Air flow measuring method based on bell mouth flow tube speed distribution model

Abstract

The invention discloses an air flow measurement method based on a bell mouth flow tube speed distribution model, and belongs to the field of aero-engine air inlet flow measurement. The implementation method comprises the steps of determining a point distribution range of a pressure measurement rake on a measurement section in a test according to an in-pipe speed distribution model, then performing data measurement of a small number of points on the measurement section to obtain an in-pipe complete speed distribution model, performing integral calculation on the obtained in-pipe complete speed distribution model to obtain in-pipe air flow, and calculating the in-pipe air flow according to the in-pipe air flow. And the air inlet flow of the aero-engine is measured. According to the method, the in-pipe velocity distribution model is divided into the constant section, the linear section, the logarithmic section and the velocity distribution characteristics of all the sections, the point distribution range and the point distribution number of the pressure measurement rakes on the measurement section for calibrating the in-pipe velocity distribution model are selected in a segmented mode, accurate measurement point distribution is achieved, the number of measurement points can be reduced, and the measurement accuracy is improved. On the premise that the measurement precision of the air inlet flow of the aero-engine is guaranteed, the flow measurement precision and the measurement efficiency are improved.

Description

technical field [0001] The invention belongs to the field of aero-engine intake air flow measurement, and relates to an air flow measurement method based on a velocity distribution model of a bell-shaped flow tube. Background technique [0002] The air intake flow measurement results of aero-engines are often used for performance evaluation and condition monitoring of the whole engine and components. The most commonly used measurement scheme is to rely on the bell-shaped flow tube equipped with a total static pressure probe for measurement, and this measurement method is currently used. There are the following two implementations. [0003] One is to set fewer measuring points for simple measurement, and obtain the flow rate in the pipe through the average of a few measuring points. This solution cannot reflect the true pressure and velocity distribution in the tube, resulting in inaccurate measurement results. [0004] The other is to obtain the air flow in the tube by the...

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Problems solved by technology

[0006] In order to solve the problems of many measuring points and high costs of labor, time, and technology, the main purpose of the present invention is to provide a flow measurement method based on the velocity distribution model of the bell-shaped flow tube, and determine the test flow rate according to the velocity distribution model in the tube. The distribution range of the pressure measurement rake on the middle measurement section, and then measure the data of a small number of points on the measurement section to obtain a complete velocity distribution model in the pipe, and perform integral calculation on the obtained complete velocity distribution model in the pipe to obtain the air flow in the pipe. For the measurement of air intake flow of aeroengines, improve the accuracy and efficiency of flow measurement

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