Editing Quantum turbulence (section)

=== Physical generation of quantum turbulence ===
[[File:Vortextangle.png|thumb|375x375px|Fig 11. A simulated vortex tangle representing quantum turbulence in a cubic volume and showing the quantized vortices]]
There are a plethora of methods that can be used to generate a vortex tangle (visualised in fig 11) in the laboratory. Here they are listed by the quantum fluid that they can be generated in.

==== QT in helium II ====

* Suddenly towing a grid in the sample of fluid at rest <ref name=":0">{{Cite journal|last1=Smith|first1=M. R.|last2=Donnelly|first2=R. J.|last3=Goldenfeld|first3=N.|last4=Vinen|first4=W. F.|date=1993-10-18|title=Decay of vorticity in homogeneous turbulence|url=https://link.aps.org/doi/10.1103/PhysRevLett.71.2583|journal=Physical Review Letters|language=en|volume=71|issue=16|pages=2583–2586|doi=10.1103/PhysRevLett.71.2583|pmid=10054718|bibcode=1993PhRvL..71.2583S |issn=0031-9007}}</ref><ref>{{Cite journal|last1=Stalp|first1=S. R.|last2=Skrbek|first2=L.|last3=Donnelly|first3=R. J.|date=1999-06-14|title=Decay of Grid Turbulence in a Finite Channel|url=https://link.aps.org/doi/10.1103/PhysRevLett.82.4831|journal=Physical Review Letters|volume=82|issue=24|pages=4831–4834|doi=10.1103/PhysRevLett.82.4831|bibcode=1999PhRvL..82.4831S }}</ref>
* Moving the fluid along pipes or channels using bellows or pumps, creating a superfluid wind tunnel (the TOUPIE experiment in Grenoble <ref>{{Cite journal|last1=Salort|first1=J.|last2=Baudet|first2=C.|last3=Castaing|first3=B.|last4=Chabaud|first4=B.|last5=Daviaud|first5=F.|last6=Didelot|first6=T.|last7=Diribarne|first7=P.|last8=Dubrulle|first8=B.|author8-link= Bérengère Dubrulle |last9=Gagne|first9=Y.|last10=Gauthier|first10=F.|last11=Girard|first11=A.|date=2010-12-01|title=Turbulent velocity spectra in superfluid flows|url=https://aip.scitation.org/doi/10.1063/1.3504375|journal=Physics of Fluids|volume=22|issue=12|pages=125102–125102–9|doi=10.1063/1.3504375|arxiv=1202.0643 |bibcode=2010PhFl...22l5102S |s2cid=118453462|issn=1070-6631}}</ref>)
* Rotating one or two propellers inside a container; the configuration of two counter-rotating propellers is called the ''"von Karman flow"'' (e.g. the SHREK experiment in Grenoble)<ref name=":0" />
* Creating shockwaves and cavitation by locally focusing ultrasound (this allows for the generation of quantum turbulence away from the boundaries)<ref>{{Cite journal|last1=Finch|first1=R. D.|last2=Kagiwada|first2=R.|last3=Barmatz|first3=M.|last4=Rudnick|first4=I.|date=1964-06-15|title=Cavitation in Liquid Helium|url=https://link.aps.org/doi/10.1103/PhysRev.134.A1425|journal=Physical Review|volume=134|issue=6A|pages=A1425–A1428|doi=10.1103/PhysRev.134.A1425|bibcode=1964PhRv..134.1425F |osti=4881344}}</ref><ref name=":1">{{Cite journal|last1=Schwarz|first1=K. W.|last2=Smith|first2=C. W.|date=1981-03-30|title=Pulsed-ion study of ultrasonically generated turbulence in superfluid 4He|url=https://www.sciencedirect.com/science/article/abs/pii/0375960181902000|journal=Physics Letters A|language=en|volume=82|issue=5|pages=251–254|doi=10.1016/0375-9601(81)90200-0|bibcode=1981PhLA...82..251S |issn=0375-9601}}</ref>
* Oscillating/vibrating forks or wires <ref>{{Cite journal|last1=Schmoranzer|first1=D.|last2=Král’ová|first2=M.|last3=Pilcová|first3=V.|last4=Vinen|first4=W. F.|last5=Skrbek|first5=L.|date=2010-06-28|title=Experiments relating to the flow induced by a vibrating quartz tuning fork and similar structures in a classical fluid|url=https://link.aps.org/doi/10.1103/PhysRevE.81.066316|journal=Physical Review E|language=en|volume=81|issue=6|pages=066316|doi=10.1103/PhysRevE.81.066316|pmid=20866531|bibcode=2010PhRvE..81f6316S |issn=1539-3755}}</ref>
* Applying a [[heat flux]] (also termed the ''"thermal counterflow''" <ref>{{Cite journal|last1=Vinen|first1=W. F.|last2=Shoenberg|first2=D.|date=1957-04-24|title=Mutual friction in a heat current in liquid helium II I. Experiments on steady heat currents|url=https://royalsocietypublishing.org/doi/10.1098/rspa.1957.0071|journal=Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences|volume=240|issue=1220|pages=114–127|doi=10.1098/rspa.1957.0071|bibcode=1957RSPSA.240..114V |s2cid=94773152}}</ref>): the prototype experiment is a channel which is open to a helium bath at one end and the opposite is closed and has a [[resistor]]. An [[electric current]] is passed through the resistor and generates [[Ohmic heating (food processing)|ohmic heat]]; the heat is carried away from the heater towards the bath by the normal fluid component, while the superfluid moves towards the heater so that the net mass flux is zero as the channel is closed. A relative velocity <math>v_{ns} = |v_n - v_s|</math> (counterflow) of the two fluid components is set up in this way which is proportional to the applied heat. Above a small critical value of the counterflow velocity, a turbulent vortex tangle is generated.
* Injecting vortex rings (rings are generated by injecting electrons which form a small bubble of about 16 [[Angstrom]]s in size that are accelerated by an electric field, until, upon exceeding the critical velocity, the vortex ring is nucleated)<ref>{{Cite journal|last1=Walmsley|first1=P. M.|last2=Golov|first2=A. I.|date=2008-06-17|title=Quantum and Quasiclassical Types of Superfluid Turbulence|url=https://link.aps.org/doi/10.1103/PhysRevLett.100.245301|journal=Physical Review Letters|volume=100|issue=24|pages=245301|doi=10.1103/PhysRevLett.100.245301|pmid=18643594|arxiv=0802.2444 |bibcode=2008PhRvL.100x5301W |s2cid=30411193}}</ref>

==== QT in <sup>3</sup>He-B and atomic condensates ====
In <sup>3</sup>He-B, quantum turbulence can be generated by the vibration of wires.<ref>{{Cite journal|last1=Bradley|first1=D. I.|last2=Clubb|first2=D. O.|last3=Fisher|first3=S. N.|last4=Guénault|first4=A. M.|last5=Haley|first5=R. P.|last6=Matthews|first6=C. J.|last7=Pickett|first7=G. R.|last8=Tsepelin|first8=V.|last9=Zaki|first9=K.|date=2006-01-23|title=<nowiki>Decay of Pure Quantum Turbulence in Superfluid $^{3}\mathrm{He}\mathrm{\text{\ensuremath{-}}}\mathrm{B}$</nowiki>|url=https://link.aps.org/doi/10.1103/PhysRevLett.96.035301|journal=Physical Review Letters|volume=96|issue=3|pages=035301|doi=10.1103/PhysRevLett.96.035301|pmid=16486721|arxiv=0706.0621|s2cid=9778797}}</ref> For atomic condensates, quantum turbulence can be generated by shaking or oscillating the trap which confines the BEC <ref name=":9" /><ref name="Navon 72–75"/> and by phase imprinting the quantum vortices.