Amplification of magnetic field due to kinematic turbulent dynamo action is studied in the regime of small magnetic Prandtl numbers. Such a regime is relevant for planets and stars interiors, as well as for liquid-metal laboratory experiments. A comprehensive analysis based on the Kazantsev-Kraichnan model is reported, which establishes the dynamo threshold and the dynamo growth rates for varying kinetic helicity of turbulent fluctuations. It is proposed that in contrast with the case of large magnetic Prandtl numbers, the kinematic dynamo action at small magnetic Prandtl numbers is significantly affected by kinetic helicity, and it can be made quite efficient with an appropriate choice of the helicity spectrum.
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http://dx.doi.org/10.1103/PhysRevLett.105.215002 | DOI Listing |
Phys Rev E
November 2024
Landau Institute for Theoretical Physics, Russian Academy of Sciences, 1-A Akademika Semenova av., 142432 Chernogolovka, Russia and National Research University Higher School of Economics, Faculty of Physics, Myasnitskaya 20, 101000 Moscow, Russia.
We study one-point statistics of helical turbulent pulsations in the background of a three-dimensional large-scale vortex in a rotating fluid. Assuming that the helical flow is created by a statistically axially symmetric random force with broken mirror symmetry, we analytically calculate the velocity-vorticity mean including its magnitude and the anisotropy. For electrically conducting liquid, we examine the α-effect in the system.
View Article and Find Full Text PDFHeliyon
May 2024
Department of Mathematics, Vellore Institute of Technology, Vellore, 632014, India.
Magnetohydrodynamic (MHD) flows have several applications in a wide area of engineering such as industrialized processes, including generating MHD electrical power, processing of magnetic materials, etc. The present examination focuses on incorporating the induced magnetic field (IMF) and multiple slips on the convective MHD Casson nanofluid flow over an elongating sheet with Brownian motion and thermophoresis effects. Heat source/sink, non-linear radiation, and suction/injection impacts are added to strengthen the study.
View Article and Find Full Text PDFHeliyon
October 2024
Industrial Engineering Department, College of Engineering, King Saud University, Riyadh 11421, Saudi Arabia.
Motivation And Objectives: The basic aim of this investigation is to explore the energy transfer impact on Eyring-Prandtl fluid, a topic that has not been previously examined, thereby paving the way for future researchers. The present literature is crucial for advancing thermal management in engineering applications. This study aims to numerically investigate the thermophoretic effects and Brownian motion of non-Newtonian nanofluid relying on Eyring-Prandtl fluid model across the stretching sheet.
View Article and Find Full Text PDFHeliyon
September 2024
IT4Innovations, VSB - Technical University of Ostrava, Ostrava, Czech Republic.
Stratified flows are commonly observed in numerous industrial processes. For example, a gas-condensate pipeline typically uses a stratified flow regime. However, this flow arrangement is stable only under a specific set of operating conditions that allows the formation of stratification.
View Article and Find Full Text PDFSci Rep
August 2024
Department of Information System, College of Computer and Information Sciences, Majmaah University, 11952, Al-Majmaah, Saudi Arabia.
The focus of present study is to incorporate the variable viscosity and temperature slip impact on heating rate and induced magnetic gradient along the moving non-conducting wedge under magnetic field. In industrial and engineering procedures, the impact of induced magnetization improves the efficiency of thermal systems to main the heating rates. The similarity transformations and stream functions are applied to reduce the governing equations into ordinary form.
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