Air Flow Characteristics in Air-Conditioned Multipurpose Hall

Abstract

SUMMARY This paper focuses on both experimental investigation and numerical modeling of full-scale modelled air-conditioned multipurpose hall fully operable. Two methodologies were used, firstly full scale experimental setup was incorporated to map the hall making use of a well-developed fully automated .wireless mobile test rig remotely controlled by pre-programmed computer and using high precision state-of-the-art measuring instruments. While the Second methodology was a numerical modeling using a well developed [CFD] 3DHVAC and Fluent computer simulation programs. Physical and Numerical investigations enable the analyses of the influence of Reynolds, Archimedes and Prandtl numbers for the air as well as the effects of shape, location, inlet air velocity of supply outlet on the flowing air parameters. These parameters include throw, drop, air induction, room local velocities, humidity ratio and temperatures distributions. The forced air supply of cooled air streams out of high wall mounted, downward inclined jets is investigated with mechanically extracted air from the top of the split air-conditioning units. On the other hand an experimental traversing mechanism, computer-based and operated by PLC was developed and used to map the velocity and temperature contours. The room was typically used as the chairman office, meeting room and seminar room. One of the main conclusions is that good agreement between both of full-scale physical modeling and numerical modeling were reported .While the reported comparisons concluded that qualitative agreements were shown, some discrepancies were also observed in the thermal parameters for comfort conditions required by different occupants. PROBLEM FORMULATION The airflow distribution in its final steady pattern is a result of different interactions such as, the airside design, objects distribution, thermal effects, occupancy movements, etc, see references [1 to 14]. The airside design and internal obstacles are the focus of the present work. The forced air supply of cooled air streams out of high wall mounted, 15 0 downward inclined jets is investigated with mechanically extracted air from the top of the split units as shown in figure 1. This configuration played an important role in the main flow pattern and the creation of main recirculation zones. The internal obstacles would naturally obstruct the airflow pattern in different ways and means, by for example increasing the recirculation zones size, relocating these and or deflecting the main airflow pattern. The present work followed both experimental and numerical approaches to properly understand and analyze room air flow patterns. A ready available commercial Fluent Computational code, [15] was used to predict the air flow patterns and thermal behavior. On the other hand an experimental traversing mechanism, computer-based and operated by PLC was developed and used to map the velocity and temperature contours. The room was typically used as the chairman office, meeting room and seminar room.