Hydrodynamic forces on heave plates for offshore systems oscillating close to the seabed or the free surface

Abstract

xiv de la distancia al fondo marino o a la superficie libre.3. El comportamiento físico del flujo, para valores de KC cercanos a su valor crítico ha sido estudiado mediante el análisis del campo de vorticidad.4. Introducir porosidad al disco, reduce la masa añadida para los valores de KC estudiados, pero se ha encontrado que la porosidad incrementa el valor del coeficiente de amortiguamiento cuando se incrementa la amplitud del movimiento, logrando un máximo de damping para un disco con 10% de porosidad.5. Los resultados numéricos y experimentales para los discos con faldón, muestran que usar este tipo de geometrías incrementa la masa añadida cuando se compara con el disco sólido, pero reduce considerablemente el coeficiente de amortiguamiento.6. Un diseño novedoso de heave plate basado en la teoría fractal ha sido experimentalmente estudiado a diferentes calados y comparado con datos experimentales obtenidos por otro autores. Los resultados muestran un comportamiento incierto de los coeficientes y por tanto este diseño debería ser estudiado más a fondo.xv

Selected topics in the Hydrodynamics of floating offshore wind turbines: heave damping and second order surge motions

“…Recently, Garrido-Mendoza (2015) confirmed that there is a relatively weak dependence of the measured added masses with frequency and a large dependence with KC for one leg (cylinder + heave plate) of the semisubmersible used in this thesis. He also performed experimental scale effect with 3 different scales of such geometry on heave oscillation test, finding no relevance scale effect for such cases confirming the possible use of smaller scale on future experimental campaign.…”

“…More recently, Garrido-Mendoza (2015) has validated Finite Volume Method (Open-Goam) to calculate axisymmetric viscous flow problem of heave plates oscillating in heave, the geometry used for validation is one leg of the one used in this thesis. He also performed a parametric study of such heave plates with different flaps using numerical tools, as well as determines the influence of bottom and free surface on damping and added The hydrodynamic load is strongly dependent on the hydrodynamic coefficients of the structure being deployed, but as it was mentioned before, the works developed up to now are focused on the geometrical features and motion features.…”

Numerical hydrodynamic design validation and highlights of the SATH floating offshore wind turbine

“…This may increase the system downtime or damage the components and acts as an important challenge which needs to be addressed. For this purpose, a possible solution is the inclusion of a heave plate [1], adopted in the SATH technology [2], which adds motion dampening mainly by viscous effects and other benefits for pitch and roll motions. This is not a common practice for oil rigs or the naval industry and, consequently, the engineering software typically employed needs to be revisited.…”