Flow control of vortex shedding by a short splitter plate asymmetrically arranged downstream of a cylinder

1999 ◽  
Vol 11 (10) ◽  
pp. 2928-2934 ◽  
Author(s):  
S. Ozono
Keyword(s):  
Flow Control ◽  
Vortex Shedding ◽  
Splitter Plate

Numerical investigation of wake flow control by a splitter plate

1998 ◽  
Vol 12 (1) ◽  
pp. 123-131 ◽  
Author(s):  
Woe-Chul Park ◽  
Hiroshi Higuchi
Keyword(s):  
Flow Control ◽  
Numerical Investigation ◽  
Splitter Plate ◽  
Wake Flow

Organization of Cylinder Wake Using a Splitter-Plate Active Flow Control

2010 ◽  
Author(s):  
Chris Weiland ◽  
Pavlos Vlachos
Keyword(s):  
Circular Cylinder ◽  
Flow Control ◽  
Strouhal Number ◽  
Active Flow Control ◽  
Leading Edge ◽  
Splitter Plate ◽  
Cylinder Wake ◽  
Time Resolved ◽  
Image Velocimetry ◽  
Active Flow

Time Resolved Digital Particle Image Velocimetry (TRDPIV) was used in conjunction with spectral analysis to study the effects of Leading Edge Blowing (LEB) flow control on the near-wake of a circular cylinder. The airfoil was placed 1.9 circular cylinder diameters downstream, effectively acting as a splitter plate. Spectral measurements of the TRDPIV results indicated that the presence of the airfoil decreased the Strouhal number from 0.19 to 0.12 as anticipated. When activated the LEB jet organized the circular cylinder wake, effectively neutralizing the effect of the splitter plate and modifying the wake so as to return the Strouhal number to 0.19. Thus the circular cylinder wake returned to its normal shedding frequency, even in the presence of the airfoil. Evidence presented in this study supports the notion that the LEB jet directly excites the circular cylinder shear layers causing instability, roll up, and subsequent vortex shedding.

An Experimental Study on the Effect of Splitter Plate Angle on the VIV Behavior of Submarine Pipeline on an Erodible Bed Under Clear Water Condition

2013 ◽  
Author(s):  
Mohammad Javad Emamgholizadeh ◽  
Ahmad Reza Mostafa Gharabaghi ◽  
Karim Abedi ◽  
Mohammad Hossein Sedaaghi
Keyword(s):  
Vortex Shedding ◽  
Vibration Amplitude ◽  
Degrees Of Freedom ◽  
Oil And Gas ◽  
Processing Technique ◽  
Splitter Plate ◽  
Image Processing Technique ◽  
Contact Method ◽  
Hydrocarbon Reservoir ◽  
Scouring Depth

Pipeline is an appropriate method for transmission of oil and gas from seabed hydrocarbon reservoir to the land and platform or any other place where it is needed. Free spans in the line may occur initially by an uneven seabed or be created later due to under-scouring. Vortex Induced Vibration (VIV) may occur in these free spans at high Reynolds’ numbers. Resonance can occur if the frequency of vortex shedding is close to the pipeline’s natural frequency. Otherwise, it can cause pipeline’s fatigue leading to its breakage and consequently economical and environmental losses. In literature, different methods are presented for decreasing the scouring depth due to the vortex shedding. One of them is the application of splitter plate. In this paper, the effect of splitter plate’s angle with horizon (α) on the vibrating behavior of pipeline with two degrees of freedom over an erodible bed is studied experimentally. The experiments were performed for reduced velocity in the range of 2.45–5.06 and gap ratio of zero. Image processing technique as a non-contact method is used for measuring the vibrations of cylinder. Experimental results indicate that the splitter plate’s angle is an important factor on the cylinder’s vibration amplitude. According to these results, for the angle in the range of 0 ≤ α ≤ 30, the vibration amplitude is decreased while its frequency is increased, but the results are vice versa for the range of 60 ≤ α ≤ 90.

Suppression of Vortex Shedding Downstream of a Circular Cylinder Using Permeable Cylinders in Shallow Water

2013 ◽  
Author(s):  
Göktürk Memduh Özkan ◽  
Hüseyin Akıllı
Keyword(s):  
Circular Cylinder ◽  
Flow Control ◽  
Shallow Water ◽  
Flow Structure ◽  
Vortex Shedding ◽  
Outer Cylinder ◽  
Vortex Formation ◽  
Stream Velocity ◽  
Bluff Bodies ◽  
Different Diameters

The characteristics of the flow around a 50mm circular cylinder surrounded by a permeable outer cylinder were investigated by Particle Image Velocimetry (PIV) and flow visualization techniques in order to control the unsteady flow structure downstream of the cylinder in shallow water. The effect of outer permeable cylinder with a porosity of β = 0.4 on the flow control was studied using five different diameters; D = 60, 70, 80, 90, 100mm. Depth-averaged free stream velocity was kept constant as U = 170mm/s corresponding to a Reynolds number of Re = 8500 and the water height was adjusted to hw = 25mm throughout the study. The results clearly showed that the outer permeable cylinder significantly affects the flow structure of the inner cylinder. It was found that by the existence of outer cylinder, the frequency of unsteady vortex shedding is reduced, vortex formation region is elongated and fluctuations are attenuated which are good indications of effective flow control. Owing to the results, optimum parameters were defined and suggested for the suppression of vortex-induced vibrations on bluff bodies.

Passive Jet Flow Control Method for Suppressing Unsteady Vortex Shedding from a Circular Cylinder

2017 ◽  
Vol 30 (1) ◽  
pp. 04016063 ◽  
Author(s):  
Wen-Li Chen ◽  
Xiangjun Wang ◽  
Feng Xu ◽  
Hui Li ◽  
Hui Hu
Keyword(s):  
Circular Cylinder ◽  
Flow Control ◽  
Vortex Shedding ◽  
Control Method ◽  
Jet Flow
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