Theoretically optimal turbine resistance in very large wind farms

Zapata, Alejandro Uribe; Nishino, Takafumi; Delafin, Pierre-Luc

doi:10.1088/1742-6596/854/1/012051

Cited by 6 publications

(14 citation statements)

References 11 publications

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“…Figure 7 shows a comparison between the farm simulations and the Nishino model [5] for the power coefficient. As can be seen from the figure and similarly to [6], the agreement between the AD simulations and the theoretical model is very good. The FRR simulations show some consistent discrepancies from the theoretical model.…”

Section: Wind Farm Simulationssupporting

confidence: 70%

Section: Wind Farm Simulationsmentioning

confidence: 57%

“…2) is found to be around 1.9 to 2 in this study regardless of the turbine model used, while this value is around 1.5 to 1.6 in AD simulations in [6]. [6] uses a different turbine diameter (D = 100m) and turbine hub height (100m) which may explain the difference in γ observed. It can also be noted that γ = 2.03 is obtained with the FRR simulation at K s = 5m while this parameter is expected to be smaller than 2 as the turbines usually increase the turbulence intensity within the farm layer [5].…”

Section: Wind Farm Simulationsmentioning

confidence: 57%

“…The 'local' or 'effective' coefficients of thrust (C * T ) and power (C * P ) are also calculated using the farm layer wind speed U F instead of U F 0 . Similarly to [6], an increase in K s (or decrease in λ/C f 0 ) results in an increase in C P and C T , regardless of the turbine model used. Of particular interest is the comparison between AD and FRR simulations for K s = 1m.…”

Section: Wind Farm Simulationsmentioning

confidence: 98%

“…Actuator disk models are often used in such large wind farm modeling and simulations [3,5,6]. There are many earlier studies comparing actuator disk simulations and blade-resolved rotor simulations, but these studies are either for an isolated turbine [7,8] or a very small number (usually two) of turbines [9,10], not for large wind farms.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Momentum balance in a fully developed boundary layer over a staggered array of NREL 5MW rotors

Delafin

Nishino

2017

J. Phys.: Conf. Ser.

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Section: Wind Farm Simulationssupporting

confidence: 70%

Section: Wind Farm Simulationsmentioning

confidence: 57%

Section: Wind Farm Simulationsmentioning

confidence: 57%

Section: Wind Farm Simulationsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Momentum balance in a fully developed boundary layer over a staggered array of NREL 5MW rotors

Delafin

Nishino

2017

J. Phys.: Conf. Ser.

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Two-scale momentum theory for time-dependent modelling of large wind farms

Nishino

Dunstan

2020

J. Fluid Mech.

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This paper presents a theory based on the law of momentum conservation to define and help analyse the problem of large wind farm aerodynamics. The theory splits the problem into two sub-problems; namely an 'external' (or farm-scale) problem, which is a time-dependent problem considering largescale motions of the atmospheric boundary layer (ABL) to assess the amount of momentum available to the ABL's bottom resistance (due to wind turbines and land/sea surface) at a certain time; and an 'internal' (or turbine-scale) problem, which is a quasi-steady (in terms of large-scale motions of the ABL) problem describing the breakdown of the ABL's bottom resistance into wind turbine drag and land/sea surface friction. The two sub-problems are coupled to each other through a non-dimensional parameter called 'farm wind-speed reduction factor,' for which a simple analytic equation is derived that can be solved iteratively using information obtained from both sub-problems. This general form of coupling allows us to use the present theory with various types of flow models at each scale, such as a numerical weather prediction (NWP) model for the external problem and a computational fluid dynamics (CFD) model for the internal problem. The theory is presented for a simplified wind farm situation first, followed by a discussion on how the theory can be applied (in an approximate manner) to real-world problems; for example, how to estimate the power loss due to the so-called 'wind farm blockage effect' for a given large wind farm under given environmental conditions.

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Prediction of the impact of support structures on the aerodynamic performance of large wind farms

Antoniadis

2019

Journal of Renewable and Sustainable Energy

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An extended theoretical model based on a two-scale coupled momentum balance method is proposed to estimate aerodynamic effects of wind turbine towers on the performance of both ideal (infinitely large) and more realistic (large but finite-size) wind farms. A key implication of the extended model is that a normalized support-structure drag, AS/A×CD*, where A and AS are the rotor swept area and support-structure frontal projected area, respectively, and CD* is an effective support-structure drag coefficient, may play an important role in the design of future large wind farms. For the infinitely large case, the theoretical model shows that the optimal turbine spacing should increase with the value of AS/A×CD*, whereas for the large finite case, this also depends on an additional parameter describing the response characteristics of the atmospheric boundary layer to the total farm drag. To validate the theoretical model for the infinitely large case, Wall-Modeled Large-Eddy Simulations of a periodic array of actuator disks with and without support structures are conducted. The results show a reasonably good agreement (within 10% in the prediction of power) with the theoretical model.

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Theoretically optimal turbine resistance in very large wind farms

Cited by 6 publications

References 11 publications

Momentum balance in a fully developed boundary layer over a staggered array of NREL 5MW rotors

Momentum balance in a fully developed boundary layer over a staggered array of NREL 5MW rotors

Two-scale momentum theory for time-dependent modelling of large wind farms

Prediction of the impact of support structures on the aerodynamic performance of large wind farms

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