2316 微細気泡混入系非ニュートン流体の旋回流路内流動特性と気泡挙動(S42-4 複雑流体の流動現象(4),S42 複雑流体の流動現象)  [in Japanese] 2316 Non-Newtonian Flow Characteristics and Behavior of Dispersed Micro-Bubbles in Rotating Pipe Section  [in Japanese]

This report describes a swirling flow in rotating pipe section with viscoelastic fluid containing micro-bubbles. Particular attention was given to verify the flow behavior and its associated bubble motion in a viscoelastic fluid, when the dispersed micro-bubble flow is entered from a stationary pipe to the rotating pipe section. The result showed that elongated circulation vortex zones were generated, similar to Newtonian case. From experimental results, and an aid of the numerical simulation, the stagnation point moves towards the inlet region as swirl ratio Ω is increase. It was also found that the stagnation point further moves toward the inlet in the case of viscoelastic field, showing that the dependence on Re^* becomes infinitesimal. In the bubble behavior, it was shown that the big bubble fell to the stagnation point, and that the parabolic surface is formed by some smaller bubbles which are caught in orbits of the rotating flow field.