Comparative study of hybrid and nanofluid flows amidst two rotating disks with thermal stratification: Statistical and numerical approaches

In the present exploration, our objective is to investigate the importance of Hall current coatings in the establishment of Cattaneo–Christov (CC) heat flux model in an unsteady aqueous-based nanofluid flow comprising single (SWCNTs) and multi-walled (MWCNTs) carbon nanotubes (CNTs) amid two parallel rotating stretchable disks. The novelty of the presented model is strengthened with the presence of homogeneous-heterogeneous (HH) reactions and thermal stratification effects. The numerical solution of the system of coupled differential equations with high nonlinearity is obtained by applying the bvp4c function of MATLAB software. To corroborate the authenticity of the present envisioned mathematical model, a comparison table is added to this study in limiting case. An excellent harmony between the two results is obtained. Effects of numerous parameters on involved distributions are displayed graphically and are argued logically in the light of physical laws. Numerical values of coefficient of drag force and Nusselt number are also tabulated for different parameters. It is observed that tangential velocity (function of rotation parameter) is increasing for both CNTs. Further, the incremental values of thermal stratification parameter cause the decrease in fluid temperature parameter.

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A comparative study of numerical approaches for the computation of effective properties of micro‐heterogeneous materials

PAMM ◽

10.1002/pamm.202000249 ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Rama Assaf ◽

Lisa Scheunemann ◽

Carolin Birk ◽

Jörg Schröder ◽

Ean Tat Ooi

Keyword(s):

Comparative Study ◽

Effective Properties ◽

Heterogeneous Materials ◽

Numerical Approaches

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Thermodynamic Behavior of Spin-1 Heisenberg Chain: a Comparative Study

Journal of Superconductivity and Novel Magnetism ◽

10.1007/s10948-021-06086-4 ◽

2021 ◽

Author(s):

Mona Faridfar ◽

Javad Vahedi

Keyword(s):

Heat Capacity ◽

Magnetic Susceptibility ◽

Low Temperature ◽

Comparative Study ◽

Spin Wave ◽

Wave Theory ◽

Thermodynamic Quantities ◽

Heisenberg Chain ◽

Density Matrix Renormalization ◽

Numerical Approaches

AbstractIn this work, we present a comparative study of thermodynamic quantum equilibrium observables of spin-1 Heisenberg chain. As a theoretical approach, the modified spin-wave theory is chosen. From the numerical side, we consider finite-temperature Lanczos, kernel polynomial, and density matrix renormalization techniques. The results show general consistency of thermodynamic quantities, such as heat capacity and magnetic susceptibility, calculated within the approaches. For the modified spin-wave, the results show some inaccuracy especially at low temperature, failure in capturing the gapped features of spin-1 Heisenberg chain, while the numerical approaches illustrate a good achievement at $$T\rightarrow 0$$ T → 0 within the proper parameters chosen.

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