Aerodynamics of Wind Turbines, 2nd edition

Hansen, Martin Otto Lavér

doi:10.4324/9781849770408

Cited by 180 publications

(254 citation statements)

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“…In practice this means that the actuator disc acts as a volume force onto the surrounding cells. It is argued by Vaal et al (2014) that, because this method explicitly solves the wake rather than relying on simplified relations, the method should be more robust than commonly used methods such as the Pitt-Peters model (Pitt and Peters, 1983) or the Stig Øye model (Hansen, 2008). Vaal et al (2014) present a number of investigations into the relative performance of the models; for this paper, the rotor plane induction is the most interesting to compare.…”

Section: Comparison Casesmentioning

confidence: 99%

“…Tran et al (2014) also compared their results against lower-order simulations using the unsteady blade element momentum method. The Tran et al (2014) implementation of the unsteady blade element moment (UBEM) method was taken from Hansen (2008) with corrections for tip losses, wake unsteadiness and unsteady aerodynamics. This particular implementation took the platform motion into account by changing the relative inflow velocity.…”

Section: Comparison Casesmentioning

confidence: 99%

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Modern methods for investigating the stability of a pitching floating platform wind turbine

et al. 2017

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Abstract. The QBlade implementation of the lifting-line free vortex wake (LLFVW) method was tested in conditions analogous to floating platform motion. Comparisons against two independent test cases using a variety of simulation methods show good agreement in thrust forces, rotor power, blade forces and rotor plane induction. Along with the many verifications already undertaken in the literature, it seems that the code performs solidly even in these challenging cases. Further to this, the key steps are presented from a new formulation of the instantaneous aerodynamic thrust damping of a wind turbine rotor. A test case with harmonic platform motion and collective blade pitch is used to demonstrate how combining such tools can lead to a better understanding of aeroelastic stability. A second case demonstrates a non-harmonic blade pitch manoeuvre showing the versatility of the instantaneous damping method.

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Section: Comparison Casesmentioning

confidence: 99%

Section: Comparison Casesmentioning

confidence: 99%

Modern methods for investigating the stability of a pitching floating platform wind turbine

et al. 2017

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“…The geometrical dimensions of different scaled blades are proportional to the scale factor, denoted as R. Correspondingly, the structural and aerodynamic parameters are related to the scale factor, as shown in Table 2. The aerodynamic bending moment can be orthogonally divided into flap-wise moment M x and edge-wise moment M y [44]. Table 2.…”

Section: Upscaling Studies Of Sectional Bladesmentioning

confidence: 99%

Determining Division Location for Sectional Wind Turbine Blades

et al. 2017

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Sectional wind turbine blades, by dividing an intact blade into multiple segments, have the advantage of being easy to handle and transport. To determine a suitable blade division location, this study was performed to clarify some crucial aspects and challenges for sectional blades. This paper proposes a method to estimate the effects of the location of the blade division on structural, manufacturing, and assembling performance of sectional blades. The advantage of this method is the ease of the assessment process, since it can be performed at an early stage of blade design, where only the aerodynamic profile, mass density and stiffness distribution, and service fatigue loads of original blades are essential. A case study with the proposed method was carried out based on a 38-meter commercial blade. Results show that the best position for the division of sectional blades is located 20% from the blade root by balancing the three aspects listed above. The key approaches to reduce additional increases in stiffness and weight of sectional blades are related to improving the fatigue strength and the choice of low-modulus materials for connecting bolts. The effects of the division location on assembling accessibility and natural frequencies of scaled sectional blades are consistent with the basic sectional blade. Unfavorable effects occur when up-scaling the diameter of the bolts; and, harsh external loads on the connections have negative effects on the application of sectional blades with larger wind turbines. In this regard, lightweight design is indispensable to reduce bolt stress.

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“…This motion mainly affects the thrust force. Using the assumption of an ideal rotor it is possible to derive a simple one-dimensional model for estimating the thrust force, F , at tower top (Hansen, 2008) 5…”

Section: Integrated and Decoupled Dynamic Analysismentioning

confidence: 99%

Decoupled simulations of offshore wind turbines with reduced rotor loads and aerodynamic damping

Schafhirt¹,

Muskulus²

2017

Preprint

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Abstract. Decoupled load simulations are a computationally efficient method to perform a dynamic analysis of an offshore wind turbine. Modelling the dynamic interactions between rotor and support structure, especially the damping caused by the rotating rotor, is of importance, since it influences the structural response significantly and has a major impact on estimating fatigue lifetime. Linear damping is usually used for this purpose, but experimentally and analytically derived formulas to 10 calculate an aerodynamic damping ratio often show discrepancies to measurement and simulation data. In this study decoupled simulation methods with reduced and full rotor loads are compared to an integrated simulation. The accuracy of decoupled methods is evaluated and an optimization is performed to obtain aerodynamic damping ratios for different wind speeds that provide the best results with respect to variance and equivalent fatigue loads at distinct output locations. Results show that aerodynamic damping is not linear, but that it is possible to match desired output using decoupled models. 15Moreover, damping ratios obtained from the empirical study suggest that aerodynamic damping increases for higher wind speeds.

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Aerodynamics of Wind Turbines, 2nd edition

Cited by 180 publications

References 0 publications

Modern methods for investigating the stability of a pitching floating platform wind turbine

Modern methods for investigating the stability of a pitching floating platform wind turbine

Determining Division Location for Sectional Wind Turbine Blades

Decoupled simulations of offshore wind turbines with reduced rotor loads and aerodynamic damping

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