Progress in technology and industrial developments demands the efficient and successful energy utilization and its management in a greater extent. Conventional heattransfer fluids (HTFs) such as water, ethylene glycol, oils and other fluids are typically low-efficiency heat dissipation fluids. Thermal management is a key factor in diverse applications where these fluids can be used, such as in automotive, microelectronics, energy storage, medical, and nuclear cooling among others. Furthermore, the miniaturization and high efficiency of devices in these fields demand successful heat management and energy-efficient materials. The advent of nanofluids could successfully address the low thermal efficiency of HTFs since nanofluids have shown many interesting properties, and the distinctive features offering extraordinary potential for many applications. Nanofluids are engineered by homogeneously suspending nanostructures with average sizes below 100 nm within conventional fluids. This chapter aims to focus on a detail description of the thermal transport behavior, challenges and implications that involve the development and use of HTFs under the influence of atomistic-scale structures and industrial applications. Multifunctional characteristics of these nanofluids, nanostructures variables and features are discussed in this chapter; the mechanisms that promote these effects on the improvement of nanofluids thermal transport performance and the broad range of current and future applications will be included.

Purpose The purpose of this paper is to evaluate the effects of microcavities, diameter and depth, in tribological performance, of the application of laser surface texturing (LST) and LST gradient (LSTG) techniques, to understand and define the critical parameters of these techniques in sheet-metal forming tools. Design/methodology/approach The paper studies the effect of studied critical parameters of LST and LSTG techniques, on block-on-ring configuration for tribology evaluation. Experimental design parameters for LST and LSTG are proposed and evaluated for the best tribology performance (COF and wear). Findings The results show that the application of optimized LST process could represent a 42 per cent improvement on the COF and up to 86 per cent enhancement in the COF results for the LSTG application. Practical implications The results show that LST and LSTG techniques present significant positive effects on the tribological properties of sheet-metal forming materials. Originality/value This demonstrates the potential of LST technique applied to industrial tooling, and the LSTG pattern which further increases the benefits obtained with the LST technique, particularly in which friction and wear areas are critical. A response surface map is developed to determine the control parameters which are useful for the tooling design. These techniques could be used for metal-forming applications like deep-drawing, achieving an increased tool life.

Nanofluids have been recently studied for efficient and high impact dielectric and tribological fluids, which possess superb thermal transport properties, compared to conventional fluids or lubricants. The present research theoretically analyzes, through Molecular Dynamic (MD) simulations, the physical performance of hexagonal boron nitride (h-BN) nanosheets reinforced mineral oil (MO). This analysis leads to the prediction of nanofluids performance, utilizing the Lennard-Jones potential. The computational results of viscosity performance are benchmarked at various temperature levels and nanofiller concentrations. The theoretical results indicate that the simulations presented can predict the behavior of nanoreinforced fluids.Keywords: molecular dynamics, nanofluids, hexagonal boron nitride, viscosity. ResumenLos nanofluidos recientemente se han estudiado para fluidos dieléctricos y tribológicos eficientes y de alto impacto, los cuales poseen excelentes propiedades de transporte térmico, comparado con fluidos o lubricantes convencionales. La presente investi-gación analiza teóricamente, a través de simulaciones de Dinámica Molecular (MD), el desempeño físico de aceite mineral (MO) reforzado con nanohojuelas de nitruro de boro hexagonal (h-BN). Este análisis permite la predicción del desempeño de los nanofluidos, utilizando el potencial Lennard-Jones. Los resultados computacionales del desempeño en viscosidad se han referenciado en varios niveles de temperatura y concentraciones de los nanofluidos. Los resultados teóricos indican que las simulaciones presentadas pueden predecir el comportamiento de los fluidos nano-reforzados.Descriptores: dinámica molecular; nanofluidos; nitruro de boro hexagonal; viscosidad.Theoretical Prediction of Physical Properties (Viscosity) on 2D-based Nanofluids Predicción teórica de las propiedades físicas (viscosidad) en nanofluidos 2D