Measurement of Air Velocity Components of Natural Convective Interzonal Airflow

Recent flow visualization tests performed at the National Bureau of Standards Passive Solar Test Facility indicated that the natural convective interzonal flow through a doorway is three-dimensional with the velocity components perpendicular to the plane of the opening and the plane of the floor appearing dominant. In order to further investigate the velocity components of the interzonal airflow through a doorway, an experimental study was undertaken. A simple one-dimensional model is modified to apply to two-dimensional airflow. Empirical expressions for the X velocity component and interzonal mass flow rate are developed. The measured velocity and mass flow rate data and the resulting empirical expression are compared with the values predicted by the simple one-dimensional model. It is found that the natural convective interzonal airflow may be adequately represented by two one-dimensional equations, one for the outflow and a different one for the inflow, provided that proper values of the outflow and inflow discharge coefficients are known.