A Measuring Device for Turbine Blade Rotating Dynamic Airflow Exciting Force

Abstract

The turbine blade rotating dynamic airflow exciting force measuring device comprises a blade disc system, an exciting force measuring device, an airflow exciting generating device and the like. Bladesof the blade disc system are hinged to clamping blocks fixed relative to the position of the wheel disc, the installation direction of a hinged shaft is perpendicular to the first-order bending vibration direction of the blades, and the measurement error of the dynamic airflow exciting force is reduced through polishing and lubricating friction reduction at the hinged position. A dynamic tensionand pressure sensor is introduced along the blade height direction, and is installed along the first-order bending vibration direction of the blade, the side away from the blade is fixed on a rigid measuring rod and the side close to the blade is connected with the blade through a flexible rod, and finally the dynamic process of the amplitude and the action position of the dynamic airflow excitingforce are measured. The excitation force load measured by the method is helpful for perfecting a blade vibration numerical analysis model, a blade non-contact vibration measurement method and the like. By changing the airflow speed, the blade type and the like, different turbine units can be studied, and the universal applicability is achieved.

Description

technical field [0001] The invention belongs to the technical field of experimental devices, and in particular relates to a device for measuring the exciting force of rotating dynamic air flow of turbine blades. Background technique [0002] Turbine blades often work under extremely harsh and complex conditions, and are prone to forced vibrations under the impact of airflow. Practice has shown that the forced vibration of the blade due to the excitation of the airflow is the main cause of the high cycle fatigue failure of the blade. In order to study this forced vibration phenomenon, it is necessary to explore the characteristics of the exciting force, so as to provide a basis for the design of high-life turbine blades. [0003] In the vibration experiment of rotating turbine blades, the common method to introduce the exciting force on the blade is to act on the blade through the electromagnet or air flow, and generate a periodic force with exciting dynamic changes during t...

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Problems solved by technology

[0003] In the vibration experiment of rotating turbine blades, the common method to introduce the exciting force on the blade is to act on the blade through the electromagnet or air flow, and generate a periodic force with exciting dynamic changes during the rotation of the blade. However, these excitation methods The location and amplitude of the exciting force acting on the blade cannot be accurately obtained

Taking the airflow excitation as an example, only data such as the flow rate and direction of the airflow at the outlet of the nozzle can be obtained, but the blade rotation process is a dynamic process, and it is impossible to accurately obtain the airflow excitation force applied to the rotating blade in one cycle The size and action position, which makes the numerical and experimental results in the analysis of blade vibration characteristics unable to carry out effective mutual verification

In the past, the application and measurement methods of blade excitation force were only applicable to the exploration of the vibration of non-rotating blades, and it was difficult to analyze the forced vibration phenomenon of actual rotating blades under the action of airflow.

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