Study on the non-contact trapping of a small object using a pipe radiating travelling waves and a reflective rod—The effect of the shape of reflector surface on the trapping state

Flexural damped travelling waves can be excited in a lossy transmission pipe. The waves generate travelling acoustic flow in the inside of pipe and near the pipe end and the acoustic flow serves as travelling acoustic waves. It has been confirmed that a non-contact transportation of a small object can be performed in the pipe, and additionally, a small object can be trapped at a nodal point of the standing wave formed by placing a reflector rod near the pipe end. In the experiment, a polycarbonate pipe (Outer dia.:13 mm, Inner dia.:9 mm, Length:160 mm) for the lossy ultrasonic transmission pipe that a piezo-ceramic annular plate vibrating in the first radial vibration mode is adhered at the pipe end was tried and the study on the effect of the shape of reflector surface on the trapping state is considered. The reflector is made of an acrylic rod (Dia.:13 mm) and the reflective surface is formed in to the conical shape. It was confirmed that the conical shape to be adapted for the trapping exists. To impro...