Abstract:
This paper presents an initial CFD analysis using a porosity model to represent the hydrodynamic perturbation of disks under forced oscillations in a simplified way. The oscillation is used to represent a subsea equipment in a lifting, or deploying process, under a ship heave motion. The disks are, initially, solid (porosity equals to 0), in order to validate the model, and later porosity is added. The disk is forced to oscillate under a sinusoidal motion inside water. The Keulegan- Carpenter number, KC, in relation to its diameter, spans from 0.25 to 1.50, and the set porosity is 5%. The added mass and damping coefficients are calculated from the obtained hydrodynamic forces, and compared with experimental data present in the literature. For the porosity scenarios, a porous medium model is adopted rather than the actual geometry of perforated disks, the hydrodynamical forces are calculated, and the permeability coefficients are set in a iterative manner. The differences in flow patterns are then analyzed. It is expected in future works that with this study it will be able to simulate bodies with greater complexity with meaningful force outputs and accessible computational cost.
Reference:
GOMES, Gustavo Goes; DANTAS, João Lucas Dozzi; ASSI, Gustavo Roque da Silva. Numerical study of flow around oscillating simple geometric using porous médium. In: ABCM INTERNATIONAL CONGRESS OF MECHANICAL ENGINEERING, 25., 2019, Uberlândia. Proceedings… 10 p.
This paper presents an initial CFD analysis using a porosity model to represent the hydrodynamic perturbation of disks under forced oscillations in a simplified way. The oscillation is used to represent a subsea equipment in a lifting, or deploying process, under a ship heave motion. The disks are, initially, solid (porosity equals to 0), in order to validate the model, and later porosity is added. The disk is forced to oscillate under a sinusoidal motion inside water. The Keulegan- Carpenter number, KC, in relation to its diameter, spans from 0.25 to 1.50, and the set porosity is 5%. The added mass and damping coefficients are calculated from the obtained hydrodynamic forces, and compared with experimental data present in the literature. For the porosity scenarios, a porous medium model is adopted rather than the actual geometry of perforated disks, the hydrodynamical forces are calculated, and the permeability coefficients are set in a iterative manner. The differences in flow patterns are then analyzed. It is expected in future works that with this study it will be able to simulate bodies with greater complexity with meaningful force outputs and accessible computational cost.
Reference:
GOMES, Gustavo Goes; DANTAS, João Lucas Dozzi; ASSI, Gustavo Roque da Silva. Numerical study of flow around oscillating simple geometric using porous médium. In: ABCM INTERNATIONAL CONGRESS OF MECHANICAL ENGINEERING, 25., 2019, Uberlândia. Proceedings… 10 p.
