Numerical modeling of particle deposition and deposit erosion on a solid object with prescribed motion

This work presents a numerical model to study the effects of deposition and deposit erosion on a solid moving object under prescribed motion. In this model, fluid flow, particle transport, particle deposition and deposit erosion, conjugate heat transfer, and object movement are all considered simultaneously in a fully coupled manner. The deposition is modeled as a first-order reaction, while shear-driven erosion is modeled using a threshold law. The evolution of the deposit front and the moving object is captured using the level-set method with two level-set functions. The capabilities of the numerical model are demonstrated on a flat plate undergoing translational, rotational, and combined motions, as well as on a four-blade rotor undergoing translational and rotational motions. The results indicate that higher deposition typically occurs on the upstream facing surface of the moving object due to the higher particle concentration in this region compared to that of the downstream region. With an imposed volumetric heat generation within the solid object, the deposit layer acts as an insulating barrier, impairing heat transfer from the solid object to the flowing fluid and leading to a higher average temperature of the solid object compared to that of clean object. Furthermore, the total deposit volume increases with higher Damkohler numbers and critical shear stress, as well as with lower Erosion numbers. Consequently, the average solid object temperature rises with the increase in the total deposit volume.