![]() ![]() Fourth, we will study oil-ice interactions which are important for the emerging science of using oil-impregnated surfaces for anti-icing and anti-frosting applications, where oil drainage from the surface due to wicking onto ice is a pressing issue. We reveal the various phenomena that govern how soap bubbles freeze and produce a variety of beautiful effects. Third, we elucidate how bubbles deposited on a chilled and icy substrate freeze in different ambient conditions. We show how the in-plane frost growth can be passively suppressed by patterning arrays of microscopic ice stripes across a surface. Second, we present a passive anti-frosting surfaces just by using the chemistry of ice. We show that increasing the packing density of vehicles at a stop-and-go motion (e.g., vehicles at a traffic light) would not increase the efficiency of the flow once it is resumed. First, we study the solid to liquid phase change of group of people moving from rest. The main focus of this dissertation is on the dynamical phase change phenomena occurring in nature. ![]() These phenomena will be modeled using thermodynamics and fluid mechanics equations. Finally, the ``Cassie'' to ``Wenzel'' transition will be investigated for layered nano-textured surfaces. Moreover, the complex physics of oil as it wicks up sheets of frost and freezing of bubble unveil completely new forms of multiphase flows that exhibit rich physical behavior. Phase-change of solidification will be discussed for different problems. However, we are going to investigate this phase-change process and show that this long standing intuition is wrong. This phase transition is motivated by the intuition that traveling as far as possible before stopping will minimize the overall travel time. When vehicles come to a stop, for example at a red light, drivers voluntarily induce a ``phase transition'' from this ``liquid phase'' to a close-packed ``solid phase''. For example, during traffic flow, drivers keep a large distance from the vehicle in front of them to ensure safe driving. We unveil completely new forms of phase-change phenomena that exhibit rich physical behavior. In this dissertation we will address seven different phase-change problems occurring in nature. Phase transition phenomena frequently occur in our daily life examples include: a ``liquid'' to ``solid'' transition when cars decrease their distance at a traffic light, solidification of liquids droplets during winter months, and the dancing of droplets on a non-sticking pan. Another form of phase change which will be discussed here is the wetting or dewetting transitions of a superhydrophobic surface, in which the phase residing within the surface structure switches between vapor and liquid. Six different types of phase-change phenomena are possible: freezing (the substance changes from a liquid to a solid), melting (solid to liquid), condensation (gas to liquid), vaporization (liquid to gas), sublimation (solid to gas), and desublimation (gas to solid). With extreme amounts of energy, temperature, or pressure, a matter can be changed between the phases. Matter on earth exists mostly in three different phases of solid, liquid, and gas. ![]()
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