Nanobubble Generation on Nanoparticles Considering Laser Energy Absorption Variation

It is important to reveal the heat transfer and flow mechanisms of laser-induced nanobubble generation on nanoparticles in the fields of solar energy utilization, medical treatment, and seawater purification. In this study, a coupled framework integrating the phase-change lattice Boltzmann method (LBM) with the depth-first search (DFS) algorithm is proposed. The proposed framework accurately quantifies transient laser energy absorption based on instantaneous nanoparticle aggregation and nanobubble coverage. The nanoparticle trajectory in the fluid is studied based on the momentum exchange method. The convection is investigated by conjugated thermal boundary to investigate the temperature evolutions in the nanoparticles and the surrounding fluid. The interfacial thermal conductance, nanoparticle distance, the laser intensity, fluid velocity, and channel configuration effect on nanoparticle and nanobubble heat absorption, nanobubble generation, and nanoparticle motion are studied. The nanoparticle dimer enhances the nanobubble generation while the nanobubble coverage suppresses the nanobubble generation. The bubble volume ratio of the Y-shaped channel with the small bifurcation angle outstrips the vertical channel.