Numerical Investigations on the Resistance and Longitudinal Motion Stability of a High-Speed Planing Trimaran

Abstract

The planing trimaran is a novel kind of aerodynamic alleviated marine vehicle and possesses a unique hybrid hydrodynamic and aerodynamic characteristics. In this paper, to investigate the hull behavior of a planing trimaran under the effect of tunnel forces, the tunnel and demihull are treated as appendages mounted on the slender main hull. Numerical simulations were carried out for planing trimaran and a monohull which was built according to the main hull configuration. Mesh convergence studies were implemented based on the public experimental data of a similar planing trimaran. Calculated results show that the presence of tunnel and demihull could decrease the resistance of the main hull and improve the longitudinal motion stability at high speeds. Flow evolutions of waves, velocity vector, wetted length and lift distribution were performed to explain the variation of the tunnel lift and its moment and their influence on hull behavior. Parameter studies on demihull length were carried out as well. It was found that, as the demihull length is increased, the tunnel trimming moment would decrease especially in the final stage of ventilation, making resistance reduced but the motion stability weakened.

Experimental Study on Motion Behavior and Longitudinal Stability Assessment of a Trimaran Planing Hull Model in Calm Water

“…Similarly et al carried out a numerical investigation on a stepped monohull and planing trima which shared the same main hull configuration. The results indicate that the coup effect of the step and demihull has a positive impact on the motion characteristic and gitudinal stability [5]. Moreover, based on commercial software STAR-CCM+, Rosh al.…”

“…Though the ratio is nificant and non-negligible, most of the planing trimaran total weight is still compens by hydrodynamic lift. The aerodynamic effect is poorer than in the planing catam mentioned above [5]. Therefore, the navigation mechanism of a trimaran is still simil a conventional planing hull, especially in the high-speed region; i.e., the hull in the h speed region is confronted with greater resistance and weaker stability [6][7][8].…”

“…Similarly, Sun et al carried out a numerical investigation on a stepped monohull and planing trimaran, which shared the same main hull configuration. The results indicate that the coupling effect of the step and demihull has a positive impact on the motion characteristic and longitudinal stability [5]. Moreover, based on commercial software STAR-CCM+, Roshan et al numerically simulated the flow field around the hull of a planing trimaran, and the pressure distribution and stream lines in the tunnel were also presented [13].…”

Effects of a Bulbous Bow Shape on Added Resistance Acting on the Hull of a Ship in Regular Head Wave

“…CFD has been a useful and popular tool for solving problems of the hydrodynamic performance of ships with high accuracy. By applying CFD, various hull forms with small resistances have been proposed [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16].…”

“…Kahramanoğlu et al (2020) presented a study on a numerical simulation used to predict the component vertical responses of planning ships under wave conditions [14]. Sun et al (2020) studied numerical computation used to investigate ship resistance and ship motion stability for a high-speed planning trimaran [15]. Other similar studies include [11,16,29].…”