scholarly journals Applications of a formula on Beltrami flow

2018 ◽  
Vol 41 (10) ◽  
pp. 3632-3642 ◽  
Author(s):  
Yong Zeng ◽  
Zhibing Zhang
Keyword(s):  
Beltrami Flow

Gromeka-beltrami flow in a semiinfinite cylindrical pipe

1973 ◽  
Vol 6 (2) ◽  
pp. 281-284 ◽  
Author(s):  
Yu. A. Gostintsev ◽  
P. F. Pokhil ◽  
O. A. Uspenskii
Keyword(s):  
Cylindrical Pipe ◽  
Beltrami Flow

Computing Surface Uniformization Using Discrete Beltrami Flow

2015 ◽  
Vol 37 (3) ◽  
pp. A1342-A1364 ◽  
Author(s):  
Tsz Wai Wong ◽  
Hong-kai Zhao
Keyword(s):  
Beltrami Flow

Nonaxisymmetric Flow through Annular Actuator Disks: Inlet Distortion Problem

1978 ◽  
Vol 100 (4) ◽  
pp. 604-617 ◽  
Author(s):  
W. R. Hawthorne ◽  
N. A. Mitchell ◽  
J. E. McCune ◽  
C. S. Tan
Keyword(s):  
Three Dimensional ◽  
Axial Compressor ◽  
Recent Experimental Data ◽  
Recent Theory ◽  
Inlet Distortion ◽  
Actuator Disk ◽  
Beltrami Flow ◽  
Compressor Rotor ◽  
Flow Through ◽  
Absolute Coordinates

The passage of distorted flow through an annular axial compressor rotor or stator is analyzed in the actuator disk limit. In such a description the flow is steady in absolute coordinates. The resulting analysis yields an overall description of the blade row performance in the presence of inlet flow defects. The present (actuator-disk) analysis is compared successfully with Dunham’s earlier three-dimensional analysis as well as with recent experimental data. In addition, comparison with a recent theory by Greitzer, employing an alternative approach, is made. The analysis shows that at least two important distinct types of vorticity arise, the one being directly analogous to the trailing vorticity (shed circulation) of classical wing theory, and the second being analogous to the vorticity occurring in “secondary flow” theory. The latter arises directly as a result of inlet distortion. The resulting varying flow angles produce spanwise variation in blade loading, and consequent trailing vorticity (Beltrami Flow). The two types of vorticity are therefore interrelated. The static pressure field is also affected by this coupling in agreement with experiment. This problem provided a striking example for which three-dimensional and two-dimensional analyses disagree qualitatively. The vorticity as viewed in coordinates fixed in the rotor is discussed in the Addendum.

scholarly journals Kelvin waves with helical Beltrami flow structure

2008 ◽  
Vol 20 (2) ◽  
pp. 024106 ◽  
Author(s):  
Rafael González ◽  
Gustavo Sarasua ◽  
Andrea Costa
Keyword(s):  
Flow Structure ◽  
Kelvin Waves ◽  
Beltrami Flow

Can a Descending Rain Curtain in a Supercell Instigate Tornadogenesis Barotropically?

2008 ◽  
Vol 65 (8) ◽  
pp. 2469-2497 ◽  
Author(s):  
Robert Davies-Jones
Keyword(s):  
Angular Momentum ◽  
Eddy Viscosity ◽  
Vortex Breakdown ◽  
Low Pressure ◽  
Initial Condition ◽  
Pressure Center ◽  
Beltrami Flow ◽  
Tangential Wind ◽  
Simple Numerical Model ◽  
Rule Out

Abstract This paper investigates whether the descending rain curtain associated with the hook echo of a supercell can instigate a tornado through a purely barotropic mechanism. A simple numerical model of a mesocyclone is constructed in order to rule out other tornadogenesis mechanisms in the simulations. The flow is axisymmetric and Boussinesq with constant eddy viscosity in a neutrally stratified environment. The domain is closed to avoid artificial decoupling of a vortex from the storm-scale circulation. In the principal simulation, the initial condition is a balanced, slowly decaying, Beltrami flow describing an updraft that is rotating cyclonically at midlevels around a low pressure center surrounded by a concentric downdraft that revolves cyclonically but has anticyclonic vorticity. The boundary conditions are no slip on the tangential wind and free slip on the radial or vertical wind to accommodate this initial condition and to allow strong interaction of a vortex with the ground. Precipitation is released through the top above the updraft and falls to the ground near the updraft–downdraft interface in an annular curtain. The downdraft enhancement induced by the precipitation drag upsets the balance of the Beltrami flow. The downdraft and its outflow toward the axis increase low-level convergence beneath the updraft and transport air with moderately high angular momentum downward and inward where it is entrained and stretched by the updraft. The resulting tornado has a corner region with an intense axial jet and low pressure capped by a vortex breakdown and a transition to a broader vortex aloft (a tornado cyclone). A clear slot of subsiding air with anticyclonic vorticity surrounds the vortex. The vertical kinetic energy of the entire circulation declines dramatically prior to tornado formation.

scholarly journals Liouville theorem for Beltrami flow

2014 ◽  
Vol 24 (3) ◽  
pp. 916-921 ◽  
Author(s):  
Nikolai Nadirashvili
Keyword(s):  
Liouville Theorem ◽  
Beltrami Flow
Sign in / Sign up

Export Citation Format

Share Document