Near-field leakage and diffusion characteristics of Hazardous and Noxious Substance

Abstract

Owing to huge casualty and environmental pollution caused by HNS(Hazardous and Noxious Substance) leakage, accurate prediction modeling must be crucial in coping with the accidents at the early stage. Our project finally aims to develop an engineering prediction model for accurate near-field prediction of diffusive behavior in risk regions, when HNS spills occur using CFD according to various environmental circumstances and risk scenarios. As part of results for achieving the final objectives, the present study conducted three-dimensional CFD simulations using the commercial CFD code, ANSYS FLUENT(V. 16.2) based on RANS(Reynolds-Averaged Navier-Stokes) equations with the standard k-ϵ model. In particular, VOF (Volume of Fraction) model was utilized for capturing the interface between two dissimilar phases. Also, the present work examines the influence of crack size and seawater velocity on the near-field diffusion characteristics of HNS. It was found that the leakage velocity and the spill-volume depended on the crack size, showing increasing tendency with the crack size. In addition, the crack size substantially affects the leakage behavior. Longitudinal leakage distance from crack area increased with the crack size, and after dissipation of longitudinal momentum, sea water velocity dominantly affected on the leakage behavior. The present results would be useful in making estimation model and understanding the detailed physics behind the near-field characteristics of HNS diffusion. © 2016 IEEE.