DNS of turbulent flows with intermittency formed in a spherical layer with modulated velocity of rotation of the outer spherical boundary

Gritsevich

2018

J. Phys.: Conf. Ser.

Abstr act. Turbulent flows of a viscous incompressible fluid in a layer between rotating concentric spheres under the action of the modulation of the velocity of one of the spheres have been studied experimentally and numerically. The form of spectra of turbulent pulsations of the azimuthal velocity depends on the sphere whose rotational velocity is modulated, as well as on the amplitude and frequency of modulation. The possibility of the formation of turbulence with spectra qualitatively similar to spectra obtained in measurements in the upper atmosphere is established: with the slope close to -3 at low frequencies and close to -5/3 at high frequencies and with the negative longitudinal velocity structure function of the third order. It has been shown that such spectra are formed in the regions of a flow that are strongly synchronized under the action of the modulation of the rotational velocity.

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Section: Methods Of Calculationmentioning

confidence: 99%

“…The sensitivity of the results to the parameters of grid was analyzed in detail in [13], [19]. This algorithm was used for calculations with both stationary [11] and periodic [19] boundary conditions. Agreement was shown to be between the experimental and calculated results, including the integral properties of turbulent flows.…”

Section: Methods Of Calculationmentioning

confidence: 99%

The Different Types of Turbulence in Rotating Spherical Layers

Gritsevich

2018

J. Phys.: Conf. Ser.

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“…Dr. Dmitry Zhilenko, E=mail: jilenko@imec.msu.ru different turbulence intensity was shown for PCF and CCF. In SCF only temporal alternating of laminar and chaotic states was found -each state occupies the whole gap [6,7].…”

mentioning

confidence: 99%

Experimental observation of chaos-chaos intermittency types in spherical Couette flow

2014

Dokl. Phys.

Transitional processes to turbulence often are accompanied by intermittency in the form of laminar and turbulent bands, alternating in space and/or time. Intermittency was observed in transitional flows in tubes [1] and in flows, induced by the motion of the walls in opposite directions. Well-known cases of such flows are the plane Couette flow (PCF) -between flat boundaries [2,3], circular (CCF) -between rotating coaxial cylinders [4,5] and spherical [6,7] (SCF) -between coaxial rotating spheres. The possibility of coexistence in the spatial/temporal structure of distinct bands with Flows between concentric, counter rotating spherical boundaries are under investigation in the gap with size equal to inner sphere radius. Outer sphere rotational rate is fixed, while inner sphere rotational rate has time periodic variations. The

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Quasi-two-dimensional and three-dimensional turbulence in rotational spherical liquid layers

2015

Jetp Lett.