抄録
In this study, the viscosity characteristics of bimodal Al/hydroxyl-terminated polybutadiene (Al/HTPB) suspensions were experimentally investigated to improve the propulsion performance and manufacturability of low-cost solid propellants with ease of application. Several Al particles with different mean volume diameters were used to prepare the bimodal Al. The Al/HTPB suspensions behaved like a continuum in solid propellant slurries. The reason is that Al particles were sufficiently small for ammonium perchlorate particles. The suspension viscosities were measured using a rotational viscometer at 1.92 s -1. The optimum coarse fraction of Al particles in the bimodal Al/HTPB suspensions was 0.75. The viscosity of bimodal Al/HTPB suspensions was suppressed with an increase in the diameter ratio. These results were attributed to the improvement of Al packing in the suspensions. The experimental results show that the viscosity reduction by applying bimodal Al particles was more effective when the minimum void fraction was reduced. Furthermore, the performance enhancement of solid propellants was confirmed by adding the bimodal Al/HTPB. The calculation results showed that the bimodal Al/HTPB enhanced the propulsion performance of the propellant without the viscosity variation to a higher side. Moreover, the suppression of viscosity of up to 23 % could be achieved using the bimodal Al/HTPB similar to the conventional composition of solid propellants. Therefore, replacing monomodal Al particles with bimodal ones in solid propellants effectively improved the performance of the propellants.
