Effect of corrugated pipe bending on internal flow induced acoustics

Abstract

Internal flow induced acoustics is commonly noticed in corrugated pipes that provide both flexibility and strength in offshore flexible riser system. This phenomenon is commonly known as whistling when flow passes through the corrugated pipe at high pressure and high velocity. This paper evaluates the effect of corrugated pipe bending on the whistling behavior using 2D numerical simulation. It is found that the bending angle will have an effect on the peak-whistling Strouhal number (Srp-w). By incorporating the bending effect A = 360°/360°-θ in characteristic dimension, such that A(W + rup) rather than (W + rup) which was proposed in literature resulted in smaller variation of Strouhal Number, Srp-w. Hence, provide more accurate prediction of the phenomena and further enhance the practicality of the modified characteristics length in predicting the peak whistling Strouhal Number.