The effect of the boundary layer on the wake of a horizontal axis wind turbine

Sedaghatizadeh, Nima; Arjomandi, Maziar; Kelso, Richard; Cazzolato, B.; Ghayesh, Mergen H.

doi:10.1016/j.energy.2019.06.066

Cited by 22 publications

(5 citation statements)

References 28 publications

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“…The wake near the ground tends to flow around a cylinder. The effect of tower exists at 4 D downstream of wind turbine, but the effect of tower disappears due to the growth of wake and the mixing of turbulence with the increase of distance 27 …”

Section: Numerical Results and Discussionmentioning

confidence: 99%

Effect of the tip speed ratio on the wake characteristics of wind turbines using LBM‐LES

Cui,

Mao,

Wang

et al. 2024

Energy Science & Engineering

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In this paper, the wake characteristics of Zell 2000 wind turbine under different tip velocity ratios are studied by using the lattice Boltzmann method and large eddy simulation. The adaptive mesh refinement method is performed to capture the fine flow structure and wake characteristics development. In this paper, we mainly focus on the effect of the tip speed ratio on the flow structure and unsteady characteristics of wind turbine wake. The three‐dimensional flow vorticity structures, the section vorticity diagram, the pressure fluctuation of wake and the lift coefficient of wind turbine wake are utilized to explore the effect of the tip speed ratio on the unsteady physics mechanism of wind turbine wake. With the increase of the tip speed ratio, the distance between two adjacent vortex rings along the axial direction gradually decreases, as the position of the broken vortex circles gradually approaches the center of the blade, separated vortexes are rapidly generated, and the coherent structure appears closer to the wind turbine. A relationship is established between the tip speed ratios and the positions of the broken vortex circles. It is further found that the dominant frequency amplitude gradually increases with the increase of tip speed ratio and the pressure amplitude spectra of vortex increases with the decrease of the distance between the wake and the center of the blade axis. The above series of studies can provide significant physical insight into deep understanding the influence of the tip speed ratio on the wake characteristics of wind turbines.

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Section: Numerical Results and Discussionmentioning

confidence: 99%

Effect of the tip speed ratio on the wake characteristics of wind turbines using LBM‐LES

Cui,

Mao,

Wang

et al. 2024

Energy Science & Engineering

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“…Sedaghatizadeh et al. 2019). This allows us to calculate the array density (which is the ratio of the total turbine swept area to the farm area) as a function of the lateral turbine spacing , i.e.…”

Section: Multi-row Resultsmentioning

confidence: 99%

“…To estimate the unknown velocity ratio, u av /U 0 , from the theory, we consider that there are multiple rows of turbines placed equidistantly with a large streamwise spacing of 20D, where D is the turbine diameter, and assume that this distance is large enough for each turbine wake to be fully recovered (see e.g. Sedaghatizadeh et al 2019). This allows us to calculate the array density λ (which is the ratio of the total turbine swept area to the farm area) as a function of the lateral turbine spacing L, i.e.…”

Section: Local and Global Power Coefficientsmentioning

confidence: 99%

Single and multi-row turbine performance in bounded shear flow

Juniper

Nishino

2023

J. Fluid Mech.

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Predicting the performance of large turbine arrays requires the understanding of many physical factors, such as array geometry, turbine operation, inflow conditions and turbulent wake mixing. Due to the large parameter space that an array may be optimised over, low-order models with low computational cost are often employed. This paper extends one of these models, the inviscid–viscous coupled model, for multi-row turbine modelling. Firstly, an extension to the inviscid actuator disc theory is presented by removing the limit on the number of discrete streamtubes computed. The extended model allows for the quantification of the impact of shear in the bypass and core flows separately. In particular, it is shown that averaging a sheared bypass flow profile can result in a substantial over-prediction of the power of a turbine in a laterally bounded flow as the effective blockage of the flow increases. The model is also used to confirm that an approximation using a limited number of streamtubes in some previous applications of the inviscid–viscous approach has a negligible impact on the results. Secondly, we explore the performance of a multi-row array with either uniform or varying turbine resistance across different rows. Results suggest that by varying resistance across rows, the array may outperform the uniform resistance case. The performance gain is dependent, however, on the arrangement and inter-turbine spacing both in the spanwise and streamwise directions.

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“…Life of human on the planet has been changed considerably compared to the past [1,2,3,4,5]. The dramatic progress in the technologies human beings use has led to developing more efficient materials for better functionality [6,7,8,9,10,11], including heat and mass transfer phenomena [12,13,14,15,16], and taken this point into the consideration, much efficient porous (permeable) materials have been constructed and utilized during the past years [17,18,19]. Porous media are found in different shapes and sizes [20,21,22], and they have been used in a variety of applications [23,24,25,26].…”

Section: Introductionmentioning

confidence: 99%

An artificial intelligence-based prediction way to describe flowing a Newtonian liquid/gas on a permeable flat surface

Hoseinzadeh

Sohani

Ashrafi

2021

J Therm Anal Calorim

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The purpose of this study is to utilize artificial neural network (ANN), as one of the most powerful artificial intelligence methods, for modeling stream function (f) and the dimensionless temperature (θ) for the considered problem. The problem that is investigated here is flowing a Newtonian fluid on a permeable flat surface. The Homotopy Perturbation Method (HPM) recently developed by the authors for this problem is utilized to provide enough number of the input data. The best ANN is found for each of the two indicated outputs. Then, the best ANN model for each output is utilized to investigate the impact of changing the similarity variable in the range 0.0 to 10.0 on prediction error of the two mentioned outputs. Four values for porosity, which are 0.2, 0.5, 0.8, and 1.0, are investigated. According to the findings, an almost quadratic relation for changes prediction error of f as a function of η is seen, whereas after a sudden drop, the error in prediction of θ declines linearly. Moreover, for the whole range, and for both outputs, the error remains in an acceptable range, which verifies the good accuracy of ANN.

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The effect of the boundary layer on the wake of a horizontal axis wind turbine

Cited by 22 publications

References 28 publications

Effect of the tip speed ratio on the wake characteristics of wind turbines using LBM‐LES

Effect of the tip speed ratio on the wake characteristics of wind turbines using LBM‐LES

Single and multi-row turbine performance in bounded shear flow

An artificial intelligence-based prediction way to describe flowing a Newtonian liquid/gas on a permeable flat surface

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