Title :
Comparison of Empirical and Theoretical Computations of Velocity for a Cold Spray Nozzle
Author :
Dinavahi, Surya ; Champagne, Victor K. ; Helfritch, Dennis J.
Author_Institution :
Onsite CFD lead at ARL DSRC, Univ. of Alabama at Birmingham, Birmingham, AL, USA
Abstract :
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.
Keywords :
Navier-Stokes equations; aerodynamics; ceramics; computational fluid dynamics; disperse systems; flow simulation; nozzles; rockets; sprays; velocity measurement; CFD++; DoD supercomputing resource center computers; Eulerian disperse phase; RANS code; Reynolds-averaged Navier-Stokes code; ceramics; cold spray nozzle; computational fluid dynamics; department of defense; flow simulation; fluid dynamics; gas-dynamic equation; impact velocity; metal powder; micron-size particle; polymeric material; rocket nozzle; two-dimensional axi-symmetric computation; Coatings; Computational fluid dynamics; Electron tubes; Equations; Geometry; Mathematical model; Metals;
Conference_Titel :
DoD High Performance Computing Modernization Program Users Group Conference (HPCMP-UGC), 2009
Conference_Location :
San Diego, CA
Print_ISBN :
978-1-4244-5768-7
DOI :
10.1109/HPCMP-UGC.2009.10