Multiphase suspensions are complex systems where microscopic interactions between suspended bubbles, particles, and liquids can significantly alter bulk behavior. Observing the internal mechanics of such suspensions can help constrain the dynamics of natural multiphase flows. To capture these internal processes at high speed and in three dimensions, we propose the use of Swept Confocally Aligned Planar Excitation (SCAPE) microscopy in analog experiments. This imaging technique, developed for neuroscience and biology, uses a sweeping light sheet to illuminate and image fluorophores within a sample. We performed experiments using water and various oils as the liquid phases, glass or PMMA particles for solids, and air or CO₂ for gas, which we imaged at rates >50 volumes per second, over a volume size of ∼1 × 1 × 0.4 mm. We focused on three case studies: (1) bubble nucleation, growth, and rise in sparkling water, where we found that bubble detachment from angular PMMA particles left residual bubbles that also grew and detached, generating more bubbles compared to smooth particles; (2) flow of immiscible liquids (water droplets suspended in canola oil) in a porous matrix of PMMA beads, which highlighted the importance of pore and throat sizes on droplet velocities; and (3) injection of air bubbles into concentrated suspensions of glass beads or crushed PMMA particles in a refractive‐index‐matched liquid, which revealed particle motion and strong alterations of the bubble shape. We conclude that SCAPE microscopy is a powerful tool to study the dynamics of multiphase systems.

中文翻译：

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多相系统的高速3D成像：将SCAPE显微镜应用于火山学和地球科学的模拟实验

多相悬浮液是复杂的系统，其中悬浮的气泡，颗粒和液体之间的微观相互作用可以显着改变体积行为。观察此类悬浮液的内部力学特性可以帮助限制自然多相流的动力学。为了在三个维度上高速捕获这些内部过程，我们建议在模拟实验中使用扫描共聚焦对准平面激发（SCAPE）显微镜。这种为神经科学和生物学开发的成像技术，使用扫光板来照明和成像样品中的荧光团。我们使用水和各种油作为液相，玻璃或固体的PMMA颗粒以及空气或CO _{2进行了实验}对于气体，我们以每秒> 50体积的速率成像，体积约为≥1×1×0.4 mm。我们集中在三个案例研究上：（1）苏打水中气泡成核，生长和上升，我们发现气泡从有角的PMMA颗粒上脱落会留下残留的气泡，这些气泡也会生长和脱离，与光滑颗粒相比，会产生更多的气泡；（2）在PMMA珠的多孔基质中的不混溶液体（悬浮在低芥酸菜子油中的水滴）的流动，突出了孔和喉口尺寸对液滴速度的重要性；（3）将气泡注入浓缩的玻璃珠或破碎的PMMA颗粒在折射率匹配的液体中的悬浮液中，这揭示了颗粒的运动和气泡形状的强烈变化。