Experimental study of the oscillatory process in cylindrical pipes filled with gas-bubble liquid

About the authors:

Faiz A. Zaripov, Postgraduate Student, Department of Special Technologies in Education, Kazan National Research Technical University named after A. N. Tupolev — KAI (Kazan); zaripovfa@mail.ru

Grigory I. Pavlov, Dr. Sci. (Tech.), Professor, Head of the Department of Special Technologies in Education, Kazan National Research Technical University named after A. N. Tupolev — KAI (Kazan); pavlov16@mail.ru

Pavel V. Nakoryakov, Cand. Sci. (Tech.), Associate Professor, Department of Special Technologies in Education, Kazan National Research Technical University named after A. N. Tupolev — KAI (Kazan); nakorjakov@mail.ru

Oleg R. Sitnikov, Cand. Sci. (Tech.), Associate Professor, Department of Special Technologies in Education, Kazan National Research Technical University named after A. N. Tupolev — KAI (Kazan); halmer169990@mail.ru

Abstract:

In hydraulic systems, undamped oscillations often occur, the frequencies of which coincide with the natural frequencies of the elements of hydraulic systems. The resulting pressure pulsations in the liquid are harmful and can disrupt the operation of hydraulic systems and elements of its automation. The search for ways and methods to reduce the impact of wave and vibration processes on pipelines, as well as the creation of devices that ensure their implementation, is an urgent scientific and technical task. The paper proposes an original method of damping resonant vibrations by feeding gas bubbles into the acoustic circuit. The aim of the work was to evaluate the effectiveness of the proposed method for reducing the sound level in water at the resonant frequencies of the main harmonics and overtones. To test the proposed method, an experimental stand was developed, the resonant frequencies and sound levels in a liquid medium bounded by a pipe closed on one side were determined by an experimental method, the influence of the supplied gas with different volume flow rates on the sound level in the pipe at the resonant frequencies of the main harmonics and overtones was investigated. The experimental results obtained allow us to conclude that the gas supply to a liquid medium leads to a change in the properties of the medium and, as a consequence, to a decrease in the sound pressure level in the liquid from the resonant (natural) oscillation frequencies of cylindrical pipes closed at one end.

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