In this paper, an experimental method was adopted based on a 20 MHz SAW device.

A high-speed video camera and a laser diffraction analyzer were employed to construct an observation system.

The effects caused by SAW radiation and inflicted on the parent drop were recorded and classified at each reaction stage according to the applied power.

Atomized droplet size distribution generated by the SAW device was analyzed, which revealed that the diameter distribution of droplets centered on three main peaks.

Corresponding mechanisms are employed to provide a detailed explanation for each stage.

Experimental results also show that Eckart streaming and Schlichting streaming dominant different stages in generating different scale droplets.

The change of the these two kinds of streaming is determined by the aspect ratio (H/L).

Methods for predicting the mean diameter of atomized droplets are compared in this work with the result showing the method which adopts capillary wave frequency and takes characteristic geometry dimensions into account are more suitable to this experiment result.