Department of Design and Production of Radio Electronic Equipment

National Technical University of Ukraine
"Igor Sikorsky Kyiv Polytechnic Institute"

Measuring the speed of sound in liquids

Author: Fedorenko Igor Vyacheslavovich

Group: РБ-31м

Supervisor: Movchanyuk Andriy Valerіyovich

ELK: Master

Speciality: 8.05090204 Biotechnical and Medical Equipment and Systems

Summary: Subject matter of the study – liquids. Scope of the study – the speed of sound in liquids. Objective of the study – to modify pulse method with the ability to obtain data on the speed of sound in terms of strong acoustic interference. The first chapter of master’s degree work covers the importance of a priori knowledge of the speed of sound in liquids, as well as the basic methods of measurement. The multifrequency pulse method for measurement of the speed of sound in liquids was proposed. The objective and tasks of the study were formulated. The possibility of using piezoelectric circular ring transducers for both thickness and flexural vibration forms was shown based on the results of mathematical modeling in the second chapter of the work. Mathematical modeling of the distribution of sound pressure in the measuring chamber showed that adequate measurement results may be obtained only in case of flat wave front. As a result of mathematical modeling, the expression for calculation of the critical radius of measuring chamber was acquired. The requirements for individual functional units of the measurer of the speed of sound were presented in the third chapter of master’s degree work. The modeling and design of the measurer units were performed. The model sample of measurer of the speed of sound in liquids that implements the multi-pulse method was manufactured. The measured values of the speed of sound in liquids, which match the reference values with sufficient accuracy, were shown in the fourth chapter of the work. The expediency of the measurements using frequencies below the critical frequency of thickness resonance of the piezoelectric transducer was proved. The potentiality of the proposed method of measurement of the speed of sound in terms of interference concentrated in spectrum was shown.

Keywords: speed of sound, multifrequency, pulse, ultrasound, piezoelectric transducers

The work consists of:  147 pages of explanatory note and 3 appendix

Explanatory note: Full text