生活環境中的致災災害流體如土石流、雪崩、火山泥漿，一般將其簡化為顆粒流問題，而探討顆粒材料的運動行為，顆粒速度與體積濃度的描述則扮演關鍵性的角色。利用透明壓克力渠道進行顆粒流實驗，以兩個不同環境流體空氣與水分別討論穩態下乾顆粒與濕顆粒的運動行為，利用Sarno et al. (2016)提出的光學方法量測體積濃度，同時利用粒子影像測速法(digital particle image velocimetry，DPIV )量測顆粒速度。量測過程發現在底床附近當速度趨近於零時，濃度開始有振盪情形發生，乾顆粒部份發現在表面速度與濃度皆為線性分佈，另外透過μ(I)-rheology中採用的慣性數I (inertia number)來描述顆粒運動情形。由於慣性數I受制於體積濃度c，利用實驗觀察I與c發現兩者之間呈現指數關係。除了乾顆粒流，在水與顆粒的混合流體部份我們考慮平衡坡度修正底床傾角，利用Egashira et al. (1997) 水砂混合流模型、Tai et al. (2016)速度與濃度線性假設以及實驗量測的結果，探討Tai and Shen (2014)中所提出水砂混合流深度積分下所產生的四個修正係數的必要性。

The hazardous flows, such as debris flows, snow avalanches or the lava flows during volcano eruptions, sometimes are mimicked by granular flows, because of its complex composition. The distributions of volume fraction and velocity play crucial roles In investigating the dynamics of the granular flows. In the present study we performed experiments in transparent channels of acrylic plastic, where the dry granular flows and water-glass beads mixture are taken into account. Combining the optical method and the digital particle image velocimetry, we are able to measure the volume fraction and velocity distribution during the flow motion. It is notable that both of the distributions of volume fraction and velocity are approximately linear, and the measured volume fraction exhibits oscillating when the particle velocity is close to zero. In addition, since the μ(I)-rheology employed inertia number is pressure- dependent, it is concluded that its value and the volume fraction are related by an exponential formula. With the measured velocity and volume fraction, we calculated the four correction factors for sediment-water mixture. The assumption of piecewise linear distribution and sediment-water mixture model may provide comparable values to these correction factors, whose values are important in describing non-uniform flow.

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