Bubble deformation and breakup due to strain-rate-induced stress is investigated for a laminar flow configuration. The bubble shape is assumed to be a prolate ellipsoid. A new model for bubble deformation under dynamic load is introduced in the form of an ordinary differential equation for the deformation energy. Breakup is identified with a critical value of the deformation. As an application case, the flow in a joining T-junction is considered with the ratio of the volume flow rate being unity and the outflow Reynolds number being 1800. Dilute, dispersed bubbles with a diameter of 0.5 mm are injected. High-speed shadowgraphy is used and bubble parameters are evaluated via image processing. The capillary number is obtained from a single-phase flow simulation providing the instantaneous shear rate at the position of the bubble. The deformation resulting from the proposed model is then compared with the measured deformation for an exemplary bubble trajectory.

中文翻译：

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T 形接头通道流中动态气泡变形和破裂的建模


研究了层流结构中由于应变率引起的应力导致的气泡变形和破裂。假设气泡形状为长椭球体。以变​​形能常微分方程的形式引入了动态载荷下气泡变形的新模型。破裂通过变形的临界值来确定。作为应用案例，考虑连接T形接头中的流动，体积流量之比为1，流出雷诺数为1800。注入直径为0.5mm的稀分散气泡。使用高速阴影成像并通过图像处理评估气泡参数。毛细管数是通过单相流模拟获得的，提供气泡位置处的瞬时剪切速率。然后将所提出的模型产生的变形与示例性气泡轨迹的测量变形进行比较。