Skip to main content

Hyungson Ki

Ulsan National Institute of Science and Technology · Engineering

About the Lab

Professor Hyungson Ki's research lab specializes in numerical modeling and simulation of laser-material interactions, with a focus on multiphase flows, phase transformations, and energy transfer dynamics in high-precision manufacturing processes such as laser drilling, welding, and micromachining. The lab develops advanced computational techniques—such as the level set method, ray tracing, and finite-difference time-domain (FDTD) simulations—to accurately capture complex phenomena including self-evolving keyhole cavities, thermocapillary convection, vaporization, and multiple internal reflections of laser beams. Their work integrates electromagnetic field simulation, heat transfer, fluid dynamics, and phase change modeling to predict and optimize laser processing outcomes at micro- and nanoscales. The research has strong applications in materials processing, semiconductor manufacturing, and advanced energy systems.

laser-material interactionmultiphase flowlevel set methodfemtosecond laserthermal modeling

Research Overview

Papers
92
Total Citations
2,677
Papers (5y)
22
Primary Field
Engineering

Research Output Trend

Figures are computed from collected data and may differ slightly.

Publications per year (5y)
22total
2022
2023
2024
2025
2026
Citations per year (5y)
231total
20222023202420252026

Selected Papers

15
1
Article|285 citations·2002
Modeling of laser keyhole welding: Part I. mathematical modeling, numerical methodology, role of recoil pressure, multiple reflections, and free surface evolution
Hyungson Ki, J. Mazumder, Pravansu Mohanty
SJR Q1Metallurgical and Materials Transactions A
Mechanical EngineeringEngineering
2
Article|162 citations·2002
Modeling of laser keyhole welding: Part II. simulation of keyhole evolution, velocity, temperature profile, and experimental verification
Hyungson Ki, J. Mazumder, Pravansu Mohanty
SJR Q1Metallurgical and Materials Transactions A
Mechanical EngineeringEngineering
3
Article|133 citations·2001
Modelling of high-density laser-material interaction using fast level set method
Hyungson Ki, P S Mohanty, J. Mazumder
SJR Q1Journal of Physics D Applied PhysicsOA

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

Computational MechanicsEngineering
4
Article|89 citations·2002
Multiple reflection and its influence on keyhole evolution
Hyungson Ki, Pravansu Mohanty, Jyotirmoy Mazumder
SJR Q3Journal of Laser Applications

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

Computational MechanicsEngineering
5
Article|88 citations·2018
Investigation of cut quality in fiber laser cutting of CFRP
Sehyeok Oh, Inyong Lee, Young-Bin Park, Hyungson Ki
SJR Q1Optics & Laser TechnologyOA
Computational MechanicsEngineering
6
Article|58 citations·2010
Level set method for two-phase incompressible flows under magnetic fields
Hyungson Ki
SJR Q1Computer Physics Communications
Computational MechanicsEngineering
7
Article|48 citations·2019
Deep learning model for predicting hardness distribution in laser heat treatment of AISI H13 tool steel
Sehyeok Oh, Hyungson Ki
SJR Q1Applied Thermal Engineering
Mechanical EngineeringEngineering
8
Article|47 citations·2021
Deep-learning-based real-time monitoring of full-penetration laser keyhole welding by using the synchronized coaxial observation method
Hyeongwon Kim, Kimoon Nam, Sehyeok Oh, Hyungson Ki
SJR Q1Journal of Manufacturing Processes
Mechanical EngineeringEngineering
9
Article|45 citations·2017
Prediction of hardness and deformation using a 3-D thermal analysis in laser hardening of AISI H13 tool steel
Sehyeok Oh, Hyungson Ki
SJR Q1Applied Thermal EngineeringOA
Mechanical EngineeringEngineering
10
Article|38 citations·2005
A Numerical Method for Multiphase Incompressible Thermal Flows with Solid–Liquid and Liquid–Vapor Phase Transformations
Hyungson Ki, Pravansu Mohanty, J. Mazumder
SJR Q3Numerical Heat Transfer Part B Fundamentals

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

Computational MechanicsEngineering
11
Article|37 citations·2015
Pulsed laser deposition of refractive-index-graded broadband antireflection coatings for silicon solar cells
Chun Deng, Hyungson Ki
SJR Q1Solar Energy Materials and Solar Cells
Surfaces, Coatings and FilmsMaterials Science
12
Article|36 citations·2012
Process map for laser heat treatment of carbon steels
Hyungson Ki, Sangwoo So
SJR Q1Optics & Laser Technology
Computational MechanicsEngineering
13
Article|35 citations·2012
Pulsed laser deposition of functionally gradient diamond-like carbon (DLC) films using a 355 nm picosecond laser
Hongrae Cho, Sanseo Kim, Hyungson Ki
SJR Q1Acta Materialia
Materials ChemistryMaterials Science
14
Article|33 citations·2015
A study of keyhole geometry in laser welding of zinc-coated and uncoated steels using a coaxial observation method
Jaehun Kim, Sehyeok Oh, Hyungson Ki
SJR Q1Journal of Materials Processing TechnologyOA
Mechanical EngineeringEngineering
15
Article|32 citations·2014
Scaling law for penetration depth in laser welding
Jaehun Kim, Hyungson Ki
SJR Q1Journal of Materials Processing Technology
Mechanical EngineeringEngineering

Research Areas

Mechanical EngineeringComputational MechanicsMaterials ChemistryElectrical and Electronic EngineeringSurfaces, Coatings and FilmsBiomedical Engineering

Dive deeper into Hyungson Ki's research on Nubint

Open this lab's papers in the app to read with AI, summarize, and cite in your writing.