Research at Energy-X
Energy-X is particularly interested in scientific and engineering challenges that lay at the intersection of thermal-fluid, material and energy sciences. Our current research focuses on understanding the fundamental transport science of important energy carriers (such as fluid particles, phonons, photons, exciton and charged particles) at micro, nano and molecular scales. We design, fabricate and examine a wide range of meso-, micro- and nano-devices/systems to understand their underlying physics and explore new technologies and performance breakthroughs. The general themes of our research include:
Microscale Heat Transfer
Thermal management (particularly electronic/microscale thermal management)
Microscale Physics of Boiling and Condensation Heat Transfer
Interfacial Transport Phenomena at Extreme Temperatures and Pressures
Multiphase Systems under Harsh Operating Conditions
Micro and Nano-engineered Materials
Energy Conversion and Storage Devices
Example topic areas:
-Study on phase change heat transfer process on micro- and nano-textured surfaces to understand the physics of different microscale heat transfer mechanisms involved in the process
Bubbly flow and slug flow regime over embedded layered RTD sensors
-Microscale Layering of Liquid and Vapor Phases within Microstructures for a New Generation Two-Phase Heat Sink
- Transport phenomena of rarefied gas flows in curved micro heat sinks:
Study on rarefied gas flows in Si-based microchannels by developing in-house CFD codes based on FVM method in a non-orthogonal curvilinear coordinate framework.
Relative phase shift variations between two collimated beams are being used to determine the tempereture field variations in various thermal devices.
Vapor condensation on commonly used industrial metal surfaces leads to filmwise wetting behavior with a poor thermal performance. From a fundamental standpoint, high-surface-energies of typical metals not only offer highly active nucleation sites due to a low thermodynamic energy barrier predicted by classical nucleation theory but also reduce conduction resistance to droplet growth owing to their low contact angle (CA) and intrinsic hydrophilicity. A typical hydrophilic surface, however, exhibits high contact angle hysteresis (CAH) responsible for poor droplet mobility and thus filmwise condensation. Our group is currently pursuing development of novel surfaces that exhibit both low CA and CAH for enhanced condensation heat transfer.
Of particular interest to the energy-X team is development of commercially viable and energy-efficient air conditioning (AC) solutions that offer US families comfort as well as new opportunities to save on their utility bills. Space cooling load in U.S. buildings reflected an energy end-use expenditure of $61.7 Billion in 2010; comprising more than 14% of building primary energy consumption. A large portion of this energy usage can be potentially saved if latent (dehumidification) load is handled more efficiently. In addition, standard technologies have limited-to-no capabilities to adapt to part latent load conditions at which AC systems operate most of the time. Our lab is currently developing next-gen HVAC system to address the aforementioned issues.
-Study on microscale transport phenomena in multi-species microfilms constrained by a nano-porous superhydrophobic membrane
-Transport Processes in Microscale Membrane-Based Absorber/Desorber
-Water Reuse and Desalination:
Study on falling film evaporators utilized in multi-effect desalination units operating at high vapor qualities under a sub-atmospheric pressure.