Numerical analysis of the flow pattern in convergent vortex tubes for cyclone cooling applications

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

“…All the models show the expected vortex precession around the centerline, most strikingly by the models ofLRR, DY and SSG that also show that the coherent structure is in the form of a double helix. This behavior is remarkably similar to the one observed in the Delayed Detached Eddy Simulations (DDES) in a convergent vortex tube (Seibold and Weigand, 2021), and in the Direct Numerical Simulations (DNS) of swirling pipe flows of Vaidya et al (2011) who suggested it to be analogous to that found in the Taylor-Couette flow that occurs between a stationary outer cylinder and a rotating inner one. It was mentioned in the Introduction that an important feature of the Precessing Vortex Core is its effect on the processes that occur at the pipe's wall.…”

“…This paper is concerned with the prediction of turbulent swirling flows in pipes in conditions leading to the formation of coherent structures that significantly modify the physical processes present. 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).…”

Experimental investigation of the influence of film cooling hole diameter on the total cooling effectiveness for cyclone-cooled turbine blades

“…Following the early thermal investigations of cyclone cooling in swirl tubes (Glezer et al, 1996;Hedlund and Ligrani, 2000), more sophisticated experimental studies were done to analyze the internal flow structure in swirl tubes (Biegger et al, 2013) with different channel outlet geometries (Grundmann et al, 2012) and duct bends Wassermann et al (2013), Bruschewski et al (2020) and Wang et al (2021). Numerical studies were carried out to understand the swirling flow in detail Biegger et al (2015) and Seibold and Weigand (2021), but the investigated geometries are still too simplified compared to the geometry of a real turbine blade. The effect of the swirling flow on the film cooling performance was investigated experimentally with the result that the orientation of the film cooling holes with respect to the swirl influences the discharge through the holes and thereby the film cooling effectiveness (Lerch et al, 2012).…”

Experimental Investigation of the Influence of Film Cooling Hole Diameter on the Total Cooling Effectiveness for Cyclone-Cooled Turbine Blades

“…Following the early thermal investigations of cyclone cooling in swirl tubes [ (Glezer et al, 1996), (Hedlund and Ligrani, 2000)], more sophisticated experimental studies were done to analyze the internal flow structure in swirl tubes (Biegger et al, 2013) with different channel outlet geometries (Grundmann et al, 2012) and duct bends [ (Wassermann et al, 2013), (Bruschewski et al, 2020), (Wang et al, 2021)]. Numerical studies were carried out to understand the swirling flow in detail [ (Biegger et al, 2015), (Seibold and Weigand, 2021)], but the investigated geometries are still too simplified compared to the geometry of a real turbine blade. The effect of the swirling flow on the film cooling performance was investigated experimentally with the result that the orientation of the film cooling holes with respect to the swirl influences the discharge through the holes and thereby the film cooling effectiveness (Lerch et al, 2012).…”