The field of fluid mechanics is rapidly advancing, driven by unprecedented volumes data from experiments, measurements, and large-scale simulations at multiple spatiotemporal scales. Machine learning (ML) offers a wealth techniques to extract ...Read More

The unsteady hydrodynamic interaction of two bodies moving in a shallow fluid is examined by applying slender-body theory. are assumed to be each other's far field and the free surface rigid. By matched asymptotics, inner outer problems formulated pair coupled integro-differential equations for determining unknown cross-flows derived. degree coupling shown related bottom-clearance parameter. Expressions given sinkage force, trimming moment, sway yaw moment. Numerical calculations weakly...

Abstract This paper presents a novel integral‐equation technique for solving the steady‐state wave‐resistance problem. The free‐surface condition is linearized, but body satisfied exactly. An integral relation describing flow inside an arbitrarily truncated internal region first obtained by applying Green's Theorem, using only simple source function infinite fluid. next matched with eigen expansions in upstream and downstream outer regions. radiation can be exactly simply proper choice of...

This paper evaluates the technical feasibility and performance characteristics of an ocean-wave energy to electrical conversion device that is based on a moving linear generator. The UC-Berkeley design consists cylindrical floater, acting as rotor, which drives stator consisting two banks wound coils. such in waves depends hydrodynamics motion strongly coupled electromagnetic properties Mathematical models are developed reveal critical hurdles can affect efficiency design. A working physical...

To further maximize power absorption in both regular and irregular ocean wave environments, nonlinear-model-predictive control (NMPC) was applied to a model-scale point absorber developed at the University of California Berkeley, CA, USA. The NMPC strategy requires power-takeoff (PTO) unit that could be turned on off, as generator would inactive for up 60% period. confirm effectiveness this strategy, an in-house-designed permanent magnet linear (PMLG) chosen PTO. time-varying performance...

The objective of this work is to develop and validate a coupled boundary element method-finite method simulate the transient fluid-structure interaction response tidal turbines subject spatially varying inflow. focus on turbines, although methodology also applicable for analysis design wind turbines. An overview formulation both fluid solid domains, algorithms, presented. model validated by comparing predicted thrust power measurements, as well cavitation patterns, with experimental...

This paper evaluates the theoretical application of nonlinear model predictive control (NMPC) to a model-scale point absorber for wave energy conversion. The NMPC strategy will be evaluated against passive system, which utilizes no controller, using performance metric based on absorbed energy. was setup as optimization problem utilizing interior optimizer (IPOPT) package obtain time-varying optimal generator damping from power-take-off (PTO) unit. formulation is different previous...

An array of ocean-wave energy converters, compared to a stand-alone device, provides lower energy-production costs but affects the aggregate power performance. Previous studies suggested that wave-interaction effects within could increase production by over 15% per device. However, no physical constraints on WECs were considered in these studies; as result, devices can experience unrealistically large motions. A control strategy is thus desirable coordinate individual and maximize...

The full and partial ground effects on the lift generation of a flapping airfoil in normal hovering mode are investigated numerically using discrete vortex method two dimensions. To achieve effect, chord c is made to hover above center finite-sized platform length 10c. We have observed force-enhancement, force-reduction, force-recovery regimes at low, medium, high clearances line with existing literature. This paper puts special focus effect when near edge platform. Lift-modifying mechanisms...