Dependence of Lift Coefficient Clv on Reynolds Number and Surface Roughness and Its Possible Impact on SHEAR7 Prediction

An extensive literature review is carried out in order to ascertain the influence of Reynolds number and surface roughness on the lift coefficient Clv, which is one of the critical inputs to SHEAR7 VIV prediction. The effort is directed towards developing an understanding as to why, for bare pipes, SHEAR7 fatigue prediction looks reasonably good when compared with the laboratory test data, but its prediction appears to be considerably conservative when compared with the field measurements, particularly those measurements on large diameter drilling risers. Based upon the data collated, an empirical formula of Clv, together with its dependence on Reynolds number and surface roughness, is proposed.