# Numerical Simulation of Seakeeping Performance on the Preliminary Design of a Semi-Planing Craft
## 1 Introduction
Additionally, [PERSON] and [PERSON] [15] combined three-dimensional potential theory and pulsating sources to calculate trimaran motion and wave loads. [PERSON] and [PERSON] [16] recommended the use of the three-dimensional panel method to investigate the linear motion of forward-moving vessels in random incident waves. A comparison of two-dimensional strip theory and the three-dimensional panel method revealed that two-dimensional strip theory featured favorable computation speeds and accuracy. Thus, this study used two-dimensional strip theory to calculate and analyze the seakeeping performance of high-speed vessels. Fewer studies have employed two-dimensional strip theory to examine the seakeeping performance of high-speed crafts than to examine the seakeeping performance of crafts in the displacement mode. For example, [PERSON] [17] developed a semi-empirical strip theory and used it to calculate the fixed linear deadrise angles of semi-planing crafts moving at high speeds following seas and head seas. [PERSON] [18] used the nonlinear time-domain mathematical model of strip theory to calculate the motion responses of planing crafts in regular waves. [PERSON] et al. [19] extended the basic model introduced in [18] to enable the model to also measure ship motion at various deadrise angles. They also used model test-based empirical formulas to extend the applicability of the model to various sailing speeds. Similarly, [PERSON] [20] extended the methods presented in [18] and proposed the use of two-dimensional methods to calculate the added mass coefficients of vessels with various hull pressure values and deadrise angles. [PERSON] et al. [21] explored the effect of the bow shape of high-speed mono-hulls on their seakeeping performance and discovered that changing the shape of the bows above and below the waterline considerably enhanced the seakeeping performance of these mono-hulls. [PERSON] and [PERSON] [22] confirmed that strip theory could be used to predict the seakeeping performance of high-speed crafts and verified the effect of hydrodynamic force on the seakeeping performance of high-speed mono-hull crafts. [PERSON] [23] developed a nonlinear mathematical model based on two-dimensional strip theory to analyze the motion and acceleration of a planing mono-hull ship (with a fixed deadrise angle) in head seas. [PERSON] [24] examined the safety and operability of high-speed crafts in waves and established a numerical method to analyze the seakeeping performance of such vessels. For a planing or semi-planing craft, dynamic pressure distribution on the high-speed hull during forward motion supports most of the weight and, thus, lifts a large portion of the hull out of the water. Although the craft is not free to trim in the present simulation, it is still significant to understand the hydrodynamic performance and make an accurate estimation of the behavior of the craft under various operating conditions. It is also known that one of the greatest challenges of evaluating the performance of a planing or semi-planing craft, which is dependent on the Froude number, is obtaining accurate and practical results from hydrodynamic analysis. Based on the assumption of fixed draft and trim angle, this study intends to investigate the differences in seakeeping performances of a series 62 mono-hull. During full-scale sea trials trim angle measurements were not conducted. They were simply used to verify seakeeping estimation in the numerical simulation. An efficient and accurate program, in this case the strip theory based on potential flow, for predicting the motion responses of high-speed crafts plays an important role in improvement of this field due to the performance and speed requirement. Although experimental tests are the most reliable way to model ship hydrodynamics, these techniques are very costly and the measured data are achievable only for a limited number of cases.