The experimental evidences of spatial intermittency are shown for the first time in a nematic liquid crystal, when a strong turbulence is induced by an external oscillating electric field. The intermittency can be safely described by a multifractal theory which predicts the existence of the singularity spectrum f(ot) relative to the singularities c~ of the distortion energy (the analog of the dissipation fields in the isotropic fluid framework). A direct measurement of f(cO, for different values of the amplitude of the applied electric field, is presented. Furthermore the usual turbulence-turbulence transition is examined and described by means of an enhancement of the intermittency, due to the creation of strongest singularities.
Multifractal structures in electro-convective turbulence
Vincenzo Carbone;Nicola Scaramuzza;Carlo Versace
1997-01-01
Abstract
The experimental evidences of spatial intermittency are shown for the first time in a nematic liquid crystal, when a strong turbulence is induced by an external oscillating electric field. The intermittency can be safely described by a multifractal theory which predicts the existence of the singularity spectrum f(ot) relative to the singularities c~ of the distortion energy (the analog of the dissipation fields in the isotropic fluid framework). A direct measurement of f(cO, for different values of the amplitude of the applied electric field, is presented. Furthermore the usual turbulence-turbulence transition is examined and described by means of an enhancement of the intermittency, due to the creation of strongest singularities.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.