The impact of hydrodynamic cavitation is one of the key factors in the fabrication and application of metal materials. The hydrodynamic cavitation in anisotropic fluids can be much different from common fluids due to the unique fluid dynamics characteristics related to the director field. In this paper, the hydrodynamic cavitation of nematic liquid crystal 5CB flowing around a cylindrical pillar in a microchannel in the Stokes flow regime is studied at various Reynolds numbers and blockage ratios by experiments. Once the Reynolds number rises over a threshold value, the hydrodynamic cavitation of nematic liquid crystal is generated in the stokes flow in the microchannel, which is the unique phenomenon for anisotropic fluids. The critical Reynolds number of cavitation inception decreases with the increase of the blockage ratio. The Strouhal number is induced to describe this unsteady oscillating cavitation flow, while the Strouhal number increases and decreases with the increase of the blockage ratio and Reynolds number, respectively. Dynamics characteristics of the cavitation including cavity volume, oscillation frequency, and pressure difference are analyzed at different Reynolds numbers and blockage ratios by image binarization treatment and Fast Fourier Transformation analysis. The results of this study are useful for the application of microfluidic chips based on nematic liquid crystals and protection of devices in the environment of similar anisotropic fluids.

水动力空化的影响是金属材料制造和应用的关键因素之一。由于与导向场相关的独特流体动力学特性，各向异性流体中的水动力空化可能与普通流体有很大不同。本文通过实验研究了斯托克斯流态下向列相液晶5CB在微通道内圆柱柱周围流动时在不同雷诺数和阻塞比下的水动力空化现象。一旦雷诺数超过阈值，微通道内的斯托克斯流就会产生向列液晶的流体动力空化，这是各向异性流体特有的现象。空化起始临界雷诺数随着堵塞率的增加而减小。引入斯特劳哈尔数来描述这种非定常振荡空化流，而斯特劳哈尔数分别随着堵塞比和雷诺数的增加而增加和减少。通过图像二值化处理和快速傅里叶变换分析，分析了不同雷诺数和堵塞率下空化的动力学特性，包括空腔体积、振荡频率和压力差。该研究结果对于基于向列液晶的微流控芯片的应用以及类似各向异性流体环境下的器件保护具有重要意义。