Turbulent jet stability increased by ribs inside the nozzle – Stereo PIV measurement one diameter past the nozzle

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F49777513%3A23210%2F21%3A43962849" target="_blank" >RIV/49777513:23210/21:43962849 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.matec-conferences.org/articles/matecconf/pdf/2021/14/matecconf_pse2021_00006.pdf" target="_blank" >https://www.matec-conferences.org/articles/matecconf/pdf/2021/14/matecconf_pse2021_00006.pdf</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/matecconf/202134500006" target="_blank" >10.1051/matecconf/202134500006</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Turbulent jet stability increased by ribs inside the nozzle – Stereo PIV measurement one diameter past the nozzle

Popis výsledku v původním jazyce

We observe that decreasing the inner nozzle surface by adding longitudinal ribs increases the jet stability in terms of the amount of turbulent kinetic energy in the near shear layer. We try to explain our observation as a stabilization effect of secondary flow vortices emerging in the corners of the ribs. These stream-wise vortices damage the development of larger-scale structures in the near shear layer. This explanation is supported by autocorrelation function of the stream-wise velocity component, which displays slightly smaller integral length-scale in the case with ribs than in the case of smooth nozzle. The experiment is performed at Reynolds number 2.2 × 105 (based on the nozzle diameter 50 mm); the Stereo-PIV (Particle Image Velocimetry) measurement takes place at the plane perpendicular to the jet axis one diameter past the nozzle exit. Optical 3D scanner controls the real nozzle geometry. This article presents preliminary measurement at single position and single velocity only; further exploration of this problem is needed.

Název v anglickém jazyce

Turbulent jet stability increased by ribs inside the nozzle – Stereo PIV measurement one diameter past the nozzle

Popis výsledku anglicky

We observe that decreasing the inner nozzle surface by adding longitudinal ribs increases the jet stability in terms of the amount of turbulent kinetic energy in the near shear layer. We try to explain our observation as a stabilization effect of secondary flow vortices emerging in the corners of the ribs. These stream-wise vortices damage the development of larger-scale structures in the near shear layer. This explanation is supported by autocorrelation function of the stream-wise velocity component, which displays slightly smaller integral length-scale in the case with ribs than in the case of smooth nozzle. The experiment is performed at Reynolds number 2.2 × 105 (based on the nozzle diameter 50 mm); the Stereo-PIV (Particle Image Velocimetry) measurement takes place at the plane perpendicular to the jet axis one diameter past the nozzle exit. Optical 3D scanner controls the real nozzle geometry. This article presents preliminary measurement at single position and single velocity only; further exploration of this problem is needed.

Druh

D - Stať ve sborníku

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

<a href="/cs/project/EF16_026%2F0008389" target="_blank" >EF16_026/0008389: Výzkumná spolupráce pro dosažení vyšší účinnosti a spolehlivosti lopatkových strojů</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2021

Kód důvěrnosti údajů

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

Název statě ve sborníku

20th Conference on Power System Engineering

ISBN

—

ISSN

2261-236X

e-ISSN

2261-236X

Počet stran výsledku

7

Strana od-do

1-7

Název nakladatele

EDP Sciences

Místo vydání

Pilsen

Místo konání akce

Pilsen

Datum konání akce

7. 9. 2021

Typ akce podle státní příslušnosti

EUR - Evropská akce

Kód UT WoS článku

000748890700006