Pretražite po imenu i prezimenu autora, mentora, urednika, prevoditelja

Napredna pretraga

Pregled bibliografske jedinice broj: 351256

The circular internal hydraulic jump


Thorpe, S. A.; Kavčič, Iva
The circular internal hydraulic jump // Journal of Fluid Mechanics, 610 (2008), 99-129 doi:10.1017/S0022112008002553 (međunarodna recenzija, članak, znanstveni)


CROSBI ID: 351256 Za ispravke kontaktirajte CROSBI podršku putem web obrasca

Naslov
The circular internal hydraulic jump

Autori
Thorpe, S. A. ; Kavčič, Iva

Izvornik
Journal of Fluid Mechanics (0022-1120) 610 (2008); 99-129

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Hydraulic jump; Stratified fluid; Stationary waves

Sažetak
Circular hydraulic jumps are familiar in single layers. Here we report the discovery of similar jumps in two-layer flows. A thin jet of fluid impinging vertically onto a rigid horizontal plane surface submerged in a deep layer of less-dense miscible fluid spreads radially, and a near-circular internal jump forms within a few centimetres from the point of impact with the plane surface. A jump is similarly formed as a jet of relatively less-dense fluid rises to the surface of a deep layer of fluid, but it appears less stable or permanent in form. Several experiments are made to examine the case of a downward jet onto a horizontal plate, the base of a square or circular container. The inlet Reynolds numbers, Re, of the jet range from 112 to 1790. Initially jumps have an undular, laminar form with typically 2– 4 stationary waves on the interface between the dense and less-dense layers but, as the depth of the dense layer beyond the jump increases, the transitions become more abrupt and turbulent, resulting in mixing between the two layers. During the transition to a turbulent regime, single and sometimes moving multiple cusps are observed around the periphery of jumps. A semi-empirical model is devised that relates the parameters of the laboratory experiment, i.e. flow rate, inlet nozzle radius, kinematic viscosity and reduced gravity, to the layer depth beyond the jump and the radius at which an undular jump occurs. The experiments imply that surface tension is not an essential ingredient in the formation of circular hydraulic jumps and demonstrate that stationary jumps can exist in stratified shear flows which can be represented as two discrete layers. No stationary circular undular jumps are found, however, in the case of a downward jet of dense fluid when the overlying, less-dense, fluid is stratified, but a stationary turbulent transition is observed. This has implications for the existence of stationary jumps in continuously stratified geophysical flows: results based on two-layer models may be misleading. It is shown that the Froude number at which a transition of finite width occurs in a radially diverging flow may be less than unity.

Izvorni jezik
Engleski

Znanstvena područja
Matematika, Fizika, Geologija



POVEZANOST RADA


Projekti:
037-1193086-2771 - Numeričke metode u geofizičkim modelima (Singer, Saša, MZOS ) ( POIROT)

Ustanove:
Prirodoslovno-matematički fakultet, Matematički odjel, Zagreb

Profili:

Avatar Url Iva Kavčič (autor)

Citiraj ovu publikaciju:

Thorpe, S. A.; Kavčič, Iva
The circular internal hydraulic jump // Journal of Fluid Mechanics, 610 (2008), 99-129 doi:10.1017/S0022112008002553 (međunarodna recenzija, članak, znanstveni)
Thorpe, S. & Kavčič, I. (2008) The circular internal hydraulic jump. Journal of Fluid Mechanics, 610, 99-129 doi:10.1017/S0022112008002553.
@article{article, author = {Thorpe, S. A. and Kav\v{c}i\v{c}, Iva}, year = {2008}, pages = {99-129}, DOI = {10.1017/S0022112008002553}, keywords = {Hydraulic jump, Stratified fluid, Stationary waves}, journal = {Journal of Fluid Mechanics}, doi = {10.1017/S0022112008002553}, volume = {610}, issn = {0022-1120}, title = {The circular internal hydraulic jump}, keyword = {Hydraulic jump, Stratified fluid, Stationary waves} }
@article{article, author = {Thorpe, S. A. and Kav\v{c}i\v{c}, Iva}, year = {2008}, pages = {99-129}, DOI = {10.1017/S0022112008002553}, keywords = {Hydraulic jump, Stratified fluid, Stationary waves}, journal = {Journal of Fluid Mechanics}, doi = {10.1017/S0022112008002553}, volume = {610}, issn = {0022-1120}, title = {The circular internal hydraulic jump}, keyword = {Hydraulic jump, Stratified fluid, Stationary waves} }

Časopis indeksira:


  • Current Contents Connect (CCC)
  • Web of Science Core Collection (WoSCC)
    • Science Citation Index Expanded (SCI-EXP)
    • SCI-EXP, SSCI i/ili A&HCI
  • Scopus


Citati:





    Contrast
    Increase Font
    Decrease Font
    Dyslexic Font