Application of thermal-solid interface CFD on thermal protection study for rocket warhead

摘要

When an artillery rocket travels at high supersonic speed, aerodynamic heating becomes a critical issue especially at the nose cone where the warhead is normally located. If it is a TNT warhead, the TNT could be melting since its melting point is only at 80 °C and it could cause undesirable effects to the rocket. So an accurate method to predict skin temperature and temperature distribution inside TNT was needed to help the warhead designers select the proper insulation. This paper presents an application of 2D axisymmetric transient viscous CFD and its fluid-solid interface capability to estimate temperature distribution in the warhead. In the case study, the selected rocket was a 122 mm unguided rocket whose maximum speed is Mach 3.5. Trajectory data were generated using six-degree-of-freedom (6DOF) code. The free stream Mach number, ambient temperature, and ambient pressure that changed with flight time were utilized in CFD simulation. Four simulation cases were performed for the rocket with 2 mm insulation and without insulation at firing angle 10° and 45°. The results suggested that aerodynamic heating was more critical in the 10° trajectory cases and the selected insulation thickness was insufficient to prevent TNT from melting.