The purpose of this study is to investigate the deformation and breakup dynamics of compound liquid droplets in constricted microchannels under pulsatile flow conditions. This is particularly relevant to applications in biochemistry, medicine and materials science, where precise control of droplet behavior is crucial, such as mimicking the deformation of white blood cells in stenosed arteries.
This study uses numerical simulations to model the behavior of compound droplets under pulsatile flow in confined spaces. The finite element method is used to solve the governing equations, with the droplet interface being tracked using a phase-field model. The numerical data is post-processed using MATLAB, and the results are validated against reported data.
This study shows that increased flow pulsation intensity amplifies the deformation and thinning of compound droplets, resulting in non-monotonic behavior in both pinch-off times and maximum deformation. Higher constriction ratios dampen the oscillations in droplet deformation, though the maximum deformation still increases, and the pinch-off time decreases. When the constriction ratio surpasses a certain threshold, the droplet passes through the constriction intact without pinch-off. Additionally, a higher viscosity of the suspending fluid enhances oscillations, leading to greater deformation and a shorter pinch-off time. These results show pulsation, constriction and viscosity shape droplet flow dynamics.
This study is based on numerical simulations, and its findings are constrained by the assumptions and approximations inherent in the computational models. For instance, the current model is two-dimensional, whereas a full-scale three-dimensional model could enhance the applicability of the results to real-world systems, which is the future objective.
The findings of this study have practical relevance in fields such as drug delivery, inkjet printing and emulsification, where controlling droplet dynamics is essential. The insights into how pulsatile flow and microchannel constrictions influence droplet behavior can help optimize microfluidic devices and systems that rely on precise droplet formation and breakup, with potential applications in biomedical and material processing industries.
The results of this study advance microfluidic technologies, improving drug delivery and diagnostics in health care. This leads to more precise treatments and earlier disease detection. Additionally, this study supports innovations in industries like food processing, cosmetics and materials science, promoting sustainability and higher-quality products.
This study provides new insights into the behavior of compound droplets in pulsatile flow through confined microchannels, an area with limited previous exploration. This research contributes to a deeper understanding of how factors like pulsation intensity, constriction ratio and viscosity influence droplet dynamics, with implications for various industries and scientific fields where controlled droplet behavior is critical.
