Session Aims & Scope

The world is at a critical juncture where the need for sustainable energy solutions is more urgent than ever. Traditional energy sources, such as fossil fuels, are not only finite but also significant contributors to environmental degradation and climate change. As global energy demand continues to rise, there is a pressing need to explore and develop alternative, renewable energy sources. The ocean, covering over 70% of the Earth’s surface, presents a vast and largely untapped reservoir of energy. Marine New Energy, which includes tidal, wave, ocean thermal, salinity gradient, and offshore wind energy, is emerging as a promising frontier in the renewable energy sector.         

Digital Twins can be used to simulate and optimize real-world performance. In this context, Digital Twins offer the potential to revolutionize how we deploy and manage these complex energy systems. By integrating advanced modeling techniques, Digital Twins can help overcome many of the challenges associated with marine energy, such as environmental variability, system maintenance, and operational efficiency.

The session will focus on the following points

  • The development and deployment of digital twins for marine energy applications  
  • Improving the Reliability and Longevity of Marine Energy Devices
  • Promoting industry collaboration and innovation  
  • Challenges in scalability and security

Session Chair(s)

Chair

Yanjun Liu

Professor, Shandong University (China)

lyj111ky@163.com

Co-Chair

Elena De Momi

Professor, Politecnico di Milano (Italy)

elena.demomi@polimi.it

Co-Chair

Hongda Shi

Professor, Ocean University of China (China)

hd_shi@ouc.edu.cn

Session Presentation

1.

Jing Geng

Professor

Harbin Engineering University (China)

Title: Hydrodynamic analysis of multi-purpose coastal and offshore structures

Abstract 

Multi-functional coastal and offshore marine engineering structures, designed to fulfill multiple purposes such as offshore renewable energy utilization, aquaculture, and breakwater functionality, have emerged in recent years. This presentation provides a summary of our recent research in this field, encompassing hydrodynamic modeling, analysis, and design criteria. Specifically, we will present the hydrodynamic modeling of wave interaction with periodic structures and multi-body systems with complex connections. Motivated by two prototypes that have undergone sea trials in China, we offer a comprehensive analysis of the hydrodynamic behavior of these hybrid systems. Our newly proposed methodology and illustrated mechanisms have the potential to serve as a scientific foundation for the design of such hybrid systems.  

2.

Zhen Liu

Professor

Ocean University of China (China)

Title: The Establishment and Application of Digital Twin Model for Oscillating Water Column Wave Energy Converter

Abstract 

Accurately predicting the energy output of a wave energy device is important for evaluating its LCoE and facilitating commercial development. In this study, a digital twin model for the OWC device was firstly established to include both the air chamber and the turbine and associated stages. The capability of the model was comprehensively verified and validated by relevant experimental studies, and the operating performance of a prototype plant was also investigated using this digital twin model.

3.

Lei Guo

Associate Professor

Shandong University (China)

Title: The Establishment and Application of Digital Twin Model for Oscillating Water Column Wave Energy Converter

Abstract 

Present study have developed a set of “Marine Engineering Geological Environment In-situ Investigation System”, with the seabed-based static penetration and sampling platform as the main body, which can quickly and accurately obtain the engineering geological parameters of the seabed sediments in the near-sea area, sediment samples, and seabed film and video data; the study have also developed a set of “3,000-meter-class multi-parameter in-situ probe and deployment system”. A 3000m-class multi-parameter in-situ probe and deployment system has been developed, which is applicable to water depth of 3000m and has the functions of in-situ sediment sampling and in-situ detection of physical and chemical properties of deep-sea sediments, thus forming an exploration platform integrating deep-sea sediment sampling, in-situ physical and chemical property testing, and undersea camera. With the help of the two sets of equipment, a number of operational investigations have been carried out, and rich data resources have been formed in a number of sea areas. The team uploaded the resources to the “Geological Cloud” digital system, which provided information resources for the construction of the seabed boundary layer information database in the deep and shallow waters around China, which can be conveniently queried by relevant personnel.

4.

Hongwei Liu

Professor

Zhejiang University (China)

Title: The Establishment and Application of Digital Twin Model for Oscillating Water Column Wave Energy Converter

Abstract 

Present study have developed a set of “Marine Engineering Geological Environment In-situ Investigation System”, with the seabed-based static penetration and sampling platform as the main body, which can quickly and accurately obtain the engineering geological parameters of the seabed sediments in the near-sea area, sediment samples, and seabed film and video data; the study have also developed a set of “3,000-meter-class multi-parameter in-situ probe and deployment system”. A 3000m-class multi-parameter in-situ probe and deployment system has been developed, which is applicable to water depth of 3000m and has the functions of in-situ sediment sampling and in-situ detection of physical and chemical properties of deep-sea sediments, thus forming an exploration platform integrating deep-sea sediment sampling, in-situ physical and chemical property testing, and undersea camera. With the help of the two sets of equipment, a number of operational investigations have been carried out, and rich data resources have been formed in a number of sea areas. The team uploaded the resources to the “Geological Cloud” digital system, which provided information resources for the construction of the seabed boundary layer information database in the deep and shallow waters around China, which can be conveniently queried by relevant personnel.

5.

Dezhi NING

Professor

Dalian University of Technology (China)

Title: OWC wave energy converter array coupled with a parabolic-wall energy concentrator

Abstract 

A heuristic method to identify the optimal siting of the component, cylindrical OWC WECs in the array, installed in the concave opening of the wall is presented. The most advantageous location of the chambers is found to lie on a parabolic curvature line which is inset from the wall. The hydrodynamic power and efficiency of each chamber in each of the arrays is determined, and subsequently the aggregated array performance is established. It is found that the primary OWC chamber in the array configuration can attain approximately the same hydrodynamic power output as a single, isolated OWC chamber located the parabolic wall focus, albeit with a narrower energy capture bandwidth. The secondary and tertiary component chambers in the arrays contribute a lesser, yet still considerable quantity of hydrodynamic power to the consolidated system. The cumulative hydrodynamic efficiency of the collective arrays is less than the hydrodynamic efficiency of a single OWC chamber at the wall focus, but more efficient than an isolated OWC chamber positioned in open-sea conditions. Moreover, the hydrodynamic efficiency of the arrays exhibits better stability across the range of incident wave periods investigated, denoting that the individual component chambers in the array are efficacious at different incident wave conditions

6.

Yong Ma

Professor

Sun Yat-sen University (China)

Title: Experimental investigation of a Wind-Tidal Combined Power Generation Device

Abstract 

The development and utilization prospects for wind energy and tidal energy are vast; however, current devices for harnessing these energies are typically designed for single energy sources, leading to high costs, poor stability, and limited output. This paper proposes a novel semi-submersible wind-tide hybrid power generation device aimed at integrating the use of both wind and tidal energies. Experimental studies have been conducted to evaluate its performance. To address the issue of reduced hydrodynamic performance due to scale effects on the turbine and rotor, the blade surfaces were treated with roughness. Additionally, an equivalent loading system for a vertical-axis dual-rotor turbine was developed, overcoming limitations imposed by the experimental tank conditions. A comprehensive model test method and measurement platform for the semi-submersible wind-tide hybrid power generation device, considering the combined effects of wind, waves, and currents, were established. The findings of this study can serve as a valuable reference for the development of similar devices.

7.

Dahai Zhang

Professor

Zhejiang University (China)

Title: Experimental and numerical study of an evolutionary algorithm-based optimization approach for multi-mode wave energy converters

Abstract 

First of all, a brief summary concerning current status on wave energy converter optimization will be given. Then the evolutionary algorithm-based optimization approach will be introduced, including the contents of optimization procedure, algorithms setup and the geometry definition. After that, the concluding remarks will be presented.

8.

Binzhen Zhou

Professor

South China University of Technology (China)

Title: Development of oscillating body wave energy converter and relevant hybrid systems

Abstract 

Wave energy has recently become a research highlight of ocean renewable energy due to its several merits such as the vast reserves. Till now, more than a thousand wave energy converters (WECs) based on various energy conversion mechanisms have been proposed, but few of these were commercially used. As an emerging marine renewable energy, the present development stage of wave energy is hindered by high costs. Despite the mentioned premature features, wave energy also has an irreplaceable role in niche applications of powering deep-sea reefs, offshore platforms, aqua cages, and research buoys. Therefore, local supply and consumption of wave energy has become an important trend and cutting-edge topic. The report focuses on the oscillating body WECs, which are more adaptive to offshore environments, more efficient, and more flexible in construction and deployment. These oscillating body WECs are also combined with other offshore equipment to form innovative hybrid systems which exploiting the advantages of shared infrastructures and maintenance, helping reduce the cost and provide a promising application prospect. This report introduces two typical hybrid systems, including an oscillating body WEC-breakwater hybrid system and an oscillating body WEC-floating offshore wind turbine hybrid system. The hydrodynamic couplings in the multi-body systems and their influence on the dynamic and power performance of the hybrid systems are emphasized .

9.

Gang Xue

Associate Researcher

Shandong University (China)

Title: Research on Wave Energy Supply of Underwater Vehicle with Hydrofoils

Abstract 

In order to solve the current problem of renewable energy capture and motion synergy faced by underwater vehicle, a new underwater vehicle with hydrofoils is proposed, which is capable of capturing wave energy and controlling the vehicle. Firstly, a structural design of the underwater vehicle is carried out, in which four hydrofoils are circumferentially distributed in the vehicle shell, and a buoyancy adjustment device is installed in the submerged part of each hydrofoil. Secondly, a hydraulic transmission system for the underwater vehicle is designed, which can realize the conversion and storage of wave energy, drive the movement of hydrofoils and regulate the drainage volume of the vehicle. Finally, a multi-mode motion strategy for the vehicle is constructed, which can use hydrofoil motion and buoyancy drive to cooperate with each other to realize the vehicle’s underwater hovering, surfacing and diving, gliding motion, trajectory tracking, and accurate bottoming, and can also use hydrofoils to capture wave energy from the surface of the sea to continuously provide energy supply. In addition, using digital twin technology, we can create exact virtual copies of the vehicle in a digital environment that can be used to simulate and optimize its performance in different sea states. Therefore, the underwater vehicle with hydrofoils can extend the effective working time and improve the precision operation capability, which provides a new solution to the problem of energy supply and underwater movement..

10.

Tiesheng LIU

Ph.D student

Shandong University (China)

Title: Influence of the hydraulic power take-off system on the dynamic response and power output of a wind-wave hybrid system

Abstract 

The power take-off (PTO) system plays a crucial role in the wind-wave hybrid system that directly affects the efficiency of wave energy conversion and the relative motion between buoys and the platform. The hydraulic PTO system, a commonly used type of wave energy conversion, has demonstrated practicality and reliability in practical projects. Effects of the hydraulic PTO system on the dynamic response and power output of the hybrid system are unclear due to the limitations of current simulation tools. Therefore, this study proposes an aero-hydro-servo-hydraulic-mooring fully coupled simulation method to investigate the effects of hydraulic parameters on the hybrid system. The results show that the hydraulic parameters have a significant effect on the heave and pitch natural periods, while they have a negligible effect on the surge natural period. The hydraulic parameters affect the surge, heave, and pitch motion responses of the platform, and the results depend on the phase and amplitude of the reaction forces of the hydraulic PTO system at different locations in the wave energy converters (WECs) micro array. For deterministic sea states, the same set of hydraulic parameters cannot simultaneously maximize the power generation of the WEC micro array and minimize the pitch motion response of the platform. Hydraulic parameters have negligible effect on the average values of the power generation and rotor torque of the wind turbine, but affect the amplitudes. Furthermore, the established framework can effectively simulate the working process of the hydraulic PTO system in a wind-wave hybrid system, which can provide essential pre-research for the actual hydraulic control to improve the wave energy conversion efficiency and hybrid system stability.