Three-dimensional characterization of passive flow control devices over an aircraft carrier ski-jump ramp

2017 ◽  
Vol 232 (15) ◽  
pp. 2737-2744
Author(s):  
R Bardera ◽  
A Rodríguez-Sevillano ◽  
M León-Calero ◽  
J Nova-Trigueros
Keyword(s):  
Flow Control ◽  
Three Dimensional ◽  
Vortex Generator ◽  
Geometrical Parameters ◽  
Aircraft Carrier ◽  
Recirculation Bubble ◽  
Passive Flow Control ◽  
Passive Flow ◽  
Flow Control Devices ◽  
Flow Disturbances

The aircraft carrier is a key element in modern navies. On-board operations at sea take place under very severe conditions, which affect the aerodynamic flow on the flight deck. The ski-jump ramp is a curved runway that enables the aircraft to take-off using shorter runway distance. However, this geometry generates strong flow disturbances, mainly characterized by a recirculation bubble at the forward end of the ramp. This phenomenon reduces the aircraft performances and increases the pilot’s workload due to the unsteady forces which appear on the control surfaces. Passive flow control appears as a solution to this problem. Wind tunnel experimental research was developed in this study to mitigate the adverse aerodynamic effects of the ski-jump ramp presence. Different devices were tested using particle image velocimetry. Geometrical parameters of the devices were varied to study the effectiveness and select the best solution. Interesting results were found for the columnar vortex generator configurations. The optimum configuration could be applied shortly to the full-scale problem to reduce the adverse aerodynamic effects during take-off maneuvers.

Columnar vortex generator for flow control over a ski-jump ramp

2018 ◽  
Vol 28 (5) ◽  
pp. 1156-1168 ◽  
Author(s):  
Rafael Bardera ◽  
Marina León-Calero ◽  
Joaquín de Nova-Trigueros
Keyword(s):  
Flow Field ◽  
Flow Control ◽  
Vortex Generator ◽  
Geometrical Parameters ◽  
Recirculation Bubble ◽  
Content Type ◽  
Flow Configuration ◽  
Columnar Vortex ◽  
Flow Control Devices ◽  
Control Devices

Purpose Aircraft carriers are essential for modern naval operations. Takeoff maneuver is critical because of the short runway distance. The ski-jump ramp is a system which increases the angle of attack of the aircraft, so an extra lift is obtained. Regarding the flow configuration over the ski-jump ramp at ahead wind conditions, the complex aerodynamic environment generated by the ramp configuration influences aircraft operations. This flow field is mainly characterized by a low velocity recirculation bubble that reduces aircraft performances. The purpose of this paper is to find a solution to reduce these adverse effects, by means of flow control devices, which opens a wide field of research. Design/methodology/approach This paper presents wind tunnel tests performed to study the flow configuration in the vicinity of the ski-jump ramp and the flow control devices effects. A 1:100 scaled ship model was built to develop experimental tests by using flow control devices fabricated by means of additive manufacturing. Particle image velocimetry technique was used to measure the velocity flow field and the turbulence intensity maps. Findings Interesting results were obtained when the angle between the intersection of the ski-jump ramp and the columnar vortex generator (CVG) is modified. The results showed a high reduction of the recirculation bubble generated over the flight deck. Originality/value CVG has presented encouraging results as a passive flow control device. A study of the variation of CVG geometrical parameters has been developed.

Experimental Analysis on a Model of a Small Ducted Wind Turbine Equipped with Passive Flow Control Devices

2021 ◽  
Author(s):  
Elena-Alexandra Chiulan ◽  
Costin Ioan Cosoiu ◽  
Andrei-Mugur Georgescu ◽  
Anton Anton ◽  
Mircea Degeratu
Keyword(s):  
Flow Control ◽  
Wind Turbine ◽  
Experimental Analysis ◽  
Passive Flow Control ◽  
Passive Flow ◽  
Flow Control Devices ◽  
Control Devices

scholarly journals Fundamental Studies of Vortices Induced by a Vortex-Generator for Automotive Applications

2014 ◽  
Vol 553 ◽  
pp. 211-216
Author(s):  
Asiful Islam ◽  
Graham Doig
Keyword(s):  
Turbulence Models ◽  
Vortex Generator ◽  
Automotive Applications ◽  
Passive Flow Control ◽  
Passive Flow ◽  
Flow Control Devices ◽  
Simple Geometry ◽  
Image Velocimetry ◽  
Control Devices ◽  
Spatial Trajectory

For automotive applications, passive flow control devices can be used to reduce, delay or prevent flow separation. This study explores the nature of vortex generation and behaviour, numerically and experimentally, for a simple geometry at a Reynolds Number (Rex) of 5×105 and 1.945×106. The setup comprised a triangular vane vortex-generator mounted on a shallow ramp referenced from literature. Flow over the isolated ramp was validated with past experimental particle-image-velocimetry (PIV) data, which also highlighted the relative performance of various turbulence models. A parametric study was undertaken with the vane orientation defined by an angle-of-attack (β) and stream-wise location (xedge/xVG). These results revealed relationships between geometric parameters of the vortex generator, as well as the influence of the boundary layer thickness (hVG/δ), on the spatial trajectory of induced vortices.

Optimization of a columnar vortex generator installed over an aircraft carrier ski-jump ramp

2019 ◽  
Vol 234 (1) ◽  
pp. 223-230
Author(s):  
Rafael Bardera
Keyword(s):  
Vortex Generator ◽  
Wind Tunnel Testing ◽  
Low Velocity ◽  
Aircraft Carrier ◽  
Recirculation Bubble ◽  
Columnar Vortex ◽  
Flow Disturbances ◽  
Image Velocimetry ◽  
Field Velocity ◽  
Flight Deck

Aircraft performances over aircraft carriers are essential in modern navies. Take-off operation is critical due to the short runway available. The ski-jump ramp is a useful system that allows to operate under safe conditions. However, the sharp edge at the end of the runway provokes a region with recirculation bubble and low velocity producing strong flow disturbances. Hence, the aircraft performances are affected and the pilot’s workload is augmented. Previous researches showed that columnar vortex generator reduces the recirculation bubble generated over the end of flight deck. This article presents an in-depth experimental study performed by wind tunnel testing in order to determine the relation between the columnar vortex generator size and the recirculation bubble reduction. Particle image velocimetry is used to investigate the flow field velocity and flow structure around the ski-jump ramp as a non-intrusive experimental technique. Encouraging results were found for the biggest columnar vortex generator studied.

Further Investigation of Vertical Stabilizer with Passive Flow Control Devices

2020 ◽  
Author(s):  
Yasushi Ito ◽  
Shunsuke Koike ◽  
Mitsuhiro Murayama ◽  
Yoshiyasu Ichikawa ◽  
Kazuyuki Nakakita ◽  
...  
Keyword(s):  
Flow Control ◽  
Passive Flow Control ◽  
Passive Flow ◽  
Flow Control Devices ◽  
Control Devices

Influence of Passive Flow-Control Devices on the Pressure Fluctuations at Wing-Body Junction Flows

2007 ◽  
Vol 129 (8) ◽  
pp. 1030-1037 ◽  
Author(s):  
Semih M. Ölçmen ◽  
Roger L. Simpson
Keyword(s):  
Flow Control ◽  
High Surface ◽  
Pressure Fluctuations ◽  
Wall Pressure ◽  
Passive Flow Control ◽  
Passive Flow ◽  
Wall Pressure Fluctuations ◽  
Flow Control Devices ◽  
Zero Degree ◽  
Control Devices

The effectiveness of passive flow-control devices in eliminating high surface rms pressure fluctuations at the junction of several idealized wing/body junction flows was studied. Wall-pressure fluctuation measurements were made using microphones along the line of symmetry at the wing/body junction of six different wing shapes. The wings were mounted on the wind tunnel floor at a zero degree angle-of-attack. The six wing shapes tested were: a 3:2 semi-elliptical-nosed NACA 0020 tailed generic body shape (Rood wing), a parallel center-body model, a tear-drop model, a Sandia 1850 model, and NACA 0015 and NACA 0012 airfoil shapes. Eight different fence configurations were tested with the Rood wing. The two double-fence configurations were found to be the most effective in reducing the pressure fluctuations. Two of the single fence types were nearly as effective and were simpler to manufacture and test. For this reason one of these single fence types was selected for testing with all of the other wing models. The best fence flow-control devices were found to reduce rms wall-pressure fluctuations by at least 61% relative to the baseline cases.

scholarly journals Five Megawatt Wind Turbine Power Output Improvements by Passive Flow Control Devices

Energies ◽  
2017 ◽  
Vol 10 (6) ◽  
pp. 742 ◽  
Author(s):  
Unai Fernandez-Gamiz ◽  
Ekaitz Zulueta ◽  
Ana Boyano ◽  
Igor Ansoategui ◽  
Irantzu Uriarte
Keyword(s):  
Flow Control ◽  
Wind Turbine ◽  
Power Output ◽  
Passive Flow Control ◽  
Passive Flow ◽  
Flow Control Devices ◽  
Control Devices

scholarly journals Passive flow control of shock-induced dynamic stall via surface-based trapped vortex generators

2021 ◽  
pp. 095441002110112
Author(s):  
Khider Al-Jaburi ◽  
Daniel Feszty
Keyword(s):  
Flow Control ◽  
Vortex Generator ◽  
Flight Test ◽  
Dynamic Stall ◽  
Test Case ◽  
Negative Effects ◽  
Passive Flow Control ◽  
Passive Flow ◽  
Dynamics Simulations ◽  
Trapped Vortex

A novel passive approach for controlling the flow in a 2D dynamic stall at variabl freestream is investigated. 2D computational fluid dynamics simulations of an SC1095 airfoil with surface-based trapped vortex generator (STVG) type passive flow control were conducted. The airfoil was exposed to a fluctuating freestream of Mach 0.537 ± 0.205 and Re = 6.1 × 106 (based on the mean Mach number) and experienced a 10° ± 10° pitch oscillation with a frequency of 4.25 Hz. These conditions were selected as an approximation to the flow experienced by a UH-60A helicopter rotor airfoil section in an actual fast forward flight test case. The baseline simulations were cautiously validated with experimental data for both transonic flow and dynamic stall under the variable freestream. Then, 20 different local STVGs type geometry modifications were investigated as a means of passive flow control. Modifications were examined on both the airfoil’s upper and lower surfaces. Results showed that the STVGs were able to mitigate the negative effects of shock-induced dynamic stall. The best geometries could reduce the peak negative pitching moment by as much as 9–23% during the transonic phase of a cycle and by as much as 19–71% during the dynamic stall phase. Also, they were able to reduce peak drag by 8–20% in the transonic phase and by 15–44% in the dynamic stall phase. On the other hand, the lift-to-drag ratio was significantly increased by 3–28% per one rotor cycle. All the above advantages came at virtually no penalty in the lift.

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