Liquid-luelled high-velocity oxy-fuel (HVOF) thermal spraying systems are capable of generating more momentum output to powder particles in comparison with gas-fuelled systems. The use of low-cost fuel such as kerosene makes this technology particular attractive. High-quality coating requires thermal spraying systems delivering consistent performance as a result of the combustion during HVOF spraying. The combustion of kerosene is very complicated due to the variation of fuel composition and subsequently makes it extremely challenging for process control. This paper describes a 3-D simulation using mathematical models available in a commercial finite volume CFD code. The combustion and discrete particle models within the numerical code are applied to solve the combustion of kerosene and couple the motion of fuel droplets with the gas flow dynamics in a Lagrangian fashion. The effects of liquid fuel droplets on the thermodynamics of the combusting gas flow are examined thoroughly. (c) 2006 Elsevier Ltd. All rights reserved.