Study of experimental method for ablation of insulator of SRM with high acceleration (II) Convergent tube experimental method

The key technique to the investigation of ablation characteristic of the insulators of solid rocket motor with high acceleration is to develop a method to produce high concentration particles stream. A convergent tube experimental method was developed based on the previous principle experiments. A convergent tube test facility was designed to demonstrate this method. Three-dimensional two-phase numerical simulations were carried to compare the particles distributions of this test facility and the solid rocket motor with high acceleration. Numerical results show that high concentration particles distribution in test facility is similar to that in the chamber of rocket motor with 40 g longitudinal and lateral accelerations. Ablation experiments of six kinds of insulator were carried in this convergent tube facility. The experimental results show that a cavity is formed on the surface of insulator due to the erosion of high concentration particles stream. This phenomenon indicates that erosion of particles has a strong influence on the insulator ablation. The location of cavity accords with the location of the highest concentration of particles of numerical results.