Conference paper
POD analysis of flow structures behind cylinders with concave fillets
Department of Mechanical Engineering, Technical University of Denmark1
Fluid Mechanics, Coastal and Maritime Engineering, Department of Mechanical Engineering, Technical University of Denmark2
Department of Civil Engineering, Technical University of Denmark3
Section for Structural Engineering, Department of Civil Engineering, Technical University of Denmark4
Aarhus University5
Surface modifications of cylinders using fillets are investigated with respect to flow structures in a cross flow to a cylinder. Three cylinders are used: a plain cylinder, a cylinder with a helical fillet and a cylinder with a helical staggered pattern of small fillets in tangential direction. The flow field in the wake region is measured with Particle Image Velocimetry (PIV) in both a plane normal to the cylinder and a plane in the wake shear layer perpendicular to the free stream direction.
Three different Reynolds numbers in the range from 0000 to 120000 are used. The helical fillet modifies the wake to be more narrow and longer and with less turbulent kinetic energy in the wake. The staggered fillet modifies the shear layers forming at the sides of the cylinder to contain three-dimensional structures.
This reduces vortex shedding significantly resulting in even less turbulent kinetic in the ake. Proper Orthogonal Decomposition (POD) is shown to be an effective method for describing three-dimensional time varying flow structures using non-time-resolving planar measurements.
Language: | English |
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Publisher: | Center for Innovation, Technology and Policy Research IN+ |
Year: | 2018 |
Pages: | 100-111 |
Proceedings: | 19th International Symposium on the Application of Laser and Imaging Techniques to Fluid Mechanics |
Types: | Conference paper |
ORCIDs: | Meyer, Knud Erik and 0000-0001-6001-3856 |