How essential non-linear stiffness affects the adaptation of flow energy converter based on fully-passive oscillating-foil?

The objective was to develop a mathematical simulation model of a pulsed spiral hydro-mechanical flow energy converter with a variable speed operating in a pulsed mode. This simulation model can be used for calculating the optimal parameters of such devices. The mechanical energy generated by pulsed liquid can be applied in the driving gear of mini-hydroelectric generators working without drops in water pressure, pumping stations and heat networks providing pressure reduction, as well as in heater fans operating in damp or explosion-hazardous facilities. Pulsed spiral hydro-mechanical energy converters can be used for converting the energy of a liquid flow into rotational motion, which can be further transferred to an electric generator or capacitor. In this study, using the example of a hydro-mechanical converter with a cone-shaped coil, the equations of torque depending on the change in the frequency of flow interruption, the moment of inertia and the resistance in the supports were obtained. Design charts were built for the torque of a hydro-mechanical converter with a cone-shaped coil for a number of coil turns equal to 4 pcs., square tube section 0.00011 m2, and the length of the initial round 0.176 m. The validity of the equations was confirmed by a physical experiment with sufficient accuracy. The conducted comparison of simulated and experimental values showed their agreement with an error of less than 5%. According to the simulation results, design parameters for different models have their own characteristics.

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A Joint Numerical and Experimental Study of a Surging Point Absorbing Wave Energy Converter (WRASPA)

Volume 4: Ocean Engineering; Ocean Renewable Energy; Ocean Space Utilization, Parts A and B ◽

10.1115/omae2009-79392 ◽

2009 ◽

Cited By ~ 11

Author(s):

Majid A. Bhinder ◽

Clive G. Mingham ◽

Derek M. Causon ◽

Mohammad T. Rahmati ◽

George A. Aggidis ◽

...

Keyword(s):

Wave Energy ◽

Informed Choice ◽

Wave Energy Converter ◽

Body Motion ◽

Numerical Dissipation ◽

Small Scale ◽

Linear Wave ◽

Energy Converter ◽

Non Linear ◽

Experimental Project

This paper presents the findings from using several commercial computational fluid dynamics codes in a joint numerical and experimental project to simulate WRASPA, a new wave energy converter (WEC) device. A series of fully 3D non-linear simulations of WRASPA are presented. Three commercial codes STAR-CCM, CFX and FLOW-3D are considered for simulating the WRASPA device and final results are presented based on the use of Flow-3D. Results are validated by comparison to experimental data obtained from small scale tank tests undertaken at Lancaster University (LU). The primary aim of the project is to use numerical simulation to optimize the collector geometry for power production over a range of likely wave climates. A secondary aim is to evaluate the ability of commercial codes to simulate rigid body motion in linear and non-linear wave climates in order to choose the optimal code with respect to compute speed and ease of problem setup. Issues relating to the ability of a code in terms of numerical dissipation of waves, wave absorption, wave breaking, grid generation and moving bodies will all be discussed. The findings of this paper serve as a basis for an informed choice of commercial package for such simulations. However the capability of these commercial codes is increasing with every new release.

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Non-linear numerical modeling and experimental testing of a point absorber wave energy converter

Ocean Engineering ◽

10.1016/j.oceaneng.2013.12.009 ◽

2014 ◽

Vol 78 ◽

pp. 11-21 ◽

Cited By ~ 63

Author(s):

A.S. Zurkinden ◽

F. Ferri ◽

S. Beatty ◽

J.P. Kofoed ◽

M.M. Kramer

Keyword(s):

Numerical Modeling ◽

Wave Energy ◽

Experimental Testing ◽

Wave Energy Converter ◽

Energy Converter ◽

Point Absorber ◽

Non Linear

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Hydrodynamic Analysis of a Marine Current Energy Converter for Profiling Floats

Energies ◽

10.3390/en11092218 ◽

2018 ◽

Vol 11 (9) ◽

pp. 2218 ◽

Cited By ~ 1

Author(s):

Shuang Wu ◽

Yanjun Liu ◽

Qi An

Keyword(s):

Deep Water ◽

Working Hours ◽

Electrical Energy ◽

Hydrodynamic Characteristics ◽

Energy Converter ◽

Main Research ◽

Flow Energy ◽

Marine Current ◽

Sea Area ◽

Current Energy

With the continuous improvement of people’s interest in ocean exploration, research on deep-water profiling floats has received more and more attention. Energy supply is the key factor that restricts the working hours of deep-water floats. For this consideration, a marine current energy converter for deep-water profiling floats is proposed in this paper. A spiral involute blade is designed so that energy can be captured in two directions. Specifically, in the shallow sea area, the energy of the radial current is captured, and in the deep-sea area, the axial relative flow energy of the floats’ autonomous up and down motions is captured. This captured energy is then converted into electrical energy to charge the battery and extend the working time of the floats. The novel spiral involute blade has unique hydrodynamic characteristics. The turbine’s self-starting performance and its capacity coefficient are the main research topics studied using the computational fluid dynamics technique. Through numerical analysis and simulation, the self-starting response range and energy capture were obtained. This paper verifies the feasibility of this innovative idea using a theory analysis and provides the basis for future prototype testing and further applied research.

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