Department of Mechanical and Aerospace EngineeringOUR PEOPLE
Christopher Yu-Hang CHAO 趙汝恒
MS, PhD, UC Berkeley
BSc(Eng), University of Hong Kong
Head & Chair Professor of Mechanical and Aerospace Engineering



Prof. Chao graduated from the University of Hong Kong with a first class honors in Mechanical Engineering in 1988. He obtained his Master's and Doctoral degrees from the University of California at Berkeley, majoring in Thermosciences, in 1992 and 1994 respectively. He has a wide range of research interests in the areas of Built Environment, Energy and Environmental Engineering. He serves as a Regional Editor of Journal of Indoor and Built Environment and is on the editorial board of a number of other International Journals including Indoor Air, Building and Environment, and Building Simulation, etc. Prof. Chao is Director of the Building Energy Research Center (BERC). He was Associate Dean of Engineering (Research and Graduate Studies) from Sept of 2011 to June of 2014 and has been Head of Department of Mechanical and Aerospace Engineering since July of 2014. Prof. Chao is a Fellow of The American Society of Mechanical Engineers (FASME), The Institution of Mechanical Engineers (FIMechE), The Chartered Institution of Building Services Engineers (FCIBSE), The Hong Kong Institution of Engineers (FHKIE) and is also a member of The Academy of Fellows of the International Society of Indoor Air Quality and Climate (FISIAQ). He was Vice President (Policy) of the International Society of Indoor Air Quality and Climate (ISIAQ) from 2014 to 2016 and was the Vice President of the Indoor Air 2014 conference. Prof. Chao was a member of the Engineering Panel of the Hong Kong Research Grant Council (RGC) from 2011-2017, and also a vetting member of the Innovation and Technology Fund Research Projects Assessment Panel (Foundation Industry). He is a HKUST Senate member and also a Council member. Prof. Chao is a member of the Steering Committee of the Pilot Green Transport Fund of the Hong Kong Environment Bureau, the Building Committee of the Housing Authority, the Sir Edward Youde Memorial Fund Council, and the Buildings Appeal Tribunal Panel.
 

 

Teaching Activities

MECH1905 Buildings for Contemporary Living
IBTM5430 Indoor Air Quality Technology and Management

 

 

Research Interests

Energy and Built Environment: Smart Green Building Technology, Adsorption Cooling and Refrigeration, Passive Radiative Cooling, Low Speed Wind Turbine, Nanofluid Heat Transfer, Contaminant Transport in Indoor Environments, Aerosol Dynamics, Infectious Disease Transmission Risk, Combustion and Fire Safety

 

 

Research Projects

Professor Chao has managed more than 50 research projects as Project Manager and Principal Investigator with a total research grant of over HK$100 Million since he joined HKUST in 1997. Some of the ongoing projects are listed below:

  1. Study of Cooling Effect by Surface Treatment and its Application to Smart Green Buildings, Collaborative Research Fund, Research Grant Council, C6022-16G, June 30, 2017 - June 29, 2020.
  2. Development of a High Performance Passive Radiative Cooler for Buildings, Innovation and Technology Commission, ITS/013/16, Feb 1, 2017 - July 31, 2018.
  3. Development of a Capillary-assisted and Nanofluid based Evaporator for use in Adsorption Cooling Systems, Research Grant Council, 16201114, 2015-2017.
  4. Resuspension of Bioaerosols on Surfaces loaded with Dust and its Effect on Microorganism Viability, Research Grant Council, 16200315, 2016-2018.
  5. Investigation of Enhancement of Particle Deposition by Micro-structured Surfaces in Turbulent Flows, Research Grant Council, 16207817, 2018-2020.

 

 

Selected Publications

(Professor Chao has published over 120 refereed Journal Articles/ Book Chapters and over 100 conference papers and invited presentations. Some are listed below.)
 

  1. W.T. Yuen, S.C. Fu and C.Y.H. Chao, The Effect of Aerosol Size Distribution and Concentration on the Removal Efficiency of an Acoustic Aerosol Removal System, Journal of Aerosol Science, 104, pp. 79-89, 2017.
  2. C.Y. Tso, K.C. Chan and C.Y.H. Chao, A Field Investigation of Passive Radiative Cooling under Hong Kong’s Climate, Renewable Energy, 106, pp. 52-61, 2017.
  3. H.H. Lee, S.C. Fu, C.Y. Tso and C.Y.H. Chao, Study of Residue Patterns of Aqueous Nanofluid Droplets with Different Particle Sizes and Concentrations on Different Substrates, International Journal of Heat and Mass Transfer, 105, pp. 230-236, 2017.
  4. W.T. Leung, S.C. Fu, and C.Y.H. Chao, Detachment of Droplet by Air Jet Impingement, Aerosol Science and Technology, 51, pp. 467-476, 2016.
  5. A. Hussain, C.Y. Tso and C.Y.H. Chao, Experimental Investigation of a Passive Thermal Management System for High-powered Lithium Ion Batteries using Nickel Foam-paraffin Composite, Energy, 115, pp. 209-218, 2016.
  6. W.T. Yuen, S.C. Fu and C.Y.H. Chao, The Correlation between Acoustic Streaming Patterns and Aerosol Removal Efficiencies in an Acoustic Aerosol Removal System, Aerosol Science and Technology, 50, pp. 52-62, 2016.
  7. C.Y. Tso and C.Y.H. Chao, Solid-State Thermal Diode with Shape Memory Alloys, International Journal of Heat and Mass Transfer, 93, pp. 605-611, 2016.
  8. C.Y. Tso and C.Y.H. Chao, Study of Enthalpy of Evaporation, Saturated Vapor Pressure and Evaporation Rate of Aqueous Nanofluids, International Journal of Heat and Mass Transfer, 84, pp. 931-941, 2015.
  9. W.T. Yuen, S.C. Fu, J.K.C. Kwan, and C.Y.H. Chao, The Use of Nonlinear Acoustics as an Energy-Efficient Technique for Aerosol Removal, Aerosol Science and Technology, 48, pp. 907-915, 2014.
  10. S.C. Fu, W.T. Leung, and C.Y.H. Chao, Detachment of Droplets in a Fully Developed Turbulent Channel Flow, Aerosol Science and Technology, 48, pp. 916-923, 2014.
  11. C.Y. Tso, S.C. Fu and C.Y.H. Chao, A Semi-analytical Model for the Thermal Conductivity of Nanofluid and Determination of the Nanolayer Thickness, International Journal of Heat and Mass Transfer, 70, pp. 202-214, 2014.
  12. G.N. Sze-To, Y. Yang, J.K.C. Kwan, S.C.T. Yu and C.Y.H. Chao, Effects of Surface Material, Ventilation and Human Behavior on Indirect Contact Transmission Risk of Respiratory Infection, Risk Analysis, 34(5), pp. 818-830, 2014.
  13. L. Morawska, A. Afshari, G.N. Bae, G. Buonanno, C.Y.H. Chao, O. Hänninen, W. Hofmann, C. Isaxon, E.R. Jayaratne, P. Pasanen, T. Salthammer, M. Waring, and A. Wierzbicka, Indoor Aerosols: From Personal Exposure to Risk Assessment, Indoor Air, 23(6), pp. 462-487, 2013.
  14. K.C. Chan and C.Y.H. Chao, A Theoretical Model on the Effective Stagnant Thermal Conductivity of an Adsorbent Embedded with a Highly Thermal Conductive Material, International Journal of Heat and Mass Transfer, 65, pp. 863-872, 2013.
  15. W.T. Leung, S.C. Fu, G.N. Sze-To and C.Y.H. Chao, Comparison of the Resuspension Behaviour between Liquid and Solid Aerosols, Aerosol Science and Technology, 47, pp. 1239-1247, 2013.
  16. S.C. Fu, C.Y.H. Chao, R.M.C. So and W.T. Leung, Particle Resuspension in a Wall-Bounded Turbulent Flow, Journal of Fluids Engineering, 135(4), pp. 041301-9, 2013.
  17. W.T. Leung, G.N. Sze-To, C.Y.H. Chao, S.C.T. Yu and J.K.C. Kwan, Study on the Inter-Zonal Migration of Airborne Infectious Particles in an Isolation Ward Using Benign Bacteria, Indoor Air, 23, pp. 148-161, 2013.
  18. C.Y. Tso, C.Y.H. Chao and S.C. Fu, Performance Analysis of a Waste Heat Driven Activated Carbon Based Composite Adsorbent – Water Adsorption Chiller Using Simulation Model, International Journal of Heat and Mass Transfer, 55, pp. 7596-7610, 2012.
  19. K.C. Chan, C.Y.H. Chao, G.N. Sze-To and K.S. Hui, Performance Predictions for a New Zeolite 13X/CaCl2 Composite Adsorbent for Adsorption Cooling Systems, International Journal of Heat and Mass Transfer, 55, pp. 3214-3224, 2012.
  20. C.Y. Tso and C.Y.H. Chao, Activated Carbon, Silica-gel and Calcium Chloride Composite Adsorbents for Energy Efficient Solar Adsorption Cooling and Dehumidification Systems, International Journal of Refrigeration, 35(6), pp. 1626-1638, 2012.   
  21. Y. Yang, G.N. Sze-To and C.Y.H. Chao, Estimation of the Aerodynamic Sizes of Single Bacterium-laden Expiratory Aerosols using Stochastic Modeling with Experimental Validation, Aerosol Science and Technology, 46, pp. 1-12, 2012.
  22. G.R. Johnson, L. Morawska, Z.D. Ristovski, M. Hargreaves, K. Mengersen, C.Y.H. Chao, M.P. Wan, Y. Li, X. Xie, D. Katoshevski, S. Corbett, Modality of Human Expired Aerosol Size Distributions,  Journal of Aerosol Science, 42, pp. 839-851, 2011.
  23. M. Li, K.N. Hui, K.S. Hui, S.K. Lee, Y.R. Cho, H. Lee, W. Zhou, S. Cho, C.Y.H. Chao and Y. Li, Influence of Modification Method and Transition Metal Type on the Physicochemical Properties of MCM-41 Catalysts and their Performances in the Catalytic Ozonation of Toluene, Applied Catalysis B: Environmental, 107, pp. 245-252, 2011.
  24. M.P. Wan, C.L. Wu, G.N. Sze-To, T.C. Chan and C.Y.H. Chao, Ultrafine Particles and PM2.5 Generated from Cooking in Homes, Atmospheric Environment, 45, pp. 6141-6148, 2011.
  25. G.N. Sze To and C.Y.H. Chao, Use of Risk Assessment and Likelihood Estimation to Analyze Spatial Distribution Pattern of Respiratory Infection Cases, Risk Analysis, 31(3), pp. 351-369, 2011.
  26. D. Parienta, L. Morawska, G.R. Johnson, Z.D. Ristovski, M. Hargreaves, K. Mengersen, S. Corbett, C.Y.H. Chao, Y. Li, D. Katoshevski, Theoretical Analysis of the Motion and Evaporation of Exhaled Respiratory Droplets of Mixed Composition, Journal of Aerosol Science, 42, pp. 1-10, 2011.
  27. M.P. Wan, K.S. Hui, C.Y.H. Chao and C.W. Kwong, Catalytic Combustion of Methane with Ozone using Pd-exchanged Zeolite X: Experimental Investigation and Kinetics Model, Combustion Science and Technology,  182, pp. 1429-1445, 2010.
  28. K.S. Hui, C.W. Kwong and C.Y.H. Chao, Methane Emissions Abatement by Pd-ion-exchanged Zeolite 13X with Ozone, Energy and Environmental Science, 3, pp. 1092-1098, 2010.
  29. G.N. Sze To and C.Y.H. Chao, Review and Comparison between the Wells-Riley and Dose-response Approaches to Risk Assessment of Infectious Respiratory Diseases, Indoor Air, 20, pp. 2-16, 2010.
  30. C.W. Kwong and C.Y.H. Chao, Fly Ash Products from Biomass Co-Combustion for VOC Control, Bioresource Technology, 101, pp. 1075-1081, 2010.
  31. J. Pantelic, G.N. Sze-To, K.W. Tham, C.Y.H. Chao, Y.C.M. Khoo, Personalized Ventilation as a Control Measure for Airborne Transmissible Disease Spread, Journal of the Royal Society Interface, 6, pp. 715-726, 2009.
  32. G.N. Sze To, M.P. Wan, C.Y.H. Chao, L. Fang and A. Melikov, Experimental Study of Dispersion and Deposition of Expiratory Aerosols in Aircraft Cabins and Impact on Infectious Disease Transmission, Aerosol Science and Technology, 43, pp. 466-485, 2009.   
  33. L. Morawska, G.R. Johnson, Z.D. Ristovski, M. Hargreaves, K. Mengersen, S. Corbett, C.Y.H. Chao, Y. Li and D. Katoshevski, Size Distribution and Sites of Origin of Droplets Expelled during Expiratory Activities, Journal of Aerosol Science, 40, pp. 256-269, 2009. 
  34. C.Y.H. Chao, M.P. Wan, L. Morawska, G.R. Johnson, Z.D. Ristovski, M. Hargreaves, K. Mengersen, S. Corbett, Y. Li, X. Xie and D. Katoshevski,  Characterization of Expiratory Air Jets and Droplet Size Distributions immediately at the Mouth Opening, Journal of Aerosol Science, 40, pp. 122-133, 2009.   
  35. M.P. Wan, G.N. Sze To, C.Y.H. Chao, L. Fang and A. Melikov, Modeling the Fate of Expiratory Aerosols and the Associated Infection Risk in an Aircraft Cabin Environment, Aerosol Science and Technology, 43, pp. 322-343, 2009. 
  36. C.W. Kwong, C.Y.H. Chao, K.S. Hui and M.P. Wan, Catalytic Oxidation of Toluene using Zeolite and MCM-41 Materials, Environmental Science and Technology, 42, pp. 8504-8509, 2008. 
  37. K.S. Hui and C.Y.H. Chao, Methane Emissions Abatement by Multi-ion-exchanged Zeolite A Prepared from Both Commercial-grade Zeolite and Coal Fly Ash, Environmental Science and Technology, 42, pp. 7392-7397, 2008. 
  38. G.N. Sze To, M.P. Wan, C.Y.H. Chao, F. Wei, S.C.T. Yu and J.K.C. Kwan, A Methodology for Estimating Airborne Virus Exposures in Indoor Environments Using the Spatial Distribution of Expiratory Aerosols and Virus Viability Characteristics, Indoor Air, 18, pp. 425-438, 2008. 
  39. C.Y.H. Chao, M.P. Wan and G.N. Sze To, Transport and Removal of Expiratory Droplets in Hospital Ward Environment, Aerosol Science and Technology, 42, pp. 377-394, 2008.  
  40. J.S. Hu and C.Y.H. Chao, Study of a Micro Absorption Heat Pump System, International Journal of Refrigeration, 31, pp. 1198-1206, 2008. 
  41. K.S. Hui, C.Y.H. Chao, C.W. Kwong and M.P. Wan, Use of Multi-transition Metal-ion-exchanged Zeolite 13X Catalysts in Methane Emissions Abatement, Combustion and Flame, 153, pp. 119-129, 2008. 
  42. C.W. Kwong, C.Y.H. Chao, K.S. Hui and M.P. Wan, Removal of VOCs from Indoor Environment by Ozonation over Different Porous Materials, Atmospheric Environment, 42, pp. 2300-2311, 2008.   
  43. M.P. Wan, C.Y.H. Chao, Y.D. Ng, G.N. Sze To and W.C. Yu, Dispersion of Expiratory Aerosols in a General Hospital Ward with Ceiling Mixing Type Mechanical Ventilation System, Aerosol Science and Technology, 41, pp. 244-258, 2007. 
  44. P.C.W. Kwong, C.Y.H. Chao, J.H. Wang, C.W. Cheung and G. Kendall, Co-combustion Performance of Coal with Rice Husks and Bamboo, Atmospheric Environment,  41, pp. 7462-7472, 2007. 
  45. Y. Li, G.M. Leung, J.W. Tang, X. Yang, C.Y.H. Chao, J.Z. Lin, J.W. Lu, P.V. Nielsen, J. Niu, H. Qian, A.C. Sleigh, H.J. Su, J. Sundell, T.W. Wong and P.L. Yuen, Role of Ventilation in Airborne Transmission of Infectious Agents in the Built Environment – A Multidisciplinary Systematic Review, Indoor Air, 17, pp. 2-18, 2007. 
  46. J.S. Hu and C.Y.H. Chao, A Study of the Performance of Microfabricated Electroosmotic Pump, Sensors & Actuators: A. Physical, 135, pp. 273-282, 2007. 
  47. C.Y.H. Chao, K.S. Hui, W. Kong, P. Cheng and J.H. Wang, Analytical and Experimental Study of Premixed Methane-Air Flame Propagation in Narrow Channels, International Journal of Heat and Mass Transfer, 50, pp. 1302-1313, 2007.
  48. J.S. Hu and C.Y.H. Chao, An Experimental Study of the Fluid Flow and Heat Transfer Characteristics in Micro Condensers with Slug-bubbly Flow, International Journal of Refrigeration, 30, pp. 1309-1318, 2007.  
  49. J.S. Hu and C.Y.H. Chao, Numerical Study of Electroosmotic (EO) Flow in Microfabricated EO Pump with Overlapped Electrical Double Layer (EDL), International Journal of Refrigeration,  30, pp. 290-298, 2007.  
  50. C.Y.H. Chao, P.C.W. Kwong, J.H. Wang, C.W. Cheung and G. Kendall, Co-Firing Coal with Rice Husk and Bamboo and the Impact on Particulate Matters and Associated Polycyclic Aromatic Hydrocarbon Emissions, Bioresource Technology, 99, pp. 83-93, 2007.  
  51. M.P. Wan and C.Y.H. Chao, Transport Characteristics of Expiratory Droplets and Droplet Nuclei in Indoor Environments with Different Ventilation Air Flow Patterns, Journal of Biomechanical Engineering, T-ASME, 129(3), pp. 341-353, 2007.  
  52. C.Y.H. Chao, C.W. Kwong and K.S. Hui, Potential Use of a Combined Ozone and Zeolite System for Gaseous Toluene Elimination, Journal of Hazardous Materials, 143, pp. 118-127, 2007.  
  53. C.Y.H. Chao and M.P. Wan, A Study of the Dispersion of Expiratory Aerosols in Uni-Directional Downward and Ceiling-return Type Air Flows Using Multiphase Approach, Indoor Air, 16, pp. 296-312, 2006.  
  54. K.S. Hui and C.Y.H. Chao, Synthesis of MCM-41 from Coal Fly Ash by a Green Approach: Influence of Synthesis pH, Journal of Hazardous Materials, 137, pp. 1135-1148, 2006.  
  55. K.S. Hui and C.Y.H. Chao, Pure, Single Phase, High Crystalline, Chamfered-Edge Zeolite 4A Synthesized from Coal Fly Ash for Use as a Builder in Detergents, Journal of Hazardous Materials, 137(1), pp. 401-409, 2006.  
  56. M.P. Wan and C.Y.H. Chao, Numerical and Experimental Study of Velocity and Temperature Characteristics in a Ventilated Enclosure with Underfloor Ventilation Systems, Indoor Air, 15, pp. 342-355, 2005.  
  57. K.S. Hui, C.Y.H. Chao and S.C. Kot, Removal of Mixed Heavy Metal Ions in Waste Water by Zeolite 4A and Residual Products from Recycled Coal Fly Ash, Journal of Hazardous Materials, 127 (1-3), pp. 89-101, 2005.  
  58. K.S. Hui and C.Y.H. Chao, Effects of Step-Change of Synthesis Temperature on Synthesis of Zeolite 4A from Coal Fly Ash, Microporous and Mesoporous Materials, 88, pp. 145-151, 2005.  
  59. C.Y.H. Chao and M.P. Wan, Experimental Study of Ventilation Performance and Contaminant Distribution of Underfloor Ventilation Systems versus Traditional Ceiling Based Ventilation System, Indoor Air, 14(5), pp. 306-316, 2004. 
  60. C.Y.H. Chao, J.H. Wang and W. Kong, Effects of Fuel Properties on the Combustion Behaviors of Different Types of Porous Beds Soaked with Combustible Liquid, International Journal of Heat and Mass Transfer, 47(24), pp. 5201-5210, 2004.
 
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