Views: 35 Author: Site Editor Publish Time: 2018-12-29 Origin: Site
The difference between marine propeller and submarine propeller
1. Accurately speaking, the propeller itself has the so-called open water efficiency, which is an efficiency curve determined by the speed and geometry of the propeller itself. Please Baidu for details. In addition, there are so-called hull efficiency and relative rotation efficiency, etc. The product of these series of efficiencies constitutes the total propulsion efficiency. The theme of "Hood 0.5" I guess it's the value of the oar itself. Now it's okay. It was really a good time.
2. Propeller noise.
3. These two concepts are not the opposite, but the original intention of the design is different. Simply put, the emphasis of high-speed propeller is to "exert great efforts", while that of low-noise propeller is to "exert even forces". Therefore, the high-speed propeller will increase the pitch as much as possible, increase the rotational speed, uneven output, low efficiency of the propeller, as long as it can still output under the condition of high flow speed, it will achieve the goal. The low noise propeller will reduce the speed, pitch, blade number and disk ratio on the premise of meeting the target. The actual operation process is much more complex. After all, the design is a process of continuous selection, there is no absolute saying.
4. Flying shears and bulbous nose, why not use other, because other bows are not suitable for a variety of reasons. Of course, if a ship's front deck is not afraid of surfing, it does not need to use flying shears or slanting heads; if the resistance factor of a ship is not the main factor, it does not need to have a bulbous nose. There are three main types of cargo ships, bulk liquid cargo containers. Ro-ro ship is also a cargo ship, less than the three major types of ships, as the name implies, loading.
Better yet, at least in those days there was no welding. But the hull is not necessarily stronger, after all, in this era of missile attack, it is not meaningful to make so many armored steel plates.