الفهرس 
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Abstract
The main purpose of the present thesis is to investigate the effect of porosity in wave maker on surface waves generated in their presence in two layered fluids. The fluid considered is incompressible and inviscid, and the pores of the wave maker are such that Taylor’s assumption concerning the flow across the wave maker can be applied.
The thesis consists of four chapters:
In chapter 1, a brief accounts of the mathematical theory of gravity waves of small-amplitudes. Interface waves are discussed for both two-dimensional and axisymmetric motions. Relevant boundary conditions are also investigated.
In chapter 2, The steady-gravity wave motion is considered for two immiscible layers of incompressible and non-viscous fluids in the presence of a porous wave maker immersed vertically in the two fluids, the upper fluid having a free surface, and the lower fluid is of infinite depth. The boundary value problem for the velocity potentials is solved using Taylor’s assumption on the wave maker. Related scattering problems are also studied.
In chapter 3, The forced axisymmetric motion produce by a vertical cylindrical porous wave maker immersed vertically in two layered fluids with the upper fluid has a free surface is considered. Analytical solutions are obtained for two cases, when the lower fluid is of infinite depth and when it is of finite constant depth. The axisymmetric scattering problems are investigated. Wave trapping phenomenon is discussed.
In chapter 4, The motion generated by a porous wave maker in continuously two layered stratified fluids is investigated. Adopting Chwang’s method the stream function is obtained for each fluid layer. The interface depression, the hydrodynamic pressure distribution and the resultant fluid thrust on the two sides of the wave maker are calculated for particular forms of the density stratification and wave maker velocity, the effect of stratification and poristy are discussed analytically and graphically.