Fluctuating lift on a circular cylinder: review and new measurements

Apart from providing some new experimental data the paper reviews previous investigations concerning fluctuating lift acting on a stationary circular cylinder in cross-flow. In particular, effects of Reynolds number in the nominal case of an infinitely long and nonconfined cylinder in a smooth oncoming flow are discussed. The Reynolds number range covered is from about Re = 47 to 2 x 10(5), i.e., from the onset of vortex shedding up to the end of the subcritical regime. At the beginning of the subcritical regime (Reesimilar or equal to0.3 x 10(3)) a spanwise correlation length of about 30 cylinder diameters is indicated, the correlation function being based on near-cylinder velocity fluctuations in outer parts of the separated shear layer. In between Reynolds numbers 1.6 x 10(3) and 20 x 10(3), an approximate 10-fold increase in the sectional r.m.s. lift coefficient is indicated. This range contains a fundamental change-over from one flow state to another, starting off at Re similar or equal to 5 x 103 and seemingly fully developed at Re similar or equal to 8 x 10(3). (C) 2002 Elsevier Science Ltd. All rights reserved.