The application of high performance ultrasound in resonant standing waves recently has obtained some new technical applications as the ultrasonic-standing-wave-atomization (USWA) of liquids. In this application a resonant ultrasonic wave field is generated by means of two oscillating transducers facing each other on a common axis. Characterization of the wave field formation in this resonant, high-amplitude case of ultrasonic standing wave fields is of significant importance for understanding and optimization of such processes. Computational simulation of the sound field provides insight in the complex gas behaviour and atomization process. The numerical simulation of the ultrasonic field characteristics is based on the fundamental hydrodynamic conservation equations including nonlinear and viscous effects. The numerical calculation procedure and boundary conditions will be outlined. Results for the ultrasonic wave field characteristics in standard geometric arrangements as well as possibilities for energy density enhancement will be discussed.