An experimental investigation of the flow around a circular cylinder: influence of aspect ratio
- 10 January 1994
- journal article
- research article
- Published by Cambridge University Press (CUP) in Journal of Fluid Mechanics
- Vol. 258, 287-316
- https://doi.org/10.1017/s0022112094003332
Abstract
The investigation is concentrated on two important quantities – the Strouhal number and the mean base suction coefficient, both measured at the mid-span position. Reynolds numbers from about 50 to 4 × 104 were investigated. Different aspect ratios, at low blockage ratios, were achieved by varying the distance between circular end plates (end plate diameter ratios between 10 and 30). It was not possible, by using these end plates in uniform flow and at very large aspect ratios, to produce parallel shedding all over the laminar shedding regime. However, parallel shedding at around mid-span was observed throughout this regime in cases when there was a slight but symmetrical increase in the free-stream velocity towards both ends of the cylinder. At higher Re, the results at different aspect ratios were compared with those of a ‘quasi-infinite cylinder’ and the required aspect ratio to reach conditions independent of this parameter, within the experimental uncertainties, are given. For instance, aspect ratios as large as L/D = 60–70 were needed in the range Re ≈ 4 × 103–104. With the smallest relative end plate diameter and for aspect ratios smaller than 7, a bi-stable flow switching between regular vortex shedding and ‘irregular flow’ was found at intermediate Reynolds number ranges in the subcritical regime (Re ≈ 2 × 103).Keywords
This publication has 27 references indexed in Scilit:
- The natural and forced formation of spot-like ‘vortex dislocations’ in the transition of a wakeJournal of Fluid Mechanics, 1992
- An experimental study of the parallel and oblique vortex shedding from circular cylindersJournal of Fluid Mechanics, 1991
- Chaotic transport in two- and three-dimensional flow past a cylinderPhysics of Fluids A: Fluid Dynamics, 1991
- A study of the effect of aspect ratio on vortex shedding behind circular cylindersPhysics of Fluids A: Fluid Dynamics, 1991
- Ordered and chaotic vortex streets behind circular cylinders at low Reynolds numbersJournal of Fluid Mechanics, 1987
- The effect of sound on vortex shedding from cylindersJournal of Fluid Mechanics, 1985
- Influence of end plates and free ends on the shedding frequency of circular cylindersJournal of Fluid Mechanics, 1982
- Measurements of velocity distributions in the wake of a circular cylinder at low Reynolds numbersJournal of Fluid Mechanics, 1974
- On vortex shedding from a circular cylinder in the critical Reynolds number régimeJournal of Fluid Mechanics, 1969
- A disturbance-sensitive Reynolds number range of the flow past a circular cylinderJournal of Fluid Mechanics, 1965