ISSN Online: 2377-424X
ISBN Print: 978-1-56700-421-2
International Heat Transfer Conference 15
Numerical Simulation of Heat Transfer and Gas Dynamics in Warm Spray
Аннотация
Warm spray is a modification of high velocity oxygen fuel spray. In this process, the high-temperature gas is
accelerated to supersonic speed through a Laval nozzle followed by a straight barrel. By injecting gas at room
temperature into the mixing chamber, the temperature of the gas can be controlled in a range of about 1000-2500
K, so that oxidation-free coatings are made from some oxygen and temperature-sensitive materials. The purpose
of this paper is to establish a heat transfer and gas dynamics model for the supersonic flow. The model was
solved using a computational dynamics code to predict heat transfer and fluid flow behavior in warm spray. The
effects of the mixing gas (nitrogen) flow rates and the length of mixing chamber were investigated. It is shown
that the optimal operating conditions in warm spray process can be achieved by adjusting the mixing gas
flow rate. A dimensionless mixing length of 12 should be used to insure uniform temperature distribution at
the exit of the mixing chamber.