Date of Award

Winter 2000

Document Type


Degree Name

Doctor of Philosophy (PhD)


Mechanical & Aerospace Engineering


Mechanical Engineering

Committee Director

Sushil K. Chaturvedi

Committee Member

Surendra N. Tiwari

Committee Member

A. Sidney Roberts, Jr.

Committee Member

Devendra S. Parmar


Nowadays, the majority of people spend up to 90% of their time indoors; as a result, the maintenance of optimal indoor climate conditions has become important for their overall health and comfort. The main goal of this study is to predict numerically the flow and temperature patterns and the human thermal comfort conditions in an indoor environment using displacement ventilation.

A Computational Fluid Dynamics (CFD) code has been used to analyze thermal comfort conditions for a fullscale ventilated room. Unstructured grids have been used to discretize the numerical domain. Before undertaking a detailed investigation, the code was validated by comparing the numerical results with experimental data available in the literature. A total of thirteen cases have been modelled to study the effects of inlet air velocity, air temperature, room walls temperature and vent location on the indoor thermal comfort. The study has been extended to cover not only unoccupied rooms but also occupied rooms. For the occupied rooms, different occupant configurations, namely standing person and person sitting on a chair, have been investigated. A realistic 3-D human model is developed to account for the complex geometry of the human body. The interaction between the human body and its surrounding environment has been analyzed, and its effects on thermal comfort zone have been investigated.

Two different human thermal comfort indices, namely Percentage of Dissatisfaction (PD) and Effective Draft Temperature (EDT), have been used to predict the extent of thermal comfort zone inside the room space.