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In recent years, electric vehicles (EVs) have grown in popularity as a viable way to reduce greenhouse gas emissions by replacing conventional vehicles. The need for EV batteries is steadily increasing. An essential and expensive part of electric transportation is the battery. The operating temperature of the lithium-ion (Li-ion) battery significantly impacts the performance of the EV battery pack. Battery packs undergo temperature fluctuations during the charging and discharging procedures due to internal heat generation, necessitating an examination of the temperature distribution of the battery pack. The geometrical spacing between cells is considered larger and identical and is kept open on two sides for free air circulation. A novel battery thermal management system (BTMS) design is required to effectively dissipate heat from the prismatic battery pack module. The electro-thermal behaviour of the prismatic Li-ion battery pack module was investigated based on the high charge/discharge rate. This study presents the development of a three-dimensional free open-source OpenFOAM computational fluid dynamics model for prismatic cell battery packs that simulates heat generation, air flow field, and temperature distribution across the width and depth of the battery pack module. The prismatic battery pack simulation results are compared with the experimental and simulation results of the cylindrical battery pack. It was also revealed that prismatic cells generate more heat on the backside, requiring battery packs to have increased cooling and space between individual cells to ensure sufficient air circulation for cooling and gas removal. The BTMS is improved by designing with increased space among the prismatic battery cells as compared with the conventional prismatic cell battery pack design.

A viscoelastic turbulence model in a fully-developed drag reducing channel flow is improved, with turbulent eddies modelled under a k – ε representation, along with polymeric solutions described by the finitely extensible nonlinear elastic-Peterlin (FENE-P) constitutive model. The model performance is evaluated against a wide variety of direct numerical simulation data, described by different combinations of rheological parameters, which is able to predict all drag reduction (low, intermediate and high) regimes with good accuracy. Three main contributions are proposed: one with a simplified viscoelastic closure for the N L T i j term (which accounts for the interactions between the fluctuating components of the conformation tensor and the velocity gradient tensor), by removing additional damping functions and reducing complexity compared with previous models; second through a reformulation for the closure of the viscoelastic destruction term, E τ p , which removes all friction velocity dependence; lastly by an improved modified damping function capable of predicting the reduction in the eddy viscosity and thus accurately capturing the turbulent kinetic energy throughout the channel. The main advantage is the capacity to predict all flow fields for low, intermediate and high friction Reynolds numbers, up to high drag reduction without friction velocity dependence. [ABSTRACT FROM AUTHOR]

A viscoelastic turbulence model in a fully-developed drag reducing channel flow is improved, with turbulent eddies modelled under a k–ε representation, along with polymeric solutions described by the finitely extensible nonlinear elastic-Peterlin (FENE-P) constitutive model. The model performance is evaluated against a wide variety of direct numerical simulation data, described by different combinations of rheological parameters, which is able to predict all drag reduction (low, intermediate and high) regimes with good accuracy. Three main contributions are proposed: one with a simplified viscoelastic closure for the NLTij term (which accounts for the interactions between the fluctuating components of the conformation tensor and the velocity gradient tensor), by removing additional damping functions and reducing complexity compared with previous models; second through a reformulation for the closure of the viscoelastic destruction term, Eτp, which removes all friction velocity dependence; lastly by an improved modified damping function capable of predicting the reduction in the eddy viscosity and thus accurately capturing the turbulent kinetic energy throughout the channel. The main advantage is the capacity to predict all flow fields for low, intermediate and high friction Reynolds numbers, up to high drag reduction without friction velocity dependence.

In industrial applications handling potentially explosive mixtures, bends with various bending angles are often incorporated into pipes to achieve a change of process flow direction. However, the effect of pipe bending angle on pressure piling—a major explosion hazard in interconnected vessels—has been sparsely studied for dust explosions. In this study, the effect of pipe bending angle on pressure piling in coal dust explosion in fully enclosed interconnected vessels was studied using computational fluid dynamics (CFD) modelling. The pipe bending angle was varied from 0° to 165°. The angle convention used in this study was such that 0° represents a straight pipe, while 165° represents the most "acute" angle used, with the pipe almost forming a U-tube at 165°. The experimental work of Lunn et al. (1996) was used to validate the simulation results. Three major effects of pipe bends on pressure piling are reported in this study: the effect on the instantaneous pressure spike; the effect on the rate of pressure rise; and the effect on the residual pressure in the interconnected system. Simulation results show that the highest severity of pressure spike and rate of pressure rise occurred in the straight pipe system, whereas the most severe case of residual pressure occurred in the curved pipe systems. As the bending angle increased, the residual pressure increased. The combination of two 45° bends used instead of a single 90° bend reduced the severity of pressure piling. These findings have practical implications for industrial applications, such as the choice of pipe bending angles and multiple bends. [ABSTRACT FROM AUTHOR]

An improved k - ω turbulence model for viscoelastic fluids is developed to predict turbulent flows, with polymeric solutions described by the finitely extensible nonlinear elastic-Peterlin constitutive model. The k - ω model is tested against a wide range of direct numerical simulation data in fully-developed channel flow, with different rheological parameter combinations, and can predict all regimes of drag reduction (low, intermediate and high) with good performance. Closures are improved for the NLT ij term, which captures the polymer extension due to turbulent fluctuations; a modified damping function, f μ , which accounts for the turbulent kinetic energy redistribution process; and the viscoelastic destruction term, E τ p . The main advantage of the current model is its ability to predict all flow features with model simplicity and without the need for friction velocity dependence, important for flows with reattachment due to their singularity caused by the stagnation points. [ABSTRACT FROM AUTHOR]