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• Investigation of the Resistance Force Acting on a Sailing Craft in the Case of a Change of Draft Caused by a Change of Powertrain Using Numerical CFD Simulations

  30-35

  Péter Ficzere

  Emese Lévai

  Views:

  231

  Nowdays In the case of recreational craft, interfering with motor drive solutions is a common workflow due to increasingly strict rules for environmental reasons. When switching from an internal combustion engine to an electric engine, the change in draft varies from boat to boat, but it can be said in all cases that as the mass changes, so does the draft. Because of this, the magnitude of the resistance force acting on the ship also varies. In this paper, we examine, through a specific example, the benefits of a change in dive caused by weight gain at different travel speeds.

• Evaluating the Efficiency of Polyhedral Mesh Elements in Solving the Problem of the Flow around Ship’s Rudder

  241-256

  Amjd Ibraheem

  Views:

  252

  Meshing is one of the crucial key features to the success of CFD based simulations, this study is evaluating the efficiency of polyhedral elements in solving the problem of the flow around ship rudder, using a Reynolds-averaged Navier-Stokes turbulence model (SST k-ω), and compares it to a tetrahedral based mesh, considering that polyhedral elements were neglected in the past due to difficulties in implementing them, this was solved by introducing a tool by ANSYS that converges tetrahedral elements to polyhedral element, and integrating it into FLUENT software, the model was validated by comparing it with previously validated model which used the full version of ANSYS, this study was concluded using the academic version, but still it was able to produce satisfying results in predicting the lift and the drag coefficient, the pressure around the rudder surface, the velocity and the turbulent kinetic energy, finally the mesh quality was evaluated using the orthogonal quality criteria, the results showed the supremacy of the polyhedral elements in saving time and computational resources and improving mesh quality, and keeping high level of accuracy in predicting the results.