Abstract
The rapid pace of advancement in thermal spraying is in large part due to the availability of diagnostic tools that are used to measure process variables such as particle temperature, particle trajectories, and plume geometry. The work presented here deals with the adaptation of an imaging method that can be used to visualize, quantify, and distinguish between laminar, transitional, and turbulent flow regimes. The method is based on schlieren photography and an image processing procedure that extracts the density field of a flow relative to a background image. In this study, the promising new method known as background-oriented schlieren (BOS) is used to evaluate different nozzle designs for twin-wire arc spraying. The results are presented and compared with CFD simulations, conventional schlieren images, and color photographs of the spray plume.
