Phase change materials (PCMs) have the ability to increase the efficiency of energy-intensive applications, through absorbing a significant amount of latent heat during phase change. More specifically, composite PCM’s, consisting of an organic PCMs (e.g., paraffin) and inorganic (e.g., metallic alloys and salt hydrates) material, provide a superior balance of thermal conductivity and latent heat for thermal management: Organic PCMs have low thermal conductivity but high latent heat, whereas salt and metallic PCMs have high thermal conductivity but low latent heat. While most current PCM composite literature experiment with only one phase changing material, ours evaluates a composite with two phase change materials. Our inorganic material is Fields Metal (a eutectic alloy of Bi, In, and Sn) and our organic material is paraffin wax. Common variables for thermal management indication, such as a figure of merit for the cooling capacity ηef f , energy density Eeff, and the thermal conductivity kef f , were found to be larger when our Field’s Metal, Paraffin composite PCM was paired with other high latent heat metals, such as Aluminum (Al), Graphitic Carbon Fiber (GCF), and Copper (Cu). The thermal conductivity of our PCM, was compared with other well known numerical PCM models using COMSOL simulations, and found to follow most closely with a parallel model. The parallel model was then used to define equations to calculate the optimal volume fraction of Al, GCF, Copper, for varying volume fractions of Fields metal. Results show that optimal eff values occur at around a 50% volume fraction of metal and 50% volume fraction of PCM, where 50% of the PCM is field’s metal (something on timescale result). Additionally, Al, GCF and Cu showed around a 70% increase in cooling capacity and around a 220% increase in energy density when paired with Field’s Metal. These results prove to be significant in the understanding of how a composite PCM, where both organic and metallic components change phase, can be beneficial to various applications in thermal management

Document Type

Final Report

Author's School

McKelvey School of Engineering

Author's Department

Mechanical Engineering and Materials Science

Class Name

Mechanical Engineering and Material Sciences Independent Study

Date of Submission


Fom_Phi.m (7 kB)
Fom_E_eff.m (7 kB)