Experimental Study of Drag-Reduction Devices on a Flatback Airfoil

Μανωλέσος, Μαρίνος; Voutsinas, Spyros G.

doi:10.2514/1.j054901

Cited by 20 publications

(20 citation statements)

References 25 publications

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“…much wider than the spanwise coherence in the wake, which has been found to be ∼ 5 TE heights (Metzinger et al, 2018). The reason for this is that the present study will be extended to higher angle of attack (AOA), where Stall Cells (SC) (Manolesos et al, 2014a, c) appear on flatback airfoils (Manolesos et al, 2014b;Manolesos and Voutsinas, 2016b). For the accurate computation of these large structures, high-aspect-ratio (AR) computational domains are necessary.…”

Section: Numerical Set-upmentioning

confidence: 99%

“…Figure 2 presents a schematic of the measurement set-up, where the stereo PIV measurement plane is shown, along with the location of the hot-wire probe in the wake of the airfoil. Extensive details of the wind tunnel tests can be found in (Manolesos and Voutsinas, 2016b).…”

Section: Experimental Set-upmentioning

confidence: 99%

“…The corresponding Reynolds number based on the blunt TE thickness is Re TE = 1.5 × 10 5 . It is the continuation of an experimental survey that examined a number of TE devices to improve the performance of the profile (Manolesos and Voutsinas, 2016b). That work was a proof-of-concept study for a FB airfoil flap device, which proved to perform better than traditional devices.…”

Section: Introductionmentioning

confidence: 99%

“…The common aim is to increase base pressure by modifying the vortex shedding in the wake. Studies on flatback airfoils (Baker and Van Dam, 2009;Kahn et al, 2008;Krentel and Nitsche, 2013;Mayda et al, 2008;Nash, 1965) have highlighted using a single splitter plate or a pair of plates, forming a cavity at the TE, as an extremely simple and effective method.…”

Section: Introductionmentioning

confidence: 99%

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The flow past a flatback airfoil with flow control devices: benchmarking numerical simulations against wind tunnel data

Papadakis

Μανωλέσος

2020

Wind Energ. Sci.

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Abstract. As wind turbines grow larger, the use of flatback airfoils has become standard practice for the root region of the blades. Flatback profiles provide higher lift and reduced sensitivity to soiling at significantly higher drag values. A number of flow control devices have been proposed to improve the performance of flatback profiles. In the present study, the flow past a flatback airfoil at a chord Reynolds number of 1.5×106 with and without trailing edge flow control devices is considered. Two different numerical approaches are applied, unsteady Reynolds-Averaged Navier Stokes (RANS) simulations and detached eddy simulations (DES). The computational predictions are compared against wind tunnel measurements to assess the suitability of each method. The effect of each flow control device on the flow is examined based on the DES results on the finer mesh. Results agree well with the experimental findings and show that a newly proposed flap device outperforms traditional solutions for flatback airfoils. In terms of numerical modelling, the more expensive DES approach is more suitable if the wake frequencies are of interest, but the simplest 2D RANS simulations can provide acceptable load predictions.

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Section: Numerical Set-upmentioning

confidence: 99%

Section: Experimental Set-upmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The flow past a flatback airfoil with flow control devices: benchmarking numerical simulations against wind tunnel data

Papadakis

Μανωλέσος

2020

Wind Energ. Sci.

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“…Because of the complexity of automobile flow field, there is no comprehensive or in-depth understanding of its laws and the threedimensional flow separation of automobiles. How to further study the mechanism and structure of vehicle separation flow, extract the corresponding physical and mathematical models of vehicle separation flow, and improve the accuracy of numerical simulation, is currently facing a major difficulty in the study of vehicle dynamic numerical simulation [7].…”

Section: Numerical Simulation Theory Of Automobile Tailmentioning

confidence: 99%

A New Drag Reduction Method Based on Exhaust Emission Trailing Vortex Control

2019

IJOMAM

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In order to enhance the drag reduction effect and reduce the aerodynamic drag of a small car, taking a small car as the research object, firstly, by studying the influence of the longitudinal and transverse vortices on the aerodynamic drag, the generation of the drag reduction in the tail direction is obtained. Then, according to the transient calculation method, the influence principle of the tail vortices on the drag is analysed and the method of controlling tail vortex by controlling exhaust emission is also discussed. Finally, the influence of the location and angle of the tail pipe and the shape of the tail pipe on drag reduction is studied. A new method of drag reduction using off-gas pulsating emission is proposed, and the principle of drag reduction using off-gas pulsating emission is compared with that of steady off-gas pulsating emission. The results show that when the off-gas is discharged, the drag reduction effect is certain when the different arrangement and shape of the tail pipe are considered, compared with the case without the off-gas discharging. The drag reduction effect is the most obvious when the tail pipe is at a 12-degree angle to the horizontal plane, while the circular tail pipe arranged in a certain position can reduce the drag by 3.48%, and the drag reduction effect of the off-gas pulsating discharge is more obvious than that of the steady discharge, which can reach 5.38%. The new drag reduction method based on exhaust emission control tail vortex can effectively alleviate the increasingly serious energy crisis, improve the utilization efficiency of automobile fuel, and improve the driving speed of automobile, so it has significant research value and broad application prospects. A new drag reduction method for exhaust emission control is studied in depth. It is very significant to reveal the principle of the influence of exhaust emission on vehicle driving speed, which is an important step to promote the use of exhaust emission to reduce vehicle aerodynamic drag.

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