MECHANISM OF FLOW THROUGH LOUVER-FINNED SURFACES

摘要

An experimental study is performed to determine the mechanism of flow through louver-finned surfaces by means of flow visualization and laser Doppler velocimetry (LDV). The louver angle and flow velocities are varied. Results are obtained for the velocity vector, turbulence intensity, Reynolds stress, and power spectrum together with images of flow patterns in both the fin and louver spaces. It is disclosed that an increase in the louver angle promotes enhancement in mixing performance but the appearance of a separation bubble in the vicinity of louver-fin connection bend limits the louver angle. Large longitudinal vortices are induced in flow through all louvered fins. The uniqueness of the louver-finned system is its arched geometry which serves as a curvature producing the centrifugal force for the enhance mixing performance. Applications of such a system are abundant in compact heat exchange devices most well known in automotive radiators.