Engineering Commons^™

Spectral Phonon Relaxation Time Calculation Tool Based On Molecular Dynamics, Divya Chalise, Tianli Feng, Xiulin Ruan

The Summer Undergraduate Research Fellowship (SURF) Symposium

Thermal conductivity is an important material property which affects the performance of a wide range of devices from thermoelectrics to nanoelectronics. Information about phonon vibration modes and phonon relaxation time gives significant insight into understanding and engineering material’s thermal conductivity. Although different theoretical models have been developed for studying phonon modes and relaxation time, extensive knowledge of lattice dynamics and molecular dynamics is required to compute phonon modal frequencies and relaxation times. Therefore, a computational tool which can take simple inputs to calculate phonon mode frequencies and relaxation time will be beneficial. Through this research work, such computational tool has …

Numerical Simulations Of Transcritical Natural Convection, Ruiwen Wei, Carlo Scalo, Mario Tindaro Migliorino, Kukjin Kim, Jean-Pierre Hickey

The Summer Undergraduate Research Fellowship (SURF) Symposium

In modern engineering applications, system overheating is a key issue that needs to be solved with efficient and reliable cooling technologies. Among the possible mechanisms that these are based on, natural convection cooling is one of the most frequently employed, with applications ranging from cooling of computer micro-components to large nuclear reactors. While many studies have been performed on natural convection employing supercritical or subcritical fluids, little attention has been given to fluids in their transcritical regime. The latter has the potential to yield high performances while avoiding detrimental effects of two-phase systems (e.g. cavitation). In the present study, 2D …

Secondary Atomization: Drop Breakup In A Continuous Air Jet, Grant S. Sondgeroth, Longchao Yao, Catriona M.L. White, Daniel R. Guildenbecher, Jun Chen, Paul E. Sojka

The Summer Undergraduate Research Fellowship (SURF) Symposium

Understanding drop breakup will optimize aircraft engine performance, reduce agro-chemical overspray, and improve pharmaceutical tablet efficacy. Large fuel fragments in engines lead to lowered fuel economy and higher pollutant emissions, while small drops yield more agro-spray drift into surrounding residential and environmental zones. Better pharmaceutical tablets will improve drug uptake and patient comfort.

Engineers and scientists are currently unable to predict the number, size, and velocity of fragments formed during important drop breakup processes. Therefore, we are required to measure these quantities. We use digital inline holography (DIH) to record three-dimensional diameter and position data for fragments formed during multi-mode …

Enhancing The Performance Of A Transportable Environmental Control Unit (Ecu) Operated In High-Temperature Climates, Quan Jun Sun, Ammar M. Bahman, Eckhard A. Groll

The Summer Undergraduate Research Fellowship (SURF) Symposium

Numerous people live or venture into environments, such as the Middle East, where the temperatures can skyrocket as high as 54°C. This leaves many air conditioners unable to operate efficiently. Although much research has been conducted for incorporating vapor injection processes into refrigeration systems, such as ones used in supermarkets, little has been researched regarding the application in extreme heat environments. While most basic air conditioning units do not require the addition of a vapor injection process along with an economizer, this project requires the air conditioning (AC) unit to operate under extreme high temperature conditions. The project investigates the …