In polar regions, floating ice exhibits distinct characteristics across a range of spatial scales. It is well recognized that the irregular geometry of these ice formations markedly influences their dynamic behavior. ...In polar regions, floating ice exhibits distinct characteristics across a range of spatial scales. It is well recognized that the irregular geometry of these ice formations markedly influences their dynamic behavior. This study introduces a polyhedral Discrete Element Method (DEM) tailored for polar ice, incorporating the Gilbert-Johnson-Keerthi (GJK) and Expanding Polytope Algorithm (EPA) for contact detection. This approach facilitates the simulation of the drift and collision processes of floating ice, effectively capturing its freezing and fragmentation. Subsequently, the stability and reli ability of this model are validated by uniaxial compression on level ice fields, focusing specifically on the influence of compression strength on deformation resistance. Additionally, clusters of ice floes nav igating through narrow channels are simulated. These studies have qualitatively assessed the effects of Floe Size Distribution (FSD), initial concentration, and circularity on their flow dynamics. The higher power-law exponent values in the FSD, increased circularity, and decreased concentration are each as sociated with accelerated flow in ice floe fields. The simulation results distinctly demonstrate the con siderable impact of sea ice geometry on the movement of clusters, offering valuable insights into the complexities of polar ice dynamics.展开更多
Experimental investigation of ice flee breakup on waves by use of non-refrigerated breakable materials has been carried out. The incident wave heights for breakup of ice flee with different lengths, and the influence ...Experimental investigation of ice flee breakup on waves by use of non-refrigerated breakable materials has been carried out. The incident wave heights for breakup of ice flee with different lengths, and the influence of rigidity on reflection and transmission coefficients are discussed. The experimental results show that the ratio of the ice noe length, L-i, to the wavelength, L, is one of the significant factor affecting the minimum wave height to cause fracture of ice flee, and another key factor is the ratio of the ice flee thickness, h(i) and L-i.展开更多
A Reynolds averaged Navier-Stokes(RANS)computational fluid dynamics(CFD)model is built to investigate the hydrodynamic response of a circular ice floe under the influence of a passing ship in calm waters.The ship,mirr...A Reynolds averaged Navier-Stokes(RANS)computational fluid dynamics(CFD)model is built to investigate the hydrodynamic response of a circular ice floe under the influence of a passing ship in calm waters.The ship,mirroring the KRISO Container Ship’s hull design,progresses near an ice floe whose diameter is 30%of the ship’s length and its thickness is 3 m.The ship advances at a constant speed,which is handled by using the overset mesh technique.This study focuses on the ice floe’s motions and the hydrodynamic forces induced by three speeds and three transverse distances of the passing ship.Findings reveal that ship-generated wakes notably influence the ice floe’s motions,with a greater influence on sway than surge.Additionally,the ship’s speed and proximity distinctly affect the ice floe’s motions.展开更多
文摘In polar regions, floating ice exhibits distinct characteristics across a range of spatial scales. It is well recognized that the irregular geometry of these ice formations markedly influences their dynamic behavior. This study introduces a polyhedral Discrete Element Method (DEM) tailored for polar ice, incorporating the Gilbert-Johnson-Keerthi (GJK) and Expanding Polytope Algorithm (EPA) for contact detection. This approach facilitates the simulation of the drift and collision processes of floating ice, effectively capturing its freezing and fragmentation. Subsequently, the stability and reli ability of this model are validated by uniaxial compression on level ice fields, focusing specifically on the influence of compression strength on deformation resistance. Additionally, clusters of ice floes nav igating through narrow channels are simulated. These studies have qualitatively assessed the effects of Floe Size Distribution (FSD), initial concentration, and circularity on their flow dynamics. The higher power-law exponent values in the FSD, increased circularity, and decreased concentration are each as sociated with accelerated flow in ice floe fields. The simulation results distinctly demonstrate the con siderable impact of sea ice geometry on the movement of clusters, offering valuable insights into the complexities of polar ice dynamics.
基金This work was financially supported by Scientific fund for national outstanding youth under Grant No.59725919
文摘Experimental investigation of ice flee breakup on waves by use of non-refrigerated breakable materials has been carried out. The incident wave heights for breakup of ice flee with different lengths, and the influence of rigidity on reflection and transmission coefficients are discussed. The experimental results show that the ratio of the ice noe length, L-i, to the wavelength, L, is one of the significant factor affecting the minimum wave height to cause fracture of ice flee, and another key factor is the ratio of the ice flee thickness, h(i) and L-i.
文摘A Reynolds averaged Navier-Stokes(RANS)computational fluid dynamics(CFD)model is built to investigate the hydrodynamic response of a circular ice floe under the influence of a passing ship in calm waters.The ship,mirroring the KRISO Container Ship’s hull design,progresses near an ice floe whose diameter is 30%of the ship’s length and its thickness is 3 m.The ship advances at a constant speed,which is handled by using the overset mesh technique.This study focuses on the ice floe’s motions and the hydrodynamic forces induced by three speeds and three transverse distances of the passing ship.Findings reveal that ship-generated wakes notably influence the ice floe’s motions,with a greater influence on sway than surge.Additionally,the ship’s speed and proximity distinctly affect the ice floe’s motions.
