[1] The nonhydrostatic Regional Ocean Modeling System is applied to the nonlinear internal waves, or solitons, that are generated at the Luzon ridge in the South China Sea. The Luzon ridge near the Batan islands is represented by an idealized ridge with a height of 2.6 km on a flat bottom. Model runs are performed for various ridge shapes and (a)symmetric tidal forcings. The model is in the mixed tidal lee wave regime. The barotropic tide over the ridge generates first-mode waves through the internal tide release mechanism. Westward-traveling solitons emerge from these first-mode waves through nonlinear steepening. In the internal tide release mechanism, asymmetric tides with strong eastward currents can generate strong westward solitons. The eastward current creates an elevation wave with a higher energy density west of the ridge, and as soon as the current slackens, the wave is released westward. On its backslope strong solitons develop. The energy density is further enhanced by nonlinearities, such as differences in phase speeds and energy fluxes related to lee waves. A modal and harmonic decomposition shows the generation of vertical modes and higher temporal harmonics and indicates significant wave-wave interaction (e.g., triads). In the mixed tidal lee wave regime, more energy is contained in the first mode compared to the higher modes. Hence, linear internal tide beams are less well defined and strong solitons develop.

Here we report the first example of a class of additively manufactured carbon fiber reinforced composite (AMCFRC) materials which have been achieved through the use of a latent thermal cured aromatic thermoset resin system, through an adaptation of direct ink writing (DIW) 3D-printing technology. We have developed a means of printing high performance thermoset carbon fiber composites, which allow the fiber component of a resin and carbon fiber fluid to be aligned in three dimensions via controlled micro-extrusion and subsequently cured into complex geometries. Characterization of our composite systems clearly show that we achieved a high order of fiber alignment within the composite microstructure, which in turn allows these materials to outperform equivalently filled randomly oriented carbon fiber and polymer composites. Furthermore, our AM carbon fiber composite systems exhibit highly orthotropic mechanical and electrical responses as a direct result of the alignment of carbon fiber bundles in the microscale which we predict will ultimately lead to the design of truly tailorable carbon fiber/polymer hybrid materials having locally programmable complex electrical, thermal and mechanical response.

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A three-dimensional non-hydrostatic numerical model for simulation of the free-surface stratified flows is presented. The model is a non-hydrostatic extension of free-surface primitive equation model with a general vertical coordinate and horizontal orthogonal curvilinear coordinates. The model equations are integrated with mode-splitting technique and decomposition of pressure and velocity fields on hydrostatic and nonhydrostatic components. The model was tested against laboratory experiments on the steep wave transformation over the longshore bar, solitary wave impact on the vertical wall, the collapse of the mixed region in the thin pycnocline, mixing in the lock-exchange flows and water exchange through the sea strait. The agreement is generally fair.