Bubble or droplet translation
Bubble or droplet translation
Introduction Forces on particle can radically modified them,and in turn to change the interaction between particles and continuous phase. This chapter consider the translation of disperse phase consists of deformable particles
Introduction • Forces on particle can radically modified them, and in turn to change the interaction between particles and continuous phase. • This chapter consider the translation of disperse phase consists of deformable particles
Dimensional analysis Translation stress may deform particles ●Need to consider -Deformation parameters Impacts on translation velocity and shape Surface tension will be force restrain the deformation ·Assumptions: Steady translation Driven by gravity
Dimensional analysis • Translation stress may deform particles • Need to consider – Deformation parameters – Impacts on translation velocity and shape • Surface tension will be force restrain the deformation • Assumptions: – Steady translation – Driven by gravity
Dimensional analysis Surface tension force,SR When magnitude of deform force approaches SR, deformation happens. For Re<<1,the deform force woR -For Re>>1,the deform force PLW2R2 So define We =2pLW2R/S For Re<<1,deformation happens when We/Re ~1 For Re>>1,deformation happens when We ~1 Therefore woo need to be defined,so F(Re,We,Fr)=0 To define a new parameter We3 Hm Fr2Re4 mp PLu PL S3
Dimensional analysis • Surface tension force, SR • When magnitude of deform force approaches SR, deformation happens. – For Re<<1, the deform force – For Re>>1, the deform force • So define – For Re<<1, deformation happens when ~1 – For Re>>1, deformation happens when We ~1 • Therefore need to be defined, so To define a new parameter
Hm 108 HELIUM-4 -TOLUENE FREON-12 OXYGEN OXYGEN NITROGEN NITROGEN 10 HELIUM-4 METHANE WATER SODIUM MERCURY 0.2 0.4 0.6 0.8 1.0 REDUCED TEMPERATURE. （T-T,)/(Te-T) Filtered Water 0.25×10-10 Turpentine 2.41×10-9 Methyl Alcohol 0.89×10-10 Olive Oil 7.16×10-3 Mineral Oil 1.45×10-2 Syrup 0.92×106
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