Experimental and Computational Analysis of the Interaction of Carbon and Silicon Ablation Products in Expanding Hypersonic Flows
Abstract
Thermal protection is required for vehicles entering planetary atmospheres to protect against the severe heating loads experienced. Modeling ablation and heating rates, particularly in the wake region, remains a significant challenge. To better understand this complex phenomenon, experiments were conducted at the X2 expansion tunnel at the University of Queensland. Preheated strips of C-C and SiC-coated C-C were mounted in a two-dimensional compression wedge and tested in Earth entry flow. Calibrated spectral measurements were obtained for surface temperatures from approximately 1900 K to 2700 K. Emissions for C-C and SiC appeared similar in the near-stagnation region, while emissions for SiC-coated C-C displayed a distinct rise downstream of the shock, which suggests a higher concentration of ablative species. There was generally good agreement for CN emissions, which were most dominant, while the agreement was not as good for the other radiative phenomena investigated. It is believed that the underprediction of the ablation rate of the equilibrium-char model is a key factor.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 30, 2018
- Accession Number
- AD1070521
Entities
People
- Brian E Donegan
Organizations
- Air Force Institute of Technology