Investigation of near-wall cavitation bubble collapse in liquid hydrogen based on the hybrid thermal lattice Boltzmann method

The hybrid thermal lattice Boltzmann method coupled with the Redlich–Kwong–Soave real-fluid equation of state is employed to investigate the near-wall bubble collapse in liquid hydrogen. The thermodynamic consistency verification demonstrates that the simulated vapor–liquid equilibrium densities of liquid hydrogen agree well with the National Institute of Standards and Technology experimental data. Moreover, the evolution of the bubble radius is consistent with the Rayleigh–Plesset equation that accounts for thermal effects, thereby confirming the reliability of the present method. The results show that, compared with water, the cavitation bubble collapse in liquid hydrogen exhibits less deformation at the same non-dimensional stand-off distance. With increasing bubble-to-wall distance, the bubble collapses more rapidly, generating higher jet velocity, pressure, and temperature in the flow field. However, the pressure on the wall becomes weaker and more uniformly distributed. For bubbles in liquid hydrogen attached to the wall, a smaller contact angle leads to a more violent collapse, producing a pressure peak at the wall center characterized by high amplitude, short duration, and a localized impact region. In contrast, a larger contact angle causes the maximum wall pressure to appear on both sides of the wall center, with lower amplitude, longer duration, and a broader affected region.