要約

Planar particle image velocimetry measurements of the flow in a precessing cylinder are presented for nutation angles of up to 15°. For a case of a moderate Reynolds number, we observe a rapid transition to a disordered state with a brief appearance of structures of high azimuthal wave numbers. Similarity to observations reported in previous experiments and numerical simulations at much lower tilt angle, but higher Poincare number suggests, a triadic resonance as the transition mechanism. Amplitudes of the forced mode and the mean streaming flow are extracted; their scaling with Reynolds number is found to agree reasonably well with weakly nonlinear theory.