SIMULATION OF AIR DISTRIBUTION IN A ROOM

Abstract

Airflow inside a room is complex. A specific airflow pattern is determined by the supply and exhaust locations, room geometry, furnishings, as well as the heating and cooling involved. Knowledge of room air distribution, including its flow and temperature characteristics, is very important to heating ventilation and air conditioning (HVAC) engineers. This dissertation work considers the simulation of room airflows and illustrates the usefulness of computational fluid dynamics (CFD) as a design tool for ventilation systems. The time-averaged equations for conservation of mass, momentum and energy are solved using the CFD module of ANSYS 5.3. A standard k-s model is used to simulate the turbulent transport phenomenon of room air distribution. Comparing it to experimental data available and other related work validates the code. The airflow in an unfurnished room is then simulated for two different supply and exhaust locations. Based upon temperature differential and velocity distribution inside the room, particularly in the planes from the height of 1.8m to the bottom, the best location of supply and exhaust is determined. Use of computational fluid dynamics enables the velocity and temperature fields to be investigated in significantly greater detail than is possible with either analytical or experimental models. This method is also comparatively cheaper and less time consuming.