High Progressive Combustion And High-density Propellants

In the interest of seeking the essential principle and technique about how to enhancethe muzzle velocity of projectile, preparation technics and fundamental characterstics ofprogrammed splitting stick (PSS) propellants and polyether polyurethane close-grainedpropellants, this two kinds of high progressivity burning and high charging densitypropellants, were researched in this paper.By designing the mould to change the propellants model frame, selecting differentmaterials as propellant seal layer agents, studying the preparation technics, we havepreferably solved the PSS seal layer pressurize and combustion disciplinarian problem, andobtained the remarkable increasing burning surface effect.The practical increment ofΓvalue reachs 3.2 upwards conducting closed bomb firings, comparing with 19 holepropellants—the best progressivity burning in the present, whose practical increment ofΓvalue is 1.2, the PSS amplitude ofΓvalue exceeds 2.5 times. Using shape function andclassical interior ballistics theory, the influence relation of the PSS model parameter affectto splitting opportunity, increasing burning surface and interior ballistics characteristicswas researched.The splitting opportunity of PSS appears ahead the academic intending, thereason is that the thickness of outside burning layer is asymmetry, the thinner area splitsearlier, and the thicker area splits later, consequently, the PSS put up progressivity burningeffect. From the practical look, the burning progressivity effect is more profitable than thatincreasing burning surface suddenly. The results of interior ballistic theoretical simulationindicates that the single PSS charge application need propellants be provided with upperburning rate, adopting PSS and traditional model frame propellants commix charge is apractical applied technique approach.. By optimizing the PSS model frame parameter, wecan obtain "flat roof" domino offect with better even peak value "double peak" p-tcurve. Comparing with current 19 hole propellants charge with the best increasing burningsurface characteristic, the muzzle velocity of projectile can be enhanced about 55m/s, andthe instruct pressure efficiency can be enhanced about 5.7％.P(E/T) as the bond of the closed-grained propellants solidifys molding withTDI-curing agent's, taking on favorable technics and crafts adaptability. In order to enuresolidifying chemical reaction going along completely, one side, the water content of the rawmaterial should be decreased as little as possible during the preparation, on the other hand,the mass mix-ratio of curing agent's and pre-polymer needs, properly increase, adopting 1.1as R value is more reasonable. Adopting TPB as catalyzer of solidifying chemical reaction,it can distinctly quicken reactive rate. It is relatively reasonable for controling reactivetemperature at 50℃. Vacuumized and deposited one day at normal temperature before hightemperature solidifying chemical reaction, which is propitious to remove air bubble frompropellant columniation. Mechanical properties and combusition characteristics were affected evidently by the solid grain configuration and its character. Mechanical propertiesof the material system could be improved by adopting RDX and proper granularpropellants granularity rank-match. It is favorable to obtain progressivity burning effect byaffiliating increasing burning surface propellant grains. Affiliating fast burning componentthese burning rate regulator in the bond system can quicken burning rate of propellants andimprove burning progressivity.