A Novel Numerical and Experimental Investigation into Radial Injection of Suspension in Suspension High Velocity Oxy Fuel (SHVOF) Thermal Spray

Suspension High Velocity Oxy Fuel thermal spray typically utilises axial injections of suspension into the combustion chamber. There are, however, certain cases where the nano-particles and oxygen sensitive materials, especially carbon based, benefit from a reduction in the time spent in the gas flow, for instance particles may degrade or oxidise when exposed to high temperatures for a significant duration of time. Therefore, a radial injection outside of the nozzle can enable deposition of oxygen sensitive nano-materials. SHVOF thermal spray is characterised by high gas velocities of the order of magnitude of 2000 m/s and radial injection of suspension must have sufficient momentum as to penetrate the jet but not as to adversely cool the jet. This study aims to investigate the effect the suspension mass flow rate has on the breakup and penetration of the suspension into the jet. Due to the extensive previous work, we have chosen alumina as an exemplar for this work. A numerical model (eddy dissipation concept) which has high fidelity with regards to combustion is presented to model the jet. An experimental procedure is outlined, and the experimental values are compared to that of the numerical values produced from the model outlined below.