Cold spray is a process whereby micron-size particles are accelerated to high velocity through entrainment in a gas undergoing expansion in a rocket nozzle and are subsequently impacted upon a surface. The impacted particles, which can be combinations of metals, ceramics and polymeric materials, form a consolidated structure that can be several centimeters thick. The characteristics of this structure depend on the initial characteristics of the metal powder and upon the impact velocity. Two-dimensional axi-symmetric computations of the flow through a converging, diverging nozzle were performed using the Reynolds-Averaged Navier-Stokes (RANS) code, Computational Fluid Dynamics++ (CFD++), on the Army Research Laboratory, Department of Defense (DoD) Supercomputing Resource Center (ARL DSRC) computers. Aluminum particles of constant diameter were injected at the entrance of a De Laval converging, diverging nozzle. The Eulerian Disperse Phase (EDP) capability in CFD++ was used for these simulations. The EDP model couples the dispersed phase with the fluid dynamics. In addition, onedimensional (1D), isentropic, gas-dynamic equations were solved for the same geometry and initial conditions. The results from the RANS computations and 1D calculation compared favorably, considering the difference in governing equations.
Comparison of Empirical and Theoretical Computations of Velocity for a Cold Spray Nozzle
2009
5 Seiten, 5 Quellen
Aufsatz (Konferenz)
Englisch
Theoretical Study of Powder Particle Parameters in a Modified Cold Spray Nozzle
Springer Verlag | 2023
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