One of the main challenges for latent thermal energy storage (LTES) systems is slow charging due to the low thermal conductivity of most phase change materials (PCM) [1]. While close-contact melting (CCM) can accelerate this process, accurately predicting the associated rigid body dynamics remains difficult for frequently used numerical techniques such as the enthalpy-porosity method [2]. This is particularly challenging because the coupling across an interface moving due to phase change is extended with rigid body motion close to the domain boundaries, where the melting solid is separated from the heated walls by a thin liquid film. The partitioned interface-tracking strategy for constrained melting introduced in [3] is therefore extended to resolve coupled dynamics of phase change and rigid body motion. In this framework, the liquid and solid domains are solved by separate, validated solvers that exchange data iteratively. The fluid solver computes the heat flux and the hydrodynamic force and torque acting on the floating solid, while a 6-DOF motion solver built into the coupling code resolves the rigid body motion. The solid solver calculates the interface displacement due to phase change based on the Stefan condition [4]. To ensure the stability of the iterative rigid body solver, a fictitious mass method is used [5]. Furthermore, collisions between the solid phase and domain boundaries are avoided using a multi-contact distributed spring-damper model. An overset meshing technique is used to compensate for the large shrinkage of the solid phase. The component mesh follows the interface deformation, with remeshing applied at fixed time steps. The method is validated on the asymmetric close-contact melting case of Shockner et al. [2], where a rotating motion can be observed in addition to the typical sinking motion of the solid bulk. The method returns a fully resolved pressure and velocity field in the thin liquid film. REFERENCES [1] G. Ziskind et al, “Phase Change Materials for Thermal Management of Electronic Components,” in Encyclopedia of Thermal Packaging, vol. 3, A. Bar-Cohen, Ed., Maryland: World Scientific, 2018, p. 296. [2] T. Shockner et al., “Simultaneous close-contact melting on two asymmetric surfaces: Demonstration, modeling and application to thermal storage,” Int J Heat Mass Transf, vol. 232, p. 125950, Nov. 2024. [3] V. Van Riet et al, “A partitioned interface-tracking method for convective melting of constrained saturated solids,”.