Experimental study of flows over triangular riblets in cavity-like geometry

Vilkinis, Paulius; Šereika, Justas; Pedišius, Nerijus; Zygmantas, Gediminas

doi:10.1016/j.expthermflusci.2022.110621

Cited by 4 publications

(6 citation statements)

References 20 publications

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“…Flow types around airfoils can be classified depending on the Reynolds (Re) number. If the flow has a Reynolds number less than 5×10 5 , it is referred to as low Reynolds number flow. Low Reynolds number flow conditions are common in engineering applications (such as micro-drones and small-scale wind turbines) and in nature (such as birds and insects).…”

Section: Introductionmentioning

confidence: 99%

“…al. [1] experimentally investigated the effect of roughness on the Wortmann FX-63-137 airfoil using wires of different diameter sizes, at angle of attack (α) -16° to 24° and Reynolds number, Re=1×10 5 . According to their findings, they revealed that knowing the boundary layer thickness should be the first step for a critical roughness height, and that the change in wire diameter does not increase the aerodynamic performance of the wing in direct proportion.…”

Section: Introductionmentioning

confidence: 99%

“…[2] conducted both experimental and numerical studies for three different airfoils, SA7024, SA7025, and SA7026. The use of the ramp configuration with the help of trips in different positions on the airfoil's boundary layer was examined in the Reynolds number range of 1×10 5 < Re <3×10 5 . Even though their findings effectively reduce the drag and increase the lift force, they stated that the need for further studies is required for low Reynolds number airfoils.…”

Section: Introductionmentioning

confidence: 99%

“…al. [5] experimentally examined the effect of triangular riblets added into cavity. They found that as a result of decreasing the distance between the riblets placed inside the cavities, the pressure loss increased, and as the size inside the cavity decreased, the interaction between the main flow and the flow in the subcavities decreased, resulting in a decrease in pressure losses.…”

Section: Introductionmentioning

confidence: 99%

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The Effect of Riblets on the Aerodynamic Performance of NACA 0018 Airfoil

Güler,

Pınar,

Durhasan

2024

Çukurova Üniversitesi Mühendislik Fakültesi Dergisi

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In this numerical study, riblets on the airfoil were utilized to enhance the aerodynamic performance of NACA0018 airfoil. Riblets of identical height and base length are strategically placed on the suction surface of the airfoil with varying spacing ratios along the flow direction (x) and chord length (c), specifically x/c = 0.3 and 0.7. Four distinct riblet airfoil models are subjected to computational fluid dynamics (CFD) analysis within an angle of attack range from 0° to 21° at a Reynolds number of Re=1×105. The obtained results are systematically compared with the performance of the plain airfoil. Numerical analyses reveal the significant influence of the spacing ratio on flow control and the overall aerodynamic performance of the airfoil, establishing a direct relationship with riblet spacing. The presence of riblet structures is observed to increase the lift coefficient, concurrently delaying the stall angle up to 19°. Notably, the ribbed structures effectively mitigate the interaction between the laminar separation bubble and trailing edge separation, leading to a reduction in turbulent kinetic energy values.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The Effect of Riblets on the Aerodynamic Performance of NACA 0018 Airfoil

Güler,

Pınar,

Durhasan

2024

Çukurova Üniversitesi Mühendislik Fakültesi Dergisi

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“…Moreover, open cavities with different cross-sections have also been considered in the studies. One of these studies has been done by Vilkinis et al 16 In the experimental study via PIV, triangular cavities with various ratios have been used at different flow regimes. For a semi-circular cavity, wall-driven flow has been taken into consideration by Glowinski et al 17 in terms of numerical study.…”

Section: Introductionmentioning

confidence: 99%

Examination of air flow characteristics over an open rectangular cavity between the plates

Göktepeli

Atmaca

2023

International Journal of Aeroacoustics

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Air flow characteristics of an open cavity have been numerically examined by using different turbulence models of Detached Eddy Simulation (DES), k-ε Realizable, k-ω Shear Stress Transport (SST) and Large Eddy Simulation (LES) based on an experimental study of open literature. Numerical results of transient analyses have been compared to experimental results at cavity length-based Reynolds number of Re = 4600. Pressure distributions, streamline patterns, streamwise velocity components, mean velocity values and their vectors have been given in terms of contour graphics. Moreover, velocity profiles have been presented. Pressure fluctuations have been triggered by flow separation and its reattachment. Due to upstream separation of boundary layer, there was curved boundary layer obtained between the outer potential-flow-like and the recirculation zones. As a result, negative velocity values are evidence for rotational flows affected by formation of secondary flows in the cavity. Furthermore, lower pressure region has been observed as a result of rotational flow which was powerful in the open cavity. Numerical results of DES and LES turbulence models are in good agreement with the results of reference study. As the numerical results obtained by LES turbulence model are approximately same with those of experimental reference study, LES turbulence model is mostly recommended. As an option to these turbulence models, k-ω SST model could be utilized for limited computer capacity. However, k-ε Realizable model is not sufficient for capturing rotational flows which are very effective in terms of present case.

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