Energy and Propulsion Optimization of Solid-Propellant Grain of a Hybrid Power DeviceSergey S. Bondarchuk, Iliya S. Bondarchuk, Boris V. Borisov and Alexandr S. ZhukovEPJ Web of Conferences, 110 (2016) 01010DOI: https://doi.org/10.1051/epjconf/201611001010