Micro/Nanotransport Phenomena in Renewable Energy and Energy Efficiency

This article introduces a series of papers presented in a special issue entitled: “Micro/Nanotransport Phenomena in Renewable Energy and Energy Efficiency.” The papers in this issue address some of the basic aspects of renewable energy harvest/conversion, emission control, and optimization of energy. The first article describes a new method based on Femtosecond laser that can be used to fabricate high-quality metallic light absorbers. These artificially made surfaces can be used to improve the energy conversion efficiency such as thermophotovoltaics and solar energy absorbers. Articles on fuel cells cover the experimental and numerical study of cold startup of Proton Exchange Membrane (PEM) fuel cell, development of a continuum model for water transport in the Ionomer-phase of catalyst-coated membranes for PEM, and mesoscopic modeling based on the lattice Boltzmann method for water management in fuel cells. In the area of emission control, the next article discuss the use of nanosized cerium oxide particles as additives on biodiesel, reporting that these additives can appreciably reduce the emission levels of hydrocarbon and NOx through enhancing hydrocarbon oxidation and promoting complete combustion. Another article found that mesoscopic modeling of multiphysicochemical transport phenomena in porous media based on the lattice Boltzmann method (LBM) is especially effective to model the dissolving process of supercritical CO2 into geologic formations such as limestone rock. This may provide a comprehensive numerical tool to simulate the long-term fate of CO2 after injection into the geologic formations. Additional articles discuss thermal management and its role in solar technology, the use of flat-plate oscillating heat pipes for cooling photovoltaic cells with high concentration ratios, the use of nanoparticles to improve the convective heat transfer at high Reynolds number, the optimization of energy in the end use, and the “field synergy principle” as an effective tool to optimize the energy and mass flow in energy systems.