An approximation model based on convolutional neural networks (CNNs) is proposed for flow field predictions. The CNN is used to predict the velocity and pressure field in unseen flow conditions and geometries given the pixelated shape of the object. In particular, we consider Reynolds Averaged Navier-Stokes (RANS) flow solutions over airfoil shapes. The CNN can automatically detect essential features with minimal human supervision and shown to effectively estimate the velocity and pressure field orders of magnitude faster than the RANS solver, making it possible to study the impact of the airfoil shape and operating conditions on the aerodynamic forces and the flow field in near-real time. The use of specific convolution operations, parameter sharing, and robustness to noise are shown to enhance the predictive capabilities of CNN. We explore the network architecture and its effectiveness in predicting the flow field for different airfoil shapes, angles of attack, and Reynolds numbers.

This review summarizes the use of ionic liquids in Na secondary batteries and discusses their electrochemical performance with various electrode materials.

Sustainable zinc–air batteries are considered promising energy storage devices owing to their inherent safety, high energy density, wide operating temperature window, environmental friendliness, etc., showing great prospect for future applications.

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A copper phosphide/carbon (CuP2/C) composite was synthesized by using a two‐step ball‐milling process from copper metal and red phosphorous and investigated as a negative electrode for a sodium secondary battery using Na[FSA]−[C3C1pyrr][FSA] [FSA=bis(fluorosulfonyl)amide anion and C3C1pyrr=N‐methyl‐N‐propylpyrrolidinium cation] ionic liquid as the electrolyte. Operation at an intermediate temperature of 363 K revealed that the aforementioned composite showed a large reversible capacity of 595 mAh g−1 at 100 mA g−1 and a high rate capability with a capacity retention of 65 % (366 mAh g−1) at a high current density of 8000 mA g−1. Cyclability tests confirmed that 71.0 % of the initial capacity was retained at the 200th cycle with 99.5 % coulombic efficiency at 500 mA g−1. The CuP2/C composite forms a solid‐electrolyte interphase layer during the initial charging step and becomes amorphous after the initial charge‐discharge cycle at 363 K.

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The Li-ion battery operation life is strongly dependent on the operating temperature and the temperature variation that occurs within each individual cell. Liquid-cooling is very effective in removing substantial amounts of heat with relatively low flow rates. On the other hand, air-cooling is simpler, lighter, and easier to maintain. However, for achieving similar cooling performance, a much higher volumetric air flow rate is required due to its lower heat capacity. This paper describes the fundamental differences between air-cooling and liquid-cooling applications in terms of basic flow and heat transfer parameters for Li-ion battery packs in terms of QITD (inlet temperature difference). For air-cooling concepts with high QITD, one must focus on heat transfer devices with relatively high heat transfer coefficients (100–150 W/m2/K) at air flow rates of 300–400 m3/h, low flow induced noise, and low-pressure drops. This can be achieved by using turbulators, such as delta winglets. The results show that the design concepts based on delta winglets can achieve QITD of greater than 150 W/K.