Providing of Rod Piezoceramic Electroacoustic Transducers Thermal Mode Operation

Abstract

The basis of the electro-acoustic transducer is piezoceramics - a quite fragile material. A rod type transducer was chosen for analysis due to the lack of research on this type of transducer and its widespread use. The most dangerous operational load is thermal. The mechanism of the transducer heating and the negative effects that the transducer heating causes are analyzed. Ways of heat prevention are analyzed. To exclude negative effects, it is necessary to deal with undesirable heating at the stage of construction. To check the construction of the transducer for thermal loads, it is proposed to compare two methods for estimate the temperature field of the transducer. Two methods of thermal field analysis for the construction of piezoceramic electro-acoustic transducers are considered - analytical calculation and modeling in computer-aided design system. For a proper comparison of the two methods, it is necessary to take the same model of the electro-acoustic transducer for calculation and simulation. In both cases, the transducer is simplified to structurally important elements - the active element, the radiating and the back mass. The active element is CTBS-3 piezoceramic, a radiating mass is made of Amg-6 aluminum and a back mass is made of St-20 steel. The analytical method for finding the thermal field is based on the solution of the Fourier differential heat equation. A simplified model of an acoustic transducer is presented in the form of three layers, and a thermal conductivity equation is applied to each. Unknown quantities are found by substituting the heat equation into the boundary conditions. Three pairs of boundary conditions are used: the equality of temperature at the points of contact of the layers, the equality of heat flow at the border between the body and the medium, and the equality of heat flow at the boundaries of the layers. Computer simulation performed using the finite element method in the SolidWorks computer-aided design system. The advantage of the modeling method instead by the calculations is demonstrated. In addition to easy use, rapid change of parameters and the ability to solve more complex problems, modeling can show the heating of the transducer at different points in time. The heat-up process can be informative when it is impossible to change the design to improve the thermal regime and therefore heating is inevitable. In this case, it is necessary to analyze the time during which the transducer heat-up to the permissible temperature for pulse mode implementation. The obtained results can be used in the design of core piezoceramic electroacoustic transducers.