The effect of bulbous bow shapes by varying its protruding length and breadth of the bulb and the height of the bulb nose from the baseline on the resistance components and wave profiles of small ships were investigated using computational fluid dynamics (CFD) simulations. A 28.3 m purse seiner and a 35 m research vessel were chosen to be the reference hulls. Different sizes of additive bulbs were added to the purse seiner, and the research vessel stems and all these variations were simulated using the Reynolds-averaged Navier–Stokes (RANS) numerical simulations with the volume of fluid (VOF) method in modelling the free surface in full scale. The resistance results of the purse seiner and the research vessel without bulbous bow were validated with experimental test results at corresponding speeds of 10 knots and 11 knots, respectively. A grid independence study was conducted, and all the CFD simulations were simulated using 3.6 and 4.9 million grid cells for the purse seiner and the research vessel, respectively. The purse seiner and the research vessel were added with eight different bulbs sizes varying its protruding length, breadth of the bulb and the height of the bulb nose and were labelled B1, B2, B3, B4, B5, B6, B7 and B8. From the CFD results, the addition of bulbs seems not to be effective when the volumetric coefficient of the bulb is less than 0.005 for both cases. The bulbs were effective when the volumetric coefficient is in between from 0.01 to 0.09 for both cases. The bulbs seem to gain in resistance beyond the volumetric coefficient of 0.14 and 0.06 for the purse seiner and the research vessel case, respectively. From the wave profile evaluation, it can be seen that the nose of the bulb induced a high-pressure region upstream, corresponding to the first trough of the original bow wave causing a phase shift to the bow wave system, cancelling the wave system from the front shoulder, hence reducing the wave resistance of the purse seiner and the research vessel.
Investigation on the Effect of the Bulbous Bow Shape to the Resistance Components and Wave Profiles of Small Ships
Adv Struct Mater
2022-01-10
28 pages
Aufsatz/Kapitel (Buch)
Elektronische Ressource
Englisch
Bulbous bow part for reducing wave resistance of ships
Europäisches Patentamt | 2023
|Research on bulbous bow ships1
IOS Press | 1966
|Research on bulbous bow ships1
IOS Press | 1966
|