A numerical approach based on 3D Computational Fluid Dynamics (CFD) for the simulation of the interfacial dynamics during the disintegration process of liquid in a resonant ultrasonic field is presented. Because of different length- and timescales of the nonlinear sound field and droplet dynamics phenomena, a decoupling is necessary for numerical feasibility. In a first step oscillating pressure- and velocity fields of the ultrasonic fields are computed. Direct Numerical Simulations of the disintegration process are then performed with an advanced Volume of Fluid (VOF) – method. The latter is extended by interfacial momentum source terms, taking into account ultrasonic forces, which lead to disintegration of the liquid phase. To resolve the small-sized fluid structures numerically, very fine computational grids are necessary. Therefore, numerical simulations are performed with parallel computing techniques. Disintegration inside the ultrasonic field is investigated experimentally with high-speed photography. For comparison purposes between numerical and experimental results, an acoustic levitator is used as a less complex system to study the behaviour of single drops in a resonant sound field. Results obtained from numerical computations will serve for optimisation of the ultrasonic standing wave atomization (USWA) technique used for powder coating production and for application of fluid coatings of high viscosity