Revision as of 19:59, 20 April 2020

Atomisation

Turbulent jet

Diesel type Jet Atomization : Diameter: 100µm, Liquid velocity 100 ms-1, Turbulence 5%, gas velocity: 0 ms-1, ${\displaystyle \rho _{liq}}$=696 kgm-3, ${\displaystyle \rho _{gas}}$=25 kgm-3

${\displaystyle \mu _{liq}}$ =1.210-3kgm-1s-1, ${\displaystyle \mu _{gas}}$=10-5kgm-1s-1, ${\displaystyle \sigma }$=0.06Nm-1 Numerical simulation by coupling Level Set / VOF / Ghost fluid methods

Mesh : 256x256x2048 (130 millions points) MPI parallelization 128 procs.

• Jet.avi

Triple disk injector

• Coupling between internal flow simulations and DNS of primary breakup
• Radius of the jet exit: 90 microns
• Mesh 256x1024x1024 (~270 millions) dx~1.44 micron
• ~3000 nodes on the (half) jet exit
• 2048 procs
• Triple.avi

Liquid/Gas mixing layer

• Air/water mixing layer
• 30m/s in air, 0.3 in water
• Grid is 512x512x1024 nodes
• Mesh size equals 48 µm.
• 2048 procs, 20 hours for 3500 time steps; Simulation on 70000 time steps, dt~=10-6 s

• Shear.avi

Air assisted atomization

• Air/water Jet « Marmottant » Modified Rudman's method two grids
• Ugas=35m/s and Uliq=0.2m/s
• ${\displaystyle \rho _{gas}}$=1,2 kg/m3 ${\displaystyle \rho _{liq}}$ =1000 kg/m3
• Lx=45.6mm (4mm+1.7mm)x8 that is 4 the « jet +gas » diameter
• Grid: 256x256x256,(512x512x512 for level set and VOF, mesh is 90µm)
• 1024 procs on Curie, 12h wall-clock for 5000 time steps.
• Simulation is 250000 time steps.
• Marmotte.avi

2D gas/liquid shear layer

• M=${\displaystyle \rho _{gas}}$${\displaystyle U_{gas}}$^2 / ${\displaystyle \rho _{liq}}$${\displaystyle U_{liq}}$^2 = 16
• Ugas=30 m/s Uliq=0.26 m/s
• ${\displaystyle \rho _{gas}}$=1,2 kg/m3 ${\displaystyle \rho _{liq}}$ =1000 kg/m3
• Lx=80mm, Ly=40 mm 10mm water + 10mm air + 20mm quiet
• Grid: 1024x512(that is 2048x1024 level set and VOF, mesh is 40 µm)
• 512 procs on Curie
• 18h wall clock for 100000 time steps.
• Simulation on 2 000 000 time steps
• 2Dliquid_shear_layer.avi

Air assisted atomization

• Air/water Jet « Marmottant » RUDMAN-TYPE Technique with one grid
• Ugas=22.6m/s and Uliq=0.27m/s
• ${\displaystyle \rho _{gas}}$=1,2 kg/m3 ${\displaystyle \rho _{liq}}$ =1000 kg/m3
• Lx=34.2mm (4mm+1.7mm)x6 that is 3 x the « jet +gas » diameter
• Grid: 256x256x256,(mesh is 134µm)
• 512 procs on Curie, 12h wall-clock for 30000 time steps.
• Grid: 512x512x512
• Grid: 512x512x1024
• 8192 procs on TURING, 16h wall clock for 6000 time steps.
• Marmotte.avi

Air assisted atomization

• Same configuration
• Initial boundary layers included
• Grid:512x512x1024
• Oct_15_2015.avi
• Helicoïdal behaviourin simulations (experimentally observed)
• helicoid.avi