Numerical Analysis of Propagation Characteristics of Hazard and Noxious Substance (HNS) Based on the Kriging Model

Abstract

The present study is devoted to numerically investigate the propagation characteristics of hazardous noxious substances (HNS) in the transportation ships and develop a prediction model of HNS spills and propagation by using the Kriging model. ANSYS FLUENT(V. 17.2) was used for the three dimensional CFD simulations based on the RANS (Reynolds-Averaged Navier-Stokes) model together with the standard k-? model. We also solved the scalar transport equation at the same time for estimating the spatial and transient behavior of HNS. This study analyses mainly three key variables such as layer thickness, HNS concentration on the water, and propagation speed for examining the near-field characteristics of an HNS spill and propagation. Advection becomes a dominant driving force of HNS propagation as current velocity increases and the HNS layer becomes thinner. Indeed, the advection force becomes important and the HNS layer is thinner. It is found that when the current velocity increases above a certain speed (~1.5 knots), the mixing effect makes the HNS layer less dense but thicker. Lower density HNS results in increased HNS concentration at sea-level and layer width. As the velocity increases, the concentration becomes homogeneous regardless of HNS density. Also, the mean speed of propagation is linearly proportional to current velocity.