On swirling jets

1979 ◽  
Vol 14 (1) ◽  
pp. 19-26 ◽  
Author(s):  
M. A. Gol'dshtik
Keyword(s):  
Swirling Jets

scholarly journals Obtaining Expressions for Time-Dependent Functions That Describe the Unsteady Properties of Swirling Jets of Viscous Fluid

Mathematics ◽  
2021 ◽  
Vol 9 (16) ◽  
pp. 1860
Author(s):  
Eugene Talygin ◽  
Alexander Gorodkov
Keyword(s):  
Blood Flow ◽  
Viscous Fluid ◽  
Swirling Flow ◽  
Fluid Flows ◽  
Theoretical Method ◽  
Flow Channel ◽  
Navier Stokes ◽  
Swirling Jets ◽  
Continuity Equations ◽  
Dynamic Velocity

Previously, it has been shown that the dynamic geometric configuration of the flow channel of the left heart and aorta corresponds to the direction of the streamlines of swirling flow, which can be described using the exact solution of the Navier–Stokes and continuity equations for the class of centripetal swirling viscous fluid flows. In this paper, analytical expressions were obtained. They describe the functions C0t and Г0t, included in the solutions, for the velocity components of such a flow. These expressions make it possible to relate the values of these functions to dynamic changes in the geometry of the flow channel in which the swirling flow evolves. The obtained expressions allow the reconstruction of the dynamic velocity field of an unsteady potential swirling flow in a flow channel of arbitrary geometry. The proposed approach can be used as a theoretical method for correct numerical modeling of the blood flow in the heart chambers and large arteries, as well as for developing a mathematical model of blood circulation, considering the swirling structure of the blood flow.

A numerical and experimental study of confined swirling jets

1989 ◽  
Author(s):  
M. NIKJOOY ◽  
H. MONGIA ◽  
G. SAMUELSEN ◽  
V. MCDONELL
Keyword(s):  
Experimental Study ◽  
Swirling Jets

scholarly journals Scalar dissipation rate statistics in turbulent swirling jets

2016 ◽  
Vol 28 (7) ◽  
pp. 075104 ◽  
Author(s):  
V. Stetsyuk ◽  
N. Soulopoulos ◽  
Y. Hardalupas ◽  
A. M. K. P. Taylor
Keyword(s):  
Dissipation Rate ◽  
Scalar Dissipation ◽  
Scalar Dissipation Rate ◽  
Swirling Jets

scholarly journals Viscous effects in the absolute–convective instability of the Batchelor vortex

2002 ◽  
Vol 459 ◽  
pp. 371-396 ◽  
Author(s):  
C. OLENDRARU ◽  
A. SELLIER
Keyword(s):  
Reynolds Number ◽  
Convective Instability ◽  
Axial Flow ◽  
Reynolds Numbers ◽  
Absolute Instability ◽  
Viscous Effects ◽  
Swirling Jets ◽  
Bending Mode ◽  
Transitional Mode ◽  
The Absolute

The effects of viscosity on the instability properties of the Batchelor vortex are investigated. The characteristics of spatially amplified branches are first documented in the convectively unstable regime for different values of the swirl parameter q and the co-flow parameter a at several Reynolds numbers Re. The absolute–convective instability transition curves, determined by the Briggs–Bers zero-group velocity criterion, are delineated in the (a, q)-parameter plane as a function of Re. The azimuthal wavenumber m of the critical transitional mode is found to depend on the magnitude of the swirl q and on the jet (a > −0.5) or wake (a < −0.5) nature of the axial flow. At large Reynolds numbers, the inviscid results of Olendraru et al. (1999) are recovered. As the Reynolds number decreases, the pocket of absolute instability in the (a, q)-plane is found to shrink gradually. At Re = 667; the critical transitional modes for swirling jets are m = −2 or m = −3 and absolute instability prevails at moderate swirl values even in the absence of counterflow. For higher swirl levels, the bending mode m = −1 becomes critical. The results are in good overall agreement with those obtained by Delbende et al. (1998) at the same Reynolds number. However, a bending (m = +1) viscous mode is found to partake in the outer absolute–convective instability transition for jets at very low positive levels of swirl. This asymmetric branch is the spatial counterpart of the temporal viscous mode isolated by Khorrami (1991) and Mayer & Powell (1992). At Re = 100, the critical transitional mode for swirling jets is m = −2 at moderate and high swirl values and, in order to trigger an absolute instability, a slight counterflow is always required. A bending (m = +1) viscous mode again becomes critical at very low swirl values. For wakes (a < −0.5) the critical transitional mode is always found to be the bending mode m = −1, whatever the Reynolds number. However, above q = 1.5, near-neutral centre modes are found to define a tongue of weak absolute instability in the (a, q)-plane. Such modes had been analytically predicted by Stewartson & Brown (1985) in a strictly temporal inviscid framework.

Turbulence Structure in Swirling Jets

1983 ◽  
pp. 219-228 ◽  
Author(s):  
J. W. Elsner ◽  
S. Drobniak
Keyword(s):  
Turbulence Structure ◽  
Swirling Jets
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