Parametric study of single-axis acoustic levitation

Remarkable enhancement of the single-axis acoustic levitation force is achieved by properly curving the surface and enlarging the section of the reflector so as to levitate high density material like tungsten (ρ_s=18.92 g/cm³). A two-cylinder model incorporating the boundary element method simulations is presented for systematic study of the relationship between levitation capabilities and geometric parameters. The model proves to be successful in predicting resonant modes and explaining deviation of the levitated samples near the reflector and driver. The dependence of levitation force on resonant mode, reflector section radius R_band curvature radius R is revealed and summarized, which agrees with the experiment in principle and suggests that a reflector with large R_band small R (when R_b/λ≥0.982) working under mode 1 assures better levitation capabilities.