Response Surface Models for Analyzing Sinkage and Trim Effects on Planing Hull Motions in a Vertical Plane

Abstract

Further to the studies presented by Sayeed et al. (OMAE2014-23489), response surface models have been improved by including the effects of sinkage and trim to the vertical plane motions of planing hull in head sea. This was achieved by including longitudinal center of gravity (LCG) as an additional factor to the existing model and change in LCG eventually incorporated the effects of sinkage and trim. The validated non-linear mathematical model, Planing Hull Motion Program (PHMP) can predict the heave and pitch motions and bow and center of gravity accelerations with reasonable accuracy at planing and semi-planing speeds. This paper again illustrates an application of modern statistical design of experiment (DOE) methodology to develop response surface models to assess planing hull motions in a vertical plane in head seas. Responses were obtained from PHMP based on a multifactor uniform design scheme. Results showed that the simple one line regression models provided adequate fit to the generated responses and provided valuable insights into the behaviour of planing hull motions in a vertical plane. The new response surface models includes all possible influential factors that affect the vertical plane motions of planing hull in head sea. The simple surrogate models can be a quick and useful tool for the designers during the preliminary design stages.