CN115030818A - An inertial stage blade of an intake filter device based on bionic drag reduction - Google Patents

Abstract

The invention aims to provide an inertial-stage blade of an air inlet filtering device based on bionic drag reduction, which comprises a blade unit, wherein the blade unit comprises a front flow guide section, a rear flow guide section and first-fourth hydrophobic grooves, the front flow guide section is connected with the first hydrophobic groove through a first transition section, the first hydrophobic groove is connected with the second hydrophobic groove through a second transition section, the second hydrophobic groove is connected with the third hydrophobic groove through a third transition section, the third hydrophobic groove is connected with the fourth hydrophobic groove through a fourth transition section, the rear flow guide section is connected with the fourth transition section and the fourth hydrophobic groove, the first hydrophobic groove and the third hydrophobic groove are positioned on one side, and the second hydrophobic groove and the fourth hydrophobic groove are positioned on the opposite side of the first hydrophobic groove. The vortex generated by the bionic structure influences adjacent main flows, and the speed change gradient near the wall surface is reduced, so that the shearing force between layers is reduced, and the aim of reducing resistance loss of an inertia stage is fulfilled on the premise that the separation efficiency is not greatly changed.

Description

An inertial stage blade of an air intake filter device based on bionic drag reduction

technical field

The invention relates to a gas turbine blade, in particular to a gas turbine inlet blade.

Background technique

With the higher and higher requirements for the performance of ship power plant, not only the power plant is required to provide strong power, but also it is required to be able to operate stably in harsh marine environments. Gas turbines have extremely high requirements on the quality of their intake air. The impurities contained in the inhaled air will not only reduce the power of the gas turbine, but even damage its components. Inertial grade air-water separators are often installed in marine air intakes to filter impurities such as fine droplets and salt spray aerosols in the air stream.

The amount of various impurities such as small solid particles and salt mist aerosols that follow the air into the air intake is very large. These impurities will inevitably cause wear and corrosion of the intake port as the air enters the intake port; impurities such as salt mist and aerosols enter the gas turbine with the air flow and will adhere to the surface of the compressor blades, causing the blades to foul or even corrode, thereby causing The change of the profile of the compressor blade leads to a serious decrease in the aerodynamic performance of the compressor, an increase in power consumption, and even a surge of the compressor. In addition, the components in the combustion chamber need to use cooling gas to cool the components. The cooling gas comes from the gas extracted from the compressor. The inhalation of the salt mist gas will cause the blockage of the cooling channel, affect the cooling efficiency, and cause the initial temperature of the turbine to exceed the temperature. lead to damage to the turbine blades. Therefore, in order to ensure the air intake quality of the air intake system, it is necessary to use a filter device to filter out impurities such as solid particles and salt mist aerosols contained in the marine atmosphere.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an air intake filter device based on bionic drag reduction, which can reduce the drag loss of the inertial stage and improve the performance of the inertial stage without changing the shape of the existing device and the change of the separation efficiency is small. Inertia grade blades.

The object of the present invention is achieved in this way:

The present invention is an inertial stage blade of an air intake filter device based on bionic drag reduction, which is characterized in that it includes a blade unit, and the blade unit includes a front guide section, a rear guide section, and first-fourth water-repellent grooves, The front diversion section and the first hydrophobic groove are connected by a first transition section, the first hydrophobic groove and the second hydrophobic groove are connected by a second transition section, and the second hydrophobic groove and the third hydrophobic groove are connected by a third hydrophobic groove The transition section is connected, the third hydrophobic groove and the fourth hydrophobic groove are connected by a fourth transition section, the rear diversion section connects the fourth transition section and the fourth hydrophobic groove, and the first hydrophobic groove and the third hydrophobic groove are located on one side, The second hydrophobic groove and the fourth hydrophobic groove are located on opposite sides of the first hydrophobic groove.

The present invention can also include:

1. The surface of the blade body is arranged with a ridge-shaped accompanying wave drag reduction structure.

2. The grooves of the ridge-shaped traveling wave drag reduction structure are along the direction of gravity and perpendicular to the direction of movement of the airflow relative to the blade body.

3. The shape of the ridge accompanying wave drag reduction structure is semicircular, V-shaped, U-shaped or L-shaped.

4. The front guide section is connected with the arc of the first transition section, and the angle ranges from 135° to 180°.

5. The rear guide section is connected with the arc of the fourth transition section, and the angle ranges from 135° to 180°.

6. The shape of the ridge traveling wave drag reduction structure is semicircular, and the radius of the semicircle is 5%-15% of the thickness of the blade body.

The advantages of the present invention are: the present invention designs a gas turbine intake filter device, the vortex generated by the bionic structure has an impact on the adjacent main flow, and reduces the velocity gradient near the wall surface, thereby reducing the shear between layers force, so that the inertial stage can achieve the purpose of reducing the resistance loss under the premise that the separation efficiency does not change greatly.

Description of drawings

Fig. 1 is the structural representation of the present invention;

2 is a schematic diagram of some details of the present invention;

Fig. 3 is the arrangement form of the present invention under the installation state;

Fig. 4 is a schematic diagram of the local flow field of the drag reduction groove structure of the traveling wave;

FIG. 5 is a schematic diagram of the traveling wave structure of different shapes;

Figure 6 is a comparison diagram of the calculation results.

Detailed ways

The present invention will be described in more detail below in conjunction with the accompanying drawings:

1-6, the present invention is an inertial stage blade of an air intake filter device based on bionic drag reduction technology. The inertial stage blade includes a front guide section 1, a first transition section 2, a first drain groove 3, and a second transition section. Section 4 , second hydrophobic groove 5 , third transition section 6 , third hydrophobic groove 7 , fourth transition section 8 , fourth hydrophobic groove 9 , and rear diversion section 10 . The semicircular ridge structure is arranged on the surface of the blade. The groove of the ridge traveling wave drag reduction structure is along the direction of gravity and is perpendicular to the direction of airflow relative to the blade movement. The size of the groove is determined by the semicircle radius and the semicircle spacing. The semicircle radius is 5%-15% of blade thickness. The ridge-shaped accompanying wave drag-reducing structure forms a secondary vortex through the interaction of the flow field to produce the effect of reducing the drag.

其中r为半圆的直径，v为流体动力粘度系数，U平均流速，Re为来流雷诺数。Since the size of the traveling wave structure is affected by the size of the inertial stage blade and the incoming flow parameters, the dimensionless parameters are defined.

where r is the diameter of the semicircle, v is the hydrodynamic viscosity coefficient, U is the average flow velocity, and Re is the incoming Reynolds number.

When the fluid and the blade move relative to each other, a stable secondary vortex with the same shape and position will be formed in the groove of the blade on the surface of the traveling wave structure due to the interaction between its structure and the flow field. Obvious mutual influence, it causes a backflow in the opposite direction of the original fluid motion in the ridge structure, which produces a similar mechanical "rolling bearing" effect, which is affected by the counter-rotating secondary vortex, resulting in the viscosity of the ridge structure. The direction of the resistance is opposite to the direction of the total resistance, which further reduces the number of low-speed flow bands in the wall area, thereby reducing the flow instability in the wall area, weakening the process of turbulent bursting, reducing the viscous resistance, and producing a significant drag reduction effect. .

As shown in the figure, a number of such blades are arranged vertically facing the direction of the incoming airflow, and the blades are kept parallel to each other with equal spacing to work. Both the front guide section 1 and the rear guide section 10 are arranged horizontally. In order to suppress the separation of the air flow, the air inlet edge of the front guide section 1 and the air outlet edge of the rear guide section 10 both adopt arc transitions instead of straight edges with clear edges and corners. The front guide section 1 is connected with the first transition section 2 by a circular arc, and the angle ranges from 135° to 180°. The rear guide section 10 is connected with the arc 8 of the fourth transition section, and the angle ranges from 135° to 180°. A large-diameter arc transition is adopted between each transition section and each drainage groove.

Compared with the traditional inertial stage structure, the inertial stage can generate secondary flow vortices at the wave trough under the condition that the water delivery efficiency remains unchanged. Reduce the shear force between the layers to achieve the purpose of reducing the resistance loss.

In order to make the arrangement of the traveling wave structure better adapt to the streamline of the blade itself and avoid affecting the aerodynamic structure of the blade itself, the arrangement will be carried out according to the following method: The single traveling wave structure shown in Figure 4 is named as a unit, and the Strict calculation ensures that the size of the unit does not change with the development of the surface; each unit is connected end to end, and the entire traveling wave structure layout area is divided into several continuous traveling wave structure segments according to the actual size, and the starting and ending positions of each segment are determined by the leaf surface. Using such an arrangement method can not only reduce the difficulty of uniform and continuous arrangement of complex structures on the blade surface, but also adapt to the streamline shape of the blade surface as fully as possible without changing the aerodynamic characteristics of the blade itself.

More specifically, in order to adapt to different blade structures and different fluid types, the shape of the drag reduction structure can also be V-shaped, U-shaped, or L-shaped, which can be modified according to the needs of practical applications.

Claims (7)

1. An inertial stage blade of an air intake filter device based on bionic drag reduction, characterized in that: comprising a blade unit, and the blade unit comprises a front guide section, a rear guide section, and a first-fourth water-repellent groove, The front diversion section and the first hydrophobic groove are connected by a first transition section, the first hydrophobic groove and the second hydrophobic groove are connected by a second transition section, and the second hydrophobic groove and the third hydrophobic groove are connected by a third hydrophobic groove The transition section is connected, the third hydrophobic groove and the fourth hydrophobic groove are connected by a fourth transition section, the rear diversion section connects the fourth transition section and the fourth hydrophobic groove, and the first hydrophobic groove and the third hydrophobic groove are located on one side, The second hydrophobic groove and the fourth hydrophobic groove are located on opposite sides of the first hydrophobic groove. 2 . The inertial stage blade of an air intake filter device based on bionic drag reduction according to claim 1 , wherein the surface of the blade body is arranged with a ridge-shaped accompanying wave drag reduction structure. 3 . 3. The inertial stage blade of an air intake filter device based on bionics drag reduction according to claim 2, wherein the groove of the ridge-shaped accompanying wave drag reduction structure is directed along the direction of gravity and is opposite to the air flow of the blade body The direction of movement is vertical. 4. The inertial stage blade of an air intake filter device based on bionics drag reduction according to claim 2, wherein the shape of the ridge accompanying wave drag reduction structure is semicircular, V-shaped, U-shaped or L-shaped type. 5 . The inertial stage blade of an air intake filter device based on bionic drag reduction according to claim 1 , wherein the front guide section is connected with the first transition section arc, and the angle ranges from 135° to 180° 5 . °. 6 . The inertial stage blade of an air intake filter device based on bionic drag reduction according to claim 1 , wherein the rear guide section is connected with the fourth transition section arc, and the angle ranges from 135° to 180° 6 . °. 7. The inertial stage blade of an air intake filter device based on bionics drag reduction according to claim 2, wherein the shape of the ridge accompanying wave drag reduction structure is a semicircle, and the semicircle radius is the thickness of the blade body. 5%-15%.

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