任意の形状と音圧分布を持つ探触子の超音波回折現象

抄録

We investigated three-dimensional ultrasonic diffraction by numerical simulation, and derived the amplitude loss and phase shift caused by the diffraction. The simulation is based on the general solution and has been performed on a model in which a transducer consists of infinitesimally small openings, which independently satisfies the Dirichlet boundary condition on the transducer surface ; the ultrasonic wave incident from the back of the surface diffracts forward through these openings. This method is useful, when an analytical solution is unavailable. We simulated the case of near regional propagation where the wavelength is not necessarily small relative to the path length and also the case where the transducer has arbitrary geometry and strength distribution over the radiating area. These results are useful in correcting the diffractive effects in practical ultrasonic measurements.