High-velocity oxygen-fuel (HVOF) is a thermal spraying process used in various industries to enhance the wear or heat resistance of surfaces subjected to tribological or thermal loads. The coating quality depends on the temperature and velocity of the sprayed particles at impact on the target surface, as well as on the oxidation of the particles while traversing the HVOF nozzle and its exhaust jet. The size of the particle oxide layer depends on particle temperature, which is dictated by flow temperature. Therefore, numerical simulations must accurately describe particle impact quantities and particle temperature evolutions throughout the entire process to predict coating qualities. To this end, we conduct high-fidelity numerical simulations of the exhaust jet of a typical HVOF spraying process, including the volume displacement that the sprayed particles impose on the gas flow. We employ the state-of-the-art in-house code ALPACA, which implements a high-resolution Godunov-type flux-based finite-volume formulation with high-order spatial reconstruction, and extend its Lagrangian phase solver to account for particle volume displacement. Our results reveal a substantial impact of the particle volume displacement on the flow field, as illustrated in fig. 1. The decreased gas temperatures at the center of the jet cause particles to cool continuously, whereas particle temperature increases in the jet’s potential core before cooling down when particle displacement effects are not accounted for. Therefore, the maximum particle temperatures during the process change significantly due to the particle volume displacement.