HOPF-BIFURCATION WITH BROKEN REFLECTION SYMMETRY IN ROTATING RAYLEIGH-BENARD CONVECTION

Experimental observations of azimuthally traveling waves in rotating Rayleigh-Benard convection in a circular container are presented and described in terms of the theory of bifurcation with symmetry. The amplitude of the convective states varies as square-root-epsilon and the traveling-wave frequency depends linearly on epsilon with a finite value at onset. Here epsilon = R/R(c) - 1, where R(c) the critical Rayleigh number. The onset value of the frequency decreases to zero as the dimensionless rotation rate-OMEGA decreases to zero. These experimental observations are consistent with the presence of a Hopf bifurcation from the conduction state expected to arise when rotation breaks the reflection symmetry in vertical planes of the nonrotating apparatus.