Solid propellant systems

Allen et al, Evaluation of Solid Propellants and Solid-Propellant Systems for Space Applications , BMI-1863-SR (NAS-8-16831, Battelle Memorial Inst, Columbus (1963) 125) A. 

The best projected solid propellants approach the performance of current operable storable liquid systems. Current solids have a performance somewhat lower than that of the storable liquids, but density and other advantages give them a unique position in the power plant field. Reliability, readiness, ease of handling, weight savings, etc., are the basic merits of the solid propellant systems that led to the phenomenal rise in their usage. These facts emphasize that which was stated earlier, specific impulse cannot be the sole basis for comparison of various systems. 

D.P. Laverty, Carbides For Solid Propellant Nozzle Systems , Rept No AFRPL-TR-68-164, Contract F04611-67-C-0094, TRW Equipt Labs, Cleveland (1968) 25) M.L. Williams, The... 

In a solid-propellant rocket motor, the propellant is contained within the wall of the combustion chamber, as shown in Fig. 1. This contrasts with liquid systems, where both the fuel and oxidizing components are stored in tanks external to the combustion chamber and are pumped or pressure-fed to the combustor. In hybrid systems, one component, usually the fuel, is contained in the combustion chamber, while the other component is fed to the chamber from a separate storage tank, as in liquid systems. The solid-propellant motor also has an ignition system located at one end to initiate operation of the rocket. The supersonic nozzle affects the conversion of... 

Nitric oxide has a very low ionization potential and could ionize at flame temperatures. For a normal composite solid propellant containing C—H—O—N—Cl—Al, many more products would have to be considered. In fact if one lists all the possible number of products for this system, the solution to the problem becomes more difficult, requiring the use of advanced computers and codes for exact results. However, knowledge of thermodynamic equilibrium constants and kinetics allows one to eliminate many possible product species. Although the computer codes listed in Appendix I essentially make it unnecessary to eliminate any product species, the following discussion gives one the opportunity to estimate which products can be important without running any computer code. 

Ballistika Stvol nykh System i Porokhovykh Raket (Interior Ballistics of Gun Barrel Systems and of Solid Propellant Rockets), Oboronghiz, Moskva (1962). Abbreviated translation by Dr V. Nekrassoff for the US Navy, p 22 (under Bernoulli)... 

Gadolin, A.W. (1828-1892). A Russian bal-listician who, in collaboration with N.V. Mayevskii, proposed using propellant in hexagonal form with one or 7 perforations Refs 1) M.E. Serebryakoff, "Interior Ballistics of Gun Barrel Systems and of Solid Propellant Rockets", Russian Book published by Oboronghiz in 1962. Abbr translation by Dr V. Nekrassoff available in PicArsn Library 2) A.G. Gorsc, "Powders and Explosives", Mashinostroyeniye, Moscow (1972), p 9(in Russian)... 

Ref M.E. Serebriakov, "Vnutrenniayia Bal-listika Stvol nykh Si stem i Porokhovykh Raket (Interior Ballistic of Gun Barrel Systems and Solid Propellant Rockets", Oborongiz. Moskva (1962), pp 15, 19 Sc 23—5. Abbreviated Engl translation by Dr V. A. Nekrassoff, formerly of Aberdeen Proving Ground, Maryland... 

The several solid propellant manufacturing systems have been reviewed along with two systems that have not reached routine production. A comparative system of establishing the processability of new propellants has been suggested along with the instrumental analysis plan. The requirements of the product systems from a mechanical properties standpoint are mentioned in terms of the environment, and special steps to insure minimum variation between batches are described to illustrate the stringent tolerances that are met. 

Some of the unusual properties of a solid propellant results from its basic composition. The two general categories of double-base and composite rubber binder propellants have many subcategories, but no exhaustive compilation will be attempted here. Most modem propellants consist of a deformable binder phase and a crystalline salt filler, such as ammonium perchlorate and usually a powdered metallic fuel such as aluminum. Table I gives some typical compositions for both composite rubber-based and composite double-base systems. 

Such techniques have been tried with solid propellants, but reproducible results depend on attaining complete binder-filler release and adequately measuring the binder sol fraction. Preliminary swelling studies to determine a solvent system and conditions which do not degrade the propellant are required. Common extraction techniques are used to determine the sol fraction. This determination is then applied as a correction when computing crosslink density. The force-deformation relationship for swollen rubbers is... 

A prediction of useful life for solid propellant rockets is quite important, from the standpoint of operational readiness and economic considerations. The premature removal and replacement of deployed systems, based on inaccurate storage life estimates, can be costly. A specific missile system and propellant combination could become obsolete while long term storage data are being compiled. Accelerated aging tests are normally used to give qualitative indications of storability, but the deficiencies of these tests are obvious and are discussed later. 

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