No abstract

Phase change materials (PCMs) can enhance the performance of energy systems by time shifting or reducing peak thermal loads. The effectiveness of a PCM is defined by its energy and power density-the total available storage capacity (kWh m −3 ) and how fast it can be accessed (kW m −3 ). These are influenced by both material properties as well as geometry of the energy systems; however, prior efforts have primarily focused on improving material properties, namely, maximizing latent heat of fusion and increasing thermal conductivity. The latter is often at the expense of the former. Advanced manufacturing techniques hold tremendous potential to enable co-optimization of material properties and device geometry, while potentially reducing material waste and manufacturing time. There is an emerging body of research focused on additive manufacturing of PCM composites and devices for thermal energy storage (TES) and thermal management. In this article, the fundamentals and applications of PCMs are reviewed and recent additive manufacturing advances in latent heat TES for both the PCM composite and associated heat exchanger are discussed. A forward-looking perspective on the future and potential of PCM additive manufacturing for TES and thermal management is provided.

Accurate modeling of melting and solidification processes is important to many engineering applications. The research presented in this article is part of an ongoing effort to document the melting behavior of lauric acid in a 50 mm by 120 mm rectangular container with an isothermal side—an experiment commonly used to validate numerical models. This article presents new experimental data of melting occurring at 135 deg and 180 deg inclines for isothermal wall temperatures of 60∘C and 70∘C. The data were processed to show the melt interface development and the melt fraction as a function of time. Furthermore, numerical simulations using the enthalpy-porosity method of the 135 deg incline were also conducted. In the numerical simulations, the mushy zone constant was parametrically varied. Different density approaches commonly found in the literature (e.g., density as a function of temperature or Boussinesq approximation) were utilized and examined. It was found that the choice of density method had a significant effect on the results. Implications of potential modeling choices unique to the enthalpy-porosity method are discussed related to the validation of models.

Phase change materials (PCMs) are a key component to thermal energy storage solutions, which have the potential to hold a critical role in future energy storage. PCMs take advantage of large latent heat capacities as a method for storing thermal energy for later use. The research presented in this paper is part of an ongoing effort to document the melt behavior of lauric acid in an insulated rectangular container. This paper presents new experimental data of melting occurring at 180° and 135° incline. The data is processed to show the melt interface development and the melt fraction over the duration of the experiment. The results of the 135° incline experiment are compared to a numerical model and differences in results are examined.