Testing the Accuracy of the Cell-Set Model Applied on Vane-Type Sub-Boundary Layer Vortex Generators

Portal-Porras, Koldo; Fernandez-Gamiz, Unai; Aramendia, Iñigo; Teso-Fz-Betoño, Daniel; Zulueta, Ekaitz

doi:10.3390/pr9030503

Cited by 11 publications

(10 citation statements)

References 32 publications

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“…According to Portal-Porras et al [30], the LES-based technique provided better resolution per cell than conventional ones did. The LES is a mathematical turbulence model used in computational fluid dynamics [31,32].…”

Section: Simulation Physicsmentioning

confidence: 99%

“…After evaluating these parameters, the LES required another evaluation to determine if the mesh had sufficient cell resolution. Hence, Portal-Porras et al [30] mentioned that the LES mesh could be evaluated using the Taylor length scale (λ). The experiment required evaluating the value of the mean velocity of some cells, which were close to the sudden expansion.…”

Section: Mesh Development and Validationmentioning

confidence: 99%

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Estimating the Reattachment Length by Realizing a Comparison between URANS k-Omega SST and LES WALE Models on a Symmetric Geometry

et al. 2021

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In this study, a water reattachment length was calculated by adopting two different models. The first was based on Unsteady Reynolds-Averaged Navier–Stokes (URANS) k-omega with Shear Stress Transport (SST); the second was a Large Eddy Simulation (LES) with Wall-Adapting Local Eddy-Viscosity (WALE). Both models used the same mesh and were checked with Taylor length-scale analysis. After the analysis, the mesh had 11,040,000 hexahedral cells. The geometry was a symmetrical expansion–contraction tube with a 4.28 expansion ratio that created mechanical energy losses, which were taken into account. Moreover, the reattachment length was estimated by analyzing the speed values; the change of speed value from negative to positive was used as the criterion to recognize the reattachment point.

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Section: Simulation Physicsmentioning

confidence: 99%

Section: Mesh Development and Validationmentioning

confidence: 99%

Estimating the Reattachment Length by Realizing a Comparison between URANS k-Omega SST and LES WALE Models on a Symmetric Geometry

et al. 2021

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“…According to Kuczaj [29], the mesh resolution (∆ = 3 √ V cell ) should at least be in the order of λ to completely solve the Taylor length scale. This method was applied to the wake of an airfoil, at Y/δ = ±1, since this is expected to be the area where the effects of the turbulence are most noticeable and, therefore, where the best resolution is required [30]; for data extraction, 11 spanwise planes normal to the streamwise direction located on the wake behind the airfoil were considered. These planes were located from 22δ from the TE (trailing edge), separated 2δ between each other, as shown in Figure 4a.…”

Section: Calculation Model and Reliability Verificationmentioning

confidence: 99%

Aerodynamic Performance Analysis of a Modified Joukowsky Airfoil: Parametric Control of Trailing Edge Thickness

et al. 2021

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In order to ensure the blade strength of large-scale wind turbine, the blunt trailing edge airfoil structure is proposed, aiming at assessing the impact of the trailing edge shape on the flow characteristics and airfoil performance. In this paper, a Joukowsky airfoil is modified by adding the tail thickness parameter K to achieve the purpose of accurately modifying the thickness of the blunt tail edge of the airfoil. Using Ansys Fluent as a tool, a large eddy simulation (LES) model was used to analyze the vortex structure of the airfoil trailing edge. The attack angles were used as variables to analyze the aerodynamic performance of airfoils with different K-values. It was found that when α = 0°, α = 4°, and α = 8°, the lift coefficient and lift–drag ratio increased with increasing K-value. With the increase in the angle of attack from 8° to 12°, the lift–drag ratio of the airfoil with the blunt tail increased from +70% to −7.3% compared with the original airfoil, which shows that the airfoil with the blunt trailing edge has a better aerodynamic performance at a small angle of attack. The aerodynamic characteristics of the airfoil are affected by the periodic shedding of the wake vortex and also have periodic characteristics. By analyzing the vortex structure at the trailing edge, it was found that the value of K can affect the size of the vortex and the position of vortex generation/shedding. When α = 0°, α = 4°, and α = 8°, the blunt trailing edge could improve the aerodynamic performance of the airfoil; when α = 12°, the position of vortex generation changed, which reduced the aerodynamic performance of the airfoil. Therefore, when designing the trailing edge of an airfoil, the thickness of the trailing edge can be designed according to the specific working conditions. It can provide valuable information for the design and optimization of blunt trailing edge airfoil.

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“…The novel cell-set (CS) model implemented in this study does not need specific formulae and is a versatile and flexible solution when a large number of different scenarios have to be contemplated. Ibarra-Udaeta et al [20] and Portal-Porras et al [21] used the CS model to construct vortex generators and sub-boundary layer vortex generators, respectively. Ballesteros-Coll et al [22] used the CS model to generate a Gurney flap on the trailing edge of a DU91W250 airfoil and implemented a microtab on the trailing edge of a DU91W(2)250 airfoil [23].…”

Section: Introductionmentioning

confidence: 99%

Rotating Microtab Implementation on a DU91W250 Airfoil Based on the Cell-Set Model

et al. 2021

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Flow control device modeling is an engaging research field for wind turbine optimization, since in recent years wind turbines have grown in proportions and weight. The purpose of the present work was to study the performance and effects generated by a rotating microtab (MT) implemented on the trailing edge of a DU91W250 airfoil through the novel cell-set (CS) model for the first time via CFD techniques. The CS method is based on the reutilization of an already calculated mesh for the addition of new geometries on it. To accomplish that objective, the required region is split from the main domain, and new boundaries are assigned to the mentioned construction. Three different MT lengths were considered: h = 1%, 1.5% and 2% of the airfoil chord length, as well as seven MT orientations (β): from 0° to −90° regarding the horizontal axis, for five angles of attack: 0°, 2°, 4°, 6° and 9°. The numerical results showed that the increases of the β rotating angle and the MT length (h) led to higher aerodynamic performance of the airfoil, CL/CD = 164.10 being the maximum ratio obtained. All the performance curves showed an asymptotic trend as the β angle reduced. Qualitatively, the model behaved as expected, proving the relationship between velocity and pressure. Taking into consideration resulting data, the cell-set method is appropriate for computational testing of trailing edge rotating microtab geometry.

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Testing the Accuracy of the Cell-Set Model Applied on Vane-Type Sub-Boundary Layer Vortex Generators

Cited by 11 publications

References 32 publications

Estimating the Reattachment Length by Realizing a Comparison between URANS k-Omega SST and LES WALE Models on a Symmetric Geometry

Estimating the Reattachment Length by Realizing a Comparison between URANS k-Omega SST and LES WALE Models on a Symmetric Geometry

Aerodynamic Performance Analysis of a Modified Joukowsky Airfoil: Parametric Control of Trailing Edge Thickness

Rotating Microtab Implementation on a DU91W250 Airfoil Based on the Cell-Set Model

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