Evolution of mushroom-type structures behind a heated cylinder

Research output: Contribution to journalArticleAcademicpeer-review

4 Citations (Scopus)
96 Downloads (Pure)

Abstract

The three-dimensional transition in the wake flow behind a heated cylinder occurs at a much lower Reynolds number than for the unheated case. The three-dimensional transition is initialized in the near-wake by the formation of -shaped structures and manifests itself in the far-wake as escaping mushroom-type structures from the upper vortices. In this study, both experimental and numerical techniques are used to investigate the origin and development of these mushroom-type structures. The formation of the mushroom-type structures is associated with the occurrence of -shaped vortices in the near-wake. Hot fluid between the legs and the head of the -shaped structure is lifted up. This lift-up process together with the action of buoyancy pulls out hot fluid from the upper vortex cores, resulting in a mushroom-type structure, which is comprised of a so-called stem and cap. Hot fluid is continuously transported through the stem to the advancing front of the mushroom-type structure. Finally, a pinch-off phenomenon is observed of the cap, ending up as a buoyant vortex ring. An analytical model is presented for the pinch-off process.
Original languageEnglish
Article number064103
Pages (from-to)064103-1/11
Number of pages11
JournalPhysics of Fluids
Volume19
Issue number6
DOIs
Publication statusPublished - 2007

Fingerprint Dive into the research topics of 'Evolution of mushroom-type structures behind a heated cylinder'. Together they form a unique fingerprint.

Cite this