Results 261 to 270 of about 134,722 (288)

Mathematical models of diffraction and radiation problems for planar waveguide with impedance flange

MMET '96. VIth International Conference on Mathematical Methods in Electromagnetic Theory. Proceedings, 2002
The problem of diffraction and radiation for a planar semibounded waveguide with ideally conducting sides and flange has been solved by different methods more than once. In this work the problem is considered in the impedance flange case. The derivation of a singular integral equation is demonstrated in the radiation problem case.
Y. Gandel, N. Morozova
openaire   +1 more source

Topics on Boundary-Element Solutions of Wave Radiation-Diffraction Problems

1985
Abstract : Two topics on the numerical solution of boundary-integral equations arising in linear wave-body interactions are discussed. The properties of a spectral technique for the solution of the integral equation are analyzed and compared to the conventional collocation method. It is shown that, using this technique, hydrodynamic forces predicted by
Chang-Ho Lee, Paul D. Sclavounos
openaire   +1 more source

A comparison of localized finite element formulations for two‐dimensional wave diffraction and radiation problems

International Journal for Numerical Methods in Engineering, 1981
AbstractTwo of the most promising localized finite element methods are compared: the boundary series element method, in which a series of eigenfunctions is used to represent the far field solution; and the boundary integral element method, in which an integral equation is satisfied at the boundary between localized finite element and outer regions. The
Taylor, R. Eatock, Zietsman, J.
openaire   +2 more sources

A direct boundary-element method for three-D wave diffraction and radiation problems

Ocean Engineering, 1988
Abstract Three-dimensional analytical procedures are developed for determining the wave-exciting and motion-induced hydrodynamic forces for fixed and floating ocean structures in a fluid of finite or infinite depth. The fluid potential is expressed by means of a Helmholtz integral, which involves the normal fluid velocities at the fluid-structure ...
Chih-Kang Lee, Jack Y.K. Lou
openaire   +1 more source

An improved matching method to solve the diffraction—radiation problem of a ship moving in waves

Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment, 2004
On the underlying assumption that the disturbance of the far-field velocity potential caused by the motion of a ship is small and may be linearized, an improved matching method is developed. Two arrays of fundamental singularities are placed inside the ship hull, which satisfy the linear free surface condition outside the truncated fluid domain and ...
Du, S.X., Hudson, D.A., Price, W.G., Temarel, P.   +3 more
openaire   +2 more sources

Weak radiation condition in the problem of a plane wave diffraction by a wedge

MMET '96. VIth International Conference on Mathematical Methods in Electromagnetic Theory. Proceedings, 2002
The Kontorovich-Lebedev transform is used for the solution of various problems of diffraction by a wedge. A failure of this transform is that it is applicable to a narrow class of functions not containing, in particular, a complete solution to the problem of diffraction.
openaire   +1 more source

The direct problem of acoustic diffraction of an audible probe radiation by an air-saturated porous cylinder

Journal of Applied Physics, 2010
Gas-saturated, solid skeleton, porous media like geomaterials, polymeric and metallic foams or biomaterials are fundamental in a diverse range of applications, from structural materials to energy technologies. Most polymeric foams are used for noise control applications and knowledge of the manner in which the energy of sound waves is dissipated with ...
Ogam, Erick, Depollier, Claude, Fellah, Zine El Abiddine   +2 more
openaire   +2 more sources

Solution of radiation and diffraction problems with axial symmetry by the method of parabolic equation

Radioengineering
As a rule, problems of radiation and diffraction on bodies of revolution of large electrical size are solved by the method of integral equations, since in this case the original boundary value problem can be reduced to a system of two Fredholm integral equations.
V.V. Akhiyarov, E.A. Ishchenko, Yu.G. Pasternak   +2 more
openaire   +1 more source

Three-dimensional finite element analysis of the diffraction-radiation problem of hydrodynamically compact structures

Marine Structures, 1995
The finite element method for solving the linear floating body hydrodynamic problem is considered with a hierarchy of boundary damper options for modelling the far field. The computer program is validated using two simple examples for which added mass and damping coefficients are computed over a wide range of frequencies.
P. Krishnankutty, C.P. Vendhan
openaire   +1 more source

A time-domain higher-order boundary element method for 3D forward-speed radiation and diffraction problems

Journal of Marine Science and Technology, 2013
A time-domain higher-order boundary element method for seakeeping analyses in the framework of linear potential theory is newly developed. Ship waves generated by two modified Wigley models advancing at a constant forward speed in calm water or incident waves and the resultant radiation and diffraction forces are computed to validate this code.
Guanghua He, Masashi Kashiwagi
openaire   +1 more source