Propulsion, underwater

Combustion of aluminum particle as fuel, and oxygen, air, or steam as oxidant provides an attractive propulsion strategy. In addition to hydrocarbon fuel combustion, research is focussed on determining the particle size and distribution and other relevant parameters for effectively combusting aluminum/oxygen and aluminum/steam in a laboratory-scale atmospheric dump combustor by John Foote at Engineering Research and Consulting, Inc. (Chapter 8). A Monte-Carlo numerical scheme was utilized to estimate the radiant heat loss rates from the combustion products, based on the measured radiation intensities and combustion temperatures. These results provide some of the basic information needed for realistic aluminum combustor development for underwater propulsion. 

COMBUSTION OF ALUMINUM WITH STEAM FOR UNDERWATER PROPULSION... 

The goal of the present study is to provide the information needed for design of a practical underwater propulsion system utilizing powdered aluminum burned with steam. Experiments are being conducted in atmospheric pressure dump combustors using argon/oxygen mixtures and steam as oxidizers. Spectrometer measurements have been made to estimate combustion temperatures and radiant heat transfer rates, and samples of combustion products have been collected to determine the composition and particle size distribution of the products. 

CA 60, 9044(1964) (Exothermic reaction mixtures for underwater propulsion and ignition devices contg alkali metal perchlorates and powdered Al, Be or Mg are improved in regard to their burning rates and pressure stability by incorporating ca, 1% of finely divided Fe) Ad 119) Dy-namit-Nobel AG, BelgP 627561(1963) ... 

Exothermic reaction mixtures for underwater propulsion and ignition devices 6 E349... 

More recently, aluminium-air systems have been developed for reserve power units, underwater propulsion and electric vehicles. 

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]. 

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