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Full-Text Articles in Engineering
The Effect Of Viscosity On The Puddle Dynamics In Low Gravity Environment, Taif Hamed Saleh Al Juboori
The Effect Of Viscosity On The Puddle Dynamics In Low Gravity Environment, Taif Hamed Saleh Al Juboori
Dissertations and Theses
Enormous liquid puddles are observed to jump spontaneously from non-wetting substrates when exposed to the nearly step-reduction in body force common to drop tower test facilities. The phenomenon is similar to the second half of terrestrial drop bounce experiments except that (1) the initial static equilibrium configuration satisfies the static contact angle condition, (2) the initial height of the puddle is limited to the capillary height, and (3), for drop tower test durations on the order of seconds, puddle volumes can be over 104 times larger in mass (volume). The passive puddle jump mechanism provides a no-moving-parts deployment method …
Non-Contact Distillation, Rawand Muzafar Rasheed
Non-Contact Distillation, Rawand Muzafar Rasheed
Dissertations and Theses
Leidenfrost phenomenon has been studied extensively for its role in applications ranging from nuclear reactor cooling, to metals manufacturing, combustion, and other fields. Herein, Leidenfrost phenomenon is pursued towards non-contact distillation processes with hopes of reducing or even eliminating contaminant fouling. In particular, the microgravity environment of a drop tower is exploited to demonstrate the facility with which droplets achieve and sustain the Leidenfrost state. Dynamic Leidenfrost impacts in microgravity are presented for impacts on hydrophilic and superhydrophobic planar substrates, macro-pillar arrays, confined passageways, and others. Nearly ideal elastic non-contact impacts and droplet oscillation modes are observed. Dynamic Leidenfrost impacts …
Electro-Drop Bouncing In Low-Gravity, Erin Stivers Schmidt
Electro-Drop Bouncing In Low-Gravity, Erin Stivers Schmidt
Dissertations and Theses
We investigate the dynamics of spontaneous jumps of water drops from electrically charged superhydrophobic dielectric substrates during a sudden step reduction in gravity level. In the brief free-fall environment of a drop tower, with a non-homogeneous external electric field arising due to dielectric surface charges (with surface potentials 0.4-1.8 kV), body forces acting on the jumped drops are primarily supplied by polarization stress and Coulombic attraction instead of gravity. This electric body force leads to a drop bouncing behavior similar to well-known phenomena in 1-g0, though occurring for much larger drops (~0.5 mL). We show a simple …