Cavitation inception and evolution in cavitation on a chip devices at low upstream pressures

The concept of hydrodynamic cavitation on a chip offers facile generation of cavitating flows in microdomains, which can be easily scaled up by arranging short microchannels (micro-orifices) in cascade formations. In this regard, microscale cavitation in an energy-efficient test rig has the potential of increasing utilization possibilities of cavitation in a wide range of applications such as liquid-phase exfoliation. In this study, a new experimental test rig was constructed to generate microscale hydrodynamic cavitation. This setup enables cavitation bubble generation at low upstream pressures through the control of the downstream pressure of the device. Particular attention was directed to the classification of flow patterns, scale effects, and cavitating flow evolutions with an in-depth categorization of underlying mechanisms such as Kelvin-Helmholtz instability. Cavitation inception appeared in the form of a single bubble. The appearance of different attached cavitating flow patterns within the microfluidic device was accompanied by new physics, which revealed that cavitation generation and development are affected by the existence of various fluid flow phenomena, particularly the jet flow. The outcome of this study makes hydrodynamic cavitation on a chip attractive for applications, where the cavitation effects are sought in the presence of multiphase fluid flows.

Automated summary

The concept of hydrodynamic cavitation on a chip allows for easy generation of cavitating flows in microdomains and can be scaled up by arranging short microchannels in cascade formations. A new experimental test rig was constructed to generate microscale hydrodynamic cavitation, enabling cavitation bubble generation at low upstream pressures through control of downstream pressure. The study focused on flow pattern classification, scale effects, and cavitating flow evolutions, with attention to underlying mechanisms such as Kelvin-Helmholtz instability. The outcome of this study makes hydrodynamic cavitation on a chip attractive for applications involving multiphase fluid flows where cavitation effects are desired.