Influence of nickel powders on burning behaviors of single-based propellant in variable-pressure and constant-pressure combustion conditions

Abstract

Single-based propellants containing 0.4 wt%, 0.8 wt% and 1.6 wt% nickel powders(NPs) were prepared and investigated in closed bomb tester and transparent combustion chamber, which can provide variable-pressure and constant-pressure conditions for propellant burning, respectively. In closed bomb tester, propellants burned to a pressure above 5–220 MPa. The results showed that burning rate of propellants was increased by 19.0 %, 12.5 % and 11.9 % in 5–8 MPa, 8–16 MPa and 20–200 MPa, when 1.6 wt% NPs used in propellant. Meanwhile, propellants burning in combustion chamber were with a constant pressure of 1.0 MPa, 1.5 MPa, 2.0 MPa, 3.0 MPa and 5.0 MPa. The burning rate of propellants can be increased by NPs in 1.0–5.0 MPa. While the catalytic efficiency(Z) had high dependence on NPs contents and burning pressure. At 5.0 MPa, 0.4 wt%, 0.8 wt% and 1.6 wt% of NPs enhanced burning rate of propellants by 42 %, 44 % and 68 % than that of original propellants. In pressure below 3.0 MPa, burning rate of propellants cannot be increased with 0.4 wt% and 0.8 wt% NPs, but that can be enhanced with 1.6 wt% NPs, suggested that higher NPs content and higher pressure were conducive to catalytic effect, which was significant with the pressure above 5 MPa. Furthermore, after NPs incorporating into propellant, the distance from flame zone to propellant burning surface was significantly reduced. And the potential catalytic mechanism was proposed.