A5101537903- Fluid Dynamics and Vibration Analysis
- Vibration and Dynamic Analysis
- Wind and Air Flow Studies
- Fluid Dynamics Simulations and Interactions
- Wave and Wind Energy Systems
- Advanced Optical Imaging Technologies
- Ship Hydrodynamics and Maneuverability
- Advanced DC-DC Converters
- Water Quality and Pollution Assessment
- Wireless Power Transfer Systems
- Semiconductor Quantum Structures and Devices
- Isotope Analysis in Ecology
- Photorefractive and Nonlinear Optics
- Marine and Coastal Research
- Digital Holography and Microscopy
- Face and Expression Recognition
- Engineering Applied Research
- Quantum Dots Synthesis And Properties
- Nanowire Synthesis and Applications
- Fluid Dynamics and Heat Transfer
- Aerodynamics and Fluid Dynamics Research
- Ocean Waves and Remote Sensing
- Multilevel Inverters and Converters
- Lattice Boltzmann Simulation Studies
- Image and Video Stabilization
Global Core Research Center for Ships and Offshore Plants
2019-2024
Pusan National University
2015-2024
University of Michigan–Ann Arbor
2011-2018
Korea Institute of Ocean Science and Technology
2004-2018
Draper Laboratory
2013-2018
Vortex Hydro Energy (United States)
2016
Kwangwoon University
2003-2015
University of Arkansas at Fayetteville
2013
Jeonju University
2013
The University of Tokyo
1989-1999
Droplet epitaxy is a flexible nanomaterial growth technique and potential method to fabricate advanced electronic optoelectronic devices. Here, we report strain-free GaAs/Al0.33Ga0.67As quantum ring solar cells fabricated by droplet technique. Photoluminescence used study the structure of lattice-matched cells. Post-growth thermal annealing improve optical quality cell as well device efficiency. A power conversion efficiency 1.8% demonstrated from prototype cell. This work opens new...
Flow-induced motion (FIM) experiments of a single circular cylinder or multiple cylinders in an array involve several configuration and hydrodynamic parameters, such as diameter, mass, damping, stiffness, spacing, Reynolds number, flow regime, deviation from cross section. Due to the importance FIM both suppression for structural robustness enhancement hydrokinetic energy conversion, systematic are being conducted since early 1960s more decades experimentation required. Change springs...
The VIVACE converter was introduced at OMAE2006 as a single, smooth, circular-cylinder module. hydrodynamics of is being improved continuously to achieve higher density in harnessed hydrokinetic power. Intercylinder spacing and passive turbulence control (PTC) through selectively located roughness are effective tools enhancement flow induced motions (FIMs) under high damping for power harnessing. Single cylinders harness energy even 1 knot currents. For downstream cylinders, questions were...
Passive turbulence control (PTC) in the form of two straight roughness strips with variable width, and thickness about equal to boundary layer thickness, is used modify flow-induced motions (FIM) a rigid circular cylinder. The cylinder supported by end springs flow TrSL3, high-lift, regime. PTC-to-FIM Map, developed previous work, revealed zones weak suppression (WS), strong (SS), hard galloping (HG), soft (SG). In this paper, sensitivity map to: (a) width PTC covering, (b) covering single...
The primary objective of this study is to examine droplet dynamics on superhydrophobic surfaces in order develop strategies reduce adhesion. investigation utilized computational fluid simulations, employing the unsteady Reynolds-averaged Navier–Stokes equations conjunction with volume method. central focus pertains behavior two droplets a substrate characterized by contact angle 155° within two-dimensional domain. parametric studies include analyzing different freestream velocities, sizes,...
Abstract Strain-free GaAs/Al 0.33 Ga 0.67 As quantum rings are fabricated by droplet epitaxy. Both photoresponse and photoluminescence spectra confirm optical transitions in rings, suggesting that epitaxial nanomaterials applicable to intermediate band solar cells. The effects of post-growth annealing on the ring cells investigated, properties with without thermal treatment characterized technique. Rapid has resulted significant improvement material quality, which can be served as a standard...
Fabrication of advanced artificial nanomaterials is a long‐term pursuit to fulfill the promises nanomaterials. In last ten years, Droplet Epitaxy has been emerging as versatile fabrication method for various complex nanomaterials, but there lack growth protocol control vertically. Here we report vertically correlated method. We find that nanodroplets form preferable on preexisting nanorings, which enables aligned nanostructures by Epitaxy. Nucleation thermodynamics and kinetics have proposed...
The effect of tandem spacing on the flow-induced motions (FIM) two circular cylinders with passive turbulence control is investigated using two-dimensional (2D) unsteady Reynolds-averaged Navier–Stokes equations Spalart–Allmaras model. Results are compared to experiments in range Reynolds number 30,000 < Re 100,000. center-to-center between varied from 2 6 diameters. Simulation results predict well all ranges FIM including vortex-induced vibrations (VIV) and galloping match experimental...
This study predicts the power consumption of an Electric Propulsion Ship (EPS) in marine environment. The EPS is driven by a propeller rotated propulsion motor, and changes motor consumes highest percentage ships' total power. Therefore, it necessary to predict determine generation capacity design efficient EPS. constructs estimation simulator for using ship motion model including environment electric model. usage factor that represents relationship between applied prediction. Four scenarios...
This paper predicts the wake-induced vibration of tandem cylinders with pivoted rotational or translational motion using fluid–structure interaction technique. Large eddy simulation a dynamic Smagorinsky subgrid-scale model is applied for turbulent flow. Structural computation to obtain displacement downstream cylinder in cross-flow direction. Conditions such as damping ratio, natural frequency, and mass ratio are same those motion. The computational conditions Re=3790, 8470 15 160,...
This paper investigates the effect of different flow models on Pre-Swirl-Stator structural response from perspective a non-existing unified design procedure. Due to viscous effects near propeller plane, hydrodynamic solution is calculated by Computational Fluid Dynamics (CFD). Three are analysed: without propeller, with actuator disk and propeller. The main intention this clarify model stresses in calm-water waves which include ship motion. CFD simulations performed means OpenFOAM, while...