Swirl flow stability: thermodynamic analysis and experiments

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388998%3A_____%2F24%3A00587629" target="_blank" >RIV/61388998:_____/24:00587629 - isvavai.cz</a>

Result on the web

<a href="https://link.springer.com/article/10.1007/s00161-024-01303-6" target="_blank" >https://link.springer.com/article/10.1007/s00161-024-01303-6</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s00161-024-01303-6" target="_blank" >10.1007/s00161-024-01303-6</a>

Result language

angličtina

Original language name

Swirl flow stability: thermodynamic analysis and experiments

Original language description

The current paper presents a theoretical analysis of swirl flow stability, both inside a tube (vortex tube) and in a free annular swirl flow. The starting concept is the study of the evolution of velocity and temperature fluctuations. Methods of non-equilibrium thermodynamics are used to describe the magnitude of fluctuations and their properties. The important role of the total enthalpy follows from a variational analysis. Moreover, the thermodynamic criterion of the stability is formulated using the total enthalpy, and compared with experiments, numerical results and classical Rayleigh theory support its applicability. It was shown that the solid body vortex is at the margin of stability, which is experimentally observed. Analogously, the potential vortex is by the thermodynamic criterion stable, however, by the Rayleigh criteria it is on the onset of stability. The classical Taylor experiment of flowbetween two rotating cylinders is analysed from the point of viewof this criterion. These results are underlined by swirl tube experiments at the Institute of Aerospace Thermodynamics at Stuttgart University and the annular nozzle experiments performed in the Institute of Thermomechanics CAS in Prague. Both independent experiments confirm the transformation of the initial annular vortex into a stable potential-type vortex. The results of this theory can also be used to explain the exceptional stability of tropical cyclones.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

20303 - Thermodynamics

Project

<a href="/en/project/GC21-26232J" target="_blank" >GC21-26232J: Heat and mass transfer enhancement in unsteady jet flows - utilization of effects of hysteresis, bistability and intermittency</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Continuum Mechanics and Thermodynamics

ISSN

0935-1175

e-ISSN

1432-0959

Volume of the periodical

36

Issue of the periodical within the volume

4

Country of publishing house

DE - GERMANY

Number of pages

20

Pages from-to

891-910

UT code for WoS article

001220307000001

EID of the result in the Scopus database

2-s2.0-85192708228