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This paper aims to conduct a comprehensive literature review in the tidal energy physics, the ocean environment, hydrodynamics of horizontal axis tidal turbines and bio-mimicry.

The paper provides an insight of the tidal turbine blade design and need for renewable energy sources to generate electricity through clean energy sources and less CO₂ emission. The ocean environment, along with hydrodynamic design principles of a horizontal axis tidal turbine blade, is described, including theoretical maximum efficiency, blade element momentum theory and non-dimensional forces acting on tidal turbine blades.

This review gives an overview of fish locomotion identifying the attributes of the swimming like lift-based thrust propulsion, the locomotion driving factors: dorsal fins, caudal fins in propulsion, which enable the fish to be efficient even at low tidal velocities.

Finally, after understanding the phenomenon of caudal fin propulsion and its relationship with tidal turbine blade hydrodynamics, this review focuses on the implications of bio-mimicking a curved caudal fin to design an efficient horizontal axis tidal turbine.

The purpose of this paper is to design, investigate and optimize a horizontal axis tidal turbine (HATT) using computer-aided numerical simulation and computational fluid dynamics (CFD). This is the first step of research and development (R&D) for implementation in the Persian Gulf condition. To do so, suitable locations are reviewed. Then, the optimization is focused on determining the optimum fixed pitch angle (β) of a three-bladed HATT based on the widespread multiple reference frame (MRF) technique to calculate power and thrust coefficients at different operational rotating speeds.

To simplify the problem and reducing the computational costs due to cyclic symmetry only one blade, accordingly one-third of the whole computational domain is considered in the modeling. Due to flow’s nature involving rotating, separation and recirculation, a realizable κ-ε turbulence model with standard wall function is selected to capture flow characteristics influenced by the rotor and near the wall region. Simulations are conducted for two free-stream velocities, then compared with their dependencies through the dimensionless tip speed ratio (TSR) parameter.

The validation process of the simulations is carried out by the use of AeroDyn BEM code, which has been evaluated by comparing with two experimental data. As results, the highest coefficient of power is achieved at ß = 19.3° at TSR = 4 with the value around 0.41 and 0.816 for thrust coefficient. Furthermore, to comprehend the rotor’s performance and simulation method, flow characteristics due to the rise in angular velocity is discussed in detail. Moreover, the major phenomenon, cavitation occurrence, is also checked at the critical situation where it is found to be safe.

By comparing and evaluating the results to other HATTs, it implies that the proposed rotor of this study is feasible and proved by CFD evaluation at this step. However, the current rotor is awaiting a justification through experimental assessment.

This study aims to simulate Hunter turbine in Computer Forensic Examiner (CFX) environment dynamically. For this purpose, the turbine is designed in desired dimensions and simulated in ANSYS software under a specific fluid flow rate. The obtained values were then compared with previous studies for different values of angles (θ and α). The amount of validation error were obtained.

In this research, at first, the study of fluid flow and then the examination of that in the tidal turbine and identifying the turbines used for tidal energy extraction are performed. For this purpose, the equations governing flow and turbine are thoroughly investigated, and the computational fluid dynamic simulation is done after numerical modeling of Hunter turbine in a CFX environment.

The failure results showed; 11.25% for the blades to fully open, 2.5% for blades to start, and 2.2% for blades to close completely. Also, results obtained from three flow coefficients, 0.36, 0.44 and 0.46, are validated by experimental data that were in high-grade agreement, and the failure value coefficients of (0.44 and 0.46) equal (0.013 and 0.014), respectively.

In this research, at first, the geometry of the Hunter turbine is discussed. Then, the model of the turbine is designed with SolidWorks software. An essential feature of SolidWorks software, which was sorely needed in this project, is the possibility of mechanical clamping of the blades. The validation is performed by comparing the results with previous studies to show the simulation accuracy. This research’s overall objective is the dynamical simulation of Hunter turbine with the CFX. The turbine was then designed to desired dimensions and simulated in the ANSYS software at a specified fluid flow rate and verified, which had not been done so far.

The limited supply of fossil fuels, constant rise in the demand of energy and the importance of reducing greenhouse emissions have brought the adoption of renewable energy sources for generation of electrical power. One of these sources that has the potential to supply the world’s energy needs is the ocean. Currently, ocean in West African region is mostly utilized for the extraction of oil and gas from the continental shelf. However, this resource is depleting, and the adaptation of ocean energy could be of major importance. The purpose of this paper is to discuss the possibilities of ocean-based renewable energy (OBRE) and analyze the economic impact of adapting an ocean energy using a thermal gradient (OTEC) approach for energy generation.

The analysis is conducted from the perspective of cost, energy security and environmental protection.

This study shows that adapting ocean energy in the West Africa region can significantly produce the energy needed to match the rising energy demands for sustainable development of Nigeria. Although the transition toward using OBRE will incur high capital cost at the initial stage, eventually, it will lead to a cost-effective generation, transmission, environmental improvement and stable energy supply to match demand when compared with the conventional mode of generation in West Africa.

This study will be helpful in determining the feasibility, performance, issues and environmental effects related to the generation and transmission of OBRE in the West Africa region.

The study will contribute toward analysis of the opportunities for adopting renewable energy sources and increasing energy sustainability for the West Africa coast regions.

For India, with its low agricultural productivity and huge population, land acquisition has always been a serious policy challenge in the installation of land-intensive power projects. India has experienced a large number of projects getting stalled because of land conflict. Yet, there is a paucity of literature pertinent to India that tries to estimate future land requirements taking into consideration of land occupation metric.

In the present study, the dynamic land transformation and land occupation metrics of nine energy sources, both conventional and renewable, are estimated to further determine the magnitude of land requirement that India needs to prepare itself to fulfil its Intended Nationally Determined Contribution (INDC) commitments. This is illustrated through two different scenarios of energy requirement growth rates, namely, conservative and advanced.

This analysis suggests that, while nuclear energy entails the lowest dynamic land transformation when land occupation metric is taken into account, waste to energy source possesses least land requirement, followed by coal-fired source. Hydro energy source has highest requirement both in terms of dynamic land transformation and land occupation. It is also seen that land requirement will be 96% and 120% more in INDC scenario than business as usual (i.e. if India continues with its current share of renewables in its energy portfolio in 2030) considering a conservative and an advanced growth rate, respectively.

Some policy recommendations are provided that may aid policymakers to better address the trade-off between clean energy and land and incorporate it into policy planning. This study has not been able to consider future technical efficiency improvement possibilities for all energy sources, which can be incorporated in the proposed framework for further insight.

This paper provides a framework for estimation of future land requirement to fulfil India’s INDC energy plans which is not available in existing literature. The authors confirm that this manuscript is an original work.

Despite the increasing demand for renewable energy (RE) as a low-carbon energy source, the transition to RE is very slow in many regions, including Oman, the case country for this study. It is critical to offer strategic insights to energy supply chain participants towards the sustainable transition to renewable energy (STRE). The purpose of this study is to identify viable RE sources in Oman as a case study of a GCC member country, develop a comprehensive framework of STRE, and suggest future research opportunities.

The paper addressed this problem through a country/regional study of Oman by conducting a systematic literature review (SLR) of RE-related peer-reviewed publications spanning over 21 years from January 2000 to February 2021. The qualifying articles are evaluated using template analysis qualitatively to identify viable renewable energy sources, build a holistic framework of STRE and recommend future research opportunities.

Findings confirm the potential of solar, wind, biomass and geothermal energies driven by environmental, economic and social sustainability concerns. However, results suggest that to fast-track the STRE, more emphasis should be accorded to solar and wind energies owing to the geographical composition of Oman. Findings reveal that policies and regulations, advanced and cost-effective technologies, subsidy regimes, grid connectivity and capacity, storage capacity and land availability influence the STRE. Gaps in the literature are identified from the results to clarify and suggest future research opportunities.

To the best of the authors’ knowledge, this is the first study that conducted an SLR that was evaluated using the template analysis technique to build a novel and updated framework that facilitates a crystalline understanding of STRE to guide policymakers and professionals in strategic decision-making.

This study aims to investigate the noise-inducing characteristics during the start-up process of a mixed-flow pump and the impact of different start-up schemes on pump noise.

This study conducted numerical simulations on the mixed-flow pump under different start-up schemes and investigated the flow characteristics and noise distribution under these schemes.

The results reveal that the dipole noise is mainly caused by pressure fluctuations, while the quadrupole noise is mainly generated by the generation, development and breakdown of vortices. Additionally, the noise evolution characteristics during the start-up process of the mixed-flow pump can be divided into the initial stage, stable growth stage, impulse stage and stable operation stage.

The findings of this study can provide a theoretical basis for the selection of start-up schemes for mixed-flow pumps, reducing flow noise and improving the operational stability of mixed-flow pumps.

The purpose of this paper is to find some feasible measures to solve the problems faced in China's renewable energy development and promote the industrial development of China's renewable energy.

The paper summarises the status and studies the problems of China's renewable energy industrial development, and then puts forward some proposals for the industrial development.

The paper finds that most of China's renewable energy technology is still in the transitional period from research and development to industrial production, and that the renewable energy industrial development needs the establishment of a series of technical experiments and demonstration projects to analyze and investigate the resources, the conversion and market development experience, and then form complete sets of equipment design and manufacturing, cultivation and collection of biomass resources and technology development capabilities, and that regulations should be established to provide a solid foundation for the large‐scale development of China's renewable energy. As a result, some development measures are suggested in the paper.

The paper raises the problems faced in China's renewable energy development, and gives some feasible development measures for the industrial development of China's renewable energy.

In this paper we assess whether the balanced scorecard (BSC) supports the necessary functions for organizational viability. To this purpose, we use the viable system model (VSM) as a means to describe the functions required for organizational viability. Then we use the VSM as a template to assess whether and how the BSC supports these functions for organizational viability.