To investigate the impacts of tornado wind field on ship stability
the characteristics of wind loads on the ship and ship capsizing law are analyzed. A tornado wind field model is constructed on cylindrical coordinates
the flow field of the tornado is supposed as steady and the tornado funnel as axisymmetric in its shape. The air pressure drop from the tornado periphery to its center is assumed to be mainly balanced by the centrifugal force derived from tangential velocity of tornado. Taking simplified Eastern Star ship model as an example
the minimum overturning moment of the suffering ship is evaluated
and the tornado's aerodynamic impact on ship capsizing is analyzed considering the vessel sailing directions and different radial positions of the field where the vessel is located. According to the results
when sailing direction is perpendicular to the radial direction of the tornado
the ship capsizes as the pressure difference between both ship sides gets greater than its minimum overturning moment; when sailing along the radial direction
mainly due to dynamic impacts of high-speed incoming wind
the ship capsizes in the tangential direction of the tornado; when the ship sails in any direction
whether the ship capsizes depends on the ship's radial distance from the tornado center
the tangential wind speed of the tornado and the ship velocity. This results may provide a reference for ship design and tornado-warning research.
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references
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