The prime purpose off a side thruster is to enable a ship to manoeuver at zero or low speed, when a conventional rudder is of greatly reduced effectiveness. The results of the model experiment confirm the fact that the effectiveness of a side thruster diminishes with forward speed. It seems that one of these factors is caused by the interaction between a mainstream and a water jet discharging normally into a mainstream from duct off a side thruster. And a jet of fluid directed normally into a mainstream of fluid will obviously be bent into the direction of the mainstream. Therefore, this paper deals with the interaction between the curve or diffusion of the jet off fluid and side force and yawing moment acting on the ship hull. And these forces and moments acting on the ship hull are obtained as function of ship speed and jet velocity of a side thruster. As results of the theory and experiment, side force for increase of speed from zero to about three or four knots decreased to about 50%. With further increase of ship speed, side force was found to remain almost constant or to be a little improved. Considering this theory, it seems that this is caused to cease existing of reduced pressure region, that exists in the intermediate range of the ship hull and the circumference of the jet, when ship speed is about three or four knots. These results show that the curve or diffusion of the jet from the duct of a side thruster is the most important factor to influence ship speed on the effectiveness of a side thruster. (Author)

  • Corporate Authors:

    West Japan Society of Naval Architects

    Kyushu University, Hakozaki C-10-1, Higashi-ku
    Fukuoka-shi,   Japan 
  • Authors:
    • Kijima, K
    • Inoue, S
  • Publication Date: 1975-11

Media Info

  • Pagination: n.p.

Subject/Index Terms

Filing Info

  • Accession Number: 00323628
  • Record Type: Publication
  • Source Agency: Stevens Institute of Technology
  • Report/Paper Numbers: Number 50
  • Files: TRIS
  • Created Date: Feb 6 1981 12:00AM