Related Experiment Video
Updated: Feb 25, 2026

Experimental Investigation of the Flow Structure over a Delta Wing Via Flow Visualization Methods
Published on: April 23, 2018
Complete measurement of helicity and its dynamics in vortex tubes
Martin W Scheeler1, Wim M van Rees2, Hridesh Kedia1
1Department of Physics, The University of Chicago, Chicago, IL 60637, USA.
Abstract:
Helicity, a topological measure of the intertwining of vortices in a fluid flow, is a conserved quantity in inviscid fluids but can be dissipated by viscosity in real flows. Despite its relevance across a range of flows, helicity in real fluids remains poorly understood because the entire quantity is challenging to measure. We measured the total helicity of thin-core vortex tubes in water. For helical vortices that are stretched or compressed by a second vortex, we found conservation of total helicity. For an isolated helical vortex, we observed evolution toward and maintenance of a constant helicity state after the dissipation of twist helicity by viscosity. Our results show that helicity can remain constant even in a viscous fluid and provide an improved basis for understanding and manipulating helicity in real flows.
More Related Videos
13:02Three-dimensional Particle Tracking Velocimetry for Turbulence Applications: Case of a Jet Flow
Published on: February 27, 2016
11:00Experimental Investigation of Secondary Flow Structures Downstream of a Model Type IV Stent Failure in a 180° Curved Artery Test Section
Published on: July 19, 2016
Related Concept Videos
Steady, Laminar Flow in Circular Tubes
Divergence and Curl of Magnetic Field
Thin-Walled Hollow Shafts
Irrotational Flow
Torque On A Current Loop In A Magnetic Field
Consider a rectangular current-carrying loop containing N turns of wire, placed in a uniform magnetic field. The net force on a current-carrying loop...
Couette Flow