Search results for " Water column"

Event-Triggered Nonlinear Control of OWC Ocean Wave Energy Plant

2018

This paper presents event-triggered nonlinear controllers for oscillating water column (OWC) ocean wave energy plant. The study is based on event-triggered backstepping controller (ET-BSC) and event-triggered sliding mode controller (ET-SMC) to control the rotational speed of an OWC turbine coupled to a generator. The designed controllers are capable to avoid the stalling of the Wells turbine so as to maximize its output power. The aim of event-triggered control is to minimize the control updates, thus providing efficient utilization of resources without compromising the OWC performance. In this regard, aperiodic sampling has been applied using an event-triggering rule derived from Lyapunov…

ON THE WAVE-U-OWC INTERACTION IN A NUMERICAL 2D WAVE FLUME

Several wave energy conversion techniques have been patented all over the world. Despite this large variation in design, the Wave Energy Converters (WECs) are generally categorized by location, type and modes of operation. An Oscillating Water Column consists of a chamber with an opening to the sea below the water line. An OWC consists of a box with a big vertical opening in the front wall. Waves enter through this opening with only some small diffraction effects from the front wall (and they propagate on the water surface in the box. On the roof of the box there is a tube connecting the atmosphere with the air pocket enclosed between the water surface and the roof. This tube contains one o…

Use of stable isotopes to investigate dispersal of waste from fish farm as a function of hydrodynamics.

2006

Stable isotopes were used to examine differential effects of fish farm waste on the water column and sediments. To achieve this objective, we chose 3 marine fish farms located along the coast of Sicily (Mediterranean Sea) as point-source disturbances, and a control area. The hypothesis that carbon and nitrogen isotope composition of particulate (POM) and sedimentary (SOM) organic matter varied with increasing distance (from cages to 1000 m) was tested at 3 levels of hydrodynam- ics: low (mean velocity of current (MVC) ~12 cm s -1 ), intermediate (MVC ~22 cm s -1 ), and high (MVC ~40 cm s -1 ). Different isotopic signals from allochthonous (fish waste) over natural (phytoplankton, terrigenou…