arXiv subjects

Anupam Saha

Publications and source records attributed to Anupam Saha.

4 recordsLinked to original sources

arXiv2022

Characteristics of a Nickel Vanadium redox flow battery Based on COMSOL

The overpotential, dissociation rate, electrode potential distributions and current density are suggested in this study to analyze the Nickel Vanadium Redox Flow Battery (NVRFB). Due to its large capacity and ecofriendly properties, NVRFB may be a viable option in the present state of energy constraint and environmental pollution. Due to their low cost and high energy density, nickel-based flow batteries have gained popularity. This study demonstrates that the Ni2+/Ni+ and V5+/V4+ ions have a higher rate of dissociation at the membrane and a lower rate at the inlet, where the electrolyte flow velocity is greater; Because the membrane undergoes more oxidation-reduction reactions, the electrolyte flow rate is critical in the redox flow cell; Additionally, we see that when electrode thickness is reduced, current density and electrode potential increase while overpotential decreases; the model's equations are solved using the finite-element method in the COMSOL Multiphysics program. An electrolyte-electrode interface connection is used to simulate the reaction. The dissociation rate indicates that the oxidation-reduction process happens at a lower membrane potential. Improving the electrolyte flow rate enhances battery performance. Compression of the electrodes enhances conductivity and battery performance.

cond-mat.mtrl-sci↗

arXiv2022

Modeling of 3D Printable Electrical Machineries Ferromagnetic Parts

The electrical machinery core is formed with a ferromagnetic material that offers high magnetic properties. As ferromagnetic materials have high relative magnetic permeability, they are important in the formation of electromagnetic device cores. Conventional subtractive and powder metallurgy methods for fabrication electrical machineries offer significant core losses and reduce magnetic flux density and magnetic permeability. With the advancement of technology, the limitation of the traditional process can be overcome by using the additive manufacturing process. Hence, this paper proposes a 3D printable model of two types of single-phase transformers, referred to as E-I shape and U-I shape transformers respectively. Possibilities of designing the electrical machinery part which has a ferromagnetic core are investigated. The efficiency of the transformers is evaluated in terms of magnetic flux density distribution and volumetric loss density based on the results of a large number of Finite element simulation methods under various operating situations on COMSOL. The performance of various ferromagnetic materials such as Soft Iron (Fe) and Ferrite (Fe2O3) on the transformer core is evaluated. This analysis reveals that if U-I shaped transformer can be made from 3D printing, it will be the best feasible structure for higher operating frequency.

physics.app-ph↗

arXiv2022

Characteristics of a Titanium Manganese redox flow battery based on Comsol

A simulation model and design of Titanium Manganese Redox Flow Battery (TMRFB) is proposed to study the distribution of dissociation rate, overpotential, current density, and electrode potential. TMRFB is one of the most promising new energy storages because of its high capacity and eco-friendly characteristics in the current condition of energy scarcity and environmental pollution. Moreover, Mn-based flow batteries are gaining popularity due to their inexpensive cost and high energy density in lieu of all vanadium redox flow batteries which are expensive. This research shows that the surface dissociation rate of Ti4+/ Ti3+ and Mn3+/Mn2+ ions are higher at the membrane and lower at the inlet where the velocity of the electrolyte flow is higher; Furthermore, our work reveals that when the thickness of the electrode is compressed from 4.5 mm to 3 mm, overpotential reduces whereas current density and electrode potential increases. The COMSOL Multiphysics software is used to solve the model's equations using the finite element approach. From the dissociation rate it is concluded that less potential is required at the membrane for the oxidation reduction reaction and with optimized electrolyte flow rate battery performance can be improved. Thus, electrode compression increases conductivity and battery performance.

cond-mat.mtrl-sci↗

arXiv2021

Fermi Level Fluctuations, Reduced Effective Masses and Zeeman Effect during Quantum Oscillations in Nodal Line Semimetals

We probe quantum oscillations in nodal line semimetals (NLSM) by considering a NLSM continuum model under strong magnetic field and report the characteristics of the Landau level spectra and the fluctuations in the Fermi level as the field in a direction perpendicular to the nodal plane is varied through. Based on the results on parallel magnetization, we demonstrate the growth of quantum oscillation with field strength as well as its constancy in period when plotted against 1/B. We find that the density of states which show series of peaks in succession, witness bifurcation of those peaks due to Zeeman effect. For field normal to nodal plane, such bifurcations are discernible only if the electron effective mass is considerably smaller than its free value, which usually happens in these systems. Though a reduced effective mass $m^*$ causes the Zeeman splitting to become small compared to Landau level spacing, experimental results indicate a manyfold increase in the Lande $g$ factor which again amplifies the Zeeman contribution. We also consider magnetic field in the nodal plane for which the density of state peaks do not repeat periodically with energy anymore. The spectra become more spread out and the Zeeman splittings become less prominent. We find the low energy topological regime, that appears with such in-plane field set up, to shrink further with reduced $m^*$ values. However, such topological regime can be stretched out in case there are smaller Fermi velocities for electrons in the direction normal to the nodal plane.

cond-mat.str-el↗