Regression Rate Testing And Modifation Of HTPB/Parraffin-based Solid Fuels

Φ50mm hybrid motor test system and regression-rate measuring method were established in this paper. The basic composition of MA/HTPB/paraffin solid fuel was determined by consideration of performance, regression rate and density. To increase regression rate of solid fuels in hybrid motor, the action of combustion modifiers on the regression rates and performance of the solid fuels were investigated.The results showed that it is feasible to measure the regression rate of solid fuels by the Φ50mm hybrid tester when mox<25 g·s-1. The weight-loss method is an effective method to obtain regression rate. The regression-rate formula of a solid fuel can be obtained quickly and economically by the repeated-burn test method.When the content of HTPB is prefixed to 30wt%, the specific impulses of solid fuels increase greatly with the higher content of paraffin in MA/HTPB/paraffin fuels, but the density specific impulse and combustion temperature of solid fuels decrease. AP, AZT and TAGZT, Al could increase the specific impulse of solid fuels. The three modifiers except Al would decrease the combustion temperature of solid fuels. In fact, these modifiers have small influences on the specific impulses of solid fuels.When (?)ox<150 kg·m-2·s-1, AP/TBF could increase the regression rate and the exponent (n) of (?)ox greatly. The regression rate of the fuel is 0.319 mm·s-1 over that of the basic formula, which is up to 25.2% when (?)ox is 150 kg·m-2·s-1.When (?)ox<180kg·m-2·s-1, both AZT and TAGZT could increase the regression rate of solid fuels. The 10wt%TAGZT/MA/HTPB/paraffin solid fuel has the most significant increase in the experimental oxidizer mass flux rate range. The regression rate of the fuel is 0.484 mm·s-1 over that of basic formula, which is up to 38.3% when (?)ox is 150 kg·m-2·s-1. The n will increase with the higher content of AZT or TAGZT. TAGZT is a better modifier than AZT to increase the regression rate of solid fuels.When (?)ox< 180kg·m-2·s-1, The regression rate of solid fuel could be increased by super fine Al and nano-Al powder. The regression rate of the fuel with the nano-Al (average particle size:200nm) is the highest. When (?)ox=150 kg·m-2·s-1, the regression rate with 5wt% of nano-Al (200nm) is 0.188 mm-s"1 over to that of basic formula, which is up to 14.8%.When (?)ox is 150kg·m-2·s-1, the action of the modifier to increase the regression rate of solid fuels is:10wt%TAGZT>5wt%AP/TBF>5wt%AZT>5wt%200nmAl.