The Effect of Nanocomposite Polymeric Layer on the Radiation of Antisymmetric Zero-Order Lamb Wave in a Piezoelectric Plate Contacting with Liquid
Résumé
A nanocomposite polymeric layer is proposed to be used for increasing the efficiency of ultrasound radiation into the liquid by antisymmetric zero-order (A0) Lamb waves propagating in piezoelectric plates. The theoretical and experimental investigations of the influence of the nanocomposite polymeric layers on the efficiency and radiation angle of acoustic wave into liquid were carried out. It has been theoretically shown that the use of the layer of the polyethylene of low density with nanoparticles of cadmium sulfide of concentration 25% between the plate of 128YX LiNbO3 and water medium allows to increase the radiation attenuation on ∼1 dB/λ if the ratio of the thicknesses of the layer and plate is equal to 0.16 at the frequency of 1.3 MHz. The experimental data were in a good agreement with theoretical results. It has been also shown that the presence of nanocomposite film leads to the increase of the radiation angle of bulk acoustic wave in liquid and allows the effective operation of the radiator not only in the sweet water but also in salt one. The obtained results may be used for the development of effective radiators/receivers of acoustic waves in liquids for flow meters and for underwater communication systems.