The supercritical Strouhal and critical Reynolds numbers associated with the drag crisis of circular cylinders in cross-flow are known to be dependent on surface roughness and turbulence levels.To better understand th...The supercritical Strouhal and critical Reynolds numbers associated with the drag crisis of circular cylinders in cross-flow are known to be dependent on surface roughness and turbulence levels.To better understand the role of free-stream turbulence,we consider the traditional model of oscillating lift forcing together with a randomly fluctuating disturbance associated with fluid turbulence.To the extent that these two components are additive,statistically independent,and Gaussian,we are able to derive a closed-form expression describing the relationship between the effective shedding rate and free-stream turbulence.A semi-empirical model of the critical Reynolds number accounting for fluid turbulence is also presented.展开更多
文摘The supercritical Strouhal and critical Reynolds numbers associated with the drag crisis of circular cylinders in cross-flow are known to be dependent on surface roughness and turbulence levels.To better understand the role of free-stream turbulence,we consider the traditional model of oscillating lift forcing together with a randomly fluctuating disturbance associated with fluid turbulence.To the extent that these two components are additive,statistically independent,and Gaussian,we are able to derive a closed-form expression describing the relationship between the effective shedding rate and free-stream turbulence.A semi-empirical model of the critical Reynolds number accounting for fluid turbulence is also presented.
