Melting Front Evolution of a Phase Change Material Inside a Metal Foam at Different Wall Temperatures

Among the methods studied in the literature to enhance the Phase Change Materials (PCM) thermal response, the coupling of open cell metallic foams is one of the most promising. In the literature, experiments on melting fronts are mainly conducted by imposing a constant heat flux. The novelty of this work is to perform experiments at constant wall temperatures to detect the melting front propagation at fixed Rayleigh numbers. During the tests an ohmic heater provides the heat load on one side of the test cell, while a PID controller keeps the wall temperature constant. A Zinc-Selenide window, transparent to the Long Wave Infra-Red (LWIR) spectrum, allows acquiring the evolution of the foam/PCM temperature distribution with an IR camera. An in-house MATLAB® algorithm analyses the IR images and quantifies the role of the natural convection at different Rayleigh numbers.