TY - JOUR
T1 - On the onset of unsteadiness in confined vortex flows
AU - Tsitverblit, N.
AU - Kit, E.
N1 - Funding Information:
The authors acknowledge that referees’ comments stimulated improvement of presentation of the paper. This research was supported by The Israel Gordon Institute for Energy Studies.
PY - 1998/9/1
Y1 - 1998/9/1
N2 - In the experiment of Escudier [1984 Exp. Fluids, 2, 189-196], the manifestation of vortex breakdown in a cylindrical container has been accompanied by the onset of axisymmetric oscillations when the Reynolds number was increased. In this work, examination of linear stability of the independently considered different parts of the flow domain was performed along with other numerical experiments in the container and an annular geometry to study the physical nature of the oscillatory instability. It is demonstrated that the axisymmetric oscillations observed in these confined flows are not brought about by the vortex breakdown. The results also clarify the basic role in the instability mechanism played by the region of the negative Rayleigh discrimination near the cylindrical wall; this mechanism is associated with traveling Taylor-Gortler vortices. Consequently of the results with the hypothesis of nonaxisymmetric instability in the vortex breakdown is also discussed.
AB - In the experiment of Escudier [1984 Exp. Fluids, 2, 189-196], the manifestation of vortex breakdown in a cylindrical container has been accompanied by the onset of axisymmetric oscillations when the Reynolds number was increased. In this work, examination of linear stability of the independently considered different parts of the flow domain was performed along with other numerical experiments in the container and an annular geometry to study the physical nature of the oscillatory instability. It is demonstrated that the axisymmetric oscillations observed in these confined flows are not brought about by the vortex breakdown. The results also clarify the basic role in the instability mechanism played by the region of the negative Rayleigh discrimination near the cylindrical wall; this mechanism is associated with traveling Taylor-Gortler vortices. Consequently of the results with the hypothesis of nonaxisymmetric instability in the vortex breakdown is also discussed.
UR - http://www.scopus.com/inward/record.url?scp=0032169883&partnerID=8YFLogxK
U2 - 10.1016/S0169-5983(97)00058-0
DO - 10.1016/S0169-5983(97)00058-0
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AN - SCOPUS:0032169883
SN - 0169-5983
VL - 23
SP - 125
EP - 152
JO - Fluid Dynamics Research
JF - Fluid Dynamics Research
IS - 3
ER -