Hyungson Ki
UNIST 기계공학과 · 공학
Hyungson Ki 교수의 연구실은 레이저-물질 상호작용을 중심으로 고에너지 레이저 공정의 열역학적 및 유체역학적 거동을 정밀하게 수치 시뮬레이션하는 데 전문성을 가진다. 주로 레이저 용접, 레이저 drilling, 그리고 펌토세컨드 레이저에 의한 반도체 재료 가공을 대상으로 하며, 고정밀 수치해석 기법(레벨셋 방법, 레이 트레이싱, FDTD)을 활용해 상전이, 표면장력, 다중 반사, 열전달 등 복합 현상을 통합적으로 모델링한다. 특히, 레이저가 생성하는 열적 홀의 형성과 붕괴, 열전달과 광학적 에너지 전달의 상호작용을 정량적으로 분석하는 데 초점을 맞추고 있다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
A high-energy-density laser beam-material interaction process has been simulated considering a self-evolving liquid-vapour interface profile. A mathematical scheme called the level-set technique has been adopted to capture the transient liquid-vapour interface. Inherent to this technique are: the ability to simulate merger and splitting of the liquid-vapour interface and the simultaneous updating of the surface normal and the curvature. Unsteady heat transfer and fluid flow phenomena are modelle
In laser drilling and keyhole welding, multiple reflection phenomena determine how the energy is transferred from the laser beam to the workpiece, and, most importantly, all other physics such as fluid flow, heat transfer, and the cavity shape itself depend on these phenomena. In this study, a multiple reflection model inside a self-consistent (or self-evolving) cavity has been developed based on the level set method and ray tracing technique. In the case of drilling, it is observed that the las
ABSTRACT A numerical method for multiphase incompressible thermal flows with solid–liquid and liquid–vapor phase transformations is presented. The flow is mainly driven by thermocapillary force and vaporization. Based on the level set method and mixture continuum model, a set of governing equations valid for solid, liquid, and vapor phases is derived, considering phase boundary conditions as source terms in the transport equations. The vaporization process is treated as a source term in the cont
