Figure 1.

(a) The two normalised absolute 1D pressure fields, $|\widehat{p}|$, with one source’s phase output offset from the other by $\frac{\pi }{2}$. (b) The normalised acoustic forces, ${\widehat{F}}_{\mathit{ac}}$, generated by the pressure fields in (a) and the sum of these two fields. (c) The variation in particle motion per cycle vs the applied impulse, $I_{\mathit{app}}$, varied by both the maximum force and the switching time. The different lines indicate different maximum ${\mathbf{F}}_{\mathbf{ac}}$ values which the force field was normalised to and each force was applied with a $\mathrm{\Delta }{t}_s$ range from 0.1 ms up to 100 ms. Note that the lines overlap, indicating that applied impulse produces a consistent effect regardless of which component is altered.