Grain, solid propellant

A solid propellant is a mechanical (heterogeneous) or a chemical (homogeneous, or colloidal) mixture of solid-state fuel and oxidizer-rich chemicals. Specially-formed charges of solid propellant (grains) arc placed in the combustion chamber of the solid rocket motor (SRM) at a production facility. Once assembled, the engine does not require additional maintenance, making it simple, reliable and easy to use. 

Penta-erythritol Diacetate Dipropionate", ERDE 11/M/58 (Oct 1958), AD 206266 (DDCSTI users only) 6) V. Pasquale, Feasibility Study on Using Low Acetyl Cellulose Acetate Inhibitor for Production Cast Grains , NOSIH TR 317 (10 July 1970), AD 510578 (Conf) 7) CPIA Solid Propellant Manual , CPIA/M2 (28 Jan 1974), unit 1069 (Conf)... 

Specifications. For mil use, specs have been published for Ammonium Perchlorate (MIL-A-23442A, 8 Sept 1966) Ammonium Perchlorate, Technical (MIL-A-192B, 2 Sept 1965) Ammonium Perchlorate for Solid Propellant Grains Mark 75 Mark 76 (MIL-A-23946, 19 Aug 1964) and Ammonium Perchlorate, Special, Coarse for Solid Propellant Grains Mark 75 Mark 76 (MIL-A-23948,19 Aug 1964). The requirements of the First two specs are ... 

At the same time binders were introduced which gave mechanical integrety to the grains as well as acting as fuels. The list of fuel/binders used in solid propellant rockets is extensive and has ranged from as-phalt/oil mixtures to polybutadiene rubbers. 

Thermal variations. A solid propellant grain may be exposed to temperature extremes ranging from conditions of low temperature in the upper atmosphere, to tropical heat. The grain must not be too brittle at low temperature nor too soft at high temperature. The problem can be aggravated by case-bonding since different coefficients of expansion of the metal-case and the propellant can produce a very harmful effect. 

C.A.Thomas, USP 2742672 (1956) CA 50, 11018-20 (1956) (Comp proplnt prepd by coating each grain of finely divided Amm picrate-Na nitrate with liq thermosetting resin, pressure molding curing) 5)G.S.Sutherland "The Mechanism of Combustion of an Ammonium Perchlorate Polyester Resin Composite Propellant , Princeton Univ, New Jersey (1956), 233 6)A.J.Zaehringer, "Solid Propellant... 

The hybrids consist of solid and liquid substances in the same system. The most widely used hybrid concept has a hollow solid fuel grain, much like a solid propellant grain, but with no solid oxidizer present. The fuel grain may contain other. energetic solid substances. The oxidizer is generally a storable liquid propellant such as nitrogen tetroxide or chlorine trifluoride. 

Single and Double-Base Propellants. Early solid rocket propellants were based on processing methods similar to that used in the mbber industry, with propellants extmded into the desired grain configuration. Propellants... 

Monolithic charge of solid propellant of any geometry term usually applied to a formed propellant prior to final shaping (-> Grain). 

In a solid propellant grain, the minimum distance which can burn through as measured perpendicular to the burning surface (-< Burning Rate). 

---