Navigation

Professor Nesreen Ghaddar

Nesreen Ghaddar is the Associate Provost and Endowed Qatar Chair in energy Studies Professor the American University of Beirut.

Dr. Ghaddar obtained her master and PhD in Mechanical Engineering from Massachusetts Institute of Technology in 1982 and 1985, respectively. She received her Bachelor of Mechanical Engineering from Kuwait University in 1980. Her first post as assistant professor was at Kuwait University. She joined the Department of Mechanical Engineering at the American University of Beirut in 1991. She served as the chairperson of the Mechanical Engineering Department at AUB for six years from 2001-2007. In 2008-09, she was the chemical engineering program coordinator and the Acting Associate Provost. She was appointed Associate Provost in summer of 2009. She is a founding member and served as the coordinator for four years (2000-04) of the Energy Research Group which is a multi-disciplinary group conducting basic and applied energy research in Lebanon and the region towards sustainable energy in the future. She has also coordinated a major grant with colleagues where they developed a master degree program in Applied Energy in collaboration with European universities. Nesreen has published more than 60 journal papers, several book chapters and more than 50 refereed conference proceedings.

Her primary research focus is in the area of computational and experimental heat transfer enhancement for efficient cooling, solar energy applications, energy conversion, modeling of moisture and heat transport processes for walking clothed humans, thermal comfort, and energy efficiency. Recent work in thermal comfort has addressed an integrated approach to experimentally testing and modeling of a clothed-human body heat and mass transport processes and their interaction with their indoor environment and using the results to correlate human thermal comfort and clothing design to building energy consumption. She and co-workers developed a multi-node segmented bioheat model and are developing a walking human thermal model from first principles for the purpose of using it as a predictor for optimal clothing design for people working outdoor or in transitional spaces.

Prof. Ghaddar has also worked on development of design charts for the combined chilled ceiling displacement ventilation cooling systems that predicts the space thermal comfort and indoor air quality determined by room air stratification height for any selected ratio of the chilled cooling load to the total load, supply air temperature and mass flow rate, and chilled ceiling temperature. The provision of supply air conditions of temperature and flow and the chilled ceiling temperature by the design charts helps designers to size the cooling coil of the displacement ventilation system and the chilled ceiling system without need to do detailed analysis of the associated space thermal model that involves nonlinearity in heat transport and stratification present in the cooled space. Her work in this area was recognized and she recently received the American Society for Heating Refrigeration and Air conditioning Engineers ASHRAE 2008 Poster Presentation Award for the article:“Ghaddar N., K. Ghali, R. Saadeh, and A. Keblawi. 2008. Design Charts for Combined Chilled Ceiling Displacement Ventilation System, ASHRAE Transactions, 143 (2): 574-587.” The design charts are used to develop a grey box model for use in the design of an optimized online controller of the hybrid cooling system to minimize energy consumption while maintain comfort and indoor air quality in spaces.

Prof. Ghaddar is an Associate Editor to the American Society of Mechanical Engineering (ASME) Journal of Applied Mechanics (2005 – present). She is a Fellow of the American Society of Mechanical Engineering and a member of the editorial board of the International Journal of Green Energy and the International Journal of Thermal Sciences. In 2003, she has received the Outstanding Reviewer Award for the ASME Journal of Heat Transfer. She was elected to Fellow of the Islamic World Academy of Sciences on November 1, 2007.

(Click on image to enlarge)

Sample of Academician's Research

Ghaddar and co-workers developed a methodology to generate design charts for the chilled ceiling (CC) and displacement ventilation (DV) system that are based on (1) the ratio of the CC cooling load to the total load, (2) the thermal comfort represented by the temperature gradient dT/dZ, (3) indoor air quality (IAQ) determined by room air stratification height H, and (4) the amount of displaced air parameter equal to the ratio of total load to supply the air mass flow rate. The design chart parameters for steady-state operation covers the temperature ranges of the supply air, and the chilled ceiling temperatures for any feasible chilled ceiling load ratio that results in vertical temperature less than 2.5 °C/m. It also provides direct read-off of the stratification height H. The provision of supply air conditions of temperature and flow and the chilled ceiling temperature by the design charts helps the designer to size the cooling coil of the DV system and the chilled ceiling system.

The design chart for a typical load of  60-70 W/m2 is shown in the figure above. The constant-P line gives low value of R at high Tc and low Ts and gives high value of R at low Tc and high Ts. The shaded grey top region represents conditions where the vertical temperature gradient is not acceptable.

Learn more...