Rotating flow past a short, sliced cylinder at finite Rossby number

Abstract Flow past a short obstacle in a rotating reference frame generates a wake that is crucial to the overall flow structure if the Rossby number is of the order of the quarter power of the Ekman number. We present here a theory for such flows for the case when the obstacle's top is an oblique, planar surface. The results arise from a combination of asymptotic analysis and numerical computation, and show that even weak asymmetry generates significant global effect on the entire flow-field. Comparisons with the experiments reported by Foster and Davies (1996) are generally good when the high edge is at 90° to the oncoming flow.