Evaluation of Interceptor Design to Reduce Drag on Planing Hull

Abstract

A planing hull is a high-speed craft with relatively complex hydrodynamic characteristics. An increase in speed can induce a significant change in trim angle with an increment in ship drag. One solution to reduce ship resistance is to use an interceptor. This research aimed to analyze the hydrodynamics of a planing hull vessel by applying an interceptor. The fundamental aspects reviewed included the analysis of drag, trim, heave, and lift force. The interceptor would be investigated on the basis of its integrated position at its height. This research also used the computational fluid dynamic (CFD) method in calm water conditions. All simulations were conducted with the same mesh structure, which allowed the performance evaluation of the interceptor in calculating turbulent air–water flow around the ship. Numerical calculations used the Reynolds-averaged Navier–Stokes (RANS) equation with the k–ε turbulence model to predict the turbulent flow. The vertical motion of the ship was modeled using dynamic fluid–body interaction (DFBI) in the fluid domain through an overset mesh technique. The numerical approach was compared with the experimental test results of Park et al. to ensure the accuracy of the test results. The interceptor was designed at the transition phase, which showed the highest trim angle followed by high drag. The interceptor would experience negative trim at high speeds; thus, it was not recommended. The research results indicated that the most effective use of the interceptor was at Froude number 0.87 close to the chine position with a height of 100%. This interceptor could reduce a maximum of 57% drag, 17% heave, 8.48% trim, and 0.12% lift force. The interceptor could increase excessive drag and trim at Froude numbers over 1.16. The interceptor proved to be remarkably useful in trim control and ship drag reduction, but selecting the wrong dimensions and positions of the interceptor could endanger the ship. This simulation was performed on Aragon-2; thus, the interceptor performance may possibly change if a different hull geometry is used.

Planing Hull Hydrodynamic Performance Prediction Using LincoSim Virtual Towing Tank

“…Future work from the experimental side will face a wide range of wave frequencies to validate the LincoSim platform. The overall conclusions for these very first steps are that the results are very promising, as the observed differences between numerical and experimental data for heave and pitch are within a few percents, aligned with the results of [14,32,33]. More importantly, the simulation monitored output for the accelerations can spot the presence of multiple frequencies instead of just the one related to the regular encounter wave signal, thus confirming the ability of CFD simulation to account for relevant nonlinear responses of the ship while planing.…”

Reconstruction of Hull Form of Traditional Croatian Fishing Vessel and Prediction of Eff ective Power

“…The prism layer is generated at the hull surface based on its thickness, the number of cell layers and the size distribution of the layers. Within this research, wall functions are used, and the thickness of the prism layer is defi ned based on the vessel speed in such a way that the value of y  is larger than 30 [29]. The special care is given to transition from prism layer to core mesh, as done in [30], which reduces potential numerical diff usion.…”

Effect of Speed and Hull Length on the Hydrodynamic Performance of a Semi-Planing Hull of a Shallow-Draft Watercraft

“…Other studies that addressed this topic and employed computational fluid dynamics as a tool to analyze hydrodynamic factors include Samuel et al [21]. In their research, they examined the hydrodynamics of a high-speed planing hull using an interceptor [21]. The study was conducted using CFD analysis, varying both the position and height of the interceptor [21].…”