Numerical analysis on flow property of gel propellants in tapered round pipes

The flow process of gel propellants in tapered round pipes was numerically simulated. The effect of the tapered round pipe convergence angle on the axis velocity, mean apparent viscosity and pressure drop was studied. The axis velocity and mean apparent viscosity fields of gel propellants in tapered round pipes were obtained. The results show that the decrement of the mean apparent viscosity in the outlet and the inlet increases with the increasing of convergence angle. The mean apparent viscosity of the outlet decreases significantly and its value is limited by the Newtonian viscosity η∞. On the other hand, the decreasing of viscosity results in an increase of the pressure drop. In addition, the viscosity no longer decreases significantly due to the convergence angle change when it reaches a limitation. Therefore, the pipe convergence angle is an important parameter that affects the viscosity, there exist an optimum matching point between the viscosity change and the pressure drop.