Palas Farsoya (IIT Rorkee)

Direct Numerical Simulations of physicochemical phenomena in interfacial flows 

Two fluids separated by an interface add complexity to understanding both the flow field and the interface's evolution over time. While numerical methods for studying single-phase flows date back to the 1930s, methods for two-phase interfacial flows are comparatively newer, originating in the late 1970s, and remain under active development. Concurrently, advances in computational power and reduced costs have enabled the numerical study of multiphase problems. Interfacial flows, prevalent in nature and engineering applications, manifest as waves, bubbles, droplets, jets, and more. These flows are often coupled with physicochemical processes such as phase change, heat/mass transfer, chemical reactions, and surfactant effects. Although proprietary software exists for multi-physics simulations, they have not been thoroughly tested across a wide range of parameters and coupled physics scenarios. This limits scientists and engineers from exploring multi-physics interfacial problems using direct numerical simulations. In this context, we have developed open-source, scalable codes to model various physicochemical phenomena at fluid-fluid interfaces, including mass transfer, phase change, and the solutal Marangoni effect. Our numerical framework has been benchmarked against analytical and experimental data and applied to investigate bubble dissolution in turbulent flow, gas transfer in breaking waves, and surfactant effects on rising bubbles.