IFIBA   22255
INSTITUTO DE FISICA DE BUENOS AIRES
Unidad Ejecutora - UE
artículos
Título:
Effective diffusivity of passive scalars in rotating turbulence
Autor/es:
P. RODRIGUEZ IMAZIO; P. D. MININNI
Revista:
PHYSICAL REVIEW E
Editorial:
AMER PHYSICAL SOC
Referencias:
Lugar: New York; Año: 2013 vol. 87 p. 230181 - 230189
ISSN:
1539-3755
Resumen:
We use direct numerical simulations to compute turbulent transport
coefficients for passive scalars in turbulent rotating flows. Effective
diffusion coefficients in the directions parallel and perpendicular to
the rotation axis are obtained by studying the diffusion of an imposed
initial profile for the passive scalar, and calculated by measuring the
scalar average concentration and average spatial flux as a function of
time. The Rossby and Schmidt numbers are varied to quantify their effect
on the effective diffusion. It is found that rotation reduces scalar
diffusivity in the perpendicular direction. The perpendicular diffusion
can be estimated from mixing length arguments using the characteristic
velocities and lengths perpendicular to the rotation axis. Deviations
are observed for small Schmidt numbers, for which turbulent transport
decreases and molecular diffusion becomes more significant.