Theoretical basis for a unified conservation law description of the electromagnetic acoustic transduction process

A unified theoretical formulation describing the electroacoustic transduction processes governing an electromagnetic acoustic transducer is presented. This approach establishes separate electrical, mechanical, and material subsystem descriptions based on the momentum conservation forms of Maxwell's field equations in the quasi-static limit and Cauchy's law of motion. Instead of accounting for the electromagnetic acoustic material interaction by direct linkage of mechanical stress and magnetic flux through constitutive relations, the coupling of the field tensors is achieved as part of an additional material subsystem. As a result, the complete set of governing equations and associated boundary conditions can be derived from first principles in a concise way that lends itself to a quantitative numerical implementation in the time domain.