0196150 - UH-J 20013073 RIV AU eng C - Conference Paper (international conference)
Kolář, Václav - Takao, H. - Todoroki, T. - Savory, E. - Okamoto, S. - Toy, N.
Vorticity transport associated with the dominant vortical structure of twin jets in crossflow.
Proceedings of the 14th Australasian Fluid Mechanics Conference. Adelaide: Department of Mechanical Engineering, Adelaide University, 2001, s. 741-744. ISBN 1-876346-33-7.
[Australasian Fluid Mechanics Conference /14./. Adelaide (AU), 09.12.2001-14.12.2001]
R&D Projects: GA AV ČR IAA2060803
Keywords : jets in crossflow * vorticity transport
Subject RIV: BK - Fluid Dynamics

The present work is concerned with "twin jets in crossflow" (TJICF), where the configuration consists of a pair of identical jet nozzles and jet-flow conditions at the nozzle exits. The mean flow velocity vector and associated turbulence statistics of the TJICF have been determined using the standard crossed hot-wire anemometry technique. In the present contribution two geometrically symmetric TJICF arrangements, namely tandem and side-by-side arrangements (both with a nozzle centre-to-centre separation of 5D), are examined, focusing upon the dominant vortical structure rather similar to that of the well-known contrarotating vortex pair (CVP) of the single JICF. The formation and decay of this dominant vortical structure is closely associated with the turbulent vorticity transport. The two TJICF arrangements under consideration have their own specific vorticity features which are, firstly, visualized and interpreted in terms of turbulent vorticity fluxes. Secondly, the vorticity transport analysis shows the vortex-strength decay (i.e. circulation decay) as described by the corresponding integral decay-rate formula. The similarities and differences between the vorticity features associated with the two different TJICF (i.e. tandem and side-by-side) arrangements and the single jet case are examined and discussed. The TJICF flow phenomenon represents an interaction of two single JICFs and the gross qualitative features of the vortex formation process of resulting (mean-flow) dominant vortical structure are described.
Permanent Link: http://hdl.handle.net/11104/0091793