Air Flow Patterns and Heat Transfer Within the Respiratory Tract: A new method for experimental studies on models

Abstract

Abstract I ngelstedt S. and N. G. T oremalm . Air flow patterns and hat transfer within the respiratory tract. The authors have worked out an experimental method which makes it possible to determine air flow patterns in models of the respiratory tract. The method is based on the close relationship between heat transfer and pressure drop conditions which occur in a tube with a warm inner surface when air is blown or sucked through it. The air temperatures before entering and after leaving a tube of tracheal dimensions are determined and the heat transferred to the passing air is computed. Thus heat is used as a tracer. As a result of friction to flow, an aerodynamic boundary layer is built up. It is stated that the shape of this layer determines the actual degree of heat transfer between the airway mucous membranes and the respired air. The hitherto unknown biological importance of variations in the boundary layer within different parts of the respiratory tract is briefly discussed.