The emergence of unified constitutive law is a hallmark of convective
turbulence, i.e., Nu∼Raβ with β≈0.3 in the classical
and β=1/2 in the ultimate regime, where the Nusselt number Nu measures
the global heat transport and the Rayleigh number Ra quantifies the strength
of thermal forcing. In recent years, vibroconvective flows have been attractive
due to its ability to drive flow instability and generate ``artificial
gravity'', which have potential to effective heat and mass transport in
microgravity. However, the existence of constitutive laws in vibroconvective
turbulence remains unclear. To address this issue, we carry out direct
numerical simulations in a wide range of frequencies and amplitudes, and report
that the heat transport exhibits a universal scaling law Nu∼a−1Reosβ​ where a is the vibration amplitude, Reos​ is
the oscillational Reynolds number, and β is the universal exponent. We
find that the dynamics of boundary layers plays an essential role in
vibroconvective heat transport, and the Nu-scaling exponent β is
determined by the competition between the thermal boundary layer (TBL) and
vibration-induced oscillating boundary layer (OBL). Then a physical model is
proposed to explain the change of scaling exponent from β=2 in the
OBL-dominant regime to β=4/3 in the TBL-dominant regime. We conclude
that vibroconvective turbulence in microgravity defines a distinct universality
class of convective turbulence. This work elucidates the emergence of universal
constitutive laws in vibroconvective turbulence, and opens up a new avenue for
generating a controllable effective heat transport under microgravity or even
microfluidic environment in which gravity is nearly absent.Comment: 18 pages, 3 figure