Content area
Full Text
Flexural-Gravity Waves Generated by a Submarine Moving Near the Ice-Water Interface Can Allow Vessels to Surface More Safely
The use of submarines in polar regions may require them to surface from under solid ice, but there are significant disadvantages to current surfacing methods.
At present, submarines surface from under the ice by extracting water from ballasting tanks, creating positive buoyancy force. This produces static loading of the ice cover from below and allows the submarine to break through.
However, this method causes inevitable damage to the cabin, upper deck, stern rudders and external hull. Additionally, destruction of the ice cover through static loading can result in losing stability - i.e., overturning the submarine.
It should be noted that a modern submarine can only surface from under ice cover less than two meters thick, and it takes tens of minutes to surface this way, which is inadmissible in case of emergency. One should also bear in mind that more than 60 percent of the Arctic ice sheet is thicker than three meters.
In order to find alternatives to static loading, the Russian Academy of Sciences has been conducting theoretical and experimental investigations to research a method of surfacing that would excite flexural-gravity waves of a certain amplitude in the ice and cause partial or complete destruction of the ice cover. To do this, the submarine moves under the ice at a certain velocity and at a safe submergence depth, which generates flexural-gravity waves in the water-ice cover system. The waves' intensity can crack or completely break the ice cover, allowing the submarine to surface through the weakened or broken ice.
Theoretical Investigations
Nonstationary motion of a thin, almost axisymmetric body in an ideal, infinitely deep liquid under an elastic plate was considered to theoretically represent the amplitude of the ice cover deflection with a submarine moving under it.
The problem of free-surface liquid flowing around an axisymmetric body was solved by mathematically considering the flow due to a point source of strength and a point sink of strength in...