Numerical Simulation Of Three-dimensional Wave Elevation Variation Based On Uniform Flow Source Distribution

Based on the Green's function method with dissipative free surface sources,this dissertation establishes three-dimensional basic point source,two-point source and hydrofoil free surface wave elevation calculation models under uniform flow immersion,and studies the hydrodynamic problems of three-dimensional basic point source,twopoint source and hydrofoil wave elevation waveforms.The hydrodynamic behavior of three-dimensional point sources and free surface wave elevation and contours of hydrofoil with different Froude numbers,different dissipation coefficients,different immersion depths and different distances under uniform flow are numerically simulated.The following is the main work of this dissertation:(1)The simple Green's function and the Green's function method with dissipative free surface source are introduced.Using the regular integration of simple Green's function,the two-dimensional and three-dimensional hydrodynamic problems of point source integration formula under different distances,different Froude numbers,different dissipation coefficients and different immersion depths are numerically simulated.The numerical results show that under different k values,the point source integration formula changes slightly.As the number of Fn increases,the variation of regular integral expression increases.The waveform of the central axis surface rapidly descends along the direction of water flow,then rises to the horizontal line on the free surface and makes oscillate movement.With the increase of dissipation coefficient ?,the amplitude of wave crest and wave trough changes on the axial plane becomes smaller and smaller,and the degree of wave energy dissipation becomes more and more obvious.With the increasing depth of point source,the elevation of axial surface wave decreases continuously,and the amplitude of wave crest and wave trough decreases gradually.(2)Considering the hydrodynamic problem of two-point source affected by free surface under the action of submerged two-point source,the hydrodynamic behavior of two-dimensional and three-dimensional free surface wave elevation and contour lines of two-point source under different immersion depths,different Froude numbers and different dissipation coefficients is numerically simulated by using the regular integral of Green's function of two-point source with dissipation free surface source.The numerical results show that in the two-point source model,the free surface wave elevation decreases gradually with the increase of point source distance.Under the action of two-point source intensity,the free surface wave elevation overlap,and then two independent single source waves are gradually separated,and the ripples and contour lines change clearly.(3)Based on the boundary element theory,the hydrodynamic problems of threedimensional hydrofoil affected by free surface are studied.The hydrodynamic behaviors of two-dimensional and three-dimensional free surface wave elevation and contour lines of three-dimensional hydrofoil under different chord length ratios are numerically simulated by using the regular integration of Green's function with dissipative free surface source and the boundary element theory.The numerical results show that in the free surface wave elevation calculation model,the wave elevation of the free surface meet the hydrofoil in different shapes along the flow direction,and the wave forms and contour lines all change clearly.With the increase of chord length ratio of the hydrofoil,the wave radiation range of the free surface increases,and the wave forms and contour lines obviously diffuse.