Experimental Investigation of Vortex Shedding of a Jet in Crossflow

Kiel, Barry; Murawski, C. G.; Gogineni, Sivaram; Cox, A.J.; Flanagan, Michael J.

doi:10.2514/6.2003-182

Cited by 3 publications

(4 citation statements)

References 8 publications

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“…An unconfined helium conventional jet in crossflow was modeled with Fuego. As noted by researchers some time ago, a conventional jet in crossflow has a parabolic-like trajectory that is a function of the ratio of the jet nozzle and crossflow velocities [Keffer and Baines, 1963;Pratte and Baines 1967;Blevins, 1992;Kiel et al, 2003]; see Figure 104. Kiel…”

Section: Conventional Jet In Crossflowmentioning

confidence: 95%

“…Consequently, Figure 151C shows that the two jets were unable to reach the lower plate. This is a basic effect of conventional jets in crossflow [Pratte and Baines, 1967;Nirmolo, 1970;Chassaing, P. et al, 1974;Kamotani and Greber, 1974;Sucec and Bowley, 1976;Patankar, Basu, and Alpay, 1977;Goldstein and Behbahani, 1982;Kavsaoglu and Schetz, 1989;Blevins, 1992;Rivero, Ferre, and Giralt, 2001;Kiel et al, 2003;Kawai and Lele, 2007] and swirling jets in crossflow [Kavsaoglu and Schetz, 1989;Denev, Frohlich, and Bockhorn, 2009;Kamal, 2009]: the higher the ratio of crossflow velocity to jet velocity, the faster the jet will bend in a parabolic profile. Figure 151D shows the fluid temperature as seen from the bottom.…”

Section: Multiphysics Advanced Swirling-jet Lp Modelingmentioning

confidence: 99%

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Swirling jets for the mitigation of hot spots and thermal stratification in the VHTR lower plenum.

Rodríguez¹

2011

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The literature indicates that a prismatic-core very high temperature reactor can experience thermal stratification and hot spot issues in the lower plenum (LP). This research hypothesizes that the complex thermalhydraulic phenomena in the LP requires a sophisticated computational fluid dynamics (CFD) code with state-of-the-art turbulence models and advanced swirling jet technology to mitigate the two issues. The primary research goals were to increase the heat transfer and mixing capacity of swirling jets, extend swirling jet theory, and to apply those advancements for the mitigation of the thermalhydraulic issues. First, it was demonstrated that the Fuego CFD code successfully modeled a set of key LP thermalhydraulic phenomena. Thereafter, a helicoid vortex swirl model was developed to investigate the impact of the swirl number (S) on mixing and heat transfer. The development of azimuthal and axial velocities that are solely functions of S permitted the analysis of the central recirculation zone's (CRZ) impact on the LP flow field. At this point, several characteristics were found in common between the helicoid vortex and other axisymmetric, Newtonian, incompressible vortices found in the literature. This observation resulted in a more fundamental understanding of how vortices behave, and which traits can be exploited for the purpose of maximizing heat transfer and mixing. Because the CRZ is a strong function of the azimuthal and axial velocities, shaping those velocity profiles had a substantial impact. Eventually, this led to the discovery that vortices may be expressed as alternating series that expand geometrically with odd exponents. This helped corroborate that the 15 axisymmetric vortices discussed in this research are part of a vortex family with seven common traits. This also led to the development of new vortices that are based on one or two series terms that satisfy the Navier-Stokes equations and conservation of mass. In addition, the impact of Reynolds number and swirl decay were explored in order to further quantify their impact. Finally, the above theories and modeling insights were applied towards a comprehensive set of LP calculations that showed that the swirling jets mitigated the entrainment and hot spot issues, while resulting in a reasonable pressure drop. Contents

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Section: Conventional Jet In Crossflowmentioning

confidence: 95%

Section: Multiphysics Advanced Swirling-jet Lp Modelingmentioning

confidence: 99%

Swirling jets for the mitigation of hot spots and thermal stratification in the VHTR lower plenum.

Rodríguez¹

2011

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“…Consequently, Figure 19C shows that these two jets are unable to reach the lower plate. This is a basic effect of conventional jets in crossflow (Blevins, 1992;Chassaing et al, 1974;Goldstein and Behbahani, 1982;Kamotani and Greber, 1974;Kavsaoglu and Schetz, 1989;Kawai and Lele, 2007;Kiel et al, 2003;Patankar, Basu, and Alpay, 1977;Rivero, Ferre, and Giralt, 2001;Sucec and Bowley, 1976;Nirmolo, 1970;Pratte and Baines, 1967), and swirling jets in crossflow (Denev, Frohlich, and Bockhorn, 2009;Kamal, 2009;Kavsaoglu and Schetz, 1989): the higher the ratio of crossflow velocity to the jet velocity, the faster the jet will bend in a parabolic profile. Figure 19D shows the fluid temperature as seen from the bottom.…”

Section: Multiphysics Advanced Swirling-jet Lp Modelingmentioning

confidence: 99%

Recent Advances in Modeling Axisymmetric Swirl and Applications for Enhanced Heat Transfer and Flow Mixing

Rodriguez¹,

El‐Genk²

2011

Two Phase Flow, Phase Change and Numerical Modeling

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“…S/TJICFs are often encountered in practical applications such as flow-induced noise reduction (Zhao et al 2020a, b), tunnel smoke confinement, biological safety cabinet confinement, and blade cooling (Acharya et al 2006;Zhao et al 2018a, b;Luo et al 2013;Huang and Chou 2009), and as such have attracted much research interest. Many researchers have performed studies on S/TJICF from different perspectives, e.g., vortical structure development (Fearn and Weston 1974;Santiago and Dutton 1997;Kiel et al 2003), the effect of the jet number (Gutmark et al 2011;Makihata and Miyai 1979), jet interaction (Isaac 1982;Isaac and Jakubowski 1985;Yu et al 2006;Lai and Lee 2010), and effects of nozzle shape (Gutmark et al 2008;Kumar et al 2011). In the study of the jet in crossflow, the trajectory of S/TJICF has always been an important research focus because it helps to predict the overall flow field development.…”

Section: Introductionmentioning

confidence: 99%

Numerical Study of the Trajectory, Penetration, and Interaction of Single and Tandem Jets in a Crossflow Using LES

Huang,

Zhao,

Bennett

2024

J. Aerosp. Eng.

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In this paper, a large eddy simulation (LES) method was used to conduct a study on single and tandem jets in a crossflow, focusing particularly on their trajectory, penetration, and interaction. The numerical model was validated with an experimental test campaign. Examination of the time-averaged flow field allowed both the velocity and the tangential angle of the jet trajectories to be examined. In addition, the penetration depth of the jet based on a scalar transport model was analyzed. The unsteady flow characteristics around the trajectories were studied using both the power spectral density (PSD) function and a spectral proper orthogonal decomposition (SPOD). The results show that the upstream jet's trajectory changes little as a function of spacing, while the downstream jet deflects as a result of the influence of the counterrotating vortex pair. In addition, the curve height of the tandem jet trajectories is significantly higher than that of the single jet. The height of the trajectory formed by the tandem jets can reach four times that of the single jet, and the penetration depth of the tandem jets can be 2.8 times that of the single jet. Meanwhile, when the spacing between the two jets is small, the coherent structures tend toward the upstream jet distribution, and the fluctuation frequency after mixing is dominated by the upstream jet. With the increase of spacing, the fluctuation frequency after mixing is greatly affected by the downstream jet, and the frequency decreases. Furthermore, when the dimensionless spacing D 0 is 5.67, the frequency difference between both jets is minimal and the coherent structures are significantly reduced, indicating that flow mixing is optimal and stable.

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Experimental Investigation of Vortex Shedding of a Jet in Crossflow

Cited by 3 publications

References 8 publications

Swirling jets for the mitigation of hot spots and thermal stratification in the VHTR lower plenum.

Swirling jets for the mitigation of hot spots and thermal stratification in the VHTR lower plenum.

Recent Advances in Modeling Axisymmetric Swirl and Applications for Enhanced Heat Transfer and Flow Mixing

Numerical Study of the Trajectory, Penetration, and Interaction of Single and Tandem Jets in a Crossflow Using LES

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