Content Detection for Continuous and Efficient Production of Solid Rocket Fuel by Peristaltic Mixer

In recent years, expectations for low-cost and high-frequency rocket launches for space exploration have increased. Solid fuel rockets are small, inexpensive, and easy to handle. However, in the production of solid fuel, the mixing process and the transportation process are separate batch processes, leading to an increase in maintenance costs and disposal costs. In addition, being a manual process, it is difficult to manufacture large amounts simultaneously in a safe method. The authors have developed a mixing and transportation device that simulates the movement of the intestinal tract by using an elastic duct and a low pneumatic drive. In addition, actual fuel production has been carried out in a mixing and transporting experiment using this device. The effectiveness of this device has been exhibited from the combustion test of the produced fuel. In this paper, we present a high-quality and efficient method of mixing and transporting solid propellant material. This is a mixing of solid and liquid achieved by peristaltic movement done in real-time by adjusting the mixing degree of the mixture inside the device. The degree of mixing is determined by the solid propellant's volume and viscosity change. Therefore, we first investigate whether the content volume can be detected when the rigid bodies with different volumes are inserted. Next, we focus on the change in the viscosity of the mixture that occurs during the mixing process. We also examine the viscosity of the contents when fluids having different viscosities are inserted.