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Numerical simulation of low Re-number turbulence in round jets. (English) Zbl 0833.76028
Durst, Franz (ed.) et al., Turbulent shear flows 9. Selected papers from the ninth international symposium on turbulent shear flows, Kyoto, Japan, August 16-18, 1993. Berlin: Springer-Verlag. 123-145 (1995).
The turbulent flow in spatially developing round jets at low Reynolds numbers is simulated numerically in the first fifteen diameters. The simulations were started with the inviscid solution, and small axisymmetric disturbances were introduced at the entrance section to accelerate the breakdown of the Kelvin-Helmholtz vortices. The development of the flow produced a rich variety of structures. The azimuthal instability of the vortex rings leads to tube-like structures which collapse into counter-rotating streamwise vortices that interact with the vortex pairing process. A passive scalar distribution also highlights the ring-braid region and reveals the severe straining of the braids near the jet axis and the formation of mushroom-like structures as a result of the counter-rotating nature of the streamwise vortices.
For the entire collection see [Zbl 0809.00030].
76F10 Shear flows and turbulence
76M20 Finite difference methods applied to problems in fluid mechanics
76D25 Wakes and jets