Details

Autor(en) / Beteiligte

• Suto, Hitoshi
• Matsubara, Koji
• Kobayashi, Mutsuo
• Watanabe, Hidehito
• Matsudaira, Yusaku

Titel

Coherent structures in a fully developed stage of a non-isothermal round jet

Ist Teil von

• Heat transfer, Asian research, 2004-07, Vol.33 (5), p.342-356

Ort / Verlag

Hoboken: Wiley Subscription Services, Inc., A Wiley Company

Erscheinungsjahr

2004

Quelle

Wiley Online Library

Beschreibungen/Notizen

• Direct numerical simulation (DNS) was performed for a non‐isothermal air jet with a Reynolds number of 1200 in order to reveal coherent structures of the developed jet. A fourth‐order central finite difference was applied to the simulation. An effort was also made to enable experimental visualization (dye mixing and PTV) to support the validity of the instantaneous structures by DNS. Computational results for two types of inlet profiles suggested that nozzle conditions scarcely affect the turbulence statistics and the coherent structures in a jet‐established stage. Two‐point correlations of velocity and temperature show that similar distributions denoting the temperature can be used as an indicator of a vortex. A conceptual model of a hairpin‐shaped vortex was proposed and validated by two‐point correlations and PDF analysis for vortex alignment. The hairpin‐shaped vortex stands with legs inclined downstream. The inclination angle and the tilting angle between the two legs are −45° and 40°, respectively. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(5): 342–356, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20014