Flow dynamics and microparticles acceleration in the electrothermal launcher

Author

Shcolnikov, E.Ya. ; Guzeyev, M.Yu. ; Maslennikov, S.P. ; Melnik, A.V. ; Chebotarev, A.V.

Author_Institution

Eng. Phys. Inst., Moscow, Russia

Volume

35

Issue

1

fYear

1999

fDate

1/1/1999 12:00:00 AM

Firstpage

240

Lastpage

244

Abstract

Application of electrothermal launchers for obtaining powder materials coatings with improved values of density and adhesion requires formation of the gas flow region, immediately following behind the shock wave, where microparticles are being caught into acceleration. A method of such region forming by means of the shock wave space and time shaping is presented. The flow dynamics analysis on the basis of a numerical model, which was carried out for the case of two gaps in the launcher discharge unit, has shown that it is possible to accelerate microparticles up to very high velocities (2 km/s and higher) with simultaneous control of their temperature and to increase substantially the launcher efficiency. Measurements with the experimental equipment allowed us to determine dynamic parameters of flows, the velocity and extension of the shock-compressed region as well as velocities of the shock-waves and main flow region. Registration of plasma flows radiation spectra permitted determination of their temperature. The obtained experimental results are in good correlation with computer simulation data

Keywords

electrothermal launchers; plasma arc sprayed coatings; plasma arc spraying; plasma diagnostics; plasma flow; plasma shock waves; plasma temperature; spectral methods of temperature measurement; temperature control; coating adhesion; coating density; computer simulation; dynamic parameters; electrothermal launcher; flow dynamics; gas flow region formation; launcher discharge unit; launcher efficiency increase; microparticles; microparticles acceleration; plasma flows radiation spectra; plasma temperature determination; powder materials coatings; shock wave; shock wave space; shock-compressed region extension; shock-compressed region velocity; shock-wave velocities; temperature control; Acceleration; Adhesives; Coatings; Electrothermal effects; Electrothermal launching; Fluid flow; Plasma measurements; Plasma temperature; Powders; Shock waves;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.738411

Filename

738411