レーザーフォーカス変位計による鉛直流下液膜の測定 : 第3報, 円管内壁面の液膜界面波形の測定原理

概要

論文の詳細を見る
To elucidate fascinating nonlinear phenomena of waves on a film in detail, spatial temporal knowledge of the interfacial waves is essential. This paper presents a new method for measuring waves on a film flowing down a vertical tube inner wall using a laser focus displacement meter. The purposes of the study were to clarify the effectiveness of the new method for obtaining detailed information of film thickness or wave characteristics and to investigate the effect of entry length down from the film entrance on the phenomena. With this method, accurate measurements of film thickness in real time with sensitivity of 0.2 microns and 1 kilohertz were achieved. The error caused by the refraction of the laser beam passing through acylic tube, whose outer wall surface was flat, and water was estimated. As the entry length increased, the ripple on the flowing film grew to a solitary wave of about 0.5mm in height then the wave became a two-wave system. In the entry region, the wave amplitude decreased as the flow rate increased in the same manner as that in a film flowing down a plate wall.
一般社団法人日本機械学会の論文
1998-12-25