scholarly journals Nonlinear vortex solution for perturbations in the Earth’s Ionosphere

2019 ◽  
Author(s):  
Miroslava Vukcevic ◽  
Luka Č. Popović

Abstract. There are many observational evidences of different fine structures in the ionosphere and magnetosphere of the Earth. Such structures are created and evolve as a perturbation of the ionosphere’s parameters. Instead of dealing with number of linear waves, we propose to investigate and follow up the perturbations in the ionosphere by dynamics of soliton structure. Apart of the fact that it is more accurate solution, the advantage of soliton solution is its localization in space and time as consequence of balance between nonlinearity and dispersion. The existence of such structure is driven by the properties of the medium. We derive necessary condition for having nonlinear soliton wave, taking the vortex shape, as description of ionosphere parameters perturbation. We employ magnetohydrodynamical description for the ionosphere in plane geometry, including rotational effects, magnetic field effects via ponderomotive force, pressure and gravitational potential effects, treating the problem self-consistently and nonlinearly. In addition, we consider compressible perturbation. As a result, we have obtained that Coriolis force and magnetic force at one side, and pressure and gravity on the other side, determine dispersive properties. Dispersion at higher latitudes is mainly driven by rotation, while near the equator, within the E and F-layer of ionosphere, magnetic field modifies the soliton solution. Also, very general description of the ionosphere results in the conclusion that the unperturbed thickness of the ionosphere layer cannot be taken as ad hoc assumption, it is rather consequence of equilibrium property, which is shown in this calculation.

2020 ◽  
Vol 27 (2) ◽  
pp. 295-306
Author(s):  
Miroslava Vukcevic ◽  
Luka Č. Popović

Abstract. There is much observational evidence of different fine structures in the ionosphere and magnetosphere of the Earth. Such structures are created and evolve as a perturbation of the ionosphere's parameters. Instead of dealing with a number of linear waves, we propose to investigate and follow up the perturbations in the ionosphere by dynamics of soliton structure. Apart from the fact that this is a more accurate solution, the advantage of soliton solution is its localization in space and time as a consequence of the balance between nonlinearity and dispersion. The existence of such a structure is driven by the properties of the medium. We derive the necessary condition for having a nonlinear soliton wave, taking the vortex shape as a description of the ionosphere parameter perturbation. We employ a magnetohydrodynamical description for the ionosphere in plane geometry, including rotational effects, magnetic field effects via ponderomotive force, and pressure and gravitational potential effects, treating the problem self-consistently and nonlinearly. In addition, we consider compressible perturbation. As a result, we have found that Coriolis force and magnetic force on the one hand and pressure and gravity on the other hand determine dispersive properties. Dispersion at higher latitudes is mainly driven by rotation, while near the Equator, within the E and F layers of the ionosphere, the magnetic field modifies the soliton solution. Also, a very general description of the ionosphere results in the conclusion that the unperturbed thickness of the ionosphere layer cannot be taken as an ad hoc assumption: it is rather a consequence of equilibrium property, which is shown in this calculation.


2021 ◽  
Vol 13 (9) ◽  
pp. 5086
Author(s):  
Fatih Selimefendigil ◽  
Hakan F. Oztop ◽  
Ali J. Chamkha

Single and double impinging jets heat transfer of non-Newtonian power law nanofluid on a partly curved surface under the inclined magnetic field effects is analyzed with finite element method. The numerical work is performed for various values of Reynolds number (Re, between 100 and 300), Hartmann number (Ha, between 0 and 10), magnetic field inclination (γ, between 0 and 90), curved wall aspect ratio (AR, between 01. and 1.2), power law index (n, between 0.8 and 1.2), nanoparticle volume fraction (ϕ, between 0 and 0.04) and particle size in nm (dp, between 20 and 80). The amount of rise in average Nusselt (Nu) number with Re number depends upon the power law index while the discrepancy between the Newtonian fluid case becomes higher with higher values of power law indices. As compared to case with n = 1, discrepancy in the average Nu number are obtained as −38% and 71.5% for cases with n = 0.8 and n = 1.2. The magnetic field strength and inclination can be used to control the size and number or vortices. As magnetic field is imposed at the higher strength, the average Nu reduces by about 26.6% and 7.5% for single and double jets with n greater than 1 while it increases by about 4.78% and 12.58% with n less than 1. The inclination of magnetic field also plays an important role on the amount of enhancement in the average Nu number for different n values. The aspect ratio of the curved wall affects the flow field slightly while the average Nu variation becomes 5%. Average Nu number increases with higher solid particle volume fraction and with smaller particle size. At the highest particle size, it is increased by about 14%. There is 7% variation in the average Nu number when cases with lowest and highest particle size are compared. Finally, convective heat transfer performance modeling with four inputs and one output is successfully obtained by using Adaptive Neuro-Fuzzy Interface System (ANFIS) which provides fast and accurate prediction results.


2020 ◽  
Vol 102 (7) ◽  
Author(s):  
H. C. Wu ◽  
D. J. Hsieh ◽  
T. W. Yen ◽  
P. J. Sun ◽  
D. Chandrasekhar Kakarla ◽  
...  

2019 ◽  
Vol 151 (24) ◽  
pp. 244308 ◽  
Author(s):  
David Mims ◽  
Alexander Schmiedel ◽  
Marco Holzapfel ◽  
Nikita N. Lukzen ◽  
Christoph Lambert ◽  
...  

2014 ◽  
Vol 29 (20) ◽  
pp. 1450094 ◽  
Author(s):  
Ya-Bo Wu ◽  
Jun-Wang Lu ◽  
Yong-Yi Jin ◽  
Jian-Bo Lu ◽  
Xue Zhang ◽  
...  

In the probe limit, we study the holographic p-wave phase transition in the Gauss–Bonnet gravity via numerical and analytical methods. Concretely, we study the influences of the external magnetic field on the Maxwell complex vector model in the five-dimensional Gauss–Bonnet–AdS black hole and soliton backgrounds, respectively. For the two backgrounds, the results show that the magnetic field enhances the superconductor phase transition in the case of the lowest Landau level, while the increasing Gauss–Bonnet parameter always hinders the vector condensate. Moreover, the Maxwell complex vector model is a generalization of the SU(2) Yang–Mills model all the time. In addition, the analytical results backup the numerical results. Furthermore, this model might provide a holographic realization for the QCD vacuum instability.


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