Precessing vortex core in a swirling wake with heat release

Identification and dynamics of coherent structures in a Coanda swirling jet flow

“…Recent research has demonstrated the effects of temperature on the structure, with reduction of velocity at higher temperatures. Also, correlation between motion and stability has been demonstrated, showing the effects of co-rotation between the core and the precession of the vortex [6]. Other researchers [17,18,19] have also theorized and numerically or/and experimentally presented fundamental parameters under steady and transitional conditions of the structure.…”

“…The Precessing Vortex Core (PVC) is one of such structures present in Open Jet Flows (OJF) (i.e. unconfined jet flows) that has received vast attention in order to understand its behaviour and effects towards the flame in the last few decades [4,5,6]. Lucca-Negro and O'Doherty suggested that the structure improves mixing as a consequence of the creation of large turbulent scales [7].…”

Plasma vortex reactor for production of heat energy and hydrogen

“…First, the structure of the flow is determined by the counterflow zone, typical for swirled flows [5,6], Fig. 3.…”

“…Intensive studies of a plasma chemical reactor started a few years ago [2][3][4]. Peculiar properties of gas-dynamics and heat fluxes in the presence of longitudinal electric discharge in the swirl flow were studied in [5,6]. The test gases used in this experimental set are the following: argon, argon + water vapor, argon + water vapor + nickel micro-and nanoparticles.…”

A turbulence modeling study of the precessing vortex core in a pipe flow

“…Swirling flows in general are of enormous interest due to their wide-spread occurrence in nature and in engineering practice such as in combustion systems (Syred, 2006), swirl chambers (Hedlund et al, 1999), cyclone separators (Murphy et al, 2007;Huard et al, 2010), vortex tubes for cyclone cooling (Seibold and Weigand, 2021), and thermal energy separation by swirl (Kobiela et al, 2018). They are also a class of flows where turbulence closures of the type used in engineering design have proved to be inadequate unless modified in some ad-hoc way (Kobayashi and Yoda, 1987;Chang and Chen, 1993;Gorbunova et al, 2016). In the flows of interest here, the imposition of a tangential component of velocity on the axial flow gives rise to an interesting phenomenon, namely the generation of a well-defined helical vortex that precesses around the tube's centerline.…”