3D打印骨架增强石蜡燃料燃烧机理实验研究

Aiming at the issues of poor mechanical properties of paraffin-based fuel grains in hybrid rocket motors, the method of embedding 3D printing polymer skeleton into paraffin-wax was used to enhance the structural strength of paraffin-based fuel grains. The influence mechanism of direct flow/swirl injection on the combustion performance of 3D printing skeleton enhanced paraffin fuel was investigated. First, through SEM, mechanical performance test, thermodynamic analysis and combustion test under pure oxygen conditions of seven types of skeleton materials, their microscopic surface structure, mechanical properties, thermal decomposition performance and combustion performance are obtained. Then, using the direct flow and swirling solid-gaseous hybrid combustor system, combustion experiments of the helical and hexagonal skeleton enhanced paraffin fuel grain were carried out and compared with the ABS grain. The results show that among a variety of skeleton materials, ABS material has good processing properties, mechanical properties and thermal decomposition properties. During the combustion process, skeleton enhanced paraffin fuel grain has good structural stability, and the paraffin droplets mainly appeared at the paraffin-skeleton junction. Swirl injection and spiral skeleton promote the phenomenon of paraffin droplet entrainment. In direct flow condition, the groove structure of skeleton increases the contact area between the fuel and the oxidizer, and the tail skeleton has a flame stabilizing effect, which can promote the combustion in the post combustion chamber. The regression rate of paraffin fuel and skeleton is quite different, and the internal ballistic performance of the motor may be affected by this.