New Horizons-Welcome to Hyundai Heavy Industries's English Webzine

July - August 2003

Technology

Ship Maneuvering Simulation Program Developed

The need to improve the maneuverability of ships has been increasing among many international maritime societies to improve maritime safety and enhance marine environmental protection. Recently, the International Maritime Organization (IMO) adopted standards for ship maneuverability in MSC 76. These trends have increased the need for precise prediction of ship maneuverability at an early design stage.

HYMAN

Hyundai Maritime Research Institute (HMRI) has developed a ship maneuvering simulation program using empirical formulas for hydrodynamic coefficients: the HYundai ship MANeuvering simulation program (HYMAN). HYMAN accounts for various characteristics of a vessel (e.g., principal dimensions, stern hull form, stern bulb type and a variety of rudder types) in predicting ship maneuverability.

Major features of HYMAN:
. Input of ship’s principal dimensions
. Prediction of ship’s hydrodynamic coefficients
. Simulations for items contained in IMO Res. A. 751
(initial turning maneuver, turning maneuver, zig-zag maneuver, etc.)

Ship Hydrodynamic Coefficients Prediction

HYMAN uses a modular model for mathematical modeling of ship maneuvering simulation. To predict a ship’s hydrodynamic coefficients of modular model, empirical formulas have been used. The empirical formulas were obtained from linear multiple regression of almost 50 ships’ Planner Motion Mechanism (PMM) tests performed at HMRI. Input of HYMAN to predict ship maneuverability includes:

. Principal dimensions of hull (displacement, Lpp, draft, center of gravity, stern shape, etc.)
. Principal dimensions of rudder (movable part area, height, aspect ratio, rudder type, etc.)
. Principal dimensions of propeller (diameter, pitch ratio, propeller wake, etc.)
. Speed-power information
. Propeller open water characteristics

Simulation Results

HYMAN provides simulation results of ship maneuvering tests: initial turning maneuver, turning maneuver, zig-zag maneuver and spiral maneuver. Since HHI has analyzed experimental hydrodynamic coefficients of almost 50 ships, HYMAN gives reasonable simulation results for various ship types. All simulations are applicable to various maneuvering conditions corresponding to initial speeds and rudder angles. Additionally, all simulated results provided by HYMAN consider various rudder types (e.g. conventional rudder, schilling rudder, flap rudder, etc.) and stern hull form. For these reasons, HYMAN gives more accurate ship maneuvering simulations than results derived using established formulae.

Samples of HYMAN simulation results are shown below.