Flow Dynamics and Mixing of a Transverse Jet in Crossflow—Part II: Oscillating Crossflow

Zhang, Liwei; Yang, Vigor

doi:10.1115/1.4035809

Cited by 3 publications

(1 citation statement)

References 21 publications

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“…Immediately downstream of the injection slit, the kerosene flow separates and then reattaches to the wall, creating a stagnation point with a locus of positive divergence (node) at x = 90.6 mm; this structure is typical of a transverse jet in crossflow. 41,42 The swirl-induced centrifugal force and the expanding GOX stream push the kerosene toward the wall, as shown by the slightly tilted streamlines between x = 93 and 103. zone at the divergent point and a large recirculation zone in the downstream region. Secondary recirculation bubbles also appear.…”

Section: B Mean Flow Propertiesmentioning

confidence: 99%

Supercritical fluid flow dynamics and mixing in gas-centered liquid-swirl coaxial injectors

Zhang

Wang

et al. 2018

Physics of Fluids

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Gas-centered, liquid-swirl coaxial injectors similar to those used in the main chambers of oxidizerrich staged-combustion engines are investigated computationally, in terms of supercritical fluid flow dynamics and mixing. Gaseous oxygen (GOX) is axially directed through a center post at a temperature of 687.7 K. Kerosene is tangentially introduced into the outer coaxial swirler at a temperature of 492.2 K. The mean chamber pressure of 253.0 bars substantially exceeds the thermodynamic critical pressures of oxygen and kerosene. The end of the GOX post is recessed from the entrance of the taper region, which is connected downstream to an open domain. A wide range of recess lengths (and correspondingly, fuel shielding collar lengths) is considered to determine the dependence of flow characteristics on this geometric parameter. Special attention is given to the regions downstream of the GOX post end and in the taper section, where primary mixing occurs. Instantaneous and time-averaged flow properties, as well as mixing effectiveness, are examined. Results indicate that the recess length plays a critical role in determining the flow evolution and mixing behaviors. In a fully recessed injector without fuel shielding, the initial kerosene/GOX interaction resembles a swirling transverse jet into a crossflow, and flow recirculation occurs near the kerosene injection slit and the head end. In other injectors with fuel shielding, the kerosene flow is predominantly axial before it enters the mixing zone; the coflow kerosene and GOX streams expand radially and recirculate in the wake of the GOX post. Flow unsteadiness arising from the fluid injection and mixing and vorticity production in the boundary layer of the GOX stream, along the wall of the fuel passage, and at the kerosene/GOX interface cause the development of salient vortical structures in the downstream flowfield. The geometric changes at the entrance of the taper region and at the injector exit further alter the flow dynamics, inducing multiple toroidal recirculation zones and secondary vortex structures.

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Section: B Mean Flow Propertiesmentioning

confidence: 99%

Supercritical fluid flow dynamics and mixing in gas-centered liquid-swirl coaxial injectors

Zhang

Wang

et al. 2018

Physics of Fluids

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Polydisperse Spray Modeling Using Eulerian Method

Sarkar¹,

Munshi²,

Mukhopadhyay³

et al. 2020

Sustainable Development for Energy, Power, and Propulsion

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Analysis of High-Frequency Dynamics of a Reacting Jet in Crossflow Based on Large Eddy Simulation

Bonnaire,

Polifke

2023

Journal of Engineering for Gas Turbines and Power

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Distributed combustion systems have shown the potential to reduce emissions as well as increase load and fuel flexibility. A characteristic feature of such systems is a reacting jet in crossflow, which exhibits complex vortical structures. In this paper, a generic combustion chamber with elliptic reacting jets in crossflow is examined, operating under lean-premixed conditions at elevated pressure and exhibiting high-frequency transverse mode shapes. It can be seen that depending on the orientation of the elliptical shape of the jet to the crossflow, thermoacoustic modes can be suppressed. A multidimensional Fast Fourier Transform shows that low aspect ratios (major axis of the jet aligned with the crossflow) result in the mixed 1L1T mode of first longitudinal and first transverse structure, while this mode disappears at high aspect ratios. To get a more detailed insight into the different vortex systems of the various aspect ratios, Dynamic Mode Decomposition is applied. This modal decomposition technique reveals for low aspect ratios a shear layer mode that oscillates at a frequency close to the acoustic mixed mode. For this configuration, a mode representing a flapping motion is also identified. For high aspect ratios, the shear layer vortex increases its frequency and a higher-frequent mode appears in the acoustic spectrum.

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Flow Dynamics and Mixing of a Transverse Jet in Crossflow—Part II: Oscillating Crossflow

Cited by 3 publications

References 21 publications

Supercritical fluid flow dynamics and mixing in gas-centered liquid-swirl coaxial injectors

Supercritical fluid flow dynamics and mixing in gas-centered liquid-swirl coaxial injectors

Polydisperse Spray Modeling Using Eulerian Method

Analysis of High-Frequency Dynamics of a Reacting Jet in Crossflow Based on Large Eddy Simulation

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