Technology and Operations
This forum is for discussing technological & operational matters pertaining to U-boats.
RE: Top Speeds
Posted by:
joe brandt
()
Date: August 16, 2000 12:50AM
While body shape of a ship ,in this case a submarine is important the main reason a submarine is faster deep underwater than on the surface is due to higher pressure and less cavitation . Cavitation is the production and collapse of partial-vacuum cavities in the water,and it occurs when a force reduces pressure to below the vapor pressure of a liquid. So when a sub is moving on the surface its props are spinning and its blade tips cause high pressure areas to form behind and low pressure areas on the blade fronts that open up cavities that are filled with vapor. The more vapor formed the less water actualy being pushed by the prop,the high pressure areas equal higher drag. All this leads to inefficiancy and slower speeds, but with lots of wake ! But ! the the point at which cavitation occures is inversely proportional to pressure, so the deeper you go the more pessure exerted on the sub and props but less cavitation so more water coming into direct contact with the prop and higher efficiancy.The more water a prop can move the faster that boat will run.
Subject | Written By | Posted |
---|---|---|
Top Speeds | Carl Fischer | 08/14/2000 05:25PM |
RE: Top Speeds | Don Baker | 08/15/2000 12:20AM |
RE: Top Speeds | Carl Fischer | 08/15/2000 01:37PM |
RE: Top Speeds | joe brandt | 08/16/2000 12:50AM |
RE: Top Speeds | Carl Fischer | 08/16/2000 12:26PM |
RE: Top Speeds | joe brandt | 08/16/2000 07:25PM |