Simulation of manoeuvring and control of sailing craft
Simulation of manoeuvring and control of sailing craft
A mathematical model for simulation of manoeuvring motions of sailing craft in calm water was developed using the Newtonian equations of motion in surge, sway, yaw and roll. The physical model chosen for investigation is the Lord Nelson, a sail training ship. Most of the hydrodynamic coefficients of the Lord Nelson model were determined using a Horizontal Planar Motion Mechanism in the Lamont tank at Southampton University. The estimation of wind forces and moments on the hull and rig was based on regression fits to the wind tunnel test data on the Lord Nelson model by the Wolfson Unit at Southampton University.
Directional stability of the ship under full sail was investigated at different apparent wind angles. It was found that the ship under power is stable, whereas the ship under full sail is unstable in all cases except the close-hauled one, the instability being more pronounced with the wind abaft the beam. Shifting the hydrodynamic CLR more aft was found to improve stability. The exclusion of the sway-yaw-roll coupling from the equations did not alter the stability characteristics significantly.
A manoeuvring simulation program was developed. 10o-10o and 5o-5o zig-zag manoeuvres were simulated at different apparent wind angles. It was found that in unstable sailing conditions, the ship cannot successfully complete the manoeuvre. The overshoot angles are larger than those for conventional ships but heel during manoeuvres is small. A windward tack was also simulated. Simulated gust response at different apparent wind angles revealed significant trends in the behaviour of the ship when hit by a gust. The ship was found to initially bear away from the wind, but eventually to come around into the wind. The heel angles follow the ramped gust closely with hardly any overshoot.
University of Southampton
Krishnan, Dileep Kattunkal
1993
Krishnan, Dileep Kattunkal
Krishnan, Dileep Kattunkal
(1993)
Simulation of manoeuvring and control of sailing craft.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
A mathematical model for simulation of manoeuvring motions of sailing craft in calm water was developed using the Newtonian equations of motion in surge, sway, yaw and roll. The physical model chosen for investigation is the Lord Nelson, a sail training ship. Most of the hydrodynamic coefficients of the Lord Nelson model were determined using a Horizontal Planar Motion Mechanism in the Lamont tank at Southampton University. The estimation of wind forces and moments on the hull and rig was based on regression fits to the wind tunnel test data on the Lord Nelson model by the Wolfson Unit at Southampton University.
Directional stability of the ship under full sail was investigated at different apparent wind angles. It was found that the ship under power is stable, whereas the ship under full sail is unstable in all cases except the close-hauled one, the instability being more pronounced with the wind abaft the beam. Shifting the hydrodynamic CLR more aft was found to improve stability. The exclusion of the sway-yaw-roll coupling from the equations did not alter the stability characteristics significantly.
A manoeuvring simulation program was developed. 10o-10o and 5o-5o zig-zag manoeuvres were simulated at different apparent wind angles. It was found that in unstable sailing conditions, the ship cannot successfully complete the manoeuvre. The overshoot angles are larger than those for conventional ships but heel during manoeuvres is small. A windward tack was also simulated. Simulated gust response at different apparent wind angles revealed significant trends in the behaviour of the ship when hit by a gust. The ship was found to initially bear away from the wind, but eventually to come around into the wind. The heel angles follow the ramped gust closely with hardly any overshoot.
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Published date: 1993
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Local EPrints ID: 462329
URI: http://eprints.soton.ac.uk/id/eprint/462329
PURE UUID: 33b4db05-b0b6-4f44-8c38-4cb46bc3826f
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Date deposited: 04 Jul 2022 19:05
Last modified: 04 Jul 2022 19:05
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Author:
Dileep Kattunkal Krishnan
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