Mixed convection of nano-encapsulated phase change suspensions in a wavy wall lid-driven trapezoid cavity

The improvement of heat transfer and energy storage are crucial tasks in many renewable energy applications. The thermal and hydrodynamic performances of a nano-encapsulated phase change material (NEPCM) suspension are investigated under a mixed convective heat transfer regime inside a trapezoidal enclosure. As the host fluid and dispersed NEPCM particles circulate in the enclosure, the nanoparticle cores absorb/release heat and undergo a phase transition process, enhancing heat transfer. The governing equations were scaled into a general non-dimensional format and then solved by the finite element method. The influence of nanoparticles fusion temperature and concentration, as well as the wavy wall characteristics and Richardson number, was addressed on heat transfer. A suitable fusion temperature of the nanoparticles can boost the heat transfer rate by 8