scholarly journals Effect of liquid water content on blade icing shape of horizontal axis wind turbine by numerical simulation

2019 ◽  
Vol 23 (3 Part A) ◽  
pp. 1637-1645
Author(s):  
Yan Li ◽  
Ce Sun ◽  
Yu Jiang ◽  
Xian Yi ◽  
Yingwei Zhang

To research the law of the icing accretes on near the tip part of rotating blade of large-scale horizontal axis wind turbine (HAWT) influenced by liquid water content (LWC), the icing distribution on a HAWT rotor with rated power of 1.5 MW was simulated based on a Quasi-3D computation method. About 30% part length of blade from tip along span wise to blade root which are the most serious icing area was selected to research. Eight sections of this 30% part were decided and the ice distribution on each sections were simulated. Five kinds of LWC from 0.2 g/m3 to 1.4 g/m3 and two kinds of temperatures including ?6?C and ?18?C were selected. The medium volume droplet is 30 mm. Three kinds of icing time were selected to analyze the effects of icing time on ice accretion. The icing shape evaluate method was applied to quantitatively analyze the icing shape obtatined under different conditions. The results show that the icing shapes are all horn icing shape under the different LWC when the temperature is ?6?C. The icing shapes change from horn icing shape to streamline icing shape with LWC increasing under the temperature of ?18?C. The icing accretes on blade surface layer by layer with icing time increasing. The closer the section blade tip, the more icing accretes. This study can be as reference for the research on anti-icing and de-icing technologies for large-scale HAWT.

2018 ◽  
Vol 10 (11) ◽  
pp. 168781401881224 ◽  
Author(s):  
Yan Li ◽  
Ce Sun ◽  
Yu Jiang ◽  
Xian Yi ◽  
Zhi Xu ◽  
...  

To investigate the temperature effect on characteristics of icing distribution near the tip part of rotating blade of large-scale horizontal-axis wind turbine, numerical simulations were carried out on a horizontal-axis wind turbine rotor with rated power of 1.5 MW based on a quasi-three-dimensional computational method developed in this study. The icing simulation was focused on the part between blade tip and 30% length of blade from tip along span wise to blade root where the most serious icing area is according to the past researches. Eight sections along blade were selected, and the ice accretion on each airfoil was calculated. Eight temperature values from −6°C to −20°C were decided to investigate the effects of temperature on icing under the certain liquid water content and medium volume droplet. Three icing times were selected to research the ice accretion on blade surface with the increase in the time. According to the results, the icing distribution has the overall characteristics that the icing shape changes from horn icing shape to streamline icing shape with decrease in the temperature. The closer the blade airfoil section to blade tip, the more obvious the ice accretion is. This study can be a reference for the research on anti-icing and de-icing technologies for large-scale horizontal-axis wind turbine.


2019 ◽  
Vol 11 (11) ◽  
pp. 168781401989211
Author(s):  
Deyaa Nabil Elshebiny ◽  
Ali AbdelFattah Hashem ◽  
Farouk Mohammed Owis

This article introduces novel blade tip geometric modification to improve the aerodynamic performance of horizontal-axis wind turbine by adding auxiliary cascading blades toward the tip region. This study focuses on the new turbine shape and how it enhances the turbine performance in comparison with the classical turbine. This study is performed numerically for National Renewable Energy Laboratory Phase II (non-optimized wind turbine) taking into consideration the effect of adding different cascade configurations on the turbine performance using ANSYS FLUENT program. The analysis of single-auxiliary and double-auxiliary cascade blades has shown an impact on increasing the turbine power of 28% and 76%, respectively, at 72 r/min and 12.85 m/s of wind speed. Knowing that the performance of cascaded wind turbine depends on the geometry, solidity and operating conditions of the original blade; therefore, these results are not authorized for other cases.


Author(s):  
Ayse Sapmaz ◽  
Brian F. Feeny

Abstract This paper is on parametric effect in large scale horizontal-axis wind-turbine blades and speed locking phenomenon for a simplified model of the in-plane blade-hub dynamics. The relative strength of the parametric stiffness is evaluated for actual and scaled-length blades. Fixed-position natural frequencies are found at different rotation angles to show the significance of the gravity’s parametric effect. The ratio of the parametric and elastic modal stiffness is then estimated for the scaled versions of the NREL’s blades for four models to present the relation between the blade size and the parametric effects. The parametric effect on blade tip placements are investigated for superharmonic resonances at orders two and three for blades of various lengths. An analysis of speed-locking is presented, and interpreted for the various blades.


2012 ◽  
Vol 268-270 ◽  
pp. 1239-1243
Author(s):  
Kai Long ◽  
Ji Xiu Wu

In order to realize the buckling strength design for the opening door of the large-scale horizontal axis wind turbine tower, the method combined with the engineering method and the FEM was presented. The FE model of the door was established. The first-order buckling eigenvalues and buckling modes for three different structures were calculated and analyzed. Based on engineering method, the stress and buckling strength for the sections of tubular tower were obtained. Corrected by FEM results, the tower door with opening buckling strength were checked by engineering method. The results were compared with those by FEM. The safe design structure anti-buckling were presented. The method presented in this paper is feasible and effective for the opening door design in large-scale horizontal axis wind turbine tower.


2012 ◽  
Vol 512-515 ◽  
pp. 754-757
Author(s):  
Xian Yi ◽  
Kai Chun Wang ◽  
Hong Lin Ma

A three dimensional numerical method and its computer codes, which are suitable to predict the process of horizontal axis wind turbine icing, are presented. The method is composed of the Multiple Reference Frame (MRF) method to calculate flowfield of air, an Eulerian method to compute collection efficiency and a three dimensional icing model companying with an iterative arithmetic for solving the model. Ice accretion on a 1.5 MW horizontal axis wind turbine is then computed with the numerical method, and characteristics of droplet collection efficiency and ice shape/type are obtained. The results show that ice on the hub and blade root is slight and it can be neglected comparing with ice near blade tip. From blade tip to root, ice becomes thinner and glaze ice may changes into rime ice.


2018 ◽  
Vol 22 (Suppl. 2) ◽  
pp. 681-691 ◽  
Author(s):  
Yan Li ◽  
Shaolong Wang ◽  
Ce Sun ◽  
Xian Yi ◽  
Wenfeng Guo ◽  
...  

For researching on the rules of icing distribution on rotating blade of horizontal axis wind turbine, a Quasi-3-D method is proposed to research on icing on rotating blades of horizontal axis wind turbine by numerical simulation. A 2-D and 3-D method of evaluating the irregular shape of ice has been established. The model of rotating blade from a 1.5 MW horizontal axis wind turbine is used to simulate the process and shape of icing on blade. The simulation is carried out under the conditions with four important parameters including ambient temperature, liquid water content, medium volume drop diameter, and icing time. The results reveal that icing mainly happens on 50% ~ 70% of the blade surface along wingspan from tip to root of blade. There are two kinds of icing shapes including horn shape icing and streamline shape icing. The study can provide theoretical basis and numerical reference to development of anti and deicing strategy for wind turbine blades.


Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4983 ◽  
Author(s):  
Miguel Sumait Sy ◽  
Binoe Eugenio Abuan ◽  
Louis Angelo Macapili Danao

Wind energy is one of the fastest growing renewable energy sources, and the most developed energy extraction device that harnesses this energy is the Horizontal Axis Wind Turbine (HAWT). Increasing the efficiency of HAWTs is one important topic in current research with multiple aspects to look at such as blade design and rotor array optimization. This study looked at the effect of wingtip devices, a split winglet, in particular, to reduce the drag induced by the wind vortices at the blade tip, hence increasing performance. Split winglet implementation was done using computational fluid dynamics (CFD) on the National Renewable Energy Lab (NREL) Phase VI sequence H. In total, there are four (4) blade configurations that are simulated, the base NREL Phase VI sequence H blade, an extended version of the previous blade to equalize length of the blades, the base blade with a winglet and the base blade with split winglet. Results at wind speeds of 7 m/s to 15 m/s show that adding a winglet increased the power generation, on an average, by 1.23%, whereas adding a split winglet increased it by 2.53% in comparison to the extended blade. The study also shows that the increase is achieved by reducing the drag at the blade tip and because of the fact that the winglet and split winglet generating lift themselves. This, however, comes at a cost, i.e., an increase in thrust of 0.83% and 2.05% for the blades with winglet and split winglet, respectively, in comparison to the extended blade.


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