Bladeless mixer

A method of mixing a liquid by means of a bladeless mixer containing a cylindrical or tapered container of axis A and radius R, wherein R is the smallest distance between axis A of the container and a side wall of the container, the container being tiltable such that axis A forms a non-zero angle α, chosen such that the angle is less than or equal to 30° relative to vertical, and the container being rotatable, the method comprising:

• a) placing the liquid in the container such that the liquid has a free surface at a height H measured along axis A when axis A is vertical, and
• b) applying a rotational motion to the container around axis A, with an angular speed of rotation Ω, and applying the non-zero angle α to tilt the container, wherein an aspect ratio H/R of height H over radius R and angular rotational speed Ω are chosen so as to observe an unstable resonance of an inertial eigenmode of the liquid
• wherein the inertial eigenmode of the liquid is
• the first mode with 1.79≤H/R≤2.19 and (Ω×R2×α)/v>1000, or
• the second mode with 0.86≤H/R≤1.06 and (Ω×R2×α)/v>15000 or
• the third mode with 0.56≤H/R≤0.68 and (Ω×R2×α)/v>50000
• wherein Ω is the angular speed of rotation expressed in rad/s, R is the radius of the container expressed in m, H the height of the liquid in meter measured along axis A;
• α the angle of tilt between axis A and vertical, expressed in degrees °, and v the kinematic viscosity of the liquid to be mixed, expressed in m2/s.