TY - GEN
T1 - Linearization of quadratic drag to estimate calm buoy pitch motion in frequency-domain and experimental validation
AU - Salem, Amir G.
AU - Ryu, Sam
AU - Duggal, Arun S.
AU - Datla, Raju V.
PY - 2009
Y1 - 2009
N2 - Estimate of the pitch motion of an oil offloading Catenary Anchor Leg Mooring (CALM) buoy is presented. Linearization of the quadratic drag/damping term is investigated by the frequency-domain analysis. The radiation problem is solved to estimate the added mass and radiation damping coefficients, and the diffraction problem is solved for the linear wave exciting loading. The equation of motion is solved by considering the linearized nonlinear drag/damping. The pitch motion response is evaluated at each wave frequency by iterative and various linearization methods of the nonlinear drag term. Comparisons between the linear and nonlinear damping effects are presented. Time-domain simulations of the buoy pitch motion were also compared with results from the frequency-domain analysis. Various linearization methods resulted in good estimate of the peak pitch response. However, only the stochastic linearization method shows a good agreement for the period range of the incident wave where typical pitch response estimate has not been correctly estimated.
AB - Estimate of the pitch motion of an oil offloading Catenary Anchor Leg Mooring (CALM) buoy is presented. Linearization of the quadratic drag/damping term is investigated by the frequency-domain analysis. The radiation problem is solved to estimate the added mass and radiation damping coefficients, and the diffraction problem is solved for the linear wave exciting loading. The equation of motion is solved by considering the linearized nonlinear drag/damping. The pitch motion response is evaluated at each wave frequency by iterative and various linearization methods of the nonlinear drag term. Comparisons between the linear and nonlinear damping effects are presented. Time-domain simulations of the buoy pitch motion were also compared with results from the frequency-domain analysis. Various linearization methods resulted in good estimate of the peak pitch response. However, only the stochastic linearization method shows a good agreement for the period range of the incident wave where typical pitch response estimate has not been correctly estimated.
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U2 - 10.1115/OMAE2009-80212
DO - 10.1115/OMAE2009-80212
M3 - Conference contribution
AN - SCOPUS:77952845099
SN - 9780791843413
T3 - Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE
SP - 907
EP - 911
BT - Proceedings of the 28th International Conference on Ocean, Offshore and Arctic Engineering 2009, OMAE2009
T2 - 28th International Conference on Ocean, Offshore and Arctic Engineering, OMAE2009
Y2 - 31 May 2009 through 5 June 2009
ER -