阅读说明：本技术 一种减阻降噪的离心风轮 (Centrifugal wind wheel capable of reducing resistance and noise ) 是由 郭小勇 陈宗华 于 2021-01-07 设计创作，主要内容包括：本发明公开了一种减阻降噪的离心风轮,包括轮盖、多块叶片、轮盘,轮盖与轮盘同轴且间隔设置,多块叶片设置在轮盖与轮盘之间,多块叶片沿周向间隔设置,轮盖包括叶片连接的内壁面,内壁面设有多个轮盖减阻凹槽或/和轮盖减阻凸起,叶片设有多个叶片减阻凹槽或/和叶片减阻凸起,轮盖或/和轮盘的外缘设有多个降噪锯齿,多个降噪锯齿沿周向间隔设置。本发明取得的有益效果：减阻凹槽或/和减阻凸起打乱边界层内气流的流动状态,改变压力分布,降低气流的流动速度,使得边界层内的黏性底层的速度场得到改变,减少沿程阻力损失,提高效率；降噪锯齿切割涡流,加速涡流衰减,减小湍流的强度和压力脉动幅值,从而有效地降低噪声。(The invention discloses a centrifugal wind wheel for reducing resistance and noise, which comprises a wheel cover, a plurality of blades and a wheel disc, wherein the wheel cover and the wheel disc are coaxial and are arranged at intervals, the blades are arranged between the wheel cover and the wheel disc, the blades are arranged at intervals along the circumferential direction, the wheel cover comprises an inner wall surface connected with the blades, a plurality of wheel cover resistance reducing grooves or/and wheel cover resistance reducing bulges are arranged on the inner wall surface, the blades are provided with a plurality of blade resistance reducing grooves or/and blade resistance reducing bulges, a plurality of noise reducing sawteeth are arranged on the outer edge of the wheel cover or/and the wheel disc, and a plurality of noise reducing sawteeth are arranged. The invention has the following beneficial effects: the flow state of the airflow in the boundary layer is disturbed by the anti-drag grooves or/and the anti-drag bulges, the pressure distribution is changed, and the flow speed of the airflow is reduced, so that the speed field of the viscous bottom layer in the boundary layer is changed, the on-way resistance loss is reduced, and the efficiency is improved; the noise reduction sawteeth cut the vortex, accelerate the attenuation of the vortex, and reduce the intensity of the turbulent flow and the pressure pulsation amplitude, thereby effectively reducing the noise.)

1. The centrifugal wind wheel capable of reducing drag and noise comprises a wheel cover (1), blades (3) and a wheel disc (2), wherein the wheel cover (1) and the wheel disc (2) are coaxially arranged, the wheel cover (1) and the wheel disc (2) are axially arranged at intervals, a plurality of blades (3) are arranged between the wheel cover (1) and the wheel disc (2), the top ends of the blades (3) are connected with the wheel cover (1), the bottom ends of the blades (3) are connected with the wheel disc (2), the blades (3) are circumferentially arranged at intervals, the wheel cover (1) is provided with a through hole serving as an air inlet (5), and an area enclosed by the wheel cover (1), the wheel disc (2) and two adjacent blades (3) is an air outlet (6);

the utility model is characterized in that, the wheel cap (1) include with internal face (11) that blade (3) are connected, internal face (11) are equipped with a plurality of wheel cap drag reduction concave point (7) or/and wheel cap drag reduction arch, blade (3) are equipped with a plurality of blade drag reduction recess (8) or/and blade drag reduction bump, wheel cap (1) or/and the outer fringe of rim plate (2) is equipped with a plurality of sawtooth (4) of making an uproar, and is a plurality of the sawtooth (4) of making an uproar set up along circumference interval.

2. The centrifugal wind wheel according to claim 1, characterized in that the inner wall surface (11) of the wheel cover (1) is provided with a plurality of sets of wheel cover drag reduction grooves (7) or/and wheel cover drag reduction protrusions, each set of wheel cover drag reduction grooves (7) or/and wheel cover drag reduction protrusions comprises a plurality of wheel cover drag reduction grooves (7) or/and wheel cover drag reduction protrusions, the centers of the wheel cover drag reduction grooves (7) or/and the wheel cover drag reduction protrusions of each set are connected to form wheel cover drag reduction path lines (71), and the plurality of wheel cover drag reduction path lines (71) are arranged in parallel.

3. Centrifugal wind wheel according to claim 2, characterized in that the starting and ending points of the ith shroud drag reduction path line (71) and the central connection of the centre of the shroud (1) form a central angle γ_iI is 1, 2, … … and n, n is more than or equal to 2, 0 degree is less than gamma₁＝γ₂＝…＝γ_n＜360°；

The center angle formed by the connection of the starting point of the ith wheel cover resistance reducing path line (71), the starting point of the (i + 1) th wheel cover resistance reducing path line (71) and the center of the wheel cover (1) is alpha_iI is 1, 2, … …, n-1, and the center angle formed by the connection of the starting point of the nth wheel cover drag reduction path line (71), the starting point of the 1 st wheel cover drag reduction path line (71) and the center of the wheel cover (1) is alpha_n，0°＜α₁＝α₂＝…＝α_n< 180 DEG and alpha_i＝360°/n；

The center angle formed by the connection of the starting point of the ith wheel cover resistance reducing path line (71), the end point of the (i + 1) th wheel cover resistance reducing path line (71) and the center of the wheel cover (1) is beta_iI is 1, 2, … … and n-1, and the center angle formed by the connection of the end point of the nth wheel cover drag reduction path line (71), the end point of the 1 st wheel cover drag reduction path line (71) and the center of the wheel cover (1) is beta_n，0°＜β₁＝β₂＝…＝β_n< 180 DEG and beta_i＝360°/n；

The distance between the starting point of the ith wheel cover drag reduction path line (71) and the center of the wheel cover (1) is taken as a starting point radius R_qiThe distance between the terminal point of the ith wheel cover resistance reducing path line (71) and the center of the wheel cover (1) is a terminal radius R_wiThe radius of the air inlet (5) is R₁The radius of the air outlet of the wheel cover (1) is R₂，R₁＜R_qi≤R_wi＜R₂。

4. The centrifugal wind wheel according to claim 2, wherein the shroud drag reduction path line (71) is one of a spline curve, an arc line, a straight line, or a combination of multiple types of lines.

5. The centrifugal wind wheel according to any of claims 1-4, characterised in that the blades (3) are provided with a plurality of sets of blade drag reducing grooves (8) or/and blade drag reducing protrusions, each set of blade drag reducing grooves (8) or/and blade drag reducing protrusions comprises a plurality of blade drag reducing grooves (8) or/and blade drag reducing protrusions, the centers of the blade drag reducing grooves (8) or/and blade drag reducing protrusions of each set are connected to form blade drag reducing path lines (81), and the blade drag reducing path lines (81) are arranged in parallel with the flow lines of the airflow passing through the blades (3).

6. The centrifugal wind wheel according to claim 5, characterized in that the depth of the shroud drag reducing grooves (7) and the height of the shroud drag reducing protrusions are both less than one third of the thickness of the shroud (1), and the depth of the blade drag reducing grooves (8) and the height of the blade drag reducing protrusions are both less than one third of the thickness of the blades (3).

7. The centrifugal wind wheel according to any of claims 1-4, characterized in that a plurality of noise reduction serrations (4) are provided at the outer edge of the shroud (1), a plurality of noise reduction serrations (4) are provided at intervals in the circumferential direction, and the noise reduction serrations (4) are provided at equal intervals in the circumferential direction, a center angle formed by a start point and an end point of the noise reduction serrations (4) and the center of the shroud (1) in one cycle is a cycle angle θ, the number of blades (3) is Z, and θ is 360 °/Z.

8. The centrifugal wind wheel according to claim 7, wherein a plurality of the noise reduction serrations (4) are provided in each period, and the heights of the plurality of the noise reduction serrations (4) increase and decrease in one period.

9. Centrifugal wind rotor according to claim 8, characterized in that the noise-reducing serrations (4) are arranged symmetrically with respect to the bisector of the period angle θ in one period.

10. Centrifugal wind rotor according to claim 8, characterized in that the noise reducing serrations (4) have a maximum height H during a period_maxThe lowest height of the noise reduction sawteeth (4) is H_minThe radius of the wheel cover (1) is R₂，0.01·R₂≤H_min＜H_max≤0.06·R₂。

Technical Field

The invention relates to the technical field of ventilation, in particular to a centrifugal wind wheel capable of reducing drag and noise.

Background

Along with the development of social economy, the energy efficiency and the noise performance of the centrifugal wind wheel applied to the household appliance are more and more emphasized, the energy loss of the centrifugal wind wheel is reduced, the on-way resistance loss is an important part of the loss in the fan, and after the airflow enters the centrifugal wind wheel, the vortex ratio of a flow field near a wheel cover is stronger, and the generated noise is higher.

CN109578328B discloses a centrifugal wind wheel and a low-noise backward centrifugal fan comprising the wind wheel, which comprises a wind wheel front disc, a wind wheel rear disc and wind wheel blades arranged between the wind wheel front disc and the wind wheel rear disc, wherein the pressure surface and the suction surface of the blades of the adjacent wind wheel blades, the wind wheel front disc and the wind wheel rear disc jointly enclose a flow channel area, the inner ring of the chassis of the wind wheel front disc is bent and extended along the axial direction towards the direction far away from the wind wheel rear disc to form a front disc side wall, the front disc side wall forms a front disc air inlet, the circumferential edge of one or both of the wind wheel front disc or the wind wheel rear disc is provided with a plurality of groups of continuous bulge structures, each group of continuous bulge structures comprises a plurality of bulge structures with even intervals, although the bulge structures can destroy the vortex generated by flow separation near an area outlet and the vortex structures with larger scale in backflow components, the vortex noise reduction device has the advantages that a series of vortexes with smaller sizes are generated, so that the amplitude of vortex noise in fan noise is greatly reduced, however, in order to guarantee the efficiency of the wind wheel, the protruding structures are not completely arranged on the circumferential edge of the front disk or the rear disk of the wind wheel, the continuous width of each protruding structure accounts for about two thirds of the width of the corresponding runner, the runners which are not provided with the protruding structures cannot weaken vortex to a certain extent, and the noise reduction effect is limited.

CN209687789U discloses a centrifugal wind wheel and a centrifugal fan using the same, the centrifugal wind wheel comprises a wheel cover made of metal plate, a wheel disc made of metal plate and a plurality of wind blades made of composite material arranged between the wheel cover and the wheel disc, the plurality of wind blades made of composite material comprise a metal framework and a plastic shell arranged on the blade framework, the upper end and the lower end of the metal framework are respectively connected with the wheel cover and the wheel disc, the thickness H of the plastic shell is changed to improve the air flow mobility, the plastic shell and the metal framework are integrated by injection molding, the plastic shell wraps at least one part of the metal framework, the structural strength of connection is ensured, the pneumatic performance requirement on the market is met by the plastic shell, the reliability is high, although a plurality of through holes are arranged on the metal framework, the plurality of through holes of the metal framework are used for improving the bonding force between the blade framework and the plastic shell, and after the plastic shell wraps the metal framework, the surface of the wind blade is a complete surface without through holes, and the effects of reducing drag and noise are not achieved.

CN208442048U discloses an oblique flow fan, an air conditioner indoor unit and an air conditioner, wherein the oblique flow fan comprises a bottom hub, an air guide ring, an end cover and a plurality of blades, the bottom hub comprises a connecting piece, a hub plate is arranged below the connecting piece, the hub plate is in a circular truncated cone shape, and an included angle between a bus of the circular truncated cone and the bottom surface is 10-20 degrees; the lower ends of the blades are fixed on the hub plate, the outer side edges of the blades are in a sawtooth shape, the guide rings are welded at the upper ends of the blades, and the end covers are connected to the connecting pieces; although the sawteeth on the outer side of the blade can inhibit the generation of vortex and reduce the noise generated by the operation of the diagonal flow fan, the vortex is mainly generated near the outlet of the guide ring, the sawteeth on the outer side of the blade can not effectively inhibit the vortex near the outlet of the guide ring, and the noise reduction effect is limited.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide a centrifugal wind wheel for reducing resistance and noise, which comprises a wheel cover, a plurality of blades and a wheel disc, wherein the inner wall surface of the wheel disc is provided with wheel cover resistance reducing grooves or/and wheel cover resistance reducing bulges, the blades are provided with a plurality of blade resistance reducing grooves or/and blade resistance reducing bulges, the outer edge of the wheel cover or/and the wheel disc is provided with a plurality of noise reducing sawteeth which are arranged at intervals along the circumferential direction, and the centrifugal wind wheel for reducing resistance and noise has the advantages of reducing the air flow on-way resistance, improving the efficiency, weakening the eddy degree and reducing the noise.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a centrifugal wind wheel capable of reducing drag and noise comprises a wheel cover, a plurality of blades and a wheel disc, wherein the wheel cover and the wheel disc are coaxially arranged, the wheel cover and the wheel disc are axially arranged at intervals, the blades are arranged between the wheel cover and the wheel disc, the top ends of the blades are connected with the wheel cover, the bottom ends of the blades are connected with the wheel disc, the blades are circumferentially arranged at intervals, the wheel cover is provided with through holes serving as an air inlet, and an area defined by the wheel cover, the wheel disc and two adjacent blades is an air outlet;

the wheel cover comprises an inner wall face connected with the blades, a plurality of wheel cover drag reduction grooves or/and wheel cover drag reduction protrusions are arranged on the inner wall face, a plurality of blade drag reduction grooves or/and blade drag reduction protrusions are arranged on the blades, a plurality of noise reduction sawteeth are arranged on the outer edge of the wheel disc, and the plurality of noise reduction sawteeth are arranged at intervals along the circumferential direction.

Preferably, the inner wall surface of the wheel cover is provided with a plurality of groups of wheel cover resistance reducing grooves or/and wheel cover resistance reducing bulges, each group of wheel cover resistance reducing grooves or/and wheel cover resistance reducing bulges comprises a plurality of wheel cover resistance reducing grooves or/and wheel cover resistance reducing bulges, the centers of the wheel cover resistance reducing grooves or/and the wheel cover resistance reducing bulges of each group are connected to form wheel cover resistance reducing path lines, the wheel cover resistance reducing path lines are arranged in parallel, through the arrangement, when an air flow passes through the inner wall surface of the wheel cover, a generated boundary layer is a source of on-way resistance, the plurality of groups of wheel cover resistance reducing grooves or/and the wheel cover resistance reducing bulges can effectively disturb the flow state of the air flow in the original boundary layer, change the pressure distribution of the air flow near the boundary layer and reduce the flow speed of the air flow near the inner wall surface of the wheel cover, the turbulent flow is delayed, so that the velocity field of the viscous bottom layer in the boundary layer is changed, the on-way resistance loss in the flow channel is reduced, the efficiency is improved, and the wheel cover resistance reducing path lines are arranged in parallel, so that the on-way resistance loss reducing effect generated by the wheel cover resistance reducing grooves or/and the wheel cover resistance reducing bulges is uniform.

Preferably, the starting point and the end point of the drag reduction path line of the ith wheel cover and the middle of the wheel coverThe central angle formed by the connection of the cores is gamma_iI is 1, 2, … … and n, n is more than or equal to 2, 0 degree is less than gamma₁＝γ₂＝…＝γ_n＜360°；

The center angle formed by the connection of the starting point of the ith wheel cover drag reduction path line, the starting point of the (i + 1) th wheel cover drag reduction path line and the center of the wheel cover is alpha_iI is 1, 2, … …, n-1, and the center angle formed by the connection of the starting point of the nth wheel cover drag reduction path line, the starting point of the 1 st wheel cover drag reduction path line and the center of the wheel cover is alpha_n，0°≤α₁＝α₂＝…＝α_nNot more than 180 degrees and alpha_i＝360°/n；

The center angle formed by the connection of the terminal point of the ith wheel cover drag reduction path line, the terminal point of the (i + 1) th wheel cover drag reduction path line and the center of the wheel cover is beta_iI is 1, 2, … …, n-1, and the center angle formed by the end point of the nth wheel cover drag reduction path line, the end point of the 1 st wheel cover drag reduction path line and the center connection of the wheel covers is beta_n，0°≤β₁＝β₂＝…＝β_nNot more than 180 degrees and beta_i＝360°/n；

The distance between the starting point of the ith wheel cover resistance reducing path line and the center of the wheel cover is taken as a starting point radius R_qiThe distance between the terminal point of the ith wheel cover resistance reducing path line and the center of the wheel cover is the terminal radius R_wiThe radius of the air inlet is R₁The radius of the wheel cover is R₂，R₁＜R_qi≤R_wi＜R₂By means of the arrangement, when the arranged angles are different, the distribution mode of the wheel cover drag reduction grooves or/and the wheel cover drag reduction bulges is changed.

Preferably, the wheel cover resistance reducing path line is one of spline curve, arc line and straight line or the combination of various molded lines, and through the arrangement, the molded lines of the wheel cover resistance reducing path line are different, and the distribution mode of the wheel cover resistance reducing grooves or/and the wheel cover resistance reducing bulges is changed so as to adapt to the requirements of centrifugal fans with different sizes and performance requirements and the processing technology.

Preferably, the blade is provided with a plurality of groups of blade drag reduction grooves or/and blade drag reduction protrusions, each group of blade drag reduction grooves or/and blade drag reduction protrusions comprises a plurality of blade drag reduction grooves or/and blade drag reduction protrusions, the centers of the blade drag reduction grooves or/and blade drag reduction protrusions of each group are connected to form a blade drag reduction path line, the blade drag reduction path line is arranged in parallel with a flow line of the airflow flowing through the blade, and by such arrangement, when the airflow flows through the blade, the boundary layer is a source of on-way resistance, and the provision of the plurality of groups of blade drag reduction grooves or/and blade drag reduction protrusions can effectively disturb the flow state of the airflow in the original boundary layer, change the pressure distribution of the airflow near the boundary layer, and reduce the airflow velocity of the airflow near the blade, the formation of turbulence is delayed, so that the velocity field of a viscous bottom layer in a boundary layer is changed, the on-way resistance loss in a flow channel is further reduced, the efficiency is further improved, the blade resistance reducing path line is parallel to the flow line of airflow flowing through the blade, the airflow in the boundary layer continuously flows through the blade resistance reducing grooves or/and the blade resistance reducing bulges along the blade resistance reducing path line, and the resistance reducing effect of the blade is further improved.

Preferably, the depth of the wheel cover drag reduction groove and the height of the wheel cover drag reduction bulge are both smaller than one third of the thickness of the wheel cover, and the depth of the blade drag reduction groove and the height of the blade drag reduction bulge are both smaller than one third of the thickness of the blade, so that the wheel cover and the blade drag reduction effect are ensured on the premise of ensuring that the structural strength of the wheel cover and the blade is enough and the air output of the centrifugal wind wheel is not influenced; if the depth of the wheel cover drag reduction groove is greater than one third of the thickness of the wheel cover or the depth of the blade drag reduction groove is greater than one third of the thickness of the blade, the position where the wheel cover or the blade is provided with the groove is thinner, the wheel cover or the blade is easy to crack under the action of airflow pressure, rotating centrifugal force and other acting forces, and the structural strength of the wheel cover or the blade is reduced; if the height of the wheel cover drag reduction bulge is greater than one third of the thickness of the wheel cover or the height of the blade drag reduction bulge is greater than one third of the thickness of the blade, when the height of the bulge is greater than the thickness of the boundary layer, the bulge can block airflow outside the boundary layer, and therefore the efficiency and other performances of the centrifugal wind wheel are reduced.

Preferably, the plurality of noise reduction serrations are provided on the outer periphery of the shroud, the plurality of noise reduction serrations are provided at intervals in the circumferential direction, and the noise reduction serrations are provided at equal intervals in the circumferential direction, a central angle formed by a start point and an end point of the noise reduction serrations and a center of the shroud in one period is a period angle θ, and the number of the blades is Z, θ is 360 °/Z, by which the noise reduction serrations can cut vortex, accelerate attenuation of the vortex near an outlet of the shroud, reduce intensity of the turbulent flow and a pressure pulsation amplitude, thereby reducing noise, and since the vortex of the centrifugal wind rotor is mainly generated near the outlet of the shroud, the noise reduction serrations are provided on the outer periphery of the shroud, thereby attenuating the vortex generated near the outlet of the shroud, effectively reducing noise, and generating a flow field distribution in a targeted manner according to the number of the blades, the period angle θ is 360 °/Z, and the noise reduction effect can be further improved.

Preferably, a plurality of the noise reduction sawteeth are arranged in each period, the height of the noise reduction sawteeth increases gradually and then decreases gradually in one period, and through the arrangement, the height of the noise reduction sawteeth is arranged in a gradual change mode, so that the efficiency of the centrifugal wind wheel is ensured, and the noise reduction effect of the noise reduction sawteeth is also ensured.

Preferably, the noise reduction serrations are symmetrically arranged along an angular bisector of the period angle θ within one period, and the noise reduction effect is further improved by arranging such that the highest point of the noise reduction serrations is located in the middle of one period.

Preferably, the maximum height of the noise reduction sawtooth is H in one period_maxThe lowest height of the noise reduction sawtooth is H_minThe radius of the air outlet of the wheel cover is R₂，0.01R₂≤H_min＜H_max≤0.06R₂Through the arrangement, the noise reduction sawteeth are arranged on the outer edge runners of the wheel cover, so that the efficiency of the centrifugal wind wheel is ensured, and the noise reduction effect is also ensured; if H is_min＜0.01R₂The effect of the noise reduction sawtooth on cutting eddy is not obvious, and the noise reduction effect is not obvious; if H is_max>0.06·R₂Although the noise reduction saw teeth can cut eddy current well to achieve the noise reduction effect, the size of the wheel cover is increased, the required installation space is increased, and the performance may deviate from the design requirement.

Compared with the prior art, the invention has the beneficial technical effects that:

1. when the airflow flows through the wheel cover or the surface of the blade, the boundary layer generated due to viscosity of the air is the source of the on-way resistance of the airflow, the wheel cover is provided with the wheel cover resistance reducing grooves or/and the wheel cover resistance reducing bulges, and the blade is provided with the blade resistance reducing grooves or/and the blade resistance reducing bulges, so that the flow state of the airflow in the original boundary layer can be disturbed, the airflow pressure distribution near the boundary layer is changed, the flow speed near the wheel cover and the surface of the blade is reduced, the speed field of the viscous bottom layer in the boundary layer is changed, the on-way resistance loss in the flow channel is reduced, and the efficiency is improved.

2. The vortex generated at the air outlet of the centrifugal wind wheel is a main source of noise, and the noise-reducing sawteeth cut the vortex at the outlet of the centrifugal wind wheel, so that the attenuation of the vortex is accelerated, the intensity of the turbulence and the pressure pulsation amplitude are reduced, and the noise is effectively reduced.

3. The three technical achievements of the invention, namely the wheel cover resistance-reducing concave points, the blade resistance-reducing concave points and the wheel cover sawteeth, can be applied singly and can be simultaneously combined and applied by two or three.

Drawings

FIG. 1 is a top view of a centrifugal wind wheel according to an embodiment of the present invention;

FIG. 2 is an enlarged partial view of section E of FIG. 1 illustrating an embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view A-A of FIG. 1 illustrating an embodiment of the present invention;

FIG. 4 is an enlarged partial view of section F of FIG. 3 illustrating an embodiment of the present invention;

FIG. 5 is a schematic bottom view of a wheel cover according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of a portion of the structure of FIG. 5 in accordance with an embodiment of the present invention;

FIG. 7 is a schematic view of a blade according to an embodiment of the invention;

FIG. 8 shows an included angle δ formed by a plane where a drag reduction path line of a blade of the embodiment of the invention is located and a normal plane of an axis of a centrifugal wind wheel_iA schematic diagram;

FIG. 9 is a schematic view of a drag reducing groove of an embodiment of the present invention having a semi-circular cross-section and a partially enlarged view thereof;

FIG. 10 is a schematic illustration of a drag reducing groove of an embodiment of the present invention having a triangular cross-section and a partially enlarged view thereof;

FIG. 11 is a schematic illustration of a drag reducing groove of an embodiment of the present invention having a wavy cross-section and a partially enlarged view thereof;

FIG. 12 is a schematic illustration of a drag reducing groove of a rectangular cross-section and a partial enlargement thereof according to an embodiment of the present invention;

FIG. 13 is a schematic view of a drag reducing projection of an embodiment of the present invention having a semi-circular cross-section and a partially enlarged view thereof;

FIG. 14 is a schematic view of a drag reducing projection of an embodiment of the present invention having a triangular cross-section and a partially enlarged view thereof;

FIG. 15 is a schematic view of a resistance-reducing bump of an embodiment of the invention having a wavy cross-section and a partially enlarged cross-section;

FIG. 16 is a schematic illustration of a drag reducing projection of an embodiment of the present invention having a rectangular cross-section.

Wherein, the technical characteristics that each reference numeral refers to are as follows:

1-wheel cap, 2-wheel disc, 3-blade, 4-noise reduction sawtooth, 5-air inlet, 6-air outlet, 7-wheel cap drag reduction groove, 8-blade drag reduction groove, 11-inner wall surface, 12-outer wall surface, 31-suction surface, 32-pressure surface, 33-leading edge, 34-trailing edge, 35-intersecting line, 41-inner side surface, 42-outer side surface, 71-wheel cap drag reduction path line, and 81-blade drag reduction path line.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments, but the scope of the present invention is not limited to the following embodiments.

Referring to fig. 1-16, the embodiment discloses a centrifugal wind wheel with resistance and noise reduction functions, which includes a wheel cover 1, a plurality of blades 3 and a wheel disc 2, wherein the wheel cover 1 and the wheel disc 2 are coaxially arranged, the wheel cover 1 and the wheel disc 2 are axially arranged at intervals, the plurality of blades 3 are arranged between the wheel cover 1 and the wheel disc 2, the top ends of the blades 3 are connected with the wheel cover 1, the bottom ends of the blades 3 are connected with the wheel disc 2, the blades 3 are circumferentially arranged at intervals, specifically, the wheel cover 1, the blades 3 and the wheel disc 2 are integrally formed, the strength of the centrifugal wind wheel is improved, the wheel cover 1 is provided with a through hole as an air inlet 5, an area defined by the wheel cover 1, the wheel disc 2 and two adjacent blades 3 is an air outlet 6, air flow enters the centrifugal wind wheel from the air inlet 5, and flows out from the air outlet;

the wheel cover 1 comprises an inner wall surface 11 connected with the blade 3, the inner wall surface 11 is provided with a plurality of wheel cover drag reduction grooves 7 or/and wheel cover drag reduction protrusions, the blade 3 is provided with a plurality of blade drag reduction grooves 8 or/and blade drag reduction protrusions, the outer edge of the wheel cover 1 or/and the wheel disc 2 is provided with a plurality of noise reduction sawteeth 4 extending along the radial direction, and the noise reduction sawteeth 4 are arranged at intervals along the circumferential direction.

When airflow flows through the wheel cover 1 or the blades 3, the generated boundary layer is the source of the on-way resistance of the airflow, the wheel cover 1 is provided with a wheel cover resistance reducing groove 7 or/and a wheel cover resistance reducing bulge, the blades 3 are provided with blade resistance reducing grooves 8 or/and blade resistance reducing bulges, the flowing state of the airflow in the original boundary layer can be disturbed, the airflow pressure distribution near the boundary layer is changed, and the flowing speed near the wheel cover 1 and the blades 3 is reduced, so that the speed field of the viscous bottom layer in the boundary layer is changed, the on-way resistance loss in a flow channel is reduced, and the efficiency is improved; the vortex generated by the centrifugal wind wheel at the air outlet 6 is a main source of pneumatic noise, and the noise reduction sawteeth 4 cut the vortex at the outlet of the centrifugal wind wheel, so that the attenuation of the vortex is accelerated, the intensity of the turbulence and the pressure pulsation amplitude are reduced, and the noise is effectively reduced.

In the embodiment, the inner wall surface 11 of the wheel cover 1 is provided with a plurality of groups of wheel cover resistance reducing grooves 7 or/and wheel cover resistance reducing bulges, the centers of the wheel cover resistance reducing grooves 7 or/and the wheel cover resistance reducing bulges of each group are connected to form wheel cover resistance reducing path lines 71, and the wheel cover resistance reducing path lines 71 are arranged in parallel, the inner wall surface 11 of the wheel cover 1 is provided with a plurality of groups of wheel cover resistance reducing grooves 7, each group of wheel cover resistance reducing grooves 7 comprises a plurality of wheel cover resistance reducing grooves 7, the centers of the wheel cover resistance reducing grooves 7 of each group are connected to form the wheel cover resistance reducing path lines 7, through test tests, the resistance reducing effect of the wheel cover resistance reducing grooves 7 is better than that of the wheel cover resistance reducing bulges, when an air flow passes through the inner wall surface 11 of the wheel cover 1, a generated boundary layer is a source of on-course resistance along the position, the multiple groups of wheel cover resistance reducing grooves 7 or/and wheel cover resistance reducing bulges can effectively disturb the flow state of air flow in the original boundary layer, change the pressure distribution of the air flow near the boundary layer, reduce the flow speed of the air flow near the inner wall surface 11 of the wheel cover 1, and delay the formation of turbulence, so that the speed field of the viscous bottom layer in the boundary layer is changed, the on-way resistance loss in a flow channel is reduced, the efficiency is improved, and the multiple wheel cover resistance reducing path lines 71 are arranged in parallel, so that the effect of reducing the on-way resistance loss generated by the wheel cover resistance reducing grooves 7 or/and the wheel cover resistance reducing bulges is uniform.

The starting point and the end point of the ith wheel cover drag reduction path line 71 and the central angle formed by the connection of the centers of the wheel covers 1 are gamma_iI is 1, 2, … … and n, n is more than or equal to 2, 0 degree is less than gamma₁＝γ₂＝…＝γ_n＜360°；

The center angle formed by the connection of the starting point of the ith wheel cover resistance reducing path line 71, the starting point of the (i + 1) th wheel cover resistance reducing path line 71 and the center of the wheel cover 1 is alpha_iI is 1, 2, … …, n-1, and the center angle formed by the connection of the starting point of the nth wheel cover drag reduction path line 71, the starting point of the 1 st wheel cover drag reduction path line 71 and the center of the wheel cover 1 is alpha_n，0°＜α₁＝α₂＝…＝α_n＜180°；

The central angle formed by the connection of the terminal point of the ith wheel cover resistance reducing path line 71, the terminal point of the (i + 1) th wheel cover resistance reducing path line 71 and the center of the wheel cover 1 isβ_iI is 1, 2, … …, n-1, and the center angle formed by the connection of the end point of the nth wheel cover drag reduction path line 71, the end point of the 1 st wheel cover drag reduction path line 71 and the center of the wheel cover 1 is beta_n，0°＜β₁＝β₂＝…＝β_n＜180°；

The distance between the starting point of the ith wheel cover drag reduction path line 71 and the center of the wheel cover 1 is taken as the starting point radius R_qiThe distance between the terminal point of the ith wheel cover drag reduction path line 71 and the center of the wheel cover 1 is the terminal radius R_wiThe radius of the air inlet 5 is R₁The radius of the air outlet of the wheel cover 1 is R₂，R₁＜R_qi≤R_wi＜R₂When the set angles are different, the distribution mode of the wheel cover drag reduction grooves 7 or/and the wheel cover drag reduction bulges is changed so as to adapt to the requirements of centrifugal fans with different sizes and performance requirements and the processing technology.

In one embodiment, a plurality of sets of the wheel cover drag reduction grooves 7 or/and the wheel cover drag reduction protrusions are arranged at equal angular intervals along the circumferential direction, the wheel cover drag reduction grooves 7 or/and the wheel cover drag reduction protrusions of each set are arranged at equal angular intervals along the direction of the wheel cover drag reduction path line 71, and γ is₁＝γ₂＝…＝γ_n＝30°，α₁＝α₂＝…＝α_n＝10°，β₁＝β₂＝…＝β_n＝10°，R₁＜R_qi＜R_wi＜R₂Therefore, the wheel cover resistance reducing grooves 7 or/and the wheel cover resistance reducing bulges are/is densely distributed, and the resistance reducing effect is good.

In one embodiment, the plurality of sets of the wheel cover drag reduction grooves 7 or/and the wheel cover drag reduction protrusions are arranged at equal intervals along the axial direction, that is, each wheel cover drag reduction path line 71 is an arc line concentric with the wheel cover 1, the wheel cover drag reduction grooves 7 or/and the wheel cover drag reduction protrusions of each set are arranged at equal intervals along the direction of the wheel cover drag reduction path line 71, and γ is₁＝γ₂＝…＝γ_n＝350°，α₁＝α₂＝…＝α_n＝0°，β₁＝β₂＝…＝β_n＝0°，R₁≤R_qi＝R_wi≤R₂I.e. the cap drag reduction grooves 7 or/and the cap reducers of each groupThe circular space is enclosed between the resistance bulges, the production process is simple, and the resistance reducing effect is good.

The wheel cover drag reduction path line 71 is one of spline curve, arc line and straight line or the combination of various types of lines, the lines of the wheel cover drag reduction path line 71 are different, the distribution mode of the wheel cover drag reduction groove 7 or/and the wheel cover drag reduction bulge is changed, the blade 3 comprises a pressure surface 32 which does work on the air flow and a suction surface 31 which does not do work on the air flow, the pressure surface 32 and the suction surface 31 of the blade 3 are oppositely arranged, usually, intersecting lines 35 which are parallel to each other are formed between the pressure surface 32 of the blade 3 and the inner wall surface 11 of the wheel cover 1 and between the suction surface 31 of the blade 3 and the inner wall surface 11 of the wheel cover 1, preferably, the intersecting lines 35 formed between the pressure surface 32 of the blade 3 and the inner wall surface 11 of the wheel cover 1 or between the suction surface 31 of the blade 3 and the inner wall surface 11 of the wheel cover 1 are parallel to the wheel cover drag reduction path line 71, and the flow lines 35 of the inner wall surface 11 of the wheel cover 1 are parallel to each other under the action of the pressure surface, when the shroud drag reduction path line 71 is parallel to the intersection line 35, the airflow continuously passes through the shroud drag reduction groove 7 or the shroud drag reduction protrusion along the shroud drag reduction path line 71, which can further improve the drag reduction effect of the shroud 1.

The blade 3 is provided with a plurality of groups of blade drag reduction grooves 8 or/and blade drag reduction bulges, each group of blade drag reduction grooves 8 or/and blade drag reduction bulges comprises a plurality of blade drag reduction grooves 8 or/and blade drag reduction bulges, the centers of the blade drag reduction grooves 8 or/and the blade drag reduction bulges of each group are connected to form a blade drag reduction path line 81, the blade drag reduction path line 81 is arranged in parallel with the flow line of airflow flowing through the blade 3, in the embodiment, the blade 3 is provided with a plurality of groups of blade drag reduction grooves 8, each group of blade drag reduction grooves 8 comprises a plurality of blade drag reduction grooves 8, the center lines of the blade drag reduction grooves 8 of each group are connected to form the blade drag reduction path line 81, and similarly, the drag reduction effect of the blade drag reduction grooves 8 is better than that of the blade drag reduction bulges, when the airflow flows through the blade 3, the generated boundary layer is the source of the on-course resistance at the position, and the The flow state of the inner air flow changes the air flow pressure distribution near the boundary layer, reduces the air flow speed of the air flow near the blade 3, and delays the stroke of turbulence, so that the speed field of the viscous bottom layer in the boundary layer is changed, the on-way resistance loss in the flow channel is further reduced, the efficiency is further improved, the blade resistance reduction path line 81 is parallel to the flow line of the air flow flowing through the blade 3, the air flow in the boundary layer continuously flows through the blade resistance reduction grooves 8 or/and the blade resistance reduction bulges along the blade resistance reduction path line 81, and the resistance reduction effect of the blade 3 is further improved.

An included angle delta formed by a plane where the ith blade resistance reduction path line 81 is located and a normal plane of the axis of the centrifugal wind wheel_iAngle delta_iThe pressure surface 32 or the suction surface 31 of the blade 3 determines a blade drag reduction path line 81, i is 1, 2, … … and n, n is more than or equal to 2, and delta is more than or equal to 0 degree_i< 90 DEG, when 0 DEG is delta₁＝δ₂＝δ₃……＝δ_nSo that the planes of the blade drag reduction path lines 81 are parallel to each other, and the drag reduction effect is further improved.

The blade 3 comprises a front edge 33 and a rear edge 34, airflow flows in from the front edge 33 of the blade 3 and then flows out from the rear edge 34 of the blade 3, the distance between two adjacent blade drag reduction path lines 81 is D, the length of the rear edge 34 is L, the number of groups of blade drag reduction grooves 8 or/and blade drag reduction bulges is X, and D is more than 0 and less than L/X.

The depth of the wheel cover resistance-reducing groove 7 and the height of the wheel cover resistance-reducing bulge are both less than one third of the thickness of the wheel cover 1, the depth of the blade resistance-reducing groove 8 and the height of the blade resistance-reducing bulge are both less than one third of the thickness of the blade 3, and the resistance-reducing effect of the wheel cover 1 and the blade 3 is ensured on the premise that the structural strength of the wheel cover 1 and the blade 3 is enough and the air output of the centrifugal wind wheel is not influenced; if the depth of the wheel cover drag reduction groove 7 is greater than one third of the thickness of the wheel cover 1 or the depth of the blade drag reduction groove 8 is greater than one third of the thickness of the blade 3, the position where the wheel cover 1 or the blade 3 is provided with the groove is thinner, the wheel cover 1 or the blade 3 is easy to crack or break under the action of external forces such as airflow pressure, rotating centrifugal force and the like, and unstable factors such as increased deformation of the wheel cover 1 or the blade 3 in operation are aggravated; if the height of the wheel cover drag reduction bulge is greater than one third of the thickness of the wheel cover 1 or the height of the blade drag reduction bulge is greater than one third of the thickness of the blade 3, when the height of the bulge is greater than the thickness of the boundary layer, the bulge can block airflow outside the boundary layer, and therefore the flow loss in the running process of the impeller is increased.

The shape of the wheel cover drag reduction groove 7 or the blade drag reduction groove 8 is one of a semicircle, a triangle, a wave, a rectangle or a trapezoid, the shape of the wheel cover drag reduction protrusion or the blade drag reduction protrusion is one of a semicircle, a triangle, a wave, a rectangle or a trapezoid, the depth of the wheel cover drag reduction groove 7 or the height of the wheel cover drag reduction protrusion or the depth of the blade drag reduction groove 8 or the height of the blade drag reduction protrusion is B, the length of the wheel cover drag reduction groove 7 or the wheel cover drag reduction protrusion along the wheel cover drag reduction path line 71 or the length of the blade drag reduction groove 8 or the blade drag reduction protrusion along the blade drag reduction path line 81 is K, the distance between two adjacent wheel cover drag reduction grooves 7 or two adjacent wheel cover drag reduction protrusions or the distance between the two adjacent wheel cover drag reduction grooves 7 and the wheel cover drag reduction protrusion along the wheel cover drag reduction path line 71 or the distance between the two adjacent blade drag reduction grooves 8 or the two adjacent blade drag reduction protrusions or the blade drag reduction grooves 8 and the blade drag reduction protrusion along the The radial lines 81 are spaced apart by a distance C, preferably 0 < B < 0.8mm, 0 < K < 0.8mm, C.gtoreq.K.

A plurality of noise reduction sawteeth 4 are arranged at the outer edge of the wheel cover 1, the noise reduction sawteeth 4 are arranged at intervals along the circumferential direction, the noise reduction sawteeth 4 are arranged along the circumferential direction at equal periods, the central angle formed by the starting point and the end point of the noise reduction sawtooth 4 and the center of the shroud 1 in one period is a period angle theta, the number of the blades 3 is Z, and theta is 360 DEG/Z, the noise reduction sawtooth 4 can cut the vortex, accelerate the attenuation of the vortex, reduce the intensity of the turbulent flow and the pressure pulsation amplitude, thereby reducing the noise, and because the vortex of the centrifugal wind wheel is mainly generated near the outlet of the wheel cover 1, the noise reduction saw teeth 4 are arranged at the outer edge of the wheel cover 1, the vortex generated near the outlet of the wheel cover 1 can be weakened in a targeted manner, the noise is effectively reduced, according to the flow field distribution generated by the number of the blades 3, the periodic angle θ is 360 °/Z, and the noise reduction effect can be further improved.

Be equipped with a plurality of sawtooth 4 of making an uproar that fall in every cycle, in a cycle, a plurality of sawtooth 4 of making an uproar that fall highly increase progressively and then decrease progressively, the sawtooth 4 of making an uproar that falls highly is the form setting of gradual change, when guaranteeing centrifugal wind wheel's efficiency, has guaranteed the noise reduction effect of the sawtooth 4 of making an uproar that falls again.

In one period, the noise reduction sawteeth 4 are symmetrically arranged by an angular bisector of the period angle theta, namely, the highest point of the noise reduction sawteeth 4 is positioned in the middle of one period, so that the noise reduction effect is further improved.

The maximum height of the noise reduction saw teeth 4 in one period is H_maxThe lowest height of the noise reduction sawtooth 4 is H_minRadius of the wheel cover 1 is R₂，0.01·R₂≤H_min＜H_max≤0.06·R₂Noise reduction sawteeth 4 are arranged on the outer edge runners of the wheel cover 1, so that the efficiency of the centrifugal wind wheel is ensured, and the noise reduction effect is also ensured; if H is_min＜0.01·R₂The effect of the noise reduction saw teeth 4 on cutting the eddy current is not obvious, and the noise reduction effect is not obvious; if H is_max＞0.06·R₂Although the noise reduction saw teeth 4 can cut eddy currents well to reduce noise, the size of the wheel cover 1 is increased, the required installation space is increased, and the performance may deviate from the design requirement.

The shape of the noise reduction serrations 4 may be one or more combinations of triangular, rectangular, circular or spline curves, and in the present embodiment, the shape of the noise reduction serrations 4 is a spline curve.

In this embodiment, the noise reduction saw teeth 4 are arranged in a saw tooth manner, that is, the starting point and the end point of the ith noise reduction saw tooth 4 form a saw tooth angle epsilon with the central connecting line of the wheel cover 1_iIf i is 1, 2, … …, n is not less than 2, then epsilon₁＝ε₂＝…＝ε_nAnd the noise reduction effect is good.

In this embodiment, air outlet 6 of centrifugal wind wheel is the diffusion setting, and the flaring setting means along the flow direction of air current, and the interval between wheel cap 1 and the rim plate 2 increases gradually for the regional area increase that encloses between wheel cap 1, rim plate 2 and two adjacent blades 3 reaches the diffusion effect.

In an embodiment, the wheel cover 1 further includes an outer wall surface 12, the outer wall surface 12 is disposed opposite to the inner wall surface 11, the noise reduction sawteeth 4 include an outer side surface 42 and an inner side surface 41, and along the flow direction of the air flow, obtuse angles are formed between the inner side surface 41 of the noise reduction sawteeth 4 and the inner wall surface 11 of the wheel cover 1 and between the outer side surface 42 of the noise reduction sawteeth 4 and the outer wall surface 12 of the wheel cover 1, so that eddy currents can be better cut; in an embodiment, the outer wall surface 12 of the noise reduction sawtooth 4 is tangent to the inner wall surface 11 of the wheel cover 1, so that a better diffusion effect is achieved on the premise of meeting the noise reduction requirement.

Variations and modifications to the above-described embodiments may occur to those skilled in the art, which fall within the scope and spirit of the above description. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and variations of the present invention should fall within the scope of the claims of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.