Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Numerical investigation of a perturbed swirling annular two-phase jet
AU - Siamas, George A.
AU - Jiang, Xi
AU - Wrobel, Luiz C.
PY - 2009/6
Y1 - 2009/6
N2 - A swirling annular gas-liquid two-phase jet flow system has been investigated by solving the compressible, time-dependent, non-dimensional Navier-Stokes equations using highly accurate numerical methods. The mathematical formulation for the flow system is based on an Eulerian approach with mixed-fluid treatment while an adjusted volume of fluid method is utilised to account for the gas compressibility. Surface tension effects are captured by a continuum surface force model. Swirling motion is applied at the inlet while a small helical perturbation is also applied to initiate the instability. Three-dimensional spatial direct numerical simulation has been performed with parallelisation of the code based on domain decomposition. The results show that the flow is characterised by a geometrical recirculation zone adjacent to the nozzle exit and by a central recirculation zone further downstream. Swirl enhances the flow instability and vorticity and promotes liquid dispersion in the cross-stream wise directions. A dynamic precessing vortex core is developed demonstrating that the growth of such a vortex in annular configurations can be initiated even at low swirl numbers, in agreement with experimental findings. Analysis of the averaged results revealed the existence of a geometrical recirculation zone and a swirl induced central recirculation zone in the flow field.
AB - A swirling annular gas-liquid two-phase jet flow system has been investigated by solving the compressible, time-dependent, non-dimensional Navier-Stokes equations using highly accurate numerical methods. The mathematical formulation for the flow system is based on an Eulerian approach with mixed-fluid treatment while an adjusted volume of fluid method is utilised to account for the gas compressibility. Surface tension effects are captured by a continuum surface force model. Swirling motion is applied at the inlet while a small helical perturbation is also applied to initiate the instability. Three-dimensional spatial direct numerical simulation has been performed with parallelisation of the code based on domain decomposition. The results show that the flow is characterised by a geometrical recirculation zone adjacent to the nozzle exit and by a central recirculation zone further downstream. Swirl enhances the flow instability and vorticity and promotes liquid dispersion in the cross-stream wise directions. A dynamic precessing vortex core is developed demonstrating that the growth of such a vortex in annular configurations can be initiated even at low swirl numbers, in agreement with experimental findings. Analysis of the averaged results revealed the existence of a geometrical recirculation zone and a swirl induced central recirculation zone in the flow field.
KW - Direct numerical simulation
KW - Two-phase
KW - Jet
KW - Swirl
KW - Perturbation
KW - Annular
KW - PRECESSING VORTEX CORE
KW - COHERENT STRUCTURES
KW - INFLOW CONDITIONS
KW - LIQUID SHEET
KW - SIMULATION
KW - FLOW
KW - DYNAMICS
KW - RECIRCULATION
KW - TURBULENCE
KW - INTERFACE
U2 - 10.1016/j.ijheatfluidflow.2009.02.020
DO - 10.1016/j.ijheatfluidflow.2009.02.020
M3 - Journal article
VL - 30
SP - 481
EP - 493
JO - International Journal of Heat and Fluid Flow
JF - International Journal of Heat and Fluid Flow
SN - 0142-727X
IS - 3
ER -