الفهرس 
Mathematical Notation
LITERATURE REVIEWOnly 14 pages are availabe for public view
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Abstract
Research on indoor environments has received more
attention recently because requirements of thermal comfort,
reports of symptoms and other health complaints have been
increasing. Heating, ventilating, and air-conditioning (HVAC)
systems are used to control the indoor environment. Therefore, it
is necessary to provide a good thermal comfort levels and a good
ventilation system that can provide good indoor environment.
To improve thermal comfort levels and indoor environment,
the study of airflow with the assistance of the distribution of
several significant parameters on indoor environment was done in
this study.
In this research numerical simulations through
computational-fluid-dynamics (CFD) was used. The majority of
the CFD is based on the solution of Navier-Stokes equations,
the energy equation, the mass and conservation equations as
well as the transport equations for turbulent velocity and its
scale. Commercial program of ANSYS- CFX as a solution tool is
used to perform the analysis at steady state condition and threedimensional.
The program, used in this research, was validated.
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By using the validated program, numerical simulations of several
different cases of wall supply air grilles and the floor-supply
system were conducted to evaluate the design and the
performance of the system. Temperature and Velocity
distributions over various virtual planes for all the cases studied
were analyzed and the evaluation criterion is thermal comfort;
temperature difference and velocity are calculated to get the
optimum air conditioning systems to achieving the maximum
comfort for the occupants.
The results are reported in terms of thermal comfort, which
indicate that the occupants will experience most comfort if the air
conditioning system is placed on the position, which the wall
diffusers located on the same side of the exits, where diffusers
and exits are 2.44 [m] and 1.9 [m] above the floor respectively.
Also the study includes a floor-supply displacement
ventilation system that can provide fresh air directly to the
occupied zone. However, the existing floor-supply displacement
ventilation systems have some problems. Hence, the objectives of
this research were to improve the disadvantage of this system, and
to develop a new design for the floor-supply displacement
ventilation system with floor diffusers. The results show that the
impacts of several parameters, such as the air change rate, number
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of air supply diffusers, the air supply location, air supply
temperature, air supply velocity, number of exhaust grills and
exhaust location on the indoor environment were investigated
based on the thermal comfort level. from the results, the
parameters were ranked in the order of their impact.
Also this thesis focuses on effect of office dimensions and
people number on displacement ventilation. Multiple Plumes and
Wall Heat Transfer Three-Node Displacement Ventilation Room
Air Model (Energy Plus program) was used to estimate previous
factors on displacement ventilation. Multiple Plumes and Wall
Heat Transfer models are used to estimate main subzones
temperature. The study shows that, those are affected by office
dimensions and people number. So that displacement ventilation
is suitable for higher no. of people, more height of walls, longer
distance between inlet and outlet. It is recommended to use
displacement ventilation in zones, which having high walls, long
distance between inlet and outlet and big number of people like
big offices, theaters, cinemas ….and so on.
This result can be used for more specific case studies of each
building design and also can be extended to a more complex air
conditioning system like those in industries, hospitals as well as
the gigantic shopping malls and also to study the indoor Quality.