Simulation of ship spiral test for ballast and full load conditions - Open Research Data - Bridge of Knowledge

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Simulation of ship spiral test for ballast and full load conditions

Description

The data show the results of the spiral test for the simplified ship model, taking into account two states of loading: ballast and full load. The data set contains the results of time simulation for sea state 10 on the Beaufort scale: changes in rudder angle delta_tab[deg]; angular velocity r_tab[deg/s]; surge velocity u_tab (m/s); sway velocity v_tab (m/s); surge position x_tab (m); sway position y_tab (m); course kurs_tab (deg); relative pitch of main propeller Hs_tab (-); initial propeller speed ns_tab (in revolution per second).

The spiral test consists in performing an orderly sequence of circles by changing the rudder angle. According to the regulations of the Polish Register of Shipping (PRS), it starts from the rudder angle of 15º. After setting the constant angular velocity, the rudder angle is reduced initially every 5º, and then every 2º. When the direction of angular velocity changes, the test shall continue in the same way for negative rudder angle values as for positive ones. The results of the test shall be shown on the graph of the relationship between the angular velocity (𝑟) and the rudder angle (dR). If the 𝑟 chart intersects the origin, the vessel shall be stable, otherwise it shall show a lack of straight-line stability. The measure of instability is determined by the size of the instability loop (𝑙𝑟). The Polish Register of Shipping defines the spiral test as an additional test. It is recommended to carry out this test when the standard tests indicate dynamic instability or limit stability of the ship. It is very time-consuming, especially for large and slow vessels, and the results obtained are very dependent on the weather conditions during the test. After this test, detailed information on the instability, if any, is obtained. The resulting manuvering characteristics diagram is a component of the simplified ship mathematical model used for course control.

Illustration of the publication
Illustration of the publication

Basic technical parameters of the ship model: overall length 181(m), width 165(m). Ballast condition: draught at the bow 5.5(m), draught at the stern 6.7(m), displacement 16400(m3). In full load condition: draught at the bow 9.64(m), draught at the stern 9.64(m), displacement 28350(m3).

Dataset file

spiral_tests.rar
17.5 MB, S3 ETag 0d50200fa7d783c17cf9a5149d177179-1, downloads: 30
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File details

License:
Creative Commons: by 4.0 open in new tab
CC BY
Attribution
Raw data:
Data contained in dataset was not processed.
Software:
Matlab

Details

Year of publication:
2020
Verification date:
2020-12-17
Creation date:
2009
Dataset language:
English
Fields of science:
  • Automation, electronic and electrical engineering (Engineering and Technology)
DOI:
DOI ID 10.34808/85sr-s841 open in new tab
Verified by:
Gdańsk University of Technology

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