An Investigation of the Cold Gas Dynamic Supersonic Spray Process
Particle/Flow Field
This research was conducted in
collaboration with Centerline (Windsor)
Ltd. It involved a study of the Cold Gas Dynamic Spray (CGDS) process for metal
deposition using supersonic jets. A computational fluid dynamic model of the process
was developed. The gas dynamic flow field and particle trajectories within an
oval shaped supersonic nozzle, near the impact target as well as in the jet
that forms in the immediate surroundings of the nozzle exit was
predicted. The flow field calculation inside the nozzle was found to be in good agreement with a series of pressure
measurements at the nozzle wall. In addition, predicted particle velocity
results at the nozzle exit were compared with the experimental
data obtained from a forward-scatter laser Doppler anemometer (LDA) with
frequency shifting capability. The numerical results are in
qualitative agreement with the velocity profiles along the major and minor axis
at the nozzle exit.
The results are used to determine the details of the pattern of particle
release into the surroundings. The locations and concentrations of particles
leaving the boundaries of the domain of interest are determined and presented
in a graphical manner that is easy to interpret. This information is important
in the design of particle collection equipment to be used
in the process.
Mo Karimi successfully defended his M.A.Sc.
thesis, based on this work, in the Fall of 2005.