Evaluation of Ventilation Systems through Numerical Computation and Presentation of a New Ventilation Model

Abstract

The efficiency of various types of ventilation systems is examined by numerical calculation for two-dimensional, isothermal, and turbulent flow models. It is found that the ventilation is effective when the main pass length of the supplied air flow in a room is long. Since the slope of the concentration decay seems to become virtually constant and independent of the position in the room, this slope is proposed as a criterion for the ventilation efficiency. Further, a new convenient ventilation model is presented with the introduction of two parameters showing the ventilation efficiency and the effect of the pollutant generation site.