Applications underwater propulsion

These batteries may also be designed to be activated with seawater. They have been used for sonobuoys, other marine applications (lifejacket lights, etc.), and underwater propulsion. Activation can occur upon immersion into seawater or require the forced flow of seawater through the system. Many of these seawater batteries use a magnesium aUoy anode with a metal salt cathode, as shown in Table 16.1. 

Magnesium seawater-activated batteries, using dissolved oxygen in the seawater as the cathode reactant, also have been developed for application in buoys, communications, and underwater propulsion. These batteries, as well as the use of other metals as anodes for water-activated batteries, are covered in Chaps. 16 and 38. 

The combustion of metals in water is of practical importance in underwater propulsion [1, 2], hydrogen gas generation [3, 4] underwater explosives with increased shock and bubble energy [5, 6]. The influence of Al/O stoichiometric ratio on both shock and bubble energy of an explosive is shown in Figure 14.1 taken from Ref. [6] and other applications [7]. 

Similar to the application discussed above, the production of heat can be used in a more complex design to generate mechanical energy in the so-called stored chemical energy propulsion systems (SCEPS). SCEPS are typically used for underwater propulsion of torpedoes (see Eigure 14.4b) and use the reaction between molten hthium and any gaseous fluorine compound (see Eigure 14.4a) such as SF [18] or fluorocarbons such as Freon [19]. 

Propellers are the predominant propulsive devices driving ships, although water jets are now used in some high-speed ships. An experimental installation in a small ship of a magnetohydrodynamic propulsor has been tested, but it achieved rather low propulsive efficiency. Fish-like propulsion also has been examined for possible application to ships and underwater vehicles. 

KNO)9>0, anhyd Ammoxalate 6.9 and Ammbichrornate 5- parts with 0.7pChina clay added as a compn proposed for propulsion of the reciprocal energetic "William James motor, and with 2.5p China clay added as a compn proposed for driving a rotary blower motor Z) encet Chemical Co, Kansas City, Missouri reports "Ammonium Nitrate Explosives for Underwater Applications , Jan 18,... 

Zinc, aluminum, or magnesium alloys are being used in reserve batteries using air as the cathode. With aluminum or magnesium, these batteries may be activated with saline electrolytes, and in some underwater application they may use oxygen dissolved in the seawater. Reserve or mechanically rechargeable air batteries, for higher-power applications such as for standby power or electric-vehicle propulsion, use zinc or aluminum alloys with alkaline electrolytes (also see Chapter 38). 

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