages of universality for any type of fan, no need of parameterizing research on the positions of the grooves according to each research object, and great design time saving.
Wherein the drag coefficient is defined as follows:
C f ＝2τ x /ρ·v 2 (1)
wherein τ x For shear stress along the flow direction, ρ is the fluid density and v is the incoming flow velocity.
In some embodiments, step S1, obtaining a plurality of blade high sections with different preset heights of the fan blade, and performing aerodynamic simulation on the blade profiles of the blade high sections respectively, specifically, for a fan needing aerodynamic performance optimization, performing aerodynamic performance analysis on a typical blade profile of the blade high section first.
Pneumatic simulation calculation is respectively carried out on the extracted two-dimensional blade profile, and a pneumatic performance calculation and analysis tool can be selected from commercial software, open source CFD software, self-programming and the like to obtain the distribution of various pneumatic parameters along the surface of the blade. Wherein the most critical parameter is the drag coefficient curve C f Distribution along the blade surface, by C f The distribution of the blade profile along the high-section blade can determine the approximate flow state of the blade surface.
In some embodiments, S2, determining a corresponding separation point at each preset height according to a drag coefficient curve obtained by pneumatic simulation and determining a position of the first row of grooves on the suction surface according to the corresponding separation point at each preset height, further includes:
and determining the chord length position of the first row of grooves on the blade according to the axial chord length position of the corresponding separation point at each preset height in the blade profile of the blade high section and the blade profile installation angle.
Specifically, if C f When the vane suddenly and sharply descends at a certain position or has a negative value smaller than zero, it can be judged that flow separation exists or stall occurs at the position, so that when the groove design of the vane-type section is performed, the position of the first row of grooves can be determined according to the position of the separation point, for example, the chord-wise position of the first row of grooves can be at the upstream position near the separation point. The blade profile installation angle is an included angle between the chord length direction of the blade and the horizontal line.
Taking the fan as an example, FIG. 4 shows a curve C of the drag coefficient corresponding to the blade profile at the high section of 50% of the blade f Along the profile of the high section of the blade, it is evident that, at the Cax position, which is 55% of the axial chord length, the drag coefficient curve C f A point below zero is present, indicating that a reflux of the boundary layer occurs near this location, flow separation occurs, and then the drag coefficient curve C f Is always less than zero, which means that the boundary layer is always in a flow separation state from the separation point to the region of the profiled trailing edge. Based on the design method provided by the invention, in the case, the first row of groove arrays of the blade profile at the high section of the blade can be arranged in front of the separation point, and can be arranged at the axial chord length of 50%; other design methods corresponding to the leaf profile (such as 10% leaf height, 20% leaf height, 30% leaf height, 40% leaf height, 50% leaf height, 60% leaf height, 70% leaf height, 80% leaf height, 90% leaf height) at the leaf high section and so on. Finally, a schematic diagram of the first row of grooves corresponding to the selected blade high section is shown in fig. 5.
The chord length is the distance from LE to TE, and the axial chord length is the projection of the chord length on the horizontal plane, namely, the axial chord length can be obtained by multiplying the chord length by the residual chord value of the blade profile installation angle. And by analogy, dividing the axial chord length by the residual chord value of the blade profile installation angle to obtain the chord length.
In some embodiments, step S3 determines the position of the last row of grooves according to the thickness of the trailing edge of the blade and the depth of the grooves, specifically, considering that for large-scale separation, especially in stall working conditions, the control effect of the grooves of one row may be limited, and considering that the thickness of the blade profile of the electronic fan near the trailing edge is very small, approximately only about 1mm, and is not suitable for slotting, so that the chord position of the last row of grooves may not be greater than 90% of the axial chord length.
In some embodiments, S4, determining the positions of the columns of intermediate grooves based on the positions of the first column of grooves and the last column of grooves further comprises:
equally dividing the positions of the axial chord lengths corresponding to the first grooves and the positions of the axial chord lengths corresponding to the last row of grooves along the axial chord length direction;
and determining the chord length positions of the columns of intermediate grooves on the blade according to the blade profile mounting angle and the position of each cutting point on the axial chord length.
Specifically, based on the equidistant and average distribution of the first row and the last row along the axial chord length direction, the chord length positions of a plurality of rows of grooves at the high section of the selected blade can be determined;
in some embodiments, S1, obtaining a plurality of blade height sections of the fan blade with different preset heights and performing aerodynamic simulation on the blade profile of the blade height section respectively, further includes:
and acquiring sections of the first preset blade height, the second preset blade height and the third preset blade height of the fan blade, and respectively carrying out pneumatic simulation on the blade profile of the blade height section.
Specifically, the typical 10%, 50% and 90% high-section blade profile of the blade can be selected, if special requirements exist, the number of sections can be properly increased, and the two-dimensional blade profile required to be subjected to simulation calculation can be extracted.
In some embodiments, S2, determining a corresponding separation point at each preset height according to a drag coefficient curve obtained by pneumatic simulation and determining a position of the first column of grooves according to the corresponding separation point at each preset height, further includes:
determining chord length positions of three grooves in the first row of grooves according to the obtained separation points corresponding to the three preset heights of the fan blades;
and interpolating based on chord length positions of the three grooves to obtain chord length positions of other grooves in the first row of grooves.
In some embodiments, further comprising:
each row of grooves is designed to be uniformly distributed within the range of 10% -90% of the leaf height.
In some embodiments, further comprising:
the grooves of each row are designed to be staggered along the height of the leaf.
Specifically, after the groove position and the groove geometric parameters of each typical section are obtained, a groove center point can be arranged on the suction surface of the fan blade in an interpolation mode or the like. And comprehensively considering the geometric parameters (such as blade height) of the blades and the geometric parameters (such as diameter d) of the grooves, and determining the radial groove arrangement number of the blades. The grooves are uniformly distributed within a range of 10% -90% of the blade height due to the fact that the grooves are uniformly distributed within the blade height range, and the grooves are distributed in a staggered manner along the blade height direction when interpolation is conducted on the center point of the grooves.
In some embodiments, further comprising:
the grooves are designed to be semi-circular.
In some embodiments, further comprising:
the depth of each groove is designed to be 0.2mm-0.5mm, and the diameter is designed to be 3-5 times of the depth.
Specifically, the flow control effect and the processing and manufacturing difficulty of the fan blade are comprehensively considered, and the spherical groove is a good choice for flow control. The thickness of the blades of the cooling fan of the electronic device is limited to be very thin, so that the grooves cannot be too deep, otherwise the strength of the blades is obviously and negatively affected. As described above, the ratio of groove width s to depth h (h and s being defined as described above in fig. 3) also significantly affects the control of the flow by the groove. At the same groove depth, the inner wall of the groove is closer to a sphere if the ratio of groove diameter to depth is too small. Such grooves have a stronger "throwing" action on the fluid, which, while being able to control the flow separation, also results in more dissipation losses; if the ratio of the diameter to the depth of the groove is too large, the groove is too gentle and is close to the surface shape of the original blade, and the effective flow control function cannot be exerted. Thus, the selected groove depth h may be 0.2mm to 0.5mm, with a ratio of groove diameter d to depth h of 3 to 5. In this embodiment h is preferably 0.3mm and the ratio of the groove diameter d to the depth h is 4.0. As shown in fig. 6, for a spherical recess, the diameter and depth are defined, and the width is defined. The two parameters can be properly adjusted according to the geometric parameters and the flow conditions of different blades.
The proposal provided by the invention has the advantages that the surface resistance of the fan blade can be reduced by inhibiting the flow separation of the suction surface and delaying the stall phenomenon, thereby improving the P-Q performance of the fan, reducing the power consumption and reducing the broadband aerodynamic noise; based on the principle of groove drag reduction, a design method for determining groove parameters based on a resistance coefficient curve on a two-dimensional blade profile is provided, groove parameterization research needed for obtaining a groove forward control effect can be avoided, and therefore an optimal groove design scheme can be obtained with less design time and simpler design steps. The groove structure provided by the invention can effectively inhibit the stall phenomenon for double-row counter-rotating/co-rotating fans with more complicated pneumatic layout, and can even completely eliminate the stall phenomenon for single-row fans with simpler pneumatic layout. Therefore, the design structure can improve the pneumatic efficiency of the fan blade by 5-10%, reduce the noise by 2-4 dB and reduce the power consumption by 1-3% in general, and meanwhile, the design method provided by the invention saves the design time by more than 50%.
According to another aspect of the present invention, there is provided a fan, as shown in fig. 7, comprising a plurality of blades, each of the blades having a suction surface provided with a plurality of rows of grooves, wherein the position of each row of grooves on the blade is obtained by the method according to any of the above embodiments.
The foregoing is an exemplary embodiment of the present disclosure, but it should be noted that various changes and modifications could be made herein without departing from the scope of the disclosure as defined by the appended claims. The functions, steps and/or actions of the method claims in accordance with the disclosed embodiments described herein need not be performed in any particular order. Furthermore, although elements of the disclosed embodiments may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated.
It should be understood that as used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly supports the exception. It should also be understood that "and/or" as used herein is meant to include any and all possible combinations of one or more of the associated listed items.
The foregoing embodiment of the present invention has been disclosed with reference to the number of embodiments for the purpose of description only, and does not represent the advantages or disadvantages of the embodiments.
It will be understood by those skilled in the art that all or part of the steps for implementing the above embodiments may be implemented by hardware, or may be implemented by a program for instructing relevant hardware, and the program may be stored in a computer readable storage medium, where the storage medium may be a read-only memory, a magnetic disk or an optical disk, etc.
Those of ordinary skill in the art will appreciate that: the above discussion of any embodiment is merely exemplary and is not intended to imply that the scope of the disclosure of embodiments of the invention, including the claims, is limited to such examples; combinations of features of the above embodiments or in different embodiments are also possible within the idea of an embodiment of the invention, and many other variations of the different aspects of the embodiments of the invention as described above exist, which are not provided in detail for the sake of brevity. Therefore, any omission, modification, equivalent replacement, improvement, etc. of the embodiments should be included in the protection scope of the embodiments of the present invention.
Claims (6)
1. The design method of the fan is characterized by comprising the following steps of:
obtaining a plurality of blade high sections with different preset heights of the fan blade, and respectively carrying out pneumatic simulation on the blade profiles of the blade high sections;
determining a corresponding separation point at each preset height according to a resistance coefficient curve obtained by pneumatic simulation, and determining the position of a first row of grooves on the suction surface according to the corresponding separation point at each preset height;
determining the position of the last row of grooves according to the thickness of the tail edge of the blade and the depth of the grooves;
determining the positions of a plurality of columns of intermediate grooves based on the positions of the first column of grooves and the positions of the last column of grooves;
the method comprises the steps of determining a corresponding separation point under each preset height according to a resistance coefficient curve obtained through pneumatic simulation, determining the position of a first row of grooves on the suction surface according to the corresponding separation point under each preset height, and further comprising: determining the chord length position of the first row of grooves on the blade according to the axial chord length position of the corresponding separation point at each preset height in the blade profile of the blade high section and the blade profile mounting angle;
determining the positions of the columns of intermediate grooves based on the positions of the first column of grooves and the last column of grooves, further comprises: equally dividing the positions of the axial chord lengths corresponding to the grooves of the first row and the positions of the axial chord lengths corresponding to the grooves of the last row along the axial chord length direction; determining chord length positions of the columns of intermediate grooves on the blade according to the blade profile mounting angle and the position of each cutting point on the axial chord length;
obtaining a plurality of blade high sections with different preset heights of the fan blade, and respectively carrying out pneumatic simulation on the blade profiles of the blade high sections, and further comprising: acquiring sections of a first preset blade height, a second preset blade height and a third preset blade height of the fan blade, and respectively performing pneumatic simulation on the blade profile of the blade height section;
determining a corresponding separation point at each preset height according to a resistance coefficient curve obtained by pneumatic simulation, and determining the position of the first row of grooves according to the corresponding separation point at each preset height, and further comprising: determining chord length positions of three grooves in the first row of grooves according to the obtained separation points corresponding to the three preset heights of the fan blades; and interpolating based on chord length positions of the three grooves to obtain chord length positions of other grooves in the first row of grooves.
2. The method as recited in claim 1, further comprising: each row of grooves is designed to be uniformly distributed within the range of 10% -90% of the leaf height.
3. The method as recited in claim 1, further comprising: the grooves of each row are designed to be staggered along the height of the leaf.
4. The method as recited in claim 1, further comprising: the grooves are designed to be semi-circular.
5. The method as recited in claim 4, further comprising: the depth of each groove is designed to be 0.2mm-0.5mm, and the diameter is designed to be 3-5 times of the depth.
6. A fan comprising a plurality of blades, each blade having a suction side provided with a plurality of rows of grooves, wherein the position of each row of grooves on the blade is obtained by a method according to any one of claims 1-5.
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| CN202210396080.1A CN114673686B (en) | 2022-04-15 | 2022-04-15 | Fan design method and corresponding fan |
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105090098A (en) * | 2014-05-09 | 2015-11-25 | 贵州航空发动机研究所 | Transonic fan rotor blade |
| CN112464413A (en) * | 2020-12-11 | 2021-03-09 | 华中科技大学 | Circumferential bending type axial flow fan and design method thereof |
| CN113757170A (en) * | 2021-09-30 | 2021-12-07 | 苏州浪潮智能科技有限公司 | High-air-volume low-noise fan blade, fan and design method of fan blade |
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- 2022-04-15 CN CN202210396080.1A patent/CN114673686B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105090098A (en) * | 2014-05-09 | 2015-11-25 | 贵州航空发动机研究所 | Transonic fan rotor blade |
| CN112464413A (en) * | 2020-12-11 | 2021-03-09 | 华中科技大学 | Circumferential bending type axial flow fan and design method thereof |
| CN113757170A (en) * | 2021-09-30 | 2021-12-07 | 苏州浪潮智能科技有限公司 | High-air-volume low-noise fan blade, fan and design method of fan blade |
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