TY - JOUR
T1 - Stability of periodically unsteady axisymmetric jet
AU - Carrara, M. D.
AU - Hajj, M. R.
PY - 2003/5
Y1 - 2003/5
N2 - To date, the majority of studies on stability of axisymmetric jets have been completed under the assumption of steady mean flow. Yet, many of the natural and man-made flows that are modeled by these jets can have an inherent unsteadiness; the effects of which on the stability and transition have not been determined. Moreover, controlled unsteadiness can be used to control stability and possibly the transition to turbulence. In this note, the effects of periodic variations of the mean flow on the stability of axisymmetric jets are examined. The problem is treated analytically. The results show that the governing equations and dispersion relation for the unsteady jet can be reduced to those governing the steady jet with a time transformation. It is shown that the periodic variations in the mean flow cause amplitude and phase modulations of the unstable modes. The implications of the modulations on the subsequent transition stages are discussed.
AB - To date, the majority of studies on stability of axisymmetric jets have been completed under the assumption of steady mean flow. Yet, many of the natural and man-made flows that are modeled by these jets can have an inherent unsteadiness; the effects of which on the stability and transition have not been determined. Moreover, controlled unsteadiness can be used to control stability and possibly the transition to turbulence. In this note, the effects of periodic variations of the mean flow on the stability of axisymmetric jets are examined. The problem is treated analytically. The results show that the governing equations and dispersion relation for the unsteady jet can be reduced to those governing the steady jet with a time transformation. It is shown that the periodic variations in the mean flow cause amplitude and phase modulations of the unstable modes. The implications of the modulations on the subsequent transition stages are discussed.
KW - Jets
KW - Stability
KW - Steady flow
KW - Unsteady flow
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U2 - 10.1061/(ASCE)0733-9399(2003)129:5(578)
DO - 10.1061/(ASCE)0733-9399(2003)129:5(578)
M3 - Article
AN - SCOPUS:0037991355
SN - 0733-9399
VL - 129
SP - 578
EP - 580
JO - Journal of Engineering Mechanics
JF - Journal of Engineering Mechanics
IS - 5
ER -