以雷射切頁之亮環分析固液二相流斷面流場分布

Abstract

本論文使用一個內含輸送帶的水槽和新穎的量測技術來實驗高濃度固液二相流之流場分析。該水槽可用來產生穩定之均勻自由液面，並使其在控制的條件下流動。在流體內的粒子濃度和運動速度，透過透明的固液二相流(使用折射率相同之液體與顆粒)來獲得，並且使用一條雷射切頁照亮橫斷面。 當顆粒穿過雷射切頁時，球形的粒子會產生一亮環，利用此現象來量測濃度和流速分佈。 這些量測值可用來分析粒子分布的濃度，剪應變率和層與層間剪力的關連性。

Flows of concentrated solid-liquid mixtures are studied experimentally using a moving belt flume and novel measurement techniques. The flume is used to produce steady uniform free-surface flows under controlled conditions. Measurements of particle concentration and motions inside the mixture are obtained by making the mixture transparent (using refractive index matching), and illuminating a cross section using a laser light sheet. As they cross the light sheet, the spherical particles produce bright halos, which can be interpreted to obtain concentration and velocity measurements. These measurements are analyzed to examine relationships between solid concentration, shear rate, and inter-layer stresses.