Cavitation characteristics in rectangular flow restriction microchannel seals

The shaft seal of the primary pump relies on microchannel flow to prevent coolant leakage, but cavitation increases resistance, reduces efficiency, and damages equipment, affecting safety. Therefore, studying microchannel cavitation is crucial for optimizing seal performance and equipment reliability. This study explores the cavitation flow characteristics within a 0.1 mm rectangular flow restriction microchannel seal through experimental methods and numerical simulations. First, using a microfluidic experimental platform and visualization techniques, we directly observed the cavitation phenomena in the microchannel and quantified the evolution of cavitation bubbles under different conditions. Second, by establishing a numerical model of the microchannel, we analyzed the formation mechanisms of cavitation and its impact on flow characteristics under various conditions. The results show that lower cavitation numbers significantly increase the length of cavitation jets and the distribution range of cavitation bubbles, intensifying the cavitation phenomena within the microchannel. Additionally, microchannels with closely spaced double flow restriction structures are more effective at inhibiting cavitation than channels with a single flow restriction structure. These findings offer valuable insights into the mechanisms of microchannel cavitation and provide scientific guidance for the design and optimization of shaft seals.