One Visualization Method for Secondary Flow in Curved Pipes

Abstract

A new solid-tracer method for visualizing the secondary flow in curved pipes is developed together with the measuring technique to obtain the velocity vectors of the flow field. In this method, the nylon particles suspended in the water flowing are illuminated by a sheet of a strobo light, and their paths are recorded photographically. This method is applied for steady, oscillating and pulsating flows in the fully-developed region of a circular curved pipe with a curvature ratio of 7.6. The obtained velocity vectors and profiles of the secondary flow are in good agreement with the numerical results. The availability of the present method is confirmed for visualization and velocity measurement of the secondary flow motion in curved pipes.