Impact of Micro-Scale Stochastic Zonal Flows on the Macro-Scale Visco-Resistive Magnetohydrodynamic Modes
A model is developed to simulate micro-scale turbulence driven Zonal Flows (ZFs), and their impact on the Magnetohydrodynamic (MHD) tearing and kink modes is examined. The model is based on a stochastic representation of the micro-scale ZFs with a given Alfvén Mach number, <i>M<sub...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-03-01
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| Series: | Mathematics |
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| Online Access: | https://www.mdpi.com/2227-7390/8/3/443 |
| _version_ | 1819128505134219264 |
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| author | Sara Moradi Anantanarayanan Thyagaraja |
| author_facet | Sara Moradi Anantanarayanan Thyagaraja |
| author_sort | Sara Moradi |
| collection | DOAJ |
| description | A model is developed to simulate micro-scale turbulence driven Zonal Flows (ZFs), and their impact on the Magnetohydrodynamic (MHD) tearing and kink modes is examined. The model is based on a stochastic representation of the micro-scale ZFs with a given Alfvén Mach number, <i>M<sub>S</sub></i>. Two approaches were explored: (i) passive stochastic model where the ZFs amplitudes are independent of the MHD mode amplitude, and (ii) the semi-stochastic model where the amplitudes of the ZFs have a dependence on the amplitude of the MHD mode itself. The results show that the stochastic ZFs can significantly stabilise the (2,1) and (1,1) MHD modes even at very low kinematic viscosity, where the mode is linearly unstable. Our results therefore indicate a possible mechanism for stabilisation of the MHD modes via small-scale perturbations in poloidal flow, simulating the turbulence driven ZFs. |
| first_indexed | 2024-12-22T08:28:53Z |
| format | Article |
| id | doaj.art-9d21f7f59a0c4b01a8dc131f24a8856f |
| institution | Directory Open Access Journal |
| issn | 2227-7390 |
| language | English |
| last_indexed | 2024-12-22T08:28:53Z |
| publishDate | 2020-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Mathematics |
| spelling | doaj.art-9d21f7f59a0c4b01a8dc131f24a8856f2022-12-21T18:32:33ZengMDPI AGMathematics2227-73902020-03-018344310.3390/math8030443math8030443Impact of Micro-Scale Stochastic Zonal Flows on the Macro-Scale Visco-Resistive Magnetohydrodynamic ModesSara Moradi0Anantanarayanan Thyagaraja1Laboratory for Plasma Physics - LPP-ERM/KMS, Royal Military Academy, 1000 Brussels, BelgiumAstrophysics Group, Department of Physics, University of Bristol, Bristol BS8 1TL, UKA model is developed to simulate micro-scale turbulence driven Zonal Flows (ZFs), and their impact on the Magnetohydrodynamic (MHD) tearing and kink modes is examined. The model is based on a stochastic representation of the micro-scale ZFs with a given Alfvén Mach number, <i>M<sub>S</sub></i>. Two approaches were explored: (i) passive stochastic model where the ZFs amplitudes are independent of the MHD mode amplitude, and (ii) the semi-stochastic model where the amplitudes of the ZFs have a dependence on the amplitude of the MHD mode itself. The results show that the stochastic ZFs can significantly stabilise the (2,1) and (1,1) MHD modes even at very low kinematic viscosity, where the mode is linearly unstable. Our results therefore indicate a possible mechanism for stabilisation of the MHD modes via small-scale perturbations in poloidal flow, simulating the turbulence driven ZFs.https://www.mdpi.com/2227-7390/8/3/443turbulencemhdplasma |
| spellingShingle | Sara Moradi Anantanarayanan Thyagaraja Impact of Micro-Scale Stochastic Zonal Flows on the Macro-Scale Visco-Resistive Magnetohydrodynamic Modes Mathematics turbulence mhd plasma |
| title | Impact of Micro-Scale Stochastic Zonal Flows on the Macro-Scale Visco-Resistive Magnetohydrodynamic Modes |
| title_full | Impact of Micro-Scale Stochastic Zonal Flows on the Macro-Scale Visco-Resistive Magnetohydrodynamic Modes |
| title_fullStr | Impact of Micro-Scale Stochastic Zonal Flows on the Macro-Scale Visco-Resistive Magnetohydrodynamic Modes |
| title_full_unstemmed | Impact of Micro-Scale Stochastic Zonal Flows on the Macro-Scale Visco-Resistive Magnetohydrodynamic Modes |
| title_short | Impact of Micro-Scale Stochastic Zonal Flows on the Macro-Scale Visco-Resistive Magnetohydrodynamic Modes |
| title_sort | impact of micro scale stochastic zonal flows on the macro scale visco resistive magnetohydrodynamic modes |
| topic | turbulence mhd plasma |
| url | https://www.mdpi.com/2227-7390/8/3/443 |
| work_keys_str_mv | AT saramoradi impactofmicroscalestochasticzonalflowsonthemacroscaleviscoresistivemagnetohydrodynamicmodes AT anantanarayananthyagaraja impactofmicroscalestochasticzonalflowsonthemacroscaleviscoresistivemagnetohydrodynamicmodes |