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Author

Zheng Li

Bio: Zheng Li is an academic researcher. The author has contributed to research in topics: Electrical engineering & Nanogenerator. The author has an hindex of 2, co-authored 4 publications receiving 10 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper , the authors used the Taguchi method to optimize the typical parameters of the vertical axis turbine, i.e., airfoil (NACA), pitch angle (β), enwinding ratio (ϖ), solidity ratio (σ), and small shaft position (O).

6 citations

Journal ArticleDOI
TL;DR: In this paper , a rotating tower-like triboelectric nanogenerator (RT-TENG) with an innovative circuit which combine discharge tube (DT) with voltage boost circuit (D-VBC) is proposed for ultrahigh charge density breakthrough.

Cited by
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Journal ArticleDOI
02 Aug 2022-Energies
TL;DR: In this article , a drag-lift hybrid type wind turbine structure based on an NACA0018 symmetrical airfoil was proposed, which can adaptively change the blade shape under static and low speed conditions.
Abstract: In recent years, with the continuous development of new energy, how to efficiently use wind energy has received more and more market attention. Due to cost advantages, the development of small wind turbines is accelerating. Among them, the design and research of the airfoil design and research of the lift vertical axis wind turbine has matured, but because of the aerodynamic characteristics of the lift airfoil structure, it is impossible to start itself at low wind speed, resulting in the waste of low wind speed energy. Although the drag wind turbine has good self-starting performance, the wind energy utilization efficiency in the high-speed state is inefficient. Each has its own unique shortcomings, which directly affects the marketization of small wind turbines. In order to solve these problems, this paper presents a drag-lift hybrid type wind turbine structure based on an NACA0018 symmetrical airfoil, which can adaptively change the blade shape. This design can keep the blade in the drag shape under static and low speed conditions, and adaptively change the lift shape with the increase of speed. In addition, through the research method of CFD numerical simulation combined with physical experiments, the proposed wind turbine design is studied and analyzed from multiple angles. At the same time, the “6DOF + dynamic grid” setting is used to study the influence of the opening angle factor of the drag-lift hybrid blade on the self-starting performance, and the study shows that the design of the drag-lift hybrid blade proposed in this paper has a higher self-starting torque and lower starting wind speed than the traditional lifting blade, and it is observed that the drag-lift hybrid blade has the best self-starting performance when the opening angle of the blade is 80°. At the same time, the problem of switching the blade morphology of the drag-lift hybrid blade is also analyzed, along with how to use the spring to control all this adaptively. In order to better analyze the advantages of the drag-lift hybrid design proposed in this paper, a wind tunnel test was also carried out using the physical model, and the relationship between the leaf tip speed ratio and the wind energy utilization rate was obtained, which intuitively showed the improvement of the wind energy utilization rate of the drag-lift hybrid design compared with the traditional lift blade.

2 citations

Journal ArticleDOI
TL;DR: Agarwal et al. as mentioned in this paper presented a design and analysis of garlov helical hydro turbine on index of revolution for a micro-hydropower system, where nine 3D-GHT's with a diameter and height of 0.600 m were modelled based on varying indices of revolution.

2 citations

Journal ArticleDOI
TL;DR: In this paper , two surrogate models, i.e., Kriging and artificial neural networks (ANN), were adopted for the performance prediction of a twin-VAWT with a close staggered arrangement.

2 citations

Journal ArticleDOI
TL;DR: In this article , the performance comparison of straight and helical-bladed lift-based VAHTs and the influence of design and operating conditional parameters was made and the potential research areas that need to be addressed in future studies were also found and presented.

2 citations

Journal ArticleDOI
TL;DR: In this paper , the simulation and experiments performed on a GHT by altering the index of revolution of its helical blades were addressed, and the results were found to agree with the simulations accounting for the losses.
Abstract: This article addresses the simulation and experiments performed on a Gorlov Helical Turbine (GHT) by altering the index of revolution of its helical blades. Gorlov Helical Turbine is a hydrokinetic turbine that generates energy from the perennial/tidal source. The paper serves a two-fold purpose: parametric optimisation of Gorlov Helical Turbine with respect to the index of revolution and viability of installing the turbines in river creeks. Nine models of turbines with a diameter of 0.600 m and a height of 0.600 m were generated with different indices of revolution and then subjected to simulation studies. A significant rise in the output torque of the turbine was not observed with the various indices of revolution, even as the probability of finding a section at every azimuthal position is likely to rise. Gavasheli's solidity ratio formula was used to formulate an expression for the output power. The output power as per analytical formulation is 1.11 W, which is of the order of output power obtained through simulation (0.951 W). The studies suggest that 0.25 remains the optimum value for the index of revolution of the helical blades. A model with 0.25 as the index of revolution was fabricated and tested at a river creek. The results were found to agree with the simulations accounting for the losses. The study results could encourage setting up hydrokinetic turbines in river creeks, thereby increasing the grid capacity of SHPs in India.