Session BB1.8

11:15 AM BB1.8
COMPUTATIONAL FLUID DYNAMICS MODELING OF THE HIGH-VELOCITY OXYGEN-FUEL (HVOF) THERMAL SPRAY PROCESS. Basil Hassan, William L. Oberkampf, and Amalia R. Lopez, Sandia National Laboratories, Aerosciences and Compressible Fluid Mechanics Department, Albuquerque, NM.

An overview of recent computational modeling of the high-velocity oxygen-fuel (HVOF) thermal spray process will be presented. The analyses presented are based on the application of computational fluid dynamics (CFD) to solve for the combusting, two-phase, gas and particle flow inside and outside of a HVOF thermal spray torch. Steady-state CFD results will be presented and discussed for both axisymmetric and three-dimensional devices used for a variety of coating applications. The gas dynamics of the HVOF process involve the solution of the Navier-Stokes equations for a compressible, reacting, and turbulent gas/particle mixture. The hydrocarbon-air combustion process is modeled using both instantaneous and single-step finite rate chemistry models. An Eulerian-Langrangian technique is used to couple the fluid dynamics of the combusting gas flow to that of the particles. An implicit, iterative, finite volume numerical technique is used to solve the coupled conservation of mass, momentum, and energy equations for the gas and particulate (solid and liquid) phases in a sequential manner. Details of the reacting gas flow fields and the particle dynamics will be presented and discussed for various operating conditions. In addition, the CFD results will be compared with experimental measurements of pressure inside the HVOF device and laser velocimetry measurements of the particles in the high speed jet external to the device.