Thermal insulation choice for solid rockets: a study on liner material properties and design impact

The materials used in the construction of solid rockets are critical to their overall and final performance. Among the most important components is the liner of the casing, which shields the casing from the heat generated during the solid propellant combustion. Various types of liners are available, and selecting one with high thermal performance is essential to optimizing the design and flight performance of the rocket. In this study, the effect of different liners with different materials on the overall weight and the final design of the rocket, which are key factors in its flight capabilities, is numerically investigated. Using OpenRocket, a preliminary rocket design is first performed by selecting a solid motor and constructing the remaining components. Next, thermal simulations are conducted in ANSYS Steady-State Thermal to evaluate three liner options with low, medium, and high thermophysical properties. The results show that each liner requires a specific thickness to keep the casing within safe temperature limits. Finally, these thicknesses are re-evaluated in OpenRocket to assess their impact on rocket flight performance. These findings demonstrate that the liner selection has significant effects on key flight parameters such as apogee, maximum velocity, and time to apogee. Furthermore, a poor liner choice could risk the entire success of the flight mission.