Assessment and optimization of the power performance of twin vertical axis wind turbines via numerical simulations

Since 2000, the research of uncertainty quantification (UQ) has been successfully applied in many fields and has been highly valued and strongly supported by academia and industry. This review firstly discusses the sources and the types of uncertainties and gives an overall discussion on the goal, practical significance, and basic framework of the research of UQ. Then, the core ideas and typical methods of several important UQ processes are introduced, including sensitivity analysis, uncertainty propagation, model calibration, Bayesian inference, experimental design, surrogate model, and model uncertainty analysis.

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Basic Framework and Main Methods of Uncertainty Quantification

The study on structural design and efficiency improvement of the micro impulse water turbine with the super-low specific speed has rarely been reported in literature. In this paper, a micro impulse water turbine was optimized on the base of the orthogonal array of L18(37) with six factors. The range analysis and variance analysis were conducted to present the significance ranking of factors and the optimal combinations of factors, aiming to improve the water turbine efficiency taken as the experimental indicator in the orthogonal experiment. And then the optimal parameter combination for the water turbine was calculated by orthogonal experiment. Moreover, the internal flow field and hydraulic performance were simulated numerically to investigate the principle of performance improvement by comparing the optimized water turbine with the original. Also, the numerical method was verified by experimental result from performance tests of the original water turbine. As a result, the runner torque of the optimized water turbine was 13% higher than that of the original and the water turbine efficiency was improved by 5.8 percentage points at the rated operating condition.

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Performance Improvement of a Micro Impulse Water Turbine Based on Orthogonal Array

This article investigates a drag-type vertical-axis wind turbine that is targeted for small-scale wind energy system applications. Based on aerodynamics models, the three-dimensional simulation stu...

https://journals.sagepub.com/doi/pdf/10.1177/1687814019825709

Analysis and implementation of a drag-type vertical-axis wind turbine for small distributed wind energy systems:

Optimization of twin vertical axis wind turbines through large eddy simulations and Taguchi method

Geometrical shape of a vertical axis wind turbine (VAWT) is composed of multiple structural parameters. Since there are interactions among the structural parameters, traditional research approaches, which usually focus on one parameter at a time, cannot obtain performance of the wind turbine accurately. In order to exploit overall effect of a novel VAWT, we firstly use a single parameter optimization method to obtain optimal values of the structural parameters, respectively, by Computational Fluid Dynamics (CFD) method; based on the results, we then use an orthogonal analysis method to investigate the influence of interactions of the structural parameters on performance of the wind turbine and to obtain optimization combination of the structural parameters considering the interactions. Results of analysis of variance indicate that interactions among the structural parameters have influence on performance of the wind turbine, and optimization results based on orthogonal analysis have higher wind energy utilization than that of traditional research approaches.

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Orthogonal Analysis Based Performance Optimization for Vertical Axis Wind Turbine

Traditional Savonius wind turbine has advantages such as simple structure, fast start-up, etc., however, it also has significant disadvantages of low wind energy utilization efficiency. A novel wind turbine is proposed by improving structure of Savonius wind turbine in order to increase the low wind energy utilization efficiency. To compare performance of the novel wind turbine and the Savonius wind turbines with two and three blades, two working conditions are investigated. The first is that the wind turbines work in a certain wind speed level to investigate influence of the changing load. The other is that the wind turbines work in a certain tip speed ratio level to investigate influence of environment such as wind speed changing. Considering costs of prototypes, the Computational Fluid Dynamics transient simulation method is used to achieve the analysis. The simulation results show that the novel wind turbine has high load capacities at different situation. The novel wind turbine has higher wind energy utilization efficiency and has good operating characteristics in low wind speed range than traditional Savonius wind turbines.

Simulation analysis based performance comparison for vertical axis wind turbines

Wind energy is a clean and renewable energy resource and has been paid more and more attention by scholars around the world. As a drag-drive n type Vertical Axis Wind Turbine (VAWT), traditional Savonius wind rotor has disadvantage of low wind energy utilization but has a lot of the advantages compare d with Horizontal Axis Wind Turbines (HAWTs) and lift-driven VAWTs. A fish-ridged wind rotor is proposed based Savonius rotor to improve the flow field characteristics. In this paper, the two wind rotors are analyzed and compared by computational fluid dynamics approach. The simulation results show that the flow field of the fish-ridged rotor is smoother than the Savonius rotor and the maximum value of wind energy utilization of the former rotor is bigger than that of the latter. It indicates that the ne w type of the rotor has good performance.

Hong-Zhao Liu

Papers

Orthogonal Analysis Based Performance Optimization for Vertical Axis Wind Turbine

Simulation analysis based performance comparison for vertical axis wind turbines

Performance comparison for savonius type wind turbines by numerical analysis approaches