CN201368066Y - S-shaped symmetrical wing profile - Google Patents

Abstract

The utility model discloses an S-shaped symmetrical wing blade, which is additionally provided with small blades on both sides of the blade top, the height and thickness of the additional small blades are 1-2CM, and after the end guide vanes are added to the blade tips, the suction surface end guide vanes are bent upwards to guide the airflow to flow upwards so as to increase the top gas pressure, and the pressure surface end guide vanes are bent downwards to guide the airflow to flow downwards so as to reduce the top gas pressure, thus reducing the pressure difference on both sides of the blade tip, reducing the blade tip vortex and reducing the noise; the end guide vanes play a role in isolating the boundary layer from piling up to the blade top, thereby reducing the new layer separation loss generated by the boundary layer and improving the efficiency.

Description

An S-shaped symmetrical wing blade

technical field

The utility model relates to an airfoil profile of a reversible axial flow fan impeller, in particular to an S-shaped symmetrical airfoil profile with end guide vanes.

Background technique

With the rapid development of my country's fan industry, the scope of application of reversible axial flow fans is becoming more and more extensive. In many applications, such fans require that the forward and reverse air volumes and total pressures are basically equal, and the highest total pressure efficiency is required to be more than 76%. Area ratio A sound level ≤ 26dB (A).

At present, the airfoils used in the design of reversible axial flow fan impellers can be divided into three types: two-way symmetrical airfoil, symmetrical airfoil, and asymmetrical airfoil. The two-way symmetrical airfoil is an airfoil with the same flow performance in both directions At present, there are three types: flat plate type, elliptical type and S type. Among them, the S type blade has become the preferred blade type because of its good hydrodynamic performance when transporting media in forward and reverse directions, but it is not the best relative to fan efficiency and noise. . Moreover, due to the limitation of the shape of the aerodynamic structure, the improvement of fan efficiency and the reduction of noise are at extreme positions, and the space for upward lifting is quite limited. There is a pressure difference between the suction surface and the pressure surface. Under its action, the gas flows from the pressure surface to the suction surface through the gap between the blade tip and the fan cylinder, thereby forming a blade tip vortex. The generation of the blade tip vortex and its interaction with adjacent blades The effect increases the noise of the fan. Due to the accumulation of the blade tip boundary layer and the vortex flow of the blade tip, the flow loss of the fan increases and the efficiency decreases. Most of the existing reversible axial flow fans require the forward and reverse working conditions to be basically the same. Under normal circumstances, the highest total pressure efficiency of this blade type is often only required to be about 74%, and the specific A sound level is between 28 and 30dB (A).

Contents of the invention

The utility model is an S-shaped symmetrical airfoil profile, which aims to provide an S-shaped symmetrical airfoil profile which can solve the above problems and meet the requirements of high efficiency and low noise under different working conditions.

The utility model relates to an S-shaped symmetrical airfoil profile. Small blades are added on both sides of the top of the blade. The height and thickness of the added small blades are 1-2 cm.

The beneficial effects of the utility model are: after the end guide vanes are added on both sides of the top of the blade, the end guide vanes on the suction surface are bent upwards to guide the air flow upwards to increase the gas pressure at the top, and the end guide vanes on the pressure surface are bent downward to guide the air flow The downward flow reduces the pressure of the top gas, which reduces the pressure difference on both sides of the blade tip, reduces the vortex of the blade tip, and reduces the noise; The new layer separation loss caused by the boundary layer is eliminated, and the efficiency is improved.

Description of drawings

Fig. 1 is the structural diagram of the original S-shaped symmetrical wing blade;

Fig. 2 is the utility model S-shaped symmetrical wing vane structural diagram;

Fig. 3 is the tip vortex diagram of the original S-shaped symmetrical wing blade.

Detailed ways

The utility model relates to an S-shaped symmetrical airfoil profile. Small blades are added on both sides of the top of the blade. The height and thickness of the added small blades are 1-2 cm.

After the end guide vane is added to the blade tip, the guide vane on the suction side bends upwards to guide the air flow upwards to increase the top gas pressure, and the pressure side end guide vane bends downward to guide the air flow downwards, thereby reducing the top gas pressure , so that the pressure difference on both sides of the blade tip is reduced, reducing the tip vortex and reducing the noise; the end guide vane plays the role of isolating the accumulation of the boundary layer to the tip of the blade, thus reducing the separation of new layers generated by the boundary layer loss, so that the efficiency has been improved.

Claims (2)

1, a kind of S type symmetry machine winged petiole type, it is characterized in that: it has set up small leaf in the vane tip both sides.

2, a kind of S type symmetry machine winged petiole type according to claim 1 is characterized in that: its height of the described small leaf of setting up and thickness are 1～2CM.

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