Showing 3 results for Dynamic Mesh
Amir Nikseresht, Hossein Ghazizade-Ahsaee,
Volume 1, Issue 0 (6-2013)
Abstract
In this research, numerical simulation of a symmetric impact of a 2-D wedge, considering dynamic equations in two-phase flow is taken into account. The two-phase flow around the wedge is solved based on finite volume method and volume of fluid (VOF) scheme. The dynamic mesh model is used to simulate dynamic motion of the wedge, thereby the effects of different dynamic meshes in both structured and unstructured meshes in simulating symmetric water impact phenomenon are investigated. Moreover, the effects of flow turbulence and fluid compressibility at the moment of water impact are studied. Also, the effects of different deadrise angles and body mass on the slamming force are investigated. At last, the impact problem of a wedge with constant velocity is calculated and the results are compared with the results of the impact problem solved considering dynamic equations of the motion.
Hamid Kazemi Moghadam, Rouzbeh Shafaghat,
Volume 5, Issue 0 (2-2016)
Abstract
There are different methods to reduce drag in high speed hulls. One of these methods is a change in the shape of the body by adding longitudinal side tunnels. In this paper it has been attempted to determine the influence of the tunnel height on hydrodynamic characteristics of the hull to achieving an optimum shape for the tunnel. To achieve this purpose, numerical simulation of the problem has been done using finite volume method considering moving mesh. For turbulence modeling, k-ε model and to simulate free surface, the Volume of Fluid (VOF) two phase model has been employed. The results show that creating a tunnel in the base mono-hull would lead to reduction of the total drag at high speed as well as decreasing the vessel draft of the hull over the whole range. Furthermore, in the Volumetric Froude number around 4, a reduction in the height of the tunnel could decrease the hull drag. In higher Volumetric Froude numbers, reduction of the tunnel height, to some extent, increases the drag with a slight slope.
Mehdi Mahmoodi, Roya Shademani, Mofid Gorji Bandpy,
Volume 9, Issue 0 (1-2018)
Abstract
In this paper, symmetric water entry of twin wedges is investigated for deadrise angle of 30 degree. Three numerical simulation of a symmetric impact, considering rigid body dynamic equations of motion in two-phase flow is presented. The two-phase flow around the wedges is solved by Finite Element based on Finite Volume method (FEM-FVM) which is used in conjunction with Volume of Fluid (VOF) scheme in ANSYS Fluent and ANSYS CFX and Phase Field scheme in COMSOL Multiphysics. The method and scheme of simulation are validated by experimental data for geometry with one wedge. The dynamic mesh, mesh motion and moving mesh models are used to simulate dynamic motion of the wedges in ANSYS Fluent, ANSYS CFX and COMSOL Multiphysics, respectively. The vertical velocity and pressure coefficient versus time are determined and comparisons of the computed mentioned parameters against experimental data are performed. The eight characteristics effects of fluid flow are investigated till 0.25 second after wedges falling including impact event. It is demonstrated that the ANSYS Fluent and k-ε were the best software and viscous model, respectively.
