Mohammed Faizal

A Design Outline for Floating Point Absorber Wave Energy Converters

An overview of the most important development stages of floating point absorber wave energy converters is presented. At a given location, the wave energy resource has to be first assessed for varying seasons. The mechanisms used to convert wave energy to usable energy vary for different wave energy conversion systems. The power output of the generator will have variations due to varying incident waves. The wave structure-interaction leads to modifications in the incident waves; thus, the power output is also affected. The device has to be stable enough to prevent itself from capsizing. The point absorber will give optimum performance when the incident wave frequencies correspond to the natural frequency of the device. The methods for calculating natural frequencies for pitching and heaving systems are presented. Mooring systems maintain the point absorber at the desired location. Various mooring configurations as well as the most commonly used materials for mooring lines are discussed. An overview of scaled modelling is also presented.

An Overview of Ocean Thermal and Geothermal Energy Conversion Technologies and Systems

The Earth and the oceans have a natural temperature gradient between the surface and given depths. The natural temperature gradient is used to operate renewable energy systems, such as power generation and space heating/cooling, which operate on similar thermodynamic concepts. For a given purpose, different technologies are used to extract heat from the two resources. Even though the concepts of the two systems are the same, their energy extracting performance is different. An overview of the similarities between the usages of the two thermal resources is presented in this paper. The energy balances at the surface of the Earth and the oceans, system performances, availabilities and economics are also presented.

Energy Utilisation and Ground Temperature Distribution of a Field Scale Energy Pile Under Monotonic and Cyclic Temperature Changes

The operating modes of energy piles depend on the thermal energy requirements of the built structures. The various operating modes of the energy piles lead to variations in the energy utilisation and ground temperature distribution. This paper presents the results obtained from a field-scale energy pile subjected to different modes of operations. In particular, it is found that cyclic temperatures provide better energy utilisation compared to monotonic temperatures. Also, the ground temperatures reduce with increasing radial distance from the pile for all operating modes.

A study on the flow characteristics of a direct drive turbine for energy conversion generation by experiment and CFD

A variety of technologies has been proposed to capture the energy from waves. Some of the more promising designs are undergoing demonstration testing at commercial scales. Due to the complexity of most offshore wave energy devices and their motion response in different sea states, physical tank tests are common practice for WEC design. Full scale tests are also necessary, but are expensive and only considered once the design has been optimized. Computational Fluid Dynamics (CFD) is now recognized as an important complement to traditional physical testing techniques in offshore engineering. Once properly calibrated and validated to the problem, CFD offers a high density of test data and results in a reasonable timescale to assist with design changes and improvements to the device. The purpose of this study is to investigate the performance of a newly developed direct drive hydro turbine (DDT), which will be built in a caisson for extraction of wave energy. Experiments and CFD analysis are conducted to clarify the turbine performance and internal flow characteristics. The results show that commercial CFD code can be applied successfully to the simulation of the wave motion in the water tank. The performance of the turbine for wave energy converter is studied continuously for a ongoing project.