Fully transient conjugate analysis of silica-phenolic charing ablation coupled with interior ballistics

Alanyalıoğlu, Çetin Ozan
Özyörük, Yusuf
© 2019, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.Due to its excellent insulation capability, usage of silica-phenolic charring ablator as nozzle liner is a common practice in solid rocket motor industry. During the design of a solid rocket motor employing silica-phenolic as nozzle liner, it is desired to conduct an accurate analysis yielding in-depth thermal response and recession characteristics. As the interior ballistics and nozzle recession rate mutually interact, best practice is to perform a coupled solution to both. Commonly used one-dimensional analysis tools with empirical approaches for estimation of convective heat transfer rate and blowing effect generally lack sought accuracy, and do not model the transient shape-change phenomena, which affects the nozzle performance. This work provides governing equations for charring, including pyrolysis gas injection and surface energy balance for melting ablation, along with a boundary condition governed by interior ballistics, and implements all these numerically into the commercial CFD solver FLUENT. Also, results from a static firing test conducted with a small scale ballistic evaluation motor employing a silica-phenolic nozzle insert are provided. Results from both investigations are compared and discussed. It is demonstrated that the implementation captures all the relevant physical phenomena.
Citation Formats
Ç. O. Alanyalıoğlu and Y. Özyörük, “Fully transient conjugate analysis of silica-phenolic charing ablation coupled with interior ballistics,” 2019, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/69330.