题目: First- and second-order wave forces on rigid and elastic floating bodies with time domain prediction
报告人：Dr. Fuat Kara, Cranfield University, UK
报告摘要: The application and development of an in-house transient three-dimensional numerical computational code ITU-WAVE which is based on panel method, potential theory and Neumann-Kelvin linearisation will be presented for the prediction of the hydrodynamics and dynamics characteristics of mono- and multi-hull floating bodies with and without forward speed. The time histories of the unsteady motions in ambient incident waves are directly presented with Impulse Response Functions (IRF) whilst the memory effects due to free surface are taken into account by the use of convolution integral in time domain. The steady state perturbation potentials for first-order steady forces of wave-resistance, sinkage force and trim moment are solved as steady-state limit of the surge radiation IRF. The numerical prediction of second-order mean forces which can be computed from quadratic product of first-order quantities is presented using the near-field method based on the direct pressure integration over floating body in time domain. The hydrodynamic and structural parts are fully coupled through modal analysis for hydroelastic analysis in which Euler-Bernoulli beam is used for the structural part with analytically defined mode-shapes. A stiff structure is then presented assuming that contributions of rigid body modes are much bigger than elastic modes. A discrete control of latching is used to increase the absorbed power in the case of off-resonance conditions with isolated or array wave energy converters. The prediction of hydrodynamic forces on mooring lines and aerodynamic forces on floating offshore wind turbines will be also presented. The validation of ITU-WAVE numerical results against analytical, other numerical and experimental results will be presented.
报告人简介:Dr Kara is Senior Lecturer in Offshore Engineering at Energy Theme of Cranfield University in the UK. He has BSc and MSc in Naval Architecture and Marine Engineering from Istanbul Technical University in Turkey whilst he has PhD in Marine Hydrodynamics & Hydroelasticity from University of Strathclyde in the UK. Dr Kara has developed over twenty years advanced state-of-the-art transient free-surface three-dimensional direct time domain computational code (ITU-WAVE) in numerical marine hydrodynamics & hydroelasticity. He has research interest in fluid-structure interaction focusing on fixed or floating mono- and multi-hulls including rigid and elastic ships with and without forward speed; offshore structures; isolated and array wave energy converters with control strategies; mooring analysis; floating offshore wind turbines; subsea and pipeline engineering. He was Programme/Course Director of Offshore and Ocean Technology MSc courses which had six courses; Diving Science and Underwater Technology; Offshore Materials Engineering; Offshore Renewable Energy; Pipeline Engineering; Risk Management and Subsea Engineering between 2008 and 2015 in Cranfield University. He has contributed to many European Commission (EC), Research Council UK and industry projects as a PI or Co-I whilst acts as a reviewer for Research Council UK proposals and different journals.