In this research, hydrodynamic analysis, verification and validation will be performed on Generic Prismatic Planing Hull (GPPH) using OpenFOAM v1806 solver interFoam. The numerical simulation will be compared with the experimental result, which is a new set of high-quality experimental tests performed on a large model of a high deadrise prismatic planing hull with flat of chine, tested from pre-planing to fully planing regimes. Firstly, the mesh convergence study and Verification and Validation (V&V) study are performed on the basis of fixed attitude simulations. Three grids are chosen and used to perform the free attitude simulations at the highest speed. Then, mesh convergence study is conducted for the results of highest speed free body simulations, which helps us to choose two grids for other speeds simulations. By performing free attitude simulations using two grids, resistance, heave, trim angle, wetted chine length, and wetted keel length are calculated and compared at seven different tested speeds. Computational Fluid Dynamics (CFD) results analysis regards pressure distribution on the bottom of the hull and in particular areas of interest (flat of chine, spray area, etc.), friction coefficient and volume fraction of fluid in areas where the free surface undergoes violent deformations (overturning wave at the chine and in the wake, spray jet development area). Different algorithms for dynamic mesh simulation and their effect on the quality of CFD predictions are also investigated. / Master of Science / The paper presents the first series of results obtained in an ongoing validation and verification study of inter-dynamic OpenFOAM solver framework on a new set of high quality experimental tests performed on a large (2.4m long) generic planing hull model (GPPH) with high deadrise (18deg), from the pre-planning (Fn∇=2.6) to fully planing (Fn∇=5.7) regimes. This test case is a good benchmark for the free surface capturing model implemented in OpenFOAM which is based on a rather simple transport equation for an additional scalar field that defines the fraction of water in each cell of the computational mesh. This model, in spite of its simplicity, seems capable of reproducing complex violent free surface flows such as that observed in planing hulls, that includes jet spray forming on the bottom and detaching from the chine of the planing hull and overturning waves off the wet chine region, with some nuances. The dependence of the flow solution on the mesh quality is presented and discussed. Practical indication of the level of uncertainty of CFD models for the prediction of the calm water hydrodynamics of the GPPH is given at the highest simulated speed using both fixed and free attitude simulation solutions. Predictions are then extended to the whole speed range, including resistance components, dynamic trim, heave, wetted chine length, and wetted keel length.The effect due to algorithms is also discussed by modifying the settings in wall functions and solvers for the improvements of future simulation.

The straight line calm water performance of stepped planing hulls has been studied experimentally, by prediction method, and numerically. A model test was conducted to provide a systematic understanding of the effects that displacement and step location have on the performance of a stepped planing hull. Ten different step configurations were tested at three different displacements and over a range of four different speeds in calm water. Seven of these configurations were tested at two different Longitudinal Center of Gravity (LCG) locations. Of all the configurations tested, the stepped hull configurations showed reduced resistance compared to the unstepped hull. The configurations with the largest step height aft showed the least amount of resistance over the speed range tested. Increasing displacement and shifting LCG had similar effects on craft performance for both stepped and unstepped hulls. The current stepped hull prediction method was expanded to include a three dimension wave profile and the ability for the stagnation line to cross the step. Using previous model test data and existing two dimension wave profile equations, a single equation was developed to predict the three dimension wave profile aft of a step. Formulations were added to Savitsky's planing prediction method to include very high speed craft and chines dry conditions. Lastly, two simulations were performed using two computational fluid dynamics numerical tools, OpenFOAM, and NFA. The results of these simulations were compared to the experimental test results to assess each code's relative strengths and weaknesses for use in detail design of stepped planing craft. / Ph. D.

High speed planing hulls are currently widely used for example in recreational and emergency vessel applications. However, very little CFD research has been done for planing vessels, especially for those with stepped hulls. A validated CFD method for planing stepped hulls could be a valuable improvement for the design phase of such hulls. In this thesis, a CFD method for stepped hulls, with a primary focus on two-step hulls, is developed using STAR-CCM+. As a secondary objective, porpoising instability of two-step hulls is investigated. The simulations are divided into two parts: In the first part a method is developed and validated with existing experimental and numerical data for a simple model scale planing hull with one step. In the second part the method is applied for two two-step hulls provided with Hydrolift AS. A maximum two degrees of freedom, trim and heave, are used, as well as RANS based k-w SST turbulence model and Volume of Fluid (VOF) as a free surface model. The results for the one-step hull mostly corresponded well with the validation data. For the two-step hulls, validation data did not exists and they were first simulated with a fixed trim and sinkage and compered between each other. In the simulations with free trim and heave both hulls experienced unstable porpoising behavior.