Drag Prediction in the Near Wake of a Circular Cylinder based on DPIV Data

Son, Onur; Çeti̇ner, Okşan

doi:10.18869/acadpub.jafm.68.235.24663

Cited by 7 publications

(9 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has a main test section of 790 mm depth and 1010 mm width. Detailed description of the flow facility can be found in Cetiner (2012, 2014), Son and Cetiner (2016). A non-profiled flat plate with rectangular cross section is used in this study considering low manufacturing costs and power extraction enhancement results as demonstrated by Usoh et.…”

Section: Methodsmentioning

confidence: 99%

Effect of Side-Walls on Flapping-Wing Power-Generation: an Experimental Study

Karakaş

Fenercioglu

2016

JAFM

View full text Add to dashboard Cite

Effect of constrained flow is investigated experimentally for a flapping foil power-generator. The flow structures around and in the near wake of a flat plate placed between two side walls are captured via PIV technique with simultaneous direct force measurements in uniform flow at Re = 10 000. The rectangular flat plate oscillates with periodic non-sinusoidal pitching and plunging motions about its 0.44 chord position with stroke reversal times (TR) of 0.1 (rapid reversal) to 0.5 (sinusoidal reversal), phase angles of  = 90° and 110°, plunge amplitude of 1.05 chords and pitch amplitude of 73° at a constant reduced frequency of k = 0.8. The non-dimensional distances between the side walls and the oscillating flat plate are dw = 0.1, 0.5 and 1.0. Airfoil rotation speed dictates the strength, evolution and timing of shedding of leading and trailing edge vortices; as the stroke reversal time is decreased, earlier shedding of stronger vortices are observed. Increasing the phase angle between the pitching and plunging motions decreases the power generation efficiency for all cases. The highest power extraction coefficient is acquired for the non-sinusoidal case of TR = 0.4 in free flow. Optimum choice of side-wall distance improves power generation of flapping foils compared to free flow performance, up to 6.52% increase in efficiency is observed for the non-sinusoidal case TR = 0.4 with dw = 0.5, with remarkable enhancements for the sinusoidal case; 27.85% increase is observed with dw = 0.5 and 43.50% increase with dw = 1.0 where both cases outperform the highest power generation efficiency of the finite flat plate with non-sinusoidal flapping motion.

show abstract

Section: Methodsmentioning

confidence: 99%

Effect of Side-Walls on Flapping-Wing Power-Generation: an Experimental Study

Karakaş

Fenercioglu

2016

JAFM

View full text Add to dashboard Cite

show abstract

“…Nowadays, investigations of the aerodynamic characteristics of the different airfoil types at relatively low chord-based Reynolds numbers less than 5×10 5 are becoming more actual from both fundamental and industrial points of view [1]. That is primarily due to the active development of innovations for small wind turbines [2], various types of drones, quadcopters, modern micro-air vehicles, and even biomechanics systems [3].…”

Section: Introductionmentioning

confidence: 99%

“…Besides, the methodology proposed by Antonia and Rajagopalan has also become widely available to assess the drag forces of various streamlined bodies [4]. According to it, the aerodynamic forces can to determined using instantaneous velocity and its derivatives [5]. It allows obtaining drag data without surface instrumentation or external balance mechanism, which is particularly useful for different experimental techniques [6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Drag Estimation in the Near Wake of the NREL's Airfoils Based on Hot-Wire Data

et al. 2022

View full text Add to dashboard Cite

This paper presents the results of the drag coefficient estimations for different types of NREL airfoils based on the experimental data. Namely, it was S803, S807, S813, and S817 profiles with the same chord length. The investigations were conducted at three angles of attack α=0°, α=±5°, different chord-based Reynolds numbers 0.6×105, 1.3×105 and 2.6×105. While, measuring cross-sections were placed behind the trailing edge at x∙c−1≈0.2, 0.4 and 1.0. Experimental data were collected using a hot-wire split fiber probe 55R55, which allowed us to estimate the characteristics of turbulent flow in stream-wise and crosswise directions. According to the obtained results, the highest and lowest Cd values correspond to profiles S817 and S803, respectively. Moreover, the results show that more asymmetric profiles S803 and S807 have the lowest resistance at zero angles of attack. Research background: Application of Antonia and Rajagopalan methodology to drag assessment of various stream bodies. Purpose of the article: Comparative evaluation of the drag coefficients of the NREL airfoils based on instantaneous velocity distribution behind. Methods: Hot-wire anemometry with split fiber probe 55R55. Findings & Value added: The highest drag coefficient corresponds to the S817 profile. The asymmetry of the airfoil shape has a significant impact on its drag characteristics.

show abstract

“…The formulation was then applied to complex cases. Drag prediction in the near wake of a circular cylinder based on digital particle image velocimetry (DPIV) data was accomplished by Son and Cetiner [26]. They used mean velocity profiles and investigated the closest station where the wake measurement method yields an accurate result.…”

Section: Introductionmentioning

confidence: 99%

Streamlined bodies drag force estimation using wake integration technique

Shirazi

Manshadi

2020

J Braz. Soc. Mech. Sci. Eng.

View full text Add to dashboard Cite

In this paper, the drag force calculation around the SUBOFF submarine in axisymmetric configuration was investigated using the "Wake Integration Technique." This method is usually used in wind tunnels as an auxiliary method instead of the common "surface integral technique" for flow around complex geometries or shock wave flows. The results of this method are dependent on data collection vertex space, distance, and section size, where practical suggestions were made for each parameter in this research. Furthermore, the contribution of the pressure, momentum, and fluctuation terms in the total drag force were also evaluated at different cross sections. These findings can be implemented in wind tunnels with small test section length and also to compare the results obtained by the common surface integral method. Simulations were carried out at different aspect ratios at zero angles of attack, and the capabilities of this method at inclined flows were also discussed. The obtained results were also compared against the common method, and the results show only 4% deviation at zero angle. Keywords Wake survey • Wind tunnel • Drag force • Momentum defect principle • Suboff submarine List of symbols L Body length D Maximum body diameter AR Length-to-the-diameter aspect ratio x, y, z Coordinate system Δx, Δy Grid space in x and y-direction d The ratio of grid space to diameter X Longitudinal distance from the body r Measurement radius S Surface area P , u Local pressure and velocity P ∞ , U ∞ Free-stream pressure and velocity C D Drag coefficient C p Pressure coefficient Incidence angle y + Dimensionless wall distance Fluid density xx Normal stress component

show abstract

Drag Prediction in the Near Wake of a Circular Cylinder based on DPIV Data

Cited by 7 publications

References 16 publications

Effect of Side-Walls on Flapping-Wing Power-Generation: an Experimental Study

Effect of Side-Walls on Flapping-Wing Power-Generation: an Experimental Study

Drag Estimation in the Near Wake of the NREL's Airfoils Based on Hot-Wire Data

Streamlined bodies drag force estimation using wake integration technique

Contact Info

Product

Resources

About