Research

The sloshing effect refers to the vigorous movement of the liquid’s free surface inside a container in response to the container’s motion. This phenomenon displays highly nonlinear behavior, making its precise definition quite challenging. To gain deeper insights, we conducted the Single Impact Wave experiment, which accurately identified the wave responsible for generating breaking waves. These breaking waves are known to impose significant sloshing loads, especially under low filling conditions. Consequently, we thoroughly investigated the dynamic and flow characteristics of these mesmerizing breaking waves. Moreover, to further enhance our understanding of the sloshing phenomenon, we are integrating Computational Fluid Dynamics (CFD) and AI techniques into our research.

Liquid film spreading aided by gravity, jet flow, or surface rotation plays a crucial role in various industries such as semiconductor manufacturing, glass production, cleansing processes, and airfoil icing during flight. Our research focuses on investigating the mesmerizing interplay of surface waves, contact line dynamics, and mass transfer that occur during film spreading. As precision engineering demands increase, these intriguing phenomena is capturing more attention recently. Our team conducts extensive visualizations of liquid film spreading on rotating disks and falling films, diving deep into the physics of solitary waves and partial wetting. To improve efficiency, we are developing low-order numerical models that can compute flow physics much faster than existing 3D CFD models. Furthermore, ongoing studies are centered on the control of spreading film flow.

Slug flow has drawn attention for industrial applications because it is one of the most prevalent and problematic two-phase flows due to severe pressure fluctuations. The effects of rib elements installed at the inner walls of a channel on the flow structure and pressure fluctuations are experimentally investigated with particular focus on how the rib elements alter slugging phenomena as compared with a smooth channel without ribs. For the slug flow in ribbed channels, pressure fluctuations are alleviated because of air bubble entrainment. Two distinct mechanisms of air bubble entrainment are suggested to accounts for different levels of pressure fluctuation mitigation and the increase in flow randomness, which depend on the width-to-height ratio of the rib geometry.

Sloshing refers to any motion of a free liquid surface inside a container against external forces exerted on the container. Because of a wide range of industrial applications, numerous researches have been conducted to mitigate the impact by the sloshing flow, using additional internal structures such as baffles. Furthermore, some structures should be mounted inside a container for special purposes such as pump tower, and nuclear power reactor. To better understand how internal components affect the sloshing dynamics, we experimentally investigate water level fluctuation, velocity field, and peak pressure response on tank side walls under several arrangements of cylindrical structures inside the tank.

Liquid film flow is observed in numerous industrial applications including biochemical processes, semiconductor manufacturing, engines, and condensers. Capillary waves form in most film flows, and these waves significantly influence heat/mass transport and droplet generation. Therefore, it is desirable to elucidate the statistical characteristics of the capillary waves formed by the liquid film. We experimentally investigate the liquid film flowing on a rotating disk and an inclined plate and also conduct numerical simulations based on low-order modeling to reduce computing cost.