Experimental and numerical analyses of wedge effects on the rooster tail and porpoising phenomenon of a high-speed planing craft in calm water

Abstract

This paper presents experimental and numerical investigation of stability and rooster tail of a mono-hull high-speed planing craft with a constant deadrise angle. Initially, a one-fifth scale model was tested in a towing tank, which showed porpoising phenomenon at 8 m/s (equal to the speed of sailing). Subsequently, two wedges of 5 and 10 mm heights, based on the boundary layer calculations, were mounted on the aft section of the planing hull. These wedges were shown to increase the lift at the aft section. These experiments were carried out at different speeds up to 10 m/s in calm water. The experimental results indicated that the installed wedges reduced the trim, drag, and the elapsed time for reaching the hump peak, and also eliminated the porpoising condition. All these test cases were also numerically simulated using Star CCM+ software. The free surface was modeled using the volume of fluid scheme in three-dimensional space. The examined planing craft had two degrees of freedom, and overset mesh technique was used for space discretization. The obtained numerical results were compared with experimental data and good agreement was displayed in the presented comparisons. Ultimately, the effect of the wedge on the rooster tail behind the planing craft was studied. The results of this investigation showed that by decreasing the trim at a constant speed, the height of the generated wake profile (rooster tail) behind the craft decreases, albeit its length increases.

Numerical Study of the Effect of Angle and Location of the First and Second Steps on the Performance of Planing Hull and Their Optimization Using the Taguchi Statistical Method

“…Wedge efects were frst studied by Ghadimi et al [9] in an experimental manner, considering two stern wedges with diferent heights. After that, the rooster tail of wedgemounted hulls was analyzed in a more comprehensive study via both experimental and numerical methods by Mahdi Sajedi et al [31]. Te seakeeping of wedgemounted hulls in irregular waves was also studied experimentally by Ghadimi et al [32].…”

“…Tey found that the simultaneous use of stern wedges and transverse steps could improve the vessel's undesirable performance prior to planing regime, which is one of the challenges in planing hull design. Tese extensive data [9,28,29,[31][32][33][34][35][36][37] for diferent confgurations of a single parent model present a unique opportunity to realize how diferent confgurations of step and wedge could afect a planing hull's performance.…”

Experimental study of the effects of Vee-shaped steps on the hydrodynamic performance of planing hulls

“…It should also be noted that the wedge effects on the same parent model have been assessed experimentally 9,15 and numerically. 16…”

Drag reduction configuration analysis of the grooves on amphibious vehicles walking mechanism

“…To solve this problem, some researchers verified and optimized numerical model through the comparison with model tests, and then the verified model can be used for further analysis and research. 16,20,21…”