Figure 9.

Variation of the positioning angle β defined in the inset, using 2D simulations with Oh = 0.0126, r_A/r_B = 2 and ψ_A = 30°. (a) The peak tangential momentum as a function of β, indicating that is approximately unity for β≥45°. The slight reduction of the launching momentum when β is close to 90° is due to the placement of the Buller's drop past the adaxial plane, leading to a normal momentum initially pointing away from the substrate. (b) Evolution of the tangential and normal momentum for β≥45°, indicating the dominance of the tangential component. This is the only figure adopting 2D simulations in order to accommodate large β angles. The 2D results are slightly different in magnitude from their 3D counterparts. See also electronic supplementary material, movie S8 with β = 61°.