CN117605708A - Fan blade, fan and air conditioner - Google Patents

Abstract

The invention provides a fan blade, a fan and an air conditioner. The fan blade comprises a blade body (1), wherein an intersection point of an airfoil center line of the blade body (1) and a profile line of an airfoil forms a leading edge point and a trailing edge point of the airfoil, the straight line distance between the leading edge point and the trailing edge point is C, a convex hull (2) is arranged on the airfoil surface of the blade body (1), and the convex hull (2) is arranged in a region range, close to the trailing edge point, of which the center line length is 0.25C. According to the fan blade provided by the invention, the energy gradient of the near-wall area on the surface of the airfoil can be reduced, the consumption of turbulent energy is reduced, the energy loss in the flowing process is reduced, the functional capability is improved, and the energy consumption is reduced.

Description

Fan blade, fan and air conditioner

Technical Field

The invention relates to the technical field of fans, in particular to a fan blade, a fan and an air conditioner.

Background

For the fan, the blades are the main place for fluid energy conversion, when the fan works, the wheel shaft drives the impeller to rotate at a high speed, under the action of inertial centrifugal force and the like, the fluid flows around the impeller blades, meanwhile, the blades do work on the fluid, the fluid obtains energy, and the kinetic energy and the pressure energy are increased. The impeller is an energy conversion place and is a main source of vibration and noise, so that the shape of the impeller blades is improved, and the impeller is important to improve the working efficiency of the blades and reduce the vibration noise of the pump. When fluid flows in the impeller, the front edge boundary layer separation and the trailing edge wake generated after the blade flows around can reduce the stability of flow, and is also an excitation source of vibration and noise.

The good aerodynamic performance of the blade is the most fundamental guarantee for improving the air duct system, the wing profile is used as the most basic component element of the blade, and the optimization of the wing profile is the most critical factor for improving the aerodynamic performance of the blade. The fan blade can receive the effect of air resistance in the operation, and the existence of air resistance can cause the flow loss to a certain extent.

Disclosure of Invention

The invention mainly aims to provide a fan blade, a fan and an air conditioner, which can reduce the energy gradient of a near-wall area on the surface of an airfoil, reduce the consumption of turbulent energy, reduce the energy loss in the flowing process, improve the functional capability and reduce the energy consumption.

In order to achieve the above object, according to an aspect of the present invention, there is provided a fan blade including a blade body, an intersection point of an airfoil center line of the blade body and a profile line of the airfoil forming a leading edge point and a trailing edge point of the airfoil, a straight line distance between the leading edge point and the trailing edge point being C, an airfoil surface of the blade body being provided with a convex hull, the convex hull being provided in a region of the airfoil surface near the trailing edge point where a center line length is 0.25C.

Further, along the centerline of the airfoil, the convex hull is disposed within a range of 0.75C-1C from the leading edge point; and/or the convex hull is added on the surface of the blade body.

Further, the convex hull is spherical, and the radius R of the convex hull is in the range of 0.002-0.006 ℃.

Further, the number of the convex hulls is multiple, and the interval L between two adjacent convex hulls is R-3R.

Further, the convex hulls are arranged in an array or staggered manner along the extending direction of the central line.

Further, the convex hull is streamline, and the extending direction of the convex hull is the same as the extending direction of the central line.

Further, the convex hull comprises a front streamline and a tail streamline, the gradient of the tail streamline is d, and the range of d is 0.085-0.176.

Further, the height h of the convex hull is 0.002-0.006C.

Further, the number of the convex hulls is multiple, and the interval L between every two adjacent convex hulls is h-3 h.

Further, the midline of the convex hull comprises a front flow field midline and a rear flow field midline, the length of the front flow field midline is L2, and the length of the rear flow field midline is L1, and L1/L2 is more than or equal to 1.5 and less than or equal to 3.

According to another aspect of the present invention, there is provided a fan comprising a fan blade as described above.

According to another aspect of the present invention, there is provided an air conditioner including a blower, which is the blower described above.

By applying the technical scheme of the invention, the fan blade comprises a blade body, wherein the intersection point of the airfoil center line of the blade body and the profile line of the airfoil forms a leading edge point and a trailing edge point of the airfoil, the straight line distance between the leading edge point and the trailing edge point is C, the airfoil surface of the blade body is provided with a convex hull, and the convex hull is arranged in the area range of the airfoil surface, which is close to the center line of the trailing edge point, and the length of the center line is 0.25C. The fan blade optimizes the wing profile structure of the blade body, the convex hull is arranged in the flow separation area with larger tail turbulence intensity of the blade body, the flow characteristic of air flow on the wing profile surface is changed by utilizing the convex hull, and the resistance is formed on the wing profile surface by the convex hull, so that a new adhesion layer is generated on part of the surface of the wing profile, thereby reducing the energy gradient of a near-wall area on the surface of the wing profile, reducing the consumption of turbulent energy, reducing the energy loss in the flow process, improving the acting capacity and effectively reducing the energy consumption of the fan.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention. In the drawings:

FIG. 1 illustrates a schematic structural view of a fan blade according to one embodiment of the present invention;

FIG. 2 illustrates an airfoil structural schematic of a fan blade according to an embodiment of the present invention;

FIG. 3 illustrates a partial enlarged structural schematic view of a fan blade according to one embodiment of the present invention;

FIG. 4 illustrates a schematic structural view of a streamlined nose of a fan blade according to an embodiment of the present invention;

FIG. 5 illustrates a schematic perspective view of a streamlined nose of a fan blade in accordance with an embodiment of the present invention;

FIG. 6 illustrates a simulated plot of the separation point locations of a prior art fan blade airfoil at different angles of attack;

FIG. 7 illustrates a schematic view of the pressure field of a fan blade of an embodiment of the present invention after the fan blade has a convex hull structure;

FIG. 8 illustrates a velocity field schematic of a fan blade employing a convex hull structure in accordance with an embodiment of the present invention; and

FIG. 9 illustrates a two-dimensional airfoil flow field structure schematic of a fan blade according to an embodiment of the invention.

Wherein the above figures include the following reference numerals:

1. a blade body; 2. and (5) convex hull.

Detailed Description

It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. The invention will be described in detail below with reference to the drawings in connection with embodiments.

Referring to fig. 1 to 5 in combination, according to an embodiment of the present invention, a fan blade includes a blade body 1, an intersection point of an airfoil center line of the blade body 1 and a profile line of the airfoil forms a leading edge point and a trailing edge point of the airfoil, a straight line distance between the leading edge point and the trailing edge point is C, an airfoil surface of the blade body 1 is provided with a convex hull 2, and the convex hull 2 is disposed in a region of the airfoil surface near the trailing edge point, in which a center line length is 0.25C.

The fan blade optimizes the wing structure of the blade body 1, the convex hull 2 is arranged in the flow separation area with larger tail turbulence intensity of the blade body 1, the flow characteristic of air flow on the wing surface is changed by utilizing the convex hull 2, and resistance is formed on the wing surface by the convex hull 2, so that a new adhesion layer is generated on the part of the surface of the wing, the energy gradient of a near-wall area on the wing surface is reduced, the consumption of turbulent energy is reduced, the energy loss in the flow process is reduced, the acting capacity is improved, and the energy consumption of the fan is effectively reduced.

The length of the airfoil centerline is the airfoil chord length.

In this embodiment, the structure of the airfoil surface is set to be a convex hull structure, so that the height of the airfoil surface can be increased, the setting interval of the airflow flow separation point from the convex hull 2 can be larger, the height of the convex hull 2 is higher than the height of the airfoil surface, the separation distance between the airflow and the airfoil surface is gradually increased along the position far away from the separation point, the setting of the convex hull 2 is equivalent to reducing the separation distance between the airflow and the airfoil surface, so that the convex hull 2 and the separation point have larger interval, and the convex hull 2 is higher than the airfoil surface, so that even if the interval between the convex hull 2 and the separation point is increased, the influence of the convex hull 2 can be still received in the process of separating the airflow to the trailing edge, and the airflow can be attached to the surface of the convex hull 2 under the action of the convex hull 2, so that a new attachment layer is formed, the flow field characteristics of the blade are improved, and the effective improving effect is achieved on the resistance and the blade in operation.

In one embodiment, the convex hull 2 is provided on the suction side of the blade body 1.

Referring to fig. 6, for the fan blade, as the attack angle increases, the flow separation range is enlarged, the separation point is advanced, and as shown in fig. 6, the position of the separation point S with the attack angle of 10 ° is 0.80C; the position of the separation point S with the attack angle of 12 degrees is 0.54C; the position of the angle of attack 14 ° separation point S is 0.31C. There is a strong relationship between the location of the separation point S and the angle of attack, and flow separation is not apparent when the angle of attack is small. When the attack angle is in the range of 10-14 degrees, the flow separation is obvious, and for different attack angles, the flow distribution areas with larger turbulence intensity are mainly distributed in the areas close to the tail edge points in the flow separation process of the air flow, so that the design can be carried out based on the flow distribution areas when the position of the convex hull 2 is set.

The convex hull structure should be arranged in the region of flow separation where the turbulence intensity is large, i.e. the convex hull structure should be arranged at the airfoil trailing edge, and since the length of the region where the flow separation is large is about 0.25C, the convex hull 2 needs to be arranged in the region of the airfoil surface near the trailing edge point where the mid-line length is 0.25C. The interval belongs to a flow separation area with larger turbulence intensity, and the convex hulls are arranged in the interval to have obvious drag reduction effect.

In one embodiment, the convex hull 2 should be positioned within a range of 0.6-1C from the leading edge point size, and the proportion of the centerline length C occupied by the placement area of the convex hull 2 is 0.25, i.e., the placement area of the convex hull 2 is within a range of 0.6-1C, and the centerline length occupied is 0.25C.

In one embodiment, along the centerline of the airfoil, the convex hull 2 is disposed in a region having a dimension from 0.75C to 1C from the leading edge point.

The farther the airflow is from the leading edge point in the process of flowing along the airfoil of the fan blade, the more obvious the airflow flow separation phenomenon is, and the greater the turbulence intensity is, therefore, in the process of flowing and separating the airflow, the area with the greater turbulence intensity is mainly concentrated near the trailing edge of the airfoil, and when the convex hull 2 is designed, the convex hull should be concentrated at the trailing edge position. In this embodiment, the convex hull 2 is set in the area range of 0.75C-1C from the front edge point, so that the convex hull 2 is intensively distributed in the area with larger turbulence intensity, and has a more obvious drag reduction effect on the airfoil, so that a new adhesion layer is more easily generated on part of the surface of the airfoil, thereby reducing the energy gradient of the near-wall area on the surface of the airfoil, reducing the consumption of turbulent energy, reducing the energy loss in the flowing process, improving the working capacity and reducing the energy consumption.

In one embodiment, the convex hull 2 is spherical, and the radius R of the convex hull 2 has a value in the range of 0.002C to 0.006C.

In the non-smooth surface drag reduction process of the convex hull 2, parameters with larger influence on the flow characteristics are the radius R of the convex hull and the distance L between the convex hulls, the radius R of the convex hull 2 has more direct influence on the wing type drag reduction effect, and when the radius R of the convex hull 2 is smaller, the disturbance of the convex hull structure to a boundary layer is smaller, and the drag reduction effect is lower; when the radius of the convex hull 2 is larger, the non-smooth surface of the convex hull 2 causes the friction resistance to be increased, and the drag reduction effect is reduced. When the radius of the convex hull structure is selected in the range of 0.002-0.006C, the drag reduction effect is better compared with that of a smooth wing section.

In one embodiment, the number of convex hulls 2 is plural, and the interval L between two adjacent convex hulls 2 is R-3R. In the present embodiment, the interval between the adjacent two convex hulls 2 refers to the interval between the centers of the adjacent two convex hulls 2.

The interval L between the convex hulls 2 also has a certain influence on the drag reduction effect of the wing profile, a low-speed vortex area can be formed between the convex hulls, and the number of the vortex areas can be reduced along with the increase of the interval L of the convex hulls 2. The friction force shown by the vortex between the convex hulls 2 is mainly rolling friction, so that the friction resistance tends to be reduced; the low-speed fluid in the gap has an adsorption effect on the high-speed fluid outside the convex hull 2, and the diffusion of the separation area is controlled, so that the purpose of reducing the flow resistance is achieved. Meanwhile, in the range of arranging the convex hull regions, as the interval of the convex hulls 2 increases, the number of the convex hulls 2 also decreases. The interval between the convex hulls 2 is also in a better range, and when the interval between the convex hulls 2 is selected in the range of R-3R, the drag reduction effect is better. When the interval of the convex hulls 2 is not within the interval range, the resistance reduction effect of the quantity and the interval of the convex hulls 2 on the flow field is not obvious, and the expected effect cannot be achieved.

In one embodiment, the number of the convex hulls 2 is plural, and the convex hulls 2 are arranged in an array or staggered manner along the extending direction of the central line.

The convex hulls 2 are arranged in an array or staggered manner along the extending direction of the central line, so that an effective regulating effect can be formed on the flow of the air flow, the air flow can be redistributed on the surface of the blade body 1 while the drag reduction effect is achieved on the air flow, the air flow can be more effectively attached to the surface of the blade body 1 to flow, and the turbulence intensity is reduced.

In one embodiment, the convex hull 2 is attached to the blade body 1.

After the convex hull 2 can be independently processed, the convex hull is installed and fixed on the suction surface of the blade body 1, and under the structure, the convex hull 2 hardly damages the wing-shaped structure of the blade body 1, so that the blade body 1 can keep a basic complete structure, and the wing-shaped structure is kept relatively complete, so that the fan blade can have good structural performance.

Because the convex hull 2 is additionally arranged on the blade body 1, the arrangement mode of the convex hull 2 on the blade body 1 can be adjusted according to the design structure, so that the blade is more suitable for the drag reduction characteristics of different blades.

In one embodiment, the convex hull 2 and the blade body 1 may be of an integrally formed structure.

In one embodiment, the convex hull 2 is streamlined, and the convex hull 2 extends in the same direction as the midline.

In this embodiment, a streamlined nose 2 is provided on the suction side of the blade body 1. The convex hull 2 in this embodiment has a certain installation angle with respect to the blade body 1, and has an installation angle corresponding to different incoming flow directions.

The streamline convex hull 2 can be fixedly arranged together after being formed in a split mode with the blade body 1, and can also be directly formed integrally with the blade body 1.

The convex hull 2 adopts streamline form, so that the flow of the air flow on the surface of the blade body 1 can be improved, the flow resistance of the air flow on the surface of the blade body 1 can be further reduced, the turbulence intensity of the air flow flowing on the surface of the blade body 1 is reduced, the consumption of turbulence energy is reduced, the energy loss in the flowing process is reduced, the functional capability is improved, and the energy consumption is reduced.

In one embodiment, the convex hull 2 includes a leading streamline and a trailing streamline, the trailing streamline having a slope d in the range of 0.085 to 0.176.

In this embodiment, the included angle between the tail streamline and the midline ranges from 5 ° to 10 °, and the gradient d of the corresponding tail streamline ranges from 0.085 to 0.176. The position of a separation point of fluid on the convex hull 2 can be changed by changing the gradient d, when the gradient d of the tail streamline ranges from 0.085 to 0.176, the flow separation of the airflow on the surface of the blade body 1 can be well controlled, the drag reduction effect of the convex hull 2 on the flow field is improved, the energy loss in the airflow flowing process is reduced, and the functional capability is improved.

In one embodiment, the height h of the convex hull 2 is 0.002C to 0.006C.

In the non-smooth surface drag reduction process of the convex hull 2, parameters with great influence on the flow characteristics are the height h of the convex hull and the distance L between the convex hulls, the height h of the convex hull 2 has a direct influence on the wing type drag reduction effect, and when the height h of the convex hull 2 is smaller, the disturbance of the convex hull structure on a boundary layer is smaller, and the drag reduction effect is lower; when the height of the convex hull 2 is large, the non-smooth surface of the convex hull 2 will cause an increase in friction resistance and a decrease in drag reduction effect. When the height h of the convex hull structure is selected to be in the range of 0.002-0.006C, the drag reduction effect is better compared with that of a smooth wing profile.

In one embodiment, the number of the convex hulls 2 is plural, and the interval L between the adjacent convex hulls 2 is h-3 h.

The interval L between the convex hulls 2 also has a certain influence on the drag reduction effect of the wing profile, a low-speed vortex area can be formed between the convex hulls, and the number of the vortex areas can be reduced along with the increase of the interval L of the convex hulls 2. The friction force shown by the vortex between the convex hulls 2 is mainly rolling friction, so that the friction resistance tends to be reduced; the low-speed fluid in the gap has an adsorption effect on the high-speed fluid outside the convex hull 2, and the diffusion of the separation area is controlled, so that the purpose of reducing the flow resistance is achieved. Meanwhile, in the range of arranging the convex hull regions, as the interval of the convex hulls 2 increases, the number of the convex hulls 2 also decreases. The interval between the convex hulls 2 is also in a better range, and when the interval between the convex hulls 2 is selected in the interval range of h-3 h, the drag reduction effect is better. When the interval of the convex hulls 2 is not within the interval range, the resistance reduction effect of the quantity and the interval of the convex hulls 2 on the flow field is not obvious, and the expected effect cannot be achieved.

For the streamline convex hulls 2, when the range of the height h of the convex hulls 2 is between 0.002C and 0.006C and the range of the interval L between the convex hulls is between h and 3h, the range of the interval has a good drag reduction effect.

In one embodiment, the midlines of the convex hull 2 comprise front flow field midlines and rear flow field midlines, the lengths of the front flow field midlines are L2, and the lengths of the rear flow field midlines are L1, 1.5.ltoreq.L1/L2.ltoreq.3.

The chord lines at the bottom edge of the streamline convex hull are denoted by L1 and L2, wherein L2 denotes the length of the front flow field midline, and L1 denotes the length of the rear flow field midline. The change of the airfoil shape can be achieved more directly by changing the ratio between L1 and L2, so that the aim of coping with more complex working conditions is achieved. When the ratio between L1 and L2 is between 1.5 and 3, the drag reduction effect is obvious for more complex working conditions.

As shown in connection with fig. 7-9, after the fan blade of the present embodiment is employed, the flow of the air stream is significantly improved, the energy gradient of the near-wall region on the airfoil surface is significantly reduced, and the energy loss is reduced.

According to an embodiment of the invention, the fan comprises a fan blade, which is the fan blade described above.

According to an embodiment of the invention, an air conditioner comprises a fan, which is the fan.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

It should be noted that the terms "first," "second," and the like in the description and claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that embodiments of the present application described herein may be implemented in sequences other than those illustrated or described herein.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (12)

1. The utility model provides a fan blade, its characterized in that includes blade body (1), the profile line of blade body (1) with the intersection point of the profile line of wing profile forms the leading edge point and the trailing edge point of wing profile, the straight line distance between leading edge point and the trailing edge point is C, the wing profile surface of blade body (1) is provided with convex closure (2), convex closure (2) set up the wing profile surface is close to the regional within range that the central line length of trailing edge point is 0.25C.

2. Fan blade according to claim 1, characterized in that the convex hull (2) is arranged along the centre line of the airfoil in a region of a size of 0.75-1C from the leading edge point; and/or the convex hull (2) is additionally arranged on the surface of the blade body (1).

3. Fan blade according to claim 1 or 2, characterized in that the convex hull (2) is spherical, and the radius R of the convex hull (2) has a value in the range of 0.002C-0.006C.

4. A fan blade according to claim 3, wherein the number of the convex hulls (2) is plural, and the interval L between two adjacent convex hulls (2) is R to 3R.

5. A fan blade according to claim 3, wherein the number of the convex hulls (2) is plural, and the plurality of convex hulls (2) are arranged in an array or staggered arrangement along the extending direction of the central line.

6. Fan blade according to claim 1 or 2, characterized in that the convex hull (2) is streamlined, the convex hull (2) extending in the same direction as the centre line.

7. The fan blade according to claim 6, wherein the convex hull (2) comprises a leading end streamline and a trailing end streamline, the trailing end streamline having a slope d in the range of 0.085 to 0.176.

8. The fan blade according to claim 6, characterized in that the height h of the convex hull (2) is 0.002C-0.006C.

9. Fan blade according to claim 7 or 8, characterized in that the number of the convex hulls (2) is a plurality, and the spacing L between adjacent convex hulls (2) is h-3 h.

10. The fan blade according to claim 7 or 8, wherein the midline of the convex hull (2) comprises a front flow field midline and a rear flow field midline, the length of the front flow field midline is L2, and the length of the rear flow field midline is L1, 1.5.ltoreq.l1/l2.ltoreq.3.

11. A fan comprising a fan blade, characterized in that the fan blade is a fan blade according to any of claims 1 to 10.

12. An air conditioner comprising a blower, wherein the blower is the blower of claim 11.