It is well known that several viruses, as well as SARS-CoV-2, can be transmitted through airborne diffusion of saliva micro-droplets. For this reason, many research groups have devoted their efforts in order to gain new insight into the transport of fluids and particles originated from human respiratory tracts. This paper aims to provide a contribution to the numerical modeling of saliva droplets' diffusion produced by coughing. It is worth noting that droplets' diameters of interest in this work are such that represent typical emission during a cough. Aerosolization effects are neglected since emitted droplets' diameters are greater than 10 µ m. In particular, the well-known problem around the safety distance to be held for avoiding virus transmission in the absence of external wind is further investigated. Thus, new indices capable of evaluating the contamination risk are introduced, and the possibility to inactivate virus particles by means of an external ultraviolet-C (UV-C) radiation source is studied. For this purpose, a new model which takes into account biological inactivation deriving from UV-C exposure in an Eulerian–Lagrangian framework is presented.

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The aim of this work is to test a battery thermal management system by direct immersion of a commercial 18650 LiFePO4 cell in a low boiling dielectric liquid. It is worth noting that for electric mobility applications, thermal management of Lithium-Ion batteries is a fundamental issue because batteries experience high discharge currents and temperatures. First, we present an electrical characterization of the Lithium-Ion by measuring cell potential, open circuit potential and entropic heat coefficient. Temperature measurements were carried out with thermocouples and infrared thermography. A simplified heat generation term was evaluated using the experimental data. Then, the same battery was immersed in a dielectric low boiling liquid and tested under three different discharge currents. For comparison, also the case without dielectric liquid was analyzed. This paper demonstrates the feasibility of a thermal management system based on direct immersion of a battery cell in a low boiling dielectric fluid. Indeed, the results show a substantial decrease of battery temperature when immersed.

The aim of the present work is to develop and test an innovative cooling system for the thermal management of batteries for electric vehicles (EVs). At present, the technology most used for electric propulsion is based on lithium-ion cells. The power supply unit must often deliver a large amount of power in a short time, forcing the batteries to produce a considerable amount of heat. This leads to a high working temperature that can cause a sharp decrease in the battery performance or even a malfunction. Moreover, their working outside of the prescribed temperature range (20–40 °C) or with a significant temperature gradient across the battery meaningfully accelerates their aging or breakage. In this case, a battery thermal management system (BTMS) is necessary to allow the batteries to work as efficiently as possible. In the present work, a pulsating heat pipe with a three-dimensional structure is proposed as cooling technology for a battery pack. At first the performance of the proposed PHP is evaluated in a dedicated experimental setup under different boundary conditions and a wide spectrum of power input values. Then the PHP is tested by applying, as load at the evaporator section, heat power distribution corresponding to three different discharging processes of a battery. These tests, directly referring to an applicative case, show that the proposed 3D PHP has an optimal cooling ability and the possibility to offer a powerful solution for electrical battery thermal management.

In this paper a novel battery thermal management system was experimentally studied. The batteries are submerged in a low boiling dielectric fluid with the aim to reduce the batteries surface temperature when subjected to high charge or discharge currents. The fluid change of phase allows to create a thermal buffer in case of instantaneous peak of absorbed current. This innovative system was studied on a battery pack composed of 3 cells in series and 3 cells in parallel connection for several discharge currents. For the sake of comparison, two battery packs of same dimensions were investigated: one submerged in the dielectric fluid and the second without the fluid. The cells potential and surface temperature were measured during discharges. Moreover, also the fluid temperature was evaluated in the external region. The results show a significant improvement of the thermal management since the increase of temperature is very restricted. This effect is even more evident when the fluid reaches the boiling point.