Research from Tsinghua University in Risk Management Provides New Insights (Effect of impact velocity on molten aluminum and copper droplets igniting expanded polystyrene foam): Insurance – Risk Management

2023 MAR 02 (NewsRx) -- By a News Reporter-Staff News Editor at Insurance Daily News -- Investigators publish new report on risk management. According to news reporting originating from Beijing, People’s Republic of China, by NewsRx correspondents, research stated, “Hot molten metal droplets with high fire hazard can easily ignite combustibles. Molten metal kinetics on the surface of a combustible material directly affects the ignition likelihood.”

Financial supporters for this research include National Natural Science Foundation of China; China Postdoctoral Science Foundation.

The news reporters obtained a quote from the research from Tsinghua University: “Existing research focuses on the behavior of droplets during collisions, rarely addressing the ignition of combustibles by hot metal droplets. Here, the mechanisms of aluminum and copper droplets impinging on and igniting extended polystyrene (EPS) foam boards at different velocities were investigated. The relationship between the critical ignition temperature and impact velocity of droplets with diameters of 6 and 8 mm was experimentally studied for aluminum droplets; the critical ignition temperature non-monotonically depended on the impact velocity. For copper droplets, the relationship between the ignition probability and the impact velocity of droplets with diameters in the 3.5-7 mm range was experimentally studied. The most obvious difference between the two droplet ignition types was that the impact of copper droplets was accompanied by intense splashing, and the fragmentation extent positively correlated with the impact velocity. It was challenging to ignite using completely broken copper droplets. Droplets with the diameter of 5 mm were the most dangerous under the experimental conditions of this study, because the foam could still be ignited at higher impact velocities.”

According to the news editors, the research concluded: “Numerical simulations suggested that the main factors explaining the critical ignition temperature of aluminum droplets were gas mixing and splat cooling. The main factor affecting the ignition of copper droplets was fragmentation, and experimental observations were explained using non-dimensional droplet fragmentation theories.”

For more information on this research see: Effect of impact velocity on molten aluminum and copper droplets igniting expanded polystyrene foam. Journal of Safety Science and Resilience, 2023,4(1):9-19. The publisher for Journal of Safety Science and Resilience is KeAi Communications Co., Ltd.

A free version of this journal article is available at https://doi.org/10.1016/j.jnlssr.2022.09.005.

Our news journalists report that more information may be obtained by contacting Wenjie Yang, Department of Engineering Physics, Tsinghua University, Beijing 100084, People’s Republic of China. Additional authors for this research include Rui Yang, Zishan Gao, Zhenxiang Tao, Jian Wang.

(Our reports deliver fact-based news of research and discoveries from around the world.)