The influence of a cylindrical cathode on the electro-vortex flow of liquid metal: Numerical simulations and laboratory experiments

The electro-vortex flow of liquid metal in a cylindrical cell, placed into external vertical magnetic field, in case of axial electric current application is studied numerically and experimentally. The results are compared to those previously obtained in case of a localized electric current application. In the absence of the external magnetic field, the comparison shows no qualitative change in the flow structure. In presence of the external magnetic field, a poloidal motion is suppressed. A critical magnetic field of poloidal suppression is shown to be approximately 50% higher in case of axial electric current application.

An Experimental Investigation on Cooling Performance of Battery Pack by Using Nano-Enhanced Phase Change Material

A rechargeable lithium ion battery has captured prime importance in the modern era due to its cycle life and energy density. In the present study hexagonal shaped 18650 lithium ion cylindrical cell battery pack was designed and fabricated with paraffin wax as a Phase Change Material (PCM). But low thermal conductivity of the PCM causes impediment to the development of Electrical Vehicles (EV’s) which remains as a significant challenge. In the cylindrical cell battery module the maximum temperature is obtained in the mid region which causes uneven temperature distribution among cell. In order to overcome the limitation and to achieve efficient performance of battery module, the nano enhanced Phase Change Material (Ne-PCM) was incorporated in middle four cells by using graphene platelet nano powder (GPN), Multi Walled Carbon Nano Tube (MWCNT) and Graphite Synthetic Powder (GSP). Experiments on the battery module were conducted without any cooling, with PCM cooling and with Ne-PCM cooling. The results revealed that Battery pack with Ne-PCM has shown successful performance by minimizing the temperature below 50 °C in all considered discharge rates i.e., (1C, 2C and 3C) and maintained even temperature distribution among cells.

Effective Cylindrical Cell Decompositions for Restricted Sub-Pfaffian Sets

The o-minimal structure generated by the restricted Pfaffian functions, known as restricted sub-Pfaffian sets, admits a natural measure of complexity in terms of a format ${{\mathcal{F}}}$, recording information like the number of variables and quantifiers involved in the definition of the set, and a degree $D$, recording the degrees of the equations involved. Khovanskii and later Gabrielov and Vorobjov have established many effective estimates for the geometric complexity of sub-Pfaffian sets in terms of these parameters. It is often important in applications that these estimates are polynomial in $D$. Despite much research done in this area, it is still not known whether cell decomposition, the foundational operation of o-minimal geometry, preserves polynomial dependence on $D$. We slightly modify the usual notions of format and degree and prove that with these revised notions, this does in fact hold. As one consequence, we also obtain the first polynomial (in $D$) upper bounds for the sum of Betti numbers of sets defined using quantified formulas in the restricted sub-Pfaffian structure.