Numerical Analysis of Diffusion Characteristics of Hazard and Noxious Substance (HNS) Spilled in Seawater

Abstract

Owing to huge casualty and environmental pollution caused by HNS (Hazardous and Noxious Substance) leakage, it is important to understand the diffusion characteristics of HNS and accurately estimate the propagation distance for coping withthe accidents at the early stage. The objective of this study is to develop a numerical simulation technique that predicts hazardous areas in HNS accident, and to develop such a near-field diffusion prediction model considering various accident scenarios and environmental factors. As a part of the research, this paper establishes numerical methods for estimation of diffusion in seawater and examines the propagation and diffusion characteristics for floating and sinking materials. This study used the commercial code of ANSYS FLUENT (V. 17.2) based on RANS (Reynolds-Averaged Navier-Stokes) equations with the standard k-ε model together with species transport equation for modeling the spatial and transient behavior of HNS material. Especially, for analyzing the HNS propagation characteristics, HNS layer thickness and HNS propagation speed were analyzed under the conditions of current velocity and density of HNS.