Projects | Hansol Lee

Hands-on experience on infrared (IR) measurement and data processing

Tue, 28 May 2024 10:39:32 +0000

While working as an undergraduate research intern in Applied Heat Transfer Lab., I had a chance to have a hands-on experience on IR thermometry and its data processing. Specifically, I conducted calibration of an IR camera using black body radiation and data processing to estimate local heat flux in pool boiling situation using a given temperature distribution.

To calibrate the IR camera, first, the temperature within a cavity container whose inner sides are covered by black body materials is measured by the IR camera. For this cavity container, the surface temperature and the emissivity are assumed to be known. Based on the measurement, we can estimate the uncertainty of the IR camera itself and how the measured temperature is different from the known value. The result shows that the IR camera has a maximum error of 0.86 Celcius degree within the temperature range of 20 to 180 Celcius degree.

In the field of heat transfer, the data obtained from IR cameras often require the post-processing procedure such as estimating local heat flux from it. I did a short-term project to build an in-house code to estimate the local heat flux in a pool boiling situation using IR thermometry data. This work enables me to learn about solving transient 3D conduction problems and build a continuous movie form sequential solutions. The result of the work is shown in the link above this page.

Thermal-hydraulic modeling of manifold microchannels (MMC) for embedded cooling

Mon, 27 May 2024 10:39:32 +0000

Introduction

Electronics are now facing thermal bottlenecks which limit their performance due to the physical limiation of cooling its heat generation. Introduction of 3D heterongenous integration of ICs and development of the next-generation power semiconductors both have led to the necessitiy of effective and energy-efficient cooling schemes which are capable of manage very high-heat flux over 1 kW/cm $^{2}$. A manifold microchannel (MMC) heat sink is a promising cooling solution as it has a very low pressure drop and a uniform temperature distribuiton compared to conventional heat sinks. The superior performance of MMC comes from the fluid distributing manifold on top of the microchannels. However, previous models for predicing the thermal performance of MMCs have not taken into account the effects of flow distribution on its thermal performance. In this reasearch, we have developed a one-dimensional model which accounts for the effects of flow distribution on the thermal performance of MMC for the first time.

Research objectives

Results

Thermal integrity analysis for 2.5D/3D Process-in-Momery (PIM) heterogeneous package

Sun, 26 May 2024 10:39:32 +0000

ME514 Design of Cascade Thermosiphon Loop for Data Center Cooling

Sun, 25 Dec 2022 14:14:11 +0000

With an increasing trend of energy consumption required to cool data centers, designing and implementing efficient and cost-effective cooling schemes are the most urgent issues for sustainable operation of data centers. Since the heat dissipation from server boards in data centers already reached the maximum heat flux which can be coold by conventional cooling schemes such as air cooling, single-phase liquid cooling, adoption of the next-generation cooling scheme is necessary. Immersion cooling scheme is one of the promising approaches for the next-generation cooling scheme. It is capable of relatively high heat flux, and it does not require additional power sources. However,