With the global economy continually growing, the oil industry is rapidly expanding to meet the world’s growing energy demand. Oil production and oil transportation activities are increasing, and so are environmental concerns. Oil released on the sea surface is impactful pollution, which pollutes seawater, causes the death of marine animals, and damages marine ecosystems. Oil released in the oceans leads to the complex fluid mechanics problem of oil-wind-wave interaction. This interaction disperses the oil into droplets, and they are transported to an extensive area. When waves pile up, they overturn and break, generating complex structures spreading throughout the flow, leading to sea spray ejection, bubble breakup, oil droplet breakup, and turbulent mixing.
Using numerical simulations, we aim to get detailed information on the oil-wind-wave interaction dynamics. We perform high-fidelity numerical simulations to investigate the bubbles, water droplets, and oil droplets generated by the impingement of breaking waves on an oil slick. The flow field in the air-oil-water system is obtained by solving the incompressible Navier-Stokes equations. Using a coupled level set and volume of fluid (CLSVOF) method, the three-phase interfaces (air-water, air-oil, and water-oil) are directly captured. We study the generation and transport processes of bubbles, water droplets and oil droplets by examining their instantaneous distribution in connection with the breaking wave dynamics.
Another concern over the ecosystem in today’s world is plastic pollution. In 2016, the National Oceanic and Atmospheric Administration (NOAA) estimated that there are between 20 million and 1.8 billion pieces of plastic along the coastline of the United States. The plastics in the water system are usually small in size because of the degradation effects, which means that plastic particles fragment into smaller ones. Plastic particles smaller than 5 mm in size are commonly referred to as microplastic, which can be accidentally consumed by fish and enter the ecosystem. In previous research, microplastic particles are described as small, irregularly shaped particles, and spheroids are a good estimation of the microplastic particles. Studying microplastic with spheroidal particle models are currently underway in our group.