Mechanical Design Implications on Power Transfer Through Thick Metallic Barriers Using Piezoelectric Transducers

Abstract

Traditionally, power transfer through thick metallic barriers has required physical penetrations and wire feed-throughs, which reduces structural integrity and limits the environmental isolation provided by the barrier. The Faraday shielding presented by these barriers, however, prevents efficient transfer of electromagnetic power, limiting many RF coupling techniques. More recently, the use of ultrasound has been shown as an effective non-destructive technique for transmitting large amounts of power (100s of watts) through solid metallic mediums. By using two coaxially aligned piezoelectric transducers loaded onto opposite sides of the barrier through an acoustic couplant, an ultrasonic channel is formed through which efficient power delivery is possible. This work presents finite element modeling and simulations that help characterize the impacts of many mechanical design factors on the power transfer efficiency of these ultrasonic channels, including: transducer-wall coupling effects, transducer and wall resonance modes, transducer dimensions, and barrier composition and dimensions. Physical channel measurements are also presented to show the strong correlation between the finite element simulations and the systems modeled.