RESEARCH OF THE ROTATIONAL EFFECTS ON THE BOUNDARY LAYER OF WIND TURBINE BLADES

2009 ◽  
Vol 23 (03) ◽  
pp. 505-508 ◽  
Author(s):  
RUI YANG ◽  
REN-NIAN LI ◽  
WEI HAN ◽  
DE-SHUN LI

The flow field past the rotating blade of a horizontal axial wind turbine has been modeled with a full 3–D steady–RANS approach. Flow computations have been performed using the commercial finite–volume solver Fluent. The NREL phase VI wind turbine blade sections from the 3–D rotating geometry were chosen and the corresponding 2–D flow computations have been carried out for comparison with different angles of attack and in stalled conditions. The simulation results are analyzed. The main features of the boundary layer flow are described, for both the rotating blade and the corresponding 2–D profiles. Computed pressure distributions and aerodynamic coefficients show evidence of less lift losses after separation in the 3–D rotating case, mostly for the inward sections of the blade and the highest angles of attack, which is in agreement with the literature.

2007 ◽  
Vol 75 ◽  
pp. 012031 ◽  
Author(s):  
Carlo E Carcangiu ◽  
Jens N Sørensen ◽  
Francesco Cambuli ◽  
Natalino Mandas

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Thanh Toan Tran ◽  
Dong-Hyun Kim ◽  
Ba Hieu Nguyen

The accurate prediction of unsteady aerodynamic performance and loads, for floating offshore wind turbines (FOWTs), is still questionable because several conventional methods widely used for this purpose are applied in ways that violate the theoretical assumptions of their original formulation. The major objective of the present study is to investigate the unsteady aerodynamic effects for the rotating blade due to the periodic surge motions of an FOWT. This work was conducted using several numerical approaches, particularly unsteady computational fluid dynamics (CFD) with an overset grid-based approach. The unsteady aerodynamic effects that occur when an FOWT is subjected to the surge motion of its floating support platform is assumed as a sinusoidal function. The present CFD simulation based on an overset grid approach provides a sophisticated numerical model on complex flows around the rotating blades simultaneously having the platform surge motion. In addition, an in-house unsteady blade element momentum (UBEM) and the fast (fatigue, aerodynamic, structure, and turbulence) codes are also applied as conventional approaches. The unsteady aerodynamic performances and loads of the rotating blade are shown to be changed considerably depending on the amplitude and frequency of the platform surge motion. The results for the flow interaction phenomena between the oscillating motions of the rotating wind turbine blades and the generated blade-tip vortices are presented and investigated in detail.


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.


2017 ◽  
Vol 834 ◽  
Author(s):  
Pankaj K. Jha ◽  
Sven Schmitz

This article describes an actuator curve embedding (ACE) concept to model arbitrary lifting lines using body forces within large-eddy simulation (LES). The new method removes some inconsistencies in body-force projection of the actuator line model (ALM) commonly used to represent wind turbine blades in atmospheric boundary-layer simulations. The concept and algorithm of ACE are presented followed by selected results for various blade planform and tip shapes that signify both the predictive capability and the advantages of the ACE concept. Examples include an elliptic wing, the NREL Phase VI rotor in parked and rotating conditions, and the NREL 5-MW turbine.


2017 ◽  
Vol 867 ◽  
pp. 254-260 ◽  
Author(s):  
Vivek V. Kumar ◽  
Dilip A. Shah

Due to the rapid depletion of conventional energy resources like fossil fuels and their harmful effects on the environment, there is an urgent need to seek alternative and sustainable energy sources. Wind energy is considered as one of the efficient source of energy which can be converted to useful form of energy like electrical energy. Though the field of wind engineering has developed in the recent era there is still scope for improvement in the effective utilization of energy. Energy efficiency in wind turbine is largely determined by the aerodynamics of the turbine blades and the characteristics of the turbulent fluid flow. The objective of this paper is to have a review on the improvement of Horizontal Axis Wind Turbine (HAWT) blade design by incorporating biomimetics into blades. Biomimetics is the field of science in which we adapt designs from nature to solve modern problems. The morphology of the wing-like flipper of the humpback whale (Megaptera novaeangliae) has potential for aerodynamic applications. Instead of straight leading edges like that of conventional hydrofoils, the humpback whale flipper has a number of sinusoidal rounded bumps, called tubercles arranged periodically along the leading edge. The presence of tubercles modifies the flow over the blade surface, creating vortices between the tubercles. These vortices interact with the flow over the tubercle and accelerate that flow, helping to maintain a partially attached boundary layer. This aerodynamic effect can delay stall to higher angles of attack, increase lift and reduce drag compared to the post-stall condition of conventional airfoils. The modified airfoil is characterized by a superior lift/drag ratio (L/D ratio) due to greater boundary layer attachment from vortices energizing the boundary layer.


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