Ice-going ships play a crucial role in polar transportation and resource extraction.Different from the existing modeling approach which assumes that ships remain stationary,dynamic overset grid technology and DFBI(Dyn...Ice-going ships play a crucial role in polar transportation and resource extraction.Different from the existing modeling approach which assumes that ships remain stationary,dynamic overset grid technology and DFBI(Dynamic Fluid-Body Interaction)method are employed in this paper to enable the free-running motion of the ship in modeling.A numerical model capable of simulating a ship navigating through pack ice area is proposed,which uses Computational Fluid Dynamics(CFD)method to solve the flow field and applies the Discrete Element Method(DEM)to simulate ship-ice and ice-ice interactions.Besides,the proposed high-precision method for generating pack ice area can be used in conjunction with the proposed numerical model.By comparing the numerical results with the available model test data and experimental observations,the effectiveness of the numerical model is validated,demonstrating its strong capability of predicting resistance and simulating ship navigation in pack ice,as well as its significant potential and applicability for further studies.展开更多
采用非结构重叠网格Euler方程的CFD方法数值模拟了外挂投放。该方法在重叠网格"挖洞"时,以"离壁面距离"为挖洞判据;在建立重叠区域插值关系时,对Neighbor to Neighbor(N2N)和Alternating Digital Tree(ADT)两种方...采用非结构重叠网格Euler方程的CFD方法数值模拟了外挂投放。该方法在重叠网格"挖洞"时,以"离壁面距离"为挖洞判据;在建立重叠区域插值关系时,对Neighbor to Neighbor(N2N)和Alternating Digital Tree(ADT)两种方法的效率进行了比较。采用机翼/挂架/带舵外挂物模型开展了验证计算。在此基础上,完成了某飞行器外挂投放的初步计算。展开更多
壁面距离在当代湍流模化中仍然扮演着关键角色,然而苦于遍历计算壁面距离的高昂代价,该文考虑了求解偏微分方程的途径.基于Eikonal方程构造出类Euler形式的输运方程,这样,可以直接利用求解Euler和Navier-Stokes方程的CFD程序使用的高效...壁面距离在当代湍流模化中仍然扮演着关键角色,然而苦于遍历计算壁面距离的高昂代价,该文考虑了求解偏微分方程的途径.基于Eikonal方程构造出类Euler形式的输运方程,这样,可以直接利用求解Euler和Navier-Stokes方程的CFD程序使用的高效数值格式和部分代码.基于北航的MI-CFD(CFD for missles)数值平台,详尽地介绍了该输运方程在直角坐标下的求解过程.使用隐式LUSGS时间推进和迎风空间离散,发现该方程具有鲁棒快速的收敛特性.为了保证精度,网格度量系数必须也迎风插值计算.讨论了初始条件和边界条件的特殊处理.成功应用该壁面距离求解方法计算了几个含1-1对应网格和重叠网格的复杂外形.展开更多
文摘Ice-going ships play a crucial role in polar transportation and resource extraction.Different from the existing modeling approach which assumes that ships remain stationary,dynamic overset grid technology and DFBI(Dynamic Fluid-Body Interaction)method are employed in this paper to enable the free-running motion of the ship in modeling.A numerical model capable of simulating a ship navigating through pack ice area is proposed,which uses Computational Fluid Dynamics(CFD)method to solve the flow field and applies the Discrete Element Method(DEM)to simulate ship-ice and ice-ice interactions.Besides,the proposed high-precision method for generating pack ice area can be used in conjunction with the proposed numerical model.By comparing the numerical results with the available model test data and experimental observations,the effectiveness of the numerical model is validated,demonstrating its strong capability of predicting resistance and simulating ship navigation in pack ice,as well as its significant potential and applicability for further studies.
基金Supported by the Project on the Integration of Industry,Education and Research of Guangdong Province(No.2012B091000137)the Key Program of Hydrodynamics of China(No.9140A14030712JB11044)~~
文摘采用非结构重叠网格Euler方程的CFD方法数值模拟了外挂投放。该方法在重叠网格"挖洞"时,以"离壁面距离"为挖洞判据;在建立重叠区域插值关系时,对Neighbor to Neighbor(N2N)和Alternating Digital Tree(ADT)两种方法的效率进行了比较。采用机翼/挂架/带舵外挂物模型开展了验证计算。在此基础上,完成了某飞行器外挂投放的初步计算。
文摘壁面距离在当代湍流模化中仍然扮演着关键角色,然而苦于遍历计算壁面距离的高昂代价,该文考虑了求解偏微分方程的途径.基于Eikonal方程构造出类Euler形式的输运方程,这样,可以直接利用求解Euler和Navier-Stokes方程的CFD程序使用的高效数值格式和部分代码.基于北航的MI-CFD(CFD for missles)数值平台,详尽地介绍了该输运方程在直角坐标下的求解过程.使用隐式LUSGS时间推进和迎风空间离散,发现该方程具有鲁棒快速的收敛特性.为了保证精度,网格度量系数必须也迎风插值计算.讨论了初始条件和边界条件的特殊处理.成功应用该壁面距离求解方法计算了几个含1-1对应网格和重叠网格的复杂外形.
