Highlights

  • World leading research on synthetic and natural low-GWP refrigerant alternatives for mobile and stationary systems, and many others
  • Leads in natural refrigerant solutions; first to work on transcritical CO2 in the US; developed technology leading to best performing CO2 MAC system ever reported in open literature
  • Leading visualization techniques in oil flows in and around compressors with quantifications of oil film thickness, oil droplets size, distribution and total mass
  • First to publish performance results on transcritical CO2 ejector system with adjustable motive nozzle geometry
  • The lowest charged ammonia and HC systems in the world using novel types of microchannel heat exchangers
  • Novel approaches to condensation by incorporating condensation in superheated zone, that allows for more physical void fraction, heat transfer, pressure drop and charge models
  • New approaches in developing two phase flow
  • Addresses all performance issues in HVAV&R: energy efficiency, sustainability, compactness, cost reduction, reliability
  • Leading visualization research in two phase flow with quantifications in boiling, condensation, void fractions
  • Leads in cycle improvements: flash gas bypass, mechanical subcooling, multi-stage compression with intercooling/economizer, vapor/liquid injection, multi-evaporator systems and control
  • Innovative & durable frost-tolerant surfaces
  • World leaders in research on durable and scalable application of ultra-thin (zero HX capacity loss) coatings for enhanced phase change heat transfer, anti-icing, anti-fouling, anti-corrosion, and anti-bacterial applications
  • Developed an ultra-conformal and cost-effective superhydrophobic coating method that can be applied to arbitrary shaped aluminum HX with any fin density and enhancement geometry. Found that test runs during ambient and wind tunnel icing is delayed by 300% compared to uncoated HX
  • Leading research in visualization of flow in small channels (including in microchannel HXs) that lead to discovery of periodic reverse flow in MC evaporators
  • Leaders in understanding of micro and nanoengineered coating application methods and degradation physics. Used our extensive knowledge to develop robust coatings for next-generation HX in HVAC&R components
  • Leaders in optimization of air-side heat transfer through novel fin designs, vortex generators, nature-inspired designs, and additive manufacturing
  • Developed a device for online measurement of oil concentration in air conditioning and refrigeration systems. A digital counter-timer together with an ultrasonic transducer determines oil concentration (within ± 0.25%) from the acoustic velocity in the refrigerant-lubricant mixture
  • Made the first measurements of liquid refrigerant carryover at the exit of an evaporator, using a laser-doppler particle analyzer to measure droplet velocity and size distributions, and establishing their relationship to slug flow in the evaporator
  • Designed and built a pressurized tribotester that provides a realistic test environment for evaluating friction and wear characteristics of compressor contact geometries, material pairs, and refrigerant-lubricant combinations. Found that tests run in a pressurized environment yield results significantly different from those obtained under non-pressurized conditions used by industry for screening studies in the past