円管流れにおける再層流化についての研究

抄録

Experiments were conducted to investigate the relaminarization by visualization and pressure measurement. Two urethan pipes with different diameters were connected with a divergent duct, since the relaminarization is presumed to attain by lowering the Reynolds number. Flow in the pipe was disturbed in the divergent section and the disturbed flow condition continues for a while. After a distance, the flow became more ordered condition under lower Reynolds number in the downstream pipe than in the upstream pipe. The flow in the sufficiently downstream was specified by the local Reynolds number. We obtained the length to establish the ordered condition in the downstream from the viewpoint of entropy change.