The vorticity field of acoustic modulated free jets
2012 (English)In: Kung Cheng Je Wu Li Hsueh Pao/Journal of Engineering Thermophysics, ISSN 0253-231X, Vol. 33, no 10, 1811-1814 p.Article in journal (Refereed) Published
The motivation of this paper is to investigate the effects of acoustic modulation on the structures of free jet. Large eddy simulation is performed on three dimensional free jet of Re number 2200 with multigrid method. Comparisons of the vorticity fields are made between the unmodulated jet and perturbed jets with different modulation frequencies. When the modulation frequency is near the preferred mode of the natural jet, the flow field changes significantly. The azimuthal vorticity rolls up into large vortex rings, and the jet spreads more widely. When the modulation frequency is about the twice of the preferred mode, vortex pairing happens and the subharmonic wave becomes dominant. The flow fields are almost the same as the natural jet when the modula-tion frequency is much higher than the preferred mode. The distribution of streamwise vorticity is examined for the modulated jet near the preferred mode, and agrees qualitatively with the experiments.
Place, publisher, year, edition, pages
2012. Vol. 33, no 10, 1811-1814 p.
Acoustic modulation, Free jet, Large eddy simulation, Multi-grid method
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-106955ScopusID: 2-s2.0-84868633439OAI: oai:DiVA.org:kth-106955DiVA: diva2:574240
FunderSwedish e‐Science Research Center
QC 201212052012-12-052012-12-052013-04-08Bibliographically approved