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FIZIKA A 7 (1998) 3, 133-144
 
OBSERVATION OF LASER-INDUCED MICROSCALE VORTEX RING INTERACTIONS ON
VAPORIZING METAL SURFACE
STJEPAN LUGOMER
Ruđer Bošković Institute, Bijenička 54, 10001 Zagreb, Croatia
Received 23 June 1998; Accepted 9 November 1998
Laser-induced microscale vortex rings have been generated on vaporizing tantalum
surface, and their reconnection was studied in the presence of shock waves on the
nanosecond time scale. A rich spectrum of the ring structures was obtained, some of which
have been observed for the first time. Qualitatively, three classes of interactions are
distinguished on the basis of relative relation of the shock momentum Ps and
momentum of the circulating fluid Pc: interactions in the presence of low
momentum shock waves (Ps < Pc), of the
shock waves with a momentum comparable to the momentum of the circulating fluid (Ps
» Pc) and of the shock waves with a momentum larger
than momentum of the circulating fluid (Ps > Pc).
PACS numbers: 61.25-Mv, 68.1a-m, 81.15.F
UDC 531.3.522, 621.375
Keywords: laser-induced microscale vortex rings, tantalum surface, reconnection of rings,
shock waves, ring structures
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