CN114673686A - Design method of fan and corresponding fan - Google Patents
Design method of fan and corresponding fan Download PDFInfo
- Publication number
- CN114673686A CN114673686A CN202210396080.1A CN202210396080A CN114673686A CN 114673686 A CN114673686 A CN 114673686A CN 202210396080 A CN202210396080 A CN 202210396080A CN 114673686 A CN114673686 A CN 114673686A
- Authority
- CN
- China
- Prior art keywords
- grooves
- blade
- fan
- determining
- row
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 41
- 238000013461 design Methods 0.000 title claims abstract description 29
- 238000000926 separation method Methods 0.000 claims abstract description 54
- 238000004088 simulation Methods 0.000 claims abstract description 23
- 238000009434 installation Methods 0.000 claims description 6
- 238000005520 cutting process Methods 0.000 claims description 3
- 230000003111 delayed effect Effects 0.000 abstract description 4
- 230000008569 process Effects 0.000 abstract description 4
- 230000000694 effects Effects 0.000 description 14
- 238000009826 distribution Methods 0.000 description 9
- 239000012530 fluid Substances 0.000 description 8
- 230000017525 heat dissipation Effects 0.000 description 7
- 230000009471 action Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- 238000011160 research Methods 0.000 description 5
- 230000008901 benefit Effects 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 230000002401 inhibitory effect Effects 0.000 description 3
- 230000002411 adverse Effects 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 238000012938 design process Methods 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000005457 optimization Methods 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 230000014509 gene expression Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- 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
-
- 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
-
- 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
-
- 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
Landscapes
- 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: acquiring a plurality of blade height sections of the fan blade with different preset heights and respectively performing pneumatic simulation on blade profiles of the blade height sections; determining a corresponding separation point under 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 under 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 locations of columns of intermediate grooves based on the locations of the first column of grooves and the locations of the last column of grooves. 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 inhibited, the stalling phenomenon is delayed or even avoided on the premise of ensuring the load of the fan blade, and the resistance in the gas flow process is 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
Axial fan is one of the main components of server air-cooled heat dissipation system, in order to continuously increase the air volume and the air pressure to meet the higher and higher heat dissipation requirements of the system, and simultaneously, the server needs to take into account the limitations of fan noise and power consumption, researchers are always exploring the limit of fan performance in a limited space. The electronic heat dissipation fan for the server belongs to the field of high-pressure axial flow fans, the action mechanism of the electronic heat dissipation fan is that the fan blades rotate to do work on airflow, mechanical energy of the fan blades is converted into kinetic energy and pressure energy of the airflow, and in order to achieve higher air volume and air pressure, the design of the fan blades of the electronic fan continuously develops towards a high load direction. However, for the axial flow fan, the inherent backpressure gradient inside the axial flow fan makes the boundary layer fluid easily separate, and as the backpressure gradient further increases, a stall phenomenon occurs, the resistance of the airflow also increases rapidly, causing the blockage of the fan blade channel, seriously affecting the aerodynamic performance of the fan, resulting in the narrowing of the efficient working range of the fan, which is expressed on the server that the air volume and the air pressure brought by the fan are reduced, the power consumption is increased, and the eddy noise part also increases. The above problem becomes more serious based on the demand of the current electronic fan to further increase the load to provide a larger air volume and a higher air pressure.
In the field of electronic heat dissipation fan design, the traditional blade profile modeling optimization method and the two methods of adjusting blade profile load distribution are mainly adopted to inhibit the flow separation on the surface of the fan blade and delay the occurrence of stall phenomenon, but in recent years, some novel methods for inhibiting the flow separation are also proposed, for example, in patent CN 113757170A, the blade load is increased by increasing the blade profile deflection angle, the blade load increase can improve the capability of the fan blade for doing work on air flow, thereby increasing the air volume and the air pressure, but at the same time, the flow separation increase can be brought, so that the pneumatic efficiency is reduced and the pneumatic noise is increased, therefore, on the basis, a perforation design penetrating from one side of the pressure surface to one side of the suction surface is proposed, namely, the perforation is punched on the fan blade, the perforation can penetrate through the pressure surface and the suction surface of the fan blade, the perforation can effectively inhibit the flow separation, thereby achieving the purposes of reducing noise and reducing power consumption, therefore, the starting point of the patent is to combine the punching design on the premise of increasing the fan blade load, and the aim of the patent is to increase the upper limit of the working performance of the loaded fan blade and not to widen the effective working range of the fan. In addition, the diameter, the angle and the position distribution of the holes are related to the small holes in the design process, because the parameters correspond to the small holes, the effect is very important, but in the design process of the geometric parameters of the small holes, parameterization research is needed, different fan blade flow working conditions need to be iterated repeatedly, so that the design period is long, and meanwhile, the strength of the fan blades is easily reduced due to the thin thickness of the fan blades.
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, and postpone or even avoid the occurrence of the stall phenomenon, thereby widening the effective working range of the fan, is a problem to be solved urgently at present for improving the blade profile and the aerodynamic performance of the fan blade.
Disclosure of Invention
In view of the above, in order to overcome at least one aspect of the above problems, an embodiment of the present invention provides a method for designing a fan, including:
acquiring a plurality of blade height sections of the fan blade with different preset heights and respectively performing pneumatic simulation on blade profiles of the blade height sections;
determining a corresponding separation point under 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 under 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 locations of columns of intermediate grooves based on the locations of the first column of grooves and the locations of the last column of grooves.
In some embodiments, determining a separation point corresponding to each preset height according to a resistance coefficient curve obtained by aerodynamic simulation and determining a position of the first row of grooves according to the separation point corresponding to 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 on the blade profile with the blade height section and the blade profile installation angle.
In some embodiments, determining the locations of columns of intermediate grooves based on the locations of the first column of grooves and the locations of the last column of grooves further comprises:
equally dividing the position of the axial chord length corresponding to the first groove and the position of the axial chord length corresponding to the last row of grooves along the axial chord length direction;
and determining the chord length position of the plurality of rows of middle grooves on the blade according to the blade profile installation 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 pneumatic simulation respectively for the blade height section blade profiles further comprises:
the method comprises the steps of obtaining the sections of a fan blade with a first preset blade height, a second preset blade height and a third preset blade height, and performing pneumatic simulation on the blade section profile with the blade height.
In some embodiments, determining a separation point corresponding to each preset height according to a resistance coefficient curve obtained by aerodynamic simulation and determining a position of the first row of grooves according to the separation point corresponding to 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 blade;
and interpolating based on the chord length positions of the three grooves to obtain the 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 distributed in a staggered mode along the blade height direction.
In some embodiments, further comprising:
the groove is designed to be semicircular.
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.
Based on the same inventive concept, according to another aspect of the present invention, there is also 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 the method according to any one 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 on the surface of the fan blade can be inhibited, the stalling 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 is effectively reduced, thereby achieving the purposes of improving the air volume and the air pressure of the fan, reducing the broadband aerodynamic noise and reducing the power consumption. Meanwhile, the groove design method provided by the patent can obtain a groove scheme with a positive flow control effect at higher efficiency in shorter time.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other embodiments can be obtained by using the drawings without creative efforts.
FIG. 1 is a schematic flow chart illustrating a method for designing a fan according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of coverage of operating points of impedances of differently configured 2U server systems on a P-Q curve of a fan according to an embodiment of the present invention;
FIG. 3 is a schematic diagram illustrating the principle of the groove action on the suction surface side of the fan blade and the groove parameters;
FIG. 4 is a resistance coefficient C of a profile at a 50% profile height sectionfIn the axial directionaxA plot of direction;
FIG. 5 is a schematic view of a first row of grooves on the suction surface at different blade height sections;
FIG. 6 is a schematic diagram illustrating the definition of the depth h and 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 are described in further detail with reference to the accompanying drawings.
It should be noted that all expressions using "first" and "second" in the embodiments of the present invention are used for distinguishing two entities with the same name but different names or different parameters, and it should be noted that "first" and "second" are merely for convenience of description and should not be construed as limitations of the embodiments of the present invention, and they are not described in any more detail in the following embodiments.
According to an aspect of the present invention, an embodiment of the present invention provides a method for designing a fan, as shown in fig. 1, which may include the steps of:
s1, acquiring blade height sections of the fan blade with different preset heights and performing pneumatic simulation respectively on blade profiles of the blade height sections;
s2, determining a corresponding separation point under each preset height according to a resistance coefficient curve obtained by pneumatic simulation, and determining the position of the first row of grooves on the suction surface according to the corresponding separation point under 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 the columns of middle grooves based on the positions of the first column of grooves and the positions of the last column of grooves.
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 inhibited, the stalling phenomenon is delayed and even avoided on the premise of ensuring the load of the fan blade, and the resistance in the gas flow process is effectively reduced, thereby achieving the purposes of improving the air quantity and the air pressure of the fan, reducing the broadband aerodynamic noise and reducing the power consumption. Meanwhile, the groove design method provided by the patent can obtain a groove scheme with a positive flow control effect with higher efficiency and shorter time.
In some embodiments, as shown in fig. 2, the lower curve is a typical dimensionless P-Q diagram of the electronic fan used at present, taking its application on a 2U rack server as an example, for different configurations of the server, the position of the intersection point of the system wind resistance and the P-Q is approximately located in the rectangular range shown in the figure, it can be seen that the intersection point is located in the middle wind volume and the middle wind pressure region, and the marked part in the figure is a fan stall region, it can be clearly seen that in this region, as the flow changes, the wind pressure remains basically unchanged, which indicates that large-scale flow separation occurs on the suction surface of the fan blade, which causes the airflow to lose the pressure expansion capability, and thus causes the fan stall; if the stall phenomenon can be delayed or even avoided by adopting some methods for suppressing flow separation, the air volume and the air pressure can be effectively improved, the change trend is shown as the upper curve in fig. 2, for the server, the intersection point of the impedance and the P-Q can also move like a position with higher air volume and higher air pressure, the heat dissipation and noise performance can also be obviously improved, which means that the fan blades can overcome lower resistance to air flow under the condition of doing the same work, and the power consumption can also be reduced.
In view of the fact that the suction surface of the fan is more likely to generate flow separation and needs to be controlled to improve the flow condition, the present invention provides a design structure of an electronic fan blade with a groove structure on the suction surface, which can effectively inhibit flow separation and delay the occurrence of stall, and the specific action mechanism mainly includes the following two points: (1) as shown in fig. 3, considering that the grooves mainly reduce the blade profile loss, the two-dimensional blade profile is used for illustration, and when the air flow passes through the grooves on the Suction Surface (SS) in the process of flowing from the Leading Edge (LE) to the Trailing Edge (TE) of the fan blade, a vortex is generated, which can act like a rolling bearing, and can strengthen the mixing of the fluid in the boundary layer and the main fluid, so that the fluid in the boundary layer can obtain momentum from the fluid in the main flow region, the kinetic energy is improved, and therefore, the capability of resisting the adverse pressure gradient is stronger, and the boundary layer separation condition is improved; (2) the existence of the groove can generate a disturbance source for airflow, the disturbance source can induce the boundary layer to transition in advance, the laminar flow boundary layer is enabled to transition into a turbulent flow boundary layer in advance, and the turbulent flow boundary layer is not easy to separate, so that the phenomena of separation of the boundary layer and stall delay can be inhibited. 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 action effect of the grooves, so that it is crucial to reasonably design the geometric and position parameters of the grooves if a better flow control effect is desired and consideration is combined with the manufacturability of the grooves.
Therefore, further, the invention provides a more efficient novel groove design method based on the essential action principle of the groove. The essential reason for the creation of a boundary layer when a gas/fluid flows over a solid surface is due to the presence of drag, which separates as drag increases further. When air flows through the surface of the fan blade, the resistance acting on the air is divided into two types, namely friction resistance and pressure difference resistance. The blade profile resistance is mainly frictional resistance and the resistance coefficient C isfThe adverse pressure gradient increases in a slowly increasing trend; once the boundary layer has backflow phenomenon, the blade profile resistance is mainly pressure difference resistance and resistance coefficient CfA sudden change occurs, the value of which becomes negative, which also means that the fan experiences flow separation and even stalls. Therefore, the distribution of the blade profile surface drag coefficient curve can be used as the most intuitive and effective parameter for measuring the flow state condition of the blade surface, the initial position of flow separation/stall can be directly obtained according to the change rule of the drag coefficient curve, and the groove is designed for inhibiting flow separation and reducing drag, so that the groove is optimally arranged at the upstream position of the separation initial point. 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, and the method has the advantages that the method has universality for any fan, the parametric research on the positions of the grooves according to each research object is not needed, and the design time can be greatly saved.
Wherein the drag coefficient is defined as follows:
Cf＝2τx/ρ·v2 (1)
wherein, tauxTo shear stress along the direction of flow, ρ is the fluid density and v is the incoming flow velocity.
In some embodiments, step S1 is to obtain a plurality of blade height sections of different preset heights of the fan blade and perform an aerodynamic simulation on the blade height section blade profile, specifically, for a fan requiring aerodynamic performance optimization, first perform an aerodynamic performance analysis on a typical blade height section blade profile.
Pneumatic simulation calculation is respectively carried out aiming at the extracted two-dimensional blade profile, and commercial software, open source CFD software, self-programming and the like can be selected as a pneumatic performance calculation and analysis tool to obtain the distribution of various pneumatic parameters along the surface of the blade. Wherein the most critical parameter is the resistance coefficient curve CfDistribution along the blade surface, through CfThe distribution of the blade profile along the blade height section can judge the approximate flowing state of the blade surface.
In some embodiments, S2, determining a corresponding separation point at each preset height according to the resistance coefficient curve obtained by the aerodynamic 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 comprising:
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 on the blade profile with the blade height section and the blade profile installation angle.
In particular, if CfWhen a sudden and sharp drop or a negative value less than zero occurs at a certain position of the blade, it can be determined that there is flow separation or stall, so when designing the grooves of the blade profile section, the position of the first row of grooves can be determined according to the position of the separation point, for example, the chordwise position of the first row of grooves can be at an upstream position near the separation point. Wherein, the blade profile mounting angle is the included angle between the chord length direction of the blade and the horizontal line.
Taking the fan as an example of the research object of the present invention, FIG. 4 shows a resistance coefficient curve C corresponding to the blade profile at the section with 50% blade heightfAlong the height of the leafThe distribution curve of the blade profile of the cross section can be obviously seen that the resistance coefficient curve C is arranged at the position of 55 percent of axial chord length CaxfA point less than zero is present, indicating that the boundary layer near this point has a backflow and a flow separation has occurred, and then the resistance coefficient curve CfAlways less than zero, which indicates that the flow separation is always from the separation point to the boundary layer in the trailing edge region of the airfoil. Based on the design method proposed by the present invention, in this case, the groove array of the first row of the blade profile at the blade height section can be arranged before the separation point, where it can be arranged at 50% of the axial chord length; the corresponding design method of the blade profile at the section with other blade heights (such as 10% of blade height, 20% of blade height, 30% of blade height, 40% of blade height, 50% of blade height, 60% of blade height, 70% of blade height, 80% of blade height and 90% of blade height) and the like. Finally, a schematic diagram of the first row of grooves corresponding to the selected blade height cross 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, that is, the axial chord length can be obtained by multiplying the chord length by the cosine of the blade profile mounting angle. And by analogy, the chord length can be obtained by dividing the axial chord length by the cosine value of the mounting angle of the blade profile.
In some embodiments, step S3 determines the position of the last row of grooves according to the thickness of the blade trailing edge and the depth of the grooves, and in particular, considering that for large-scale separation, especially stall conditions, the control effect of the row of grooves is relatively limited, and considering that the thickness of the electronic fan blade shape near the trailing edge is very small, about 1mm, and is not suitable for slotting, the chordwise position of the last row of grooves may not be greater than 90% of the axial chord length.
In some embodiments, S4, determining locations of columns of intermediate grooves based on the location of the first column of grooves and the location of the last column of grooves, further comprises:
equally dividing the position of the axial chord length corresponding to the first groove and the position of the axial chord length corresponding to the last row of grooves along the axial chord length direction;
and determining the chord length position of the plurality of rows of middle grooves on the blade according to the blade profile installation angle and the position of each cutting point on the axial chord length.
Specifically, based on the equidistant and even distribution of the positions of the first row and the last row along the axial chord length direction, the chord length positions of the multiple rows of grooves at the selected blade height section can be determined;
in some embodiments, S1, obtaining blade height sections of the fan blade at a plurality of different preset heights and performing pneumatic simulation respectively for the blade height section blade profiles, further includes:
the method comprises the steps of obtaining the sections of a fan blade with a first preset blade height, a second preset blade height and a third preset blade height, and performing pneumatic simulation on the blade section profile with the blade height.
Specifically, the typical 10%, 50%, 90% blade height 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 is extracted.
In some embodiments, S2, determining a corresponding separation point at each preset height according to the resistance coefficient curve obtained by the aerodynamic simulation and determining the position of the first row 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 blade;
and interpolating based on the chord length positions of the three grooves to obtain the 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 distributed in a staggered mode along the blade height direction.
Specifically, after obtaining the groove position and the groove geometric parameters of each typical cross section, the groove center point may be arranged on the fan blade suction surface by interpolation or the like. And comprehensively considering the geometric parameters (such as the blade height) of the blades and the geometric parameters (such as the diameter d) of the grooves, and determining the arrangement number of the radial grooves of the blades. The fan blade is limited by the geometric structure of the fan blade, generally, the grooves are uniformly distributed in the range of 10% -90% of the blade height, the control effect of the grooves can be more uniform, and when interpolation is carried out on the positions of the central points of the grooves, different array grooves are distributed in a staggered mode along the blade height direction.
In some embodiments, further comprising:
the groove is designed to be semicircular.
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 blades are comprehensively considered, and the spherical groove is a better choice for flow control. The thickness of the blades of the heat dissipation fan of the electronic equipment is limited to be very thin, so that the grooves cannot be too deep, which can have obvious negative effects on the strength of the blades. As mentioned above, the ratio of the groove width s to the depth h (h and s being defined as shown in fig. 3 above) also significantly affects the flow control effect of the grooves. At the same groove depth, the inner wall of the groove is closer to spherical if the ratio of the groove diameter to the depth is too small. Such grooves have a stronger "throwing" effect on the fluid, which, although enabling control of the flow separation, also leads to more dissipation losses; and if the ratio of the diameter of the groove 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 effect 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 in particular, for a spherical recess, the diameter and depth are fixed, i.e. the width is fixed. The two parameters can be adjusted according to the geometric parameters and the flow conditions of different blades.
The scheme provided by the invention has the advantages that the surface resistance of the fan blade can be reduced by inhibiting flow separation on the suction surface side and delaying the occurrence of a stall phenomenon, so that the P-Q performance of the fan is improved, the power consumption is reduced, and the broadband aerodynamic noise is reduced; on the basis, a design method for determining groove parameters based on a two-dimensional blade profile upper resistance coefficient curve is provided from the essence principle of groove drag reduction, groove parameterization research required 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 stalling phenomenon of a double-row counter-rotating/co-rotating fan with a complex pneumatic layout, and even can completely disappear for a single-row fan with a simple pneumatic layout. Therefore, the design structure can improve the aerodynamic efficiency of the fan blades by 5% -10%, reduce the noise by 2-4 dB and reduce the power consumption by 1% -3%, and meanwhile, the design method provided by the invention saves the design time by more than 50%.
Based on the same inventive concept, according to another aspect of the present invention, there is also 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 one 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 present 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 of the invention 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 numbers of the embodiments disclosed in the embodiments of the present invention are merely for description, and do not represent the merits 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 instructing relevant hardware, and the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a magnetic disk or an optical disk, etc.
Those of ordinary skill in the art will understand that: the discussion of any embodiment above is meant to be exemplary only, and is not intended to intimate that the scope of the disclosure, including the claims, of embodiments of the invention is limited to these examples; within the idea of an embodiment of the invention, also technical features in the above embodiment or in different embodiments may be combined and there are many other variations of the different aspects of the embodiments of the invention as described above, which are not provided in detail for the sake of brevity. Therefore, any omissions, modifications, substitutions, improvements, and the like that may be made without departing from the spirit and principles of the embodiments of the present invention are intended to be included within the scope of the embodiments of the present invention.
Claims (10)
1. A design method of a fan is characterized by comprising the following steps:
acquiring a plurality of blade height sections of the fan blade with different preset heights and respectively performing pneumatic simulation on blade profiles of the blade height sections;
determining a corresponding separation point under 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 under 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 locations of columns of intermediate grooves based on the locations of the first column of grooves and the locations of the last column of grooves.
2. The method of claim 1, wherein determining a corresponding separation point at each of the predetermined heights from a drag coefficient curve obtained from the aerodynamic simulation and determining a position of the first row of grooves on the suction surface from the corresponding separation point at each of the predetermined heights, further comprising:
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 on the blade profile with the blade height section and the blade profile installation angle.
3. The method of claim 2, wherein determining locations of columns of intermediate grooves based on the location of the first column of grooves and the location of the last column of grooves, further comprises:
equally dividing along the axial chord length direction between the position of the axial chord length corresponding to the first groove and the position of the axial chord length corresponding to the last row of grooves;
and determining the chord length position of the plurality of rows of middle grooves on the blade according to the blade profile installation angle and the position of each cutting point on the axial chord length.
4. The method of claim 1, wherein obtaining a plurality of different preset heights of blade height sections of the fan blade and performing pneumatic simulation respectively for the blade height section profiles, further comprises:
the method comprises the steps of obtaining the sections of a fan blade with a first preset blade height, a second preset blade height and a third preset blade height, and performing pneumatic simulation on the blade section profile with the blade height.
5. The method of claim 4, wherein determining a corresponding separation point at each of the predetermined heights from a drag coefficient curve obtained from the aerodynamic simulation and determining a position of the first row of grooves from the corresponding separation point at each of the predetermined heights, 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 blade;
and interpolating based on the chord length positions of the three grooves to obtain the chord length positions of other grooves in the first row of grooves.
6. The method of claim 1, further comprising:
each row of grooves is designed to be uniformly distributed within the range of 10% -90% of the leaf height.
7. The method of claim 1, further comprising:
the grooves of each row are designed to be distributed in a staggered mode along the blade height direction.
8. The method of claim 1, further comprising:
the groove is designed to be semicircular.
9. The method of claim 8, 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.
10. A fan comprising a plurality of blades, each blade having a plurality of rows of grooves on a suction surface thereof, wherein the position of each row of grooves on the blade is obtained by a method according to any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210396080.1A CN114673686B (en) | 2022-04-15 | 2022-04-15 | Fan design method and corresponding fan |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210396080.1A CN114673686B (en) | 2022-04-15 | 2022-04-15 | Fan design method and corresponding fan |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114673686A true CN114673686A (en) | 2022-06-28 |
| CN114673686B CN114673686B (en) | 2024-01-26 |
Family
ID=82078077
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210396080.1A Active CN114673686B (en) | 2022-04-15 | 2022-04-15 | Fan design method and corresponding fan |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114673686B (en) |
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 |
-
2022
- 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 |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114673686B (en) | 2024-01-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6559138B2 (en) | Turbomachine component or group of components and associated turbomachine | |
| Houghton et al. | Stability enhancement by casing grooves: the importance of stall inception mechanism and solidity | |
| CN112685929B (en) | Design method of ship gas turbine compressor backflow cavity-spoiler type treatment casing | |
| CN111717381B (en) | Asymmetric double-blunt-tip airfoil profile for rotor root of high-speed helicopter and design method | |
| Shuang et al. | Effects of boundary layer suction on aerodynamic performance in a high-load compressor cascade | |
| Kumar et al. | Performance evaluation of a tandem rotor under design and off-design operation | |
| CN105179322B (en) | Blade root opens up the Profile For Compressor Stator leaf grating of wide straight-line groove | |
| Sun et al. | The influence of diversified forward sweep heights on operating range and performance of an ultra-high-load low-reaction transonic compressor rotor | |
| CN109815590B (en) | Three-dimensional blade modeling method and blade of multistage axial-flow compressor based on end region boundary layer | |
| CN114673686A (en) | Design method of fan and corresponding fan | |
| Shabbir et al. | Flow mechanism for stall margin improvement due to circumferential casing grooves on axial compressors | |
| Wu et al. | Optimization design of axial fan blade | |
| CN113757170A (en) | High-air-volume low-noise fan blade, fan and design method of fan blade | |
| CN112177680B (en) | High-pressure turbine blade structure with resistance-reducing pit array | |
| CN106930977A (en) | A kind of direct-cooled noise reduction axial flow blower | |
| CN113653672B (en) | Axial flow impeller with splitter blades | |
| Deng et al. | Unsteady tip clearance flow in a low-speed axial compressor rotor with upstream and downstream stators | |
| Tran et al. | Aerodynamic Performance of a Single-stage Transonic Axial Compressor using a Hybrid Inclined Groove-Recirculation Casing Treatment | |
| CN116467764A (en) | Tear-drop type root rounding structure, design method and application | |
| Song et al. | A numerical investigation of boundary layer suction in compound lean compressor cascades | |
| CN115169032A (en) | Design method of gas turbine working blade with blade tip groove and winglet composite structure | |
| Mao et al. | Numerical and experimental study of separation control by boundary layer aspiration in a highly-loaded axial compressor cascade | |
| Li et al. | Study of flow separation control by bleed slot and bleed holes in a transonic compressor cascade | |
| CN105298925B (en) | Conduit opens up the blade root fluting Profile For Compressor Stator to highly tapered change | |
| Chen et al. | Numerical investigation of effect of recess vane casing treatments on an axial lift fan performance |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |