Experimental and numerical investigation of hydrodynamic coefficients of subsea manifolds

Abstract

ABSTRACT Hydrodynamic coefficients of subsea manifolds are significant parameters in predicting dynamic responses during deep-water installation. To calculate these coefficients, a series of model tests of the drag coefficients of a typical subsea manifold with eight slots were carried out at Zhejiang University. A numerical simulation was performed using the computational fluid dynamics (CFD) method, and the Navier–Stokes equations were solved to obtain the drag and added mass coefficients. On the prediction of drag coefficient, a similar tendency was found for both the numerical and experimental results, proving the accuracy and reliability of the proposed CFD method. The effects of variables such as the Keulegan-Carpenter (KC) number and frequency of forced oscillation on the added mass coefficients were analysed. The added mass coefficients increase nearly linearly as the KC number increases, but the oscillation frequency has little influence on the added mass coefficients.