Grant: Discovery Grants Program - Individual

Oil spills are costly to cleanup. Total cleanup costs include costs of the response, socio-economic damage, and environmental damage. For example, the sinking of the Prestige oil tanker off the Galician coast in 2002 had a total cleanup cost ~ USD 108 million. The Deepwater Horizon oil rig explosion and fire in 2010 had an estimated total cleanup cost of ~ USD 108 billion. In 2022 there were 3 large spills and 4 medium spills reported from tankers. In-situ burning (ISB) is an effective method for oil spill cleanup on water, especially in remote areas or harsh environments, or where dispersants and/or mechanical recovery are not possible. Due to warming in the Arctic, the risk of oil spills in these northern regions will increase due to increased shipping. Therefore, it is necessary to have viable cleanup strategies for spills on and under ice and in brash ice. Although ISB can clean up the oil, it results in a large, free-buoyant (FB) pool fire that causes significant air pollution in the form of black smoke which comprises soot and particulate matter. Fire whirls (FWs) occur when a buoyant fire plume interacts with ambient air flow conditions to produce a swirling diffusion flame. They occur in wildland, large urban, industrial, commercial, and residential building fires. They are spectacular phenomena that have received much media attention due to the many recent wildland fires where FWs have occurred. Transitioning a FB pool fire into a FW can result in enhanced mixing of fuel and air, higher temperatures, and hence cleaner combustion. Thus, the overall objective of this research is to investigate the feasibility of transitioning a FB pool fire associated with ISB by inducing FWs for enhanced oil spill cleanup. In particular, the following will be undertaken: (1) investigate conditions for transition from a FB pool fire to a stable FW for a range of hydrocarbon fuels on water under different sea state conditions, in brash ice, and from ice cavities; (2) determine differences in emissions from FB pool fires and stable FWs for single component and multicomponent hydrocarbon fuels over open-water surfaces, brash ice, and in ice cavities; and (3) evaluate various potential methods of transitioning from ISB to a FW. Whilst studies of FB pool fires and FWs have been extensive, the transition from a FB pool fire to a stable FW for hydrocarbon fuels on water as a potential oil spill cleanup method has only recently started to be investigated. Thus far, these studies have been mostly confined to quiescent conditions, and only 2 recent studies have been undertaken on turbulent water. However, no studies for this transition have been done under different sea states. Likewise, FB pool fires from ice cavities have been investigated but no studies under FW conditions have been done. No research has been reported for ISB or transition to a FW on brash ice. This proposed research will be the first attempt at addressing these gaps in our knowledge.