Author: Tarek G. ZakiPublisher:
ISBN:
Category :
Languages : en
Pages : 210
Book Description
Experimental and Numerical Investigation of Flow Past a Freely Rotatable Square Cylinder
Author: Tarek G. ZakiAn Experimental Investigation of the Flow Past a Finite Circular Cylinder at a Low Subcritical Reynolds Number
Author: M. BudairPublisher:
ISBN:
Category : Boundary layer control
Languages : en
Pages : 156
Book Description
Experimental and Numerical Investigations of the Flow Development Over Cylinders with Stepwise Discontinuities in Diameter
Author: Christopher R. MortonPublisher:
ISBN:
Category :
Languages : en
Pages : 123
Book Description
Flow past circular cylinders with stepwise discontinuities in diameter was investigated experimentally and numerically for the diameter ratio D/d = 2 and three Reynolds numbers, Re = 150, 300, and 1050. The investigation was focused on the vortex shedding phenomena occurring in the wake of the cylinders. In the first series of experimental and numerical studies, the flow development past a single step cylinder was investigated. The single step cylinder model is comprised of a small diameter cylinder (d) attached coaxially to a large diameter cylinder (D). The results show that three distinct spanwise vortex cells form in the step cylinder wake: a single vortex shedding cell in the wake of the small cylinder (the S-cell) and two vortex shedding cells in the wake of the large cylinder, one in the region downstream of the step (the N-cell) and the other away from the step (the L-cell). Due to the differences in vortex shedding frequencies between the three cells, complex vortex connections occur in two vortex-interaction regions located between the adjacent cells. The region at the boundary between the S-cell and the N-cell is relatively narrow and its spanwise extent does not fluctuate significantly. In this region, vortex dislocations manifested as half-loop connections between two S-cell vortices of opposite sign. In contrast, the region at the boundary between the N-cell and the L-cell exhibits a transient behavior, with large scale vortex dislocations causing cyclic variation in the extent of N-cell vortices. For Re = 300 and 1050, small scale streamwise vortices forming in the wake complicate the vortex dynamics within the adjacent S-cell and L-cell. There is no significant Reynolds number effect on the average spanwise extent of the vortex cells and the two transition regions between neighboring cells. Finally, formation of N-cell vortices is linked to downwash fluctuations near the step. The flow development past a dual step cylinder was studied experimentally for Re = 1050. The dual step cylinder model is comprised of a small diameter cylinder (d) and a large diameter cylinder (D) mounted at the mid-span of the small cylinder. The experiments were completed for a range of large cylinder aspect ratios 0.2 [les] L/D [les] 17. The flow development is highly dependent on the aspect ratio of the large cylinder, L/D. The results identify four distinct flow regimes: (i) for L/D = 17, three vortex shedding cells form in the wake of the large cylinder, one central cell and two cells of lower frequency extending over about 4.5D from the large cylinder ends, (ii) for 7
Experimental and Numerical Investigations of the Flow Development Over Circular Cylinders with Stepwise Discontinuities in Diameter
Author: Christopher R. MortonPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Flow past circular cylinders with stepwise discontinuities in diameter was investigated experimentally and numerically for the diameter ratio D/d = 2 and three Reynolds numbers, Re = 150, 300, and 1050. The investigation was focused on the vortex shedding phenomena occurring in the wake of the cylinders. In the first series of experimental and numerical studies, the flow development past a single step cylinder was investigated. The single step cylinder model is comprised of a small diameter cylinder (d) attached coaxially to a large diameter cylinder (D). The results show that three distinct spanwise vortex cells form in the step cylinder wake: a single vortex shedding cell in the wake of the small cylinder (the S-cell) and two vortex shedding cells in the wake of the large cylinder, one in the region downstream of the step (the N-cell) and the other away from the step (the L-cell). Due to the differences in vortex shedding frequencies between the three cells, complex vortex connections occur in two vortex-interaction regions located between the adjacent cells. The region at the boundary between the S-cell and the N-cell is relatively narrow and its spanwise extent does not fluctuate significantly. In this region, vortex dislocations manifested as half-loop connections between two S-cell vortices of opposite sign. In contrast, the region at the boundary between the N-cell and the L-cell exhibits a transient behavior, with large scale vortex dislocations causing cyclic variation in the extent of N-cell vortices. For Re = 300 and 1050, small scale streamwise vortices forming in the wake complicate the vortex dynamics within the adjacent S-cell and L-cell. There is no significant Reynolds number effect on the average spanwise extent of the vortex cells and the two transition regions between neighboring cells. Finally, formation of N-cell vortices is linked to downwash fluctuations near the step. The flow development past a dual step cylinder was studied experimentally for Re = 1050. The dual step cylinder model is comprised of a small diameter cylinder (d) and a large diameter cylinder (D) mounted at the mid-span of the small cylinder. The experiments were completed for a range of large cylinder aspect ratios 0.2 ≤ L/D ≤ 17. The flow development is highly dependent on the aspect ratio of the large cylinder, L/D. The results identify four distinct flow regimes: (i) for L/D = 17, three vortex shedding cells form in the wake of the large cylinder, one central cell and two cells of lower frequency extending over about 4.5D from the large cylinder ends, (ii) for 7
Hydrodynamics Around Cylindrical Structures
Author: Jorgen FredsoePublisher: World Scientific
ISBN: 981449805X
Category :
Languages : en
Pages : 550
Book Description
This book discusses the subject of wave/current flow around a cylinder, the forces induced on the cylinder by the flow, and the vibration pattern of slender structures in a marine environment.The primary aim of the book is to describe the flow pattern and the resulting load which develops when waves or current meet a cylinder. Attention is paid to the special case of a circular cylinder. The development in the forces is related to the various flow patterns and is discussed in detail. Regular as well as irregular waves are considered, and special cases like wall proximities (pipelines) are also investigated.The book is intended for MSc students with some experience in basic fluid mechanics and for PhD students.
Experimental and Numerical Investigation of Three Equispaced Cylinders in Cross-flow
Author: Manpreet BansalPublisher:
ISBN:
Category :
Languages : en
Pages : 197
Book Description
Flow around a cluster of three equally spaced cylinders with a spacing ratio of P/D = 1.35 was studied experimentally and numerically. The main focus of this investigation is the effect of cluster orientation on flow characteristics.
Applied mechanics reviews
Author: Numerical and Experimental Investigation of Flow Past a Sphere Up to a Reynolds Number of 300
Author: Timothy A. JohnsonNumerical Experiments on the Flow Past a Circular Cylinder at Sub-critical Reynolds Number
Author: Patrick BeaudanPublisher:
ISBN:
Category : Cylinders
Languages : en
Pages : 280
Book Description
Author: Amit Mohan Thakur