Rheological behavior of nitromethane gelled with nanoparticles

Gel propellants provide rocket propulsion systems of high specific impulse, low sensitivity, and low vulnerability in combination with the capability to control the thrust, that is, variation of thrust and thrust cutoff. The rheological characterization is essential for the development of adequate gel propellant formulations and, thus, for the design of an applicable propulsion system. The rheological behavior of a gel propellant consisting of nitromethane as fuel and nanoparticles of silicon dioxide as gelling agent was examined. The experiments were conducted under steady-state shear flow and oscillatory shear. The nitromethane/silicon dioxide gels exhibit non-Newtonian flow behavior over the whole concentration range examined. Additionally, a yield stress is determined for all of the gels. The viscoelastic properties are typically gellike in that the storage and the loss moduli are both independent of frequency.