Engineering topics
Publications and source records attributed to Bartlett, E. P..
A study was conducted to correlate Apollo ablation and thermal response flight data using advanced state-of-the-art analytical procedures. The agreement between flight data and predictions is consistently excellent for in-depth temperature distributions, char density profiles, and surface ablation, thus validating the analytical procedures.
Procedures and methods for predicting aerothermodynamic heating to delta orbiter shuttle vehicles were reviewed. A number of approximate methods were found to be adequate for large scale parameter studies, but are considered inadequate for final design calculations. It is recommended that final design calculations be based on a computer code which accounts for nonequilibrium chemistry, streamline spreading, entropy swallowing, and turbulence. It is further recommended that this code be developed with the intent that it can be directly coupled with an exact inviscid flow field calculation when the latter becomes available. A nonsimilar, equilibrium chemistry computer code (BLIMP) was used to evaluate the effects of entropy swallowing, turbulence, and various three dimensional approximations. These solutions were compared with available wind tunnel data. It was found study that, for wind tunnel conditions, the effect of entropy swallowing and three dimensionality are small for laminar boundary layers but entropy swallowing causes a significant increase in turbulent heat transfer. However, it is noted that even small effects (say, 10-20%) may be important for the shuttle reusability concept.
Ablation of heat shielding materials subjected to superorbital reentry conditions, noting dependence on heating rate to surface
Thermochemical and mechanical ablation mechanisms for Apollo heat shield material, comparing surface thermochemistry computer program and arc plasma tunnel data
Computer program development for charring ablative materials, chemically reacting laminar boundary layers, and turbulent boundary layer initiation
Analyses and finite difference procedure for predicting transient in-depth response of charring ablation materials
Laminar boundary layer problems solved by integral matrix methods
Bifurcation approximation for binary and thermal diffusion coefficients, mixture viscosity, and thermal conductivity of laminar boundary layer
Nonsimilar solution to complex laminar boundary layer problems, applying matrix concept to integral relations via Taylor series expansion of parameters
Incident of severe low level turbulence in clear air
Nonsimilar solution to complex boundary layer problems, using matrix concept to integral relations via Taylor series expansion of parameters
Thermochemical interaction between ablation material and environment during manned reentry, using mainly graphite and composite materials