the effects of current on cnoidal wave

wave current interactions have been one of the most interesting topics in ocean engineering. when sea waves enter an inlet against an ebb current, changes of wave heights and wave length occur.understanding of wave characteristics in the coastal region is the most important challenge in coastal engineering. in near shore, with depth decreasing, there are parallel coastal currents from non-orthogonal wave radiation. however, these trends in the coast, with waves have influences on each other. wave current interaction is one of the most interesting issues in marine engineering and oceanography. for example, when the wave reaches the sea coast, waves and currents between parallel the beach, a interaction occurs. variable current rate and length and wave form change to the average velocity and wave current, makes a significant effect. what this paper examines is, effect on the current on wave and a new form of dispersion relation will be obtained for wave current interaction that the opposite current, and decrease the speed and wave length and increases wave sharpness and vice versa.