图书馆订购 Guest

ISSN Online: 2377-424X

International Heat Transfer Conference 12
August, 18-23, 2002, Grenoble, France

Coherent Structures of Flow and Scalar Transfer in a Round Jet

Get access (open in a dialog) DOI: 10.1615/IHTC12.2100
6 pages

摘要

Direct numerical simulation (DNS) was performed for a non-isothermal air jet of the Reynolds number equal to 1200. High order finite difference was applied to the simulation. Emphasis is put on coherent structures in the established stage. Effort was also made for experimental visualization supporting the validity of instantaneous structures by DNS. Using various vortex detectors, small scale hairpin-shape structures and large scale branch-shape structures are found in established stage. Hairpin-shape vortex was suggested to be key structure that controls scalar mixing. Conceptual model of hairpin-shape vortex is thus proposed and validated by the PDF analysis for vorticity alignment. Suggestions of the conceptual model are that hairpin-shape vortex stands with legs inclined downstream, and that the inclination angle and the tilting angle between two legs are -45° and 40°, respectively.