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A Method for Measuring Airflow Direction Velocity in Air System

A technology for measuring air flow direction and velocity, which is applied in the measurement of fluid velocity and other directions by using differential pressure, which can solve the problems of high measurement cost, complicated operation, and complicated measurement, and achieve the effect of high use cost, strict use conditions and high accuracy.

Inactive Publication Date: 2021-04-20
NORTHWESTERN POLYTECHNICAL UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] In order to avoid the deficiencies of the prior art, the present invention proposes a method for measuring the velocity of the airflow direction in the air system, which overcomes the problems of complicated measurement, high measurement cost and complicated operation of the existing flow velocity measurement method

Method used

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  • A Method for Measuring Airflow Direction Velocity in Air System
  • A Method for Measuring Airflow Direction Velocity in Air System
  • A Method for Measuring Airflow Direction Velocity in Air System

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Experimental program
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Effect test

Embodiment 1

[0051] combined with figure 1 , the axial airflow reaches the static swirl disc 1 shown in the figure and passes through the inclined hole 2, the direction of the airflow changes, and has a peripheral velocity Total speed V out The included angle with the axis is θ. The size of the airflow deflection angle θ is related to the size and direction of the incoming flow velocity, the deflection angle of the pre-rotation hole, and the aspect ratio of the pre-rotation hole. When the velocity and direction of the incoming flow are determined, when the aspect ratio of the pre-rotation hole reaches a certain After the value, the airflow deflection angle θ is equal to the deflection angle of the pre-rotation hole.

[0052] From attached figure 1 It can also be seen that the velocity in the airflow direction such as the circumferential velocity is obtained The size of is very important to obtain the flow characteristics of the airflow, and the airflow rotation ratio, the angle betwe...

Embodiment 2

[0060] As shown in the figure, the airflow enters axially and passes through the attached figure 2 The direction of the airflow changes after the swirling orifice shown, and a certain circumferential velocity is obtained. When it is necessary to know the circumferential velocity of the airflow , you can choose to use this direction speed measurement method to obtain the circumferential speed the size of. The specific parameters of the swirl orifice are shown in Table 2:

[0061] Table 2: Specific parameters of swirling orifice plate

[0062] Swirl orifice diameter 304mm Radial position of swirl hole 115mm Swirl hole diameter 7mm Axial Angle of Swirl Hole 45°

[0063] Step 1: It is necessary to select a suitable static pressure measuring point on the pitot tube. Since the swirling orifice is an axial pre-swirling air intake, the axial velocity and circumferential velocity of the airflow are relatively large. Numerical calculation resul...

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Abstract

The invention relates to a method for measuring the directional velocity of the airflow in an air system. The directional velocity can be directly obtained only by measuring two pressures, that is, a set of differential pressures. The measurement is simple and the measurement cost is greatly reduced. By comparison, it is found that the maximum absolute deviation of the direction speed measurement method proposed by the present invention and the same direction speed obtained by the traditional five-hole needle analysis is 4.72m / s, and the maximum relative deviation is 5.96%. The accuracy is very high and can be obtained accurately. The direction velocity of the airflow. It solves the lack of the traditional airflow direction velocity measurement method. When measuring the velocity, it is necessary to use a three-dimensional flow velocity measuring instrument, and then determine the velocity in each direction according to the three-dimensional flow velocity results. There are problems such as high cost of use, strict conditions of use, and complicated operation.

Description

technical field [0001] The invention belongs to the field of aero-engine air systems, and relates to a method for measuring the velocity in the airflow direction in the air system. Background technique [0002] Raising the gas temperature before the turbine inlet of the aeroengine can correspondingly increase the thrust-to-weight ratio of the aeroengine, and the thrust of the engine can be increased by about 10% for every 55°C increase in the gas temperature before the turbine inlet. At present, the temperature at the leading edge of the turbine of a modern aero-engine has reached 2000K, which far exceeds the upper limit of the temperature resistance of the metal materials used in the engine. It is becoming more and more difficult to improve the performance of the engine by improving the temperature resistance of the material. The low-temperature air is extracted from the center and passed through the engine inflow air system to effectively cool the high-temperature parts of...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01P5/16
CPCG01P5/16
Inventor 刘高文张苗冯青
Owner NORTHWESTERN POLYTECHNICAL UNIV