Accession Number : ADA622133


Title :   A Nonequilibrium Finite-Rate Carbon Ablation Model for Radiating Earth Re-entry Flows


Descriptive Note : Doctoral thesis


Corporate Author : AIR FORCE INSTITUTE OF TECHNOLOGY WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT


Personal Author(s) : Alba, Christopher R


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a622133.pdf


Report Date : 17 Sep 2015


Pagination or Media Count : 204


Abstract : Vehicles entering planetary atmospheres at high speed require an ablative heat shield in order to withstand the high thermal energy flux to the body. Numerical simulations were conducted to investigate the influence of carbon ablation on shock layer radiation. Data collected from experiments performed in the X-2 expansion tunnel at the University of Queensland was used to compare to the simulations. The model was made of isomolded graphite and was tested in 8.5 km/s Earth entry flow. The model surface was heated within a temperature range of 1770-3280 K. The radiation emitted from the CN violet bands was measured by ultraviolet spectrometry in a spectral range from 353-391 nm. This research develops a novel finite-rate surface kinetic model for determining the chemical state of an ablating boundary layer. The ablative gas species predicted by this new model improves agreement with experimental measurements than predictions provided by legacy ablation models, and represents a significant improvement in current modeling capabilities for hypersonic nonequilibrium ablating re-entry flows.


Descriptors :   *ABLATION , *HYPERSONIC CHARACTERISTICS , *RADIATION , AGREEMENTS , BOUNDARY LAYER , CARBON , CHEMICALS , EARTH(PLANET) , EXPERIMENTAL DATA , FLOW , GASES , GRAPHITE , HEAT , HEAT SHIELDS , LAYERS , MEASUREMENT , MODELS , NONEQUILIBRIUM FLOW , NUMERICAL ANALYSIS , PLANETARY ATMOSPHERES , PREDICTIONS , RANGE(EXTREMES) , SIMULATION , SPECTRA , SURFACES , TEMPERATURE , THESES , ULTRAVIOLET SPECTROMETERS , VEHICLES , VELOCITY


Subject Categories : Research and Experimental Aircraft


Distribution Statement : APPROVED FOR PUBLIC RELEASE