Burning behaviour of aluminium and its hydride in an ADN/GAP-matrix

A promising candidate for the substitution of the polluting AP/HTPB/Al propellant is an innovative ADN/GAP-based formulation. Besides its “environmentally friendly” nature, it is presumed to overcome the intrinsic limitations of the commercial solutions. ADN/GAP-based propellants have the potential to increase the specific impulse by 27 s if aluminium hydride is considered, and by 11 s in the case of aluminium. This can be reflected in a drastic increase of payload when these new formulations turn out to be attractive also in launcher applications. Therefore, the investigation of the burning behaviour of Al and AlH3 is of highest interest to understand whether these formulations fully express their energetic nature, satisfying the expectations. Particular attention must be paid to the agglomeration phenomena and dimensions, which are blamed to be the driving factor for the biggest losses in a rocket motor, the 2-phase flow loss. In this work, four aluminised formulations and two formulations containing AlH3 will be analysed and compared to understand, which the significant parameters are that influence the burning behaviour of aluminium during propellant combustion