流体力学杂志“Journal of Fluid Mechanics”由剑桥大学教授George Batchelor在1956年5月创办，在国际流体力学界享有很高的学术声望，被公认为是流体力学最著名的学术刊物之一，2005年的影响因子为2．061，雄居同类期刊之首．在它创刊50周年之际，2006年5月JFM出版了第554卷的纪念特刊，其中刊登了现任主编（美国西北大学S．H．Davis教授和英国剑桥大学T．J．Pedley教授）合写的述评：“Editorial：JFM at50”，以JFM为背景，从独特的视角对近50年来流体力学的发展进行了简明的回顾和展望，并归纳了一系列非常有启发性的有趣统计数字．2006年7月21日在剑桥大学应用数学和理论物理研究所（DAMTP）举行了创刊50周年的庆祝会．下午2点，JFM的新老编辑和来宾会聚一堂，Pedley教授致开幕词，其后是5个精彩的报告：The mysterious rattleback and its fluid counterpart（Keith Moffatt），Developments in shear instabilities（Patrick Huerre），Falling clouds（Elisabeth Guazzelli），Ecotectural fluid mechanics（Paul Linden），The success of JFM（Herbert Huppert），最后由Davis教授致闭幕词．

Journal of Fluid Mechanics创刊50周年

In this paper, robust adaptive control with dynamic control allocation is proposed for the positioning of marine vessels equipped with a thruster assisted mooring system, in the presence of parametric uncertainties, unknown disturbances and input nonlinearities. Using neural network approximation and variable structure based techniques in combination with backstepping and Lyapunov synthesis, the positioning control is developed to handle the uncertainties, input saturation and dead-zone characteristics of the mooring lines and thrusters. Full state feedback with all states measurable and output feedback using high gain observer to estimate unmeasurable states are considered. Dynamic control allocation is presented for actuation of the position mooring system. Under the proposed robust adaptive control, semi-global uniform boundedness of the closed-loop signals are guaranteed. Numerical simulations are carried out to show the effectiveness of the proposed control.

Robust Adaptive Position Mooring Control for Marine Vessels

Loads for use in the design of ships and offshore structures

This paper presents combined theoretical and experimental studies of the two-dimensional piston-like steady-state motions of a fluid in a moonpool formed by two rectangular hulls (e.g. a dual pontoon or catamaran). Vertical harmonic excitation of the partly submerged structure in calm water is assumed. A high-precision analytically oriented linear-potential-flow method, which captures the singular behaviour of the velocity potential at the corner points of the rectangular structure, is developed. The linear steady-state results are compared with new experimental data and show generally satisfactory agreement. The influence of vortex shedding has been evaluated by using the local discrete-vortex method of Graham (1980). It was shown to be small. Thus, the discrepancy between the theory and experiment may be related to the free-surface nonlinearity.

http://www.iwwwfb.org/Abstracts/iwwwfb21/iwwwfb21_14.pdf

Two-dimensional resonant piston-like sloshing in a moonpool

http://www.iwwwfb.org/Abstracts/iwwwfb27/iwwwfb27_32.pdf

Experimental and numerical study of the sloshing motion in a rectangular tank with a perforated screen

Global hydroelastic model for ship-type bodies is presented and validated both in frequency and time domain. Since we are interested in the global response, the structural part of the body is modelled by the so called non-uniform "Timoshenko beam model" using the finite element method, while the hydrodynamic part is modelled by the classical 3D Boundary Integral Equation (BIE) technique. The coupling is performed using the modal approach, which means that the final body response (motions/deformations) is decomposed into a series of the structural "dry" modes. An additional hydodynamic boundary value problem for each mode is created and soloved by 3D BIE method. The numerical model is validated through comparisons with data from especially dedicated model tests on an elastic barge. The barge was modelled with 12 pontoons connected with two elastic plates.

Hydroelastic response of a barge to impulsive and non-impulsive wave loads

Experimental and numerical study of the gap resonances in-between two rectangular barges.

Inertia effects in TLD sloshing with perforated screens

In this paper an extension of the theoretical model of Molin (J. Fluid Mech., vol. 430, 2001, pp. 27–50) is proposed, where the assumptions of infinite depth and infinite horizontal extent of the support are released. The fluid domain is decomposed into two subdomains: the moonpool (or the gap) and a lower subdomain bounded by the seafloor and by an outer cylinder where the linearized velocity potential is assumed to be nil. Eigenfunction expansions are used to describe the velocity potential in both subdomains. Garrett’s method is then applied to match the velocity potentials at the common boundary and an eigenvalue problem is formulated and solved, yielding the natural frequencies and associated modal shapes of the free surface. Applications are made, first in the case of a circular moonpool, then in the rectangular gap and moonpool cases. Based on so-called single-mode approximations, simple formulas are proposed that give the resonant frequencies.

/pdf/on-natural-modes-in-moonpools-and-gaps-in-finite-depth-2ies46b8p2.pdf

Fabien Remy

Papers

Experimental and numerical study of the sloshing motion in a rectangular tank with a perforated screen

Hydroelastic response of a barge to impulsive and non-impulsive wave loads

Experimental and numerical study of the gap resonances in-between two rectangular barges.

Inertia effects in TLD sloshing with perforated screens

On natural modes in moonpools and gaps in finite depth