Selected Papers from the ASME-ATI-UIT 2015 Conference on Thermal Energy Systems: Production, Storage, Utilization, and the Environment

It is our great pleasure and honor to present this special issue of Heat Transfer Engineering to highlight some of the research works presented at the ASME-ATI-UIT 2015 Conference on Thermal Energy Systems: Production, Storage, Utilization, and the Environment that took place on May 17–20, 2015, in Napoli, Italy. The conference was organized under the auspices of the American Society of Mechanical Engineers (ASME), Associazione Termotecnica Italiana (ATI), and Unione Italiana di Termofluidodinamica (UIT). Ten papers included in this special issue were edited by Professor Afshin Ghajar, Editor-in-Chief of Heat Transfer Engineering. The papers report studies of heat transfer related to its enhancement and application to energy systems. The contents open with a paper on experimental measurements in flow boiling heat transfer of low-GWP (Global Warming Potential) refrigerant R1234yf. It is followed by an experimental investigation of volumetric heat transfer coefficient in three-phase direct contact condenser. A study, both experimental and numerical, on dropwise cooling is also presented on studying the cooling effect of two water droplets gently released onto a heated solid surface. Under the framework of passive heat transfer enhancement, a numerical investigation of laminar mixed convection in a two-dimensional, symmetrically, and partially heated vertical channel with nanofluids is provided. Followed by a study that used Ethylene glycol and water (60:40 EG/W mass ratio) as base fluid with SiO2 nanoparticles as nanofluid in order to compute Nusselt number and friction factor for turbulent pipe flow under the heat flux boundary condition. An active method of enhancing cooling of an array of heat sources mounted in a duct was numerically addressed in another paper. The papers on applications in energy systems starts with a numerical analysis of freezing of phase change materials in a thermal energy storage device integrated with a milk storage cooling cycle. Also given is a study on dynamic models for analyzing and evaluating energy storage concepts and interactions with a concentrated solar power system. Moreover, correlations developed from experimental data for predicting dehumidification and thermal performance of a desiccant wheels are presented. They correlate inlet air temperature and humidity ratio, regeneration temperature, air flow rates, and rotational speed. To complete the energy systems topic, a study on two small second-generation compressed air energy storage systems based on a recuperated gas turbine is presented. Special thanks are due to the authors of the papers in this special issue and the reviewers. We extend special thanks to Professor Afshin Ghajar, Editor-in-Chief of Heat Transfer Engineering, who has whole-heartedly supported this conference and the Special Issue. His tireless efforts in assuring high-quality publications are sincerely appreciated.