Theoretical and numerical investigations of wave resonance between two floating bodies in close proximity  

作　　者：谭雷 唐国强 周忠兵 Liang Cheng Xiaobo Chen 吕林 

机构地区：[1]State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology,Dalian 116023,China [2]DUT-UWA Joint Research Centre of Ocean Engineering,Dalian University of Technology,Dalian 116023,China [3]School of Civil,Environmental and Mining Engineering,The University of Western Australia,Crawley,Australia [4]Deepwater Technology Research Centre,Bureau Veritas,Singapore

出　　处：《Journal of Hydrodynamics》2017年第5期805-816,共12页水动力学研究与进展B辑（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.51490673,51479025 and 51279029)

摘　　要：A simple theoretical dynamic model with a linearized damping coefficient is proposed for the gap resonance problem, as often referred to as the piston mode wave motion in a narrow gap formed by floating bodies. The relationship among the resonant response amplitude and frequency, the reflection and transmission coefficients, the gap width, and the damping coefficient is obtained. A quantitative link between the damping coefficient of the theoretical dynamic model（ε） and that devised for the modified potential flow model（μ_p） is established, namely, μ_p=3πεω_n/8 （where ω_n is the natural frequency）. This link clarifies the physical meaning of the damping term introduced into the modified potential flow model. A new explicit approach to determine the damping coefficient for the modified potential model is proposed, without resorting to numerically tuning the damping coefficient by trial and error tests. The effects of the body breadth ratio on the characteristics of the gap resonance are numerically investigated by using both the modified potential flow model and the viscous RNG turbulent model. It is found that the body breadth ratio has a significant nonlinear influence on the resonant wave amplitude and the resonant frequency. With the modified potential flow model with the explicit damping coefficient, reasonable predictions are made in good agreement with the numerical solutions of the viscous fluid model.A simple theoretical dynamic model with a linearized damping coefficient is proposed for the gap resonance problem, as often referred to as the piston mode wave motion in a narrow gap formed by floating bodies. The relationship among the resonant response amplitude and frequency, the reflection and transmission coefficients, the gap width, and the damping coefficient is obtained. A quantitative link between the damping coefficient of the theoretical dynamic model（ε） and that devised for the modified potential flow model（μ_p） is established, namely, μ_p=3πεω_n/8 （where ω_n is the natural frequency）. This link clarifies the physical meaning of the damping term introduced into the modified potential flow model. A new explicit approach to determine the damping coefficient for the modified potential model is proposed, without resorting to numerically tuning the damping coefficient by trial and error tests. The effects of the body breadth ratio on the characteristics of the gap resonance are numerically investigated by using both the modified potential flow model and the viscous RNG turbulent model. It is found that the body breadth ratio has a significant nonlinear influence on the resonant wave amplitude and the resonant frequency. With the modified potential flow model with the explicit damping coefficient, reasonable predictions are made in good agreement with the numerical solutions of the viscous fluid model.

关 键 词：Water wave narrow gap fluid resonance energy dissipation artificial damping 

分 类 号：O353[理学—流体力学]