Banca de DEFESA: RAFAEL FEHÉR

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : RAFAEL FEHÉR
DATE: 29/11/2022
TIME: 10:00
LOCAL: CAMPUS DE SANTO ANDRE, REMOTAMENTE
TITLE:

Vortex-Induced Vibration Model With Two Degrees of Freedom of Rigid Cylinders Near A Plane Boundary Based On Wake Oscillator

PAGES: 150
BIG AREA: Engenharias
AREA: Engenharia Mecânica
SUBÁREA: Mecânica dos Sólidos
SPECIALTY: Dinâmica dos Corpos Rígidos, Elásticos e Plásticos
SUMMARY:

Pipelines are long steel pipes that rest on the seabed, used to transport oil offshore. A free span is formed between the pipelines and the seabed due to the erosion of the latter. Such structures, when immersed in a current, are subjected to cyclic hydrodynamic loads. A critical situation occurs when the underwater current acts parallel to the seabed and normal to the axis of the pipeline, producing its vibration by the shedding of downstream vortices. There is the problem of vibration induced by pipeline vortices, which can produce their premature failure due to fatigue. Despite its importance in the offshore oil production industry, this phenomenon has been little addressed by the scientific community and this is where this master's work is inserted. To conduct a pipeline fluid-structure interaction analysis, which is of low computational cost, the idea of using wake oscillators arises distributed along the structure to model the hydrodynamic loads arises. Within this context, this master's work aims to develop a vortex-induced vibration model of an elastically mounted rigid cylinder with two degrees of freedom. in the proximity of a plane boundary. The cylinder is considered rigid rather than flexible, i.e., its deformation is not considered. The model consists of three coupled differential equations: two equations for cylinder motion, called structure oscillators, and one equation for hydrodynamic force, which is the wake oscillator. The latter is developed based on the van der Pol equation.

As a result of this research, a wake oscillator model was developed to predict the vortex-induced vibrations of a rigid cylinder elastically mounted with two degrees of freedom near a plane boundary. The model was able to predict different experimental data available in literature, such as the lock-in range, maximum amplitude of vibration and reduced frequency.

BANKING MEMBERS:
Presidente - Interno ao Programa - 1761050 - JUAN PABLO JULCA AVILA
Membro Titular - Examinador(a) Externo à Instituição - ANDRÉ LUÍS CONDINO FUJARRA
Membro Titular - Examinador(a) Externo à Instituição - RUI MARCOS GROMBONE DE VASCONCELLOS
Membro Suplente - Examinador(a) Interno ao Programa - 1604343 - KARL PETER BURR