Accession Number : ADA307270

Title :   Analytical Study of Diffusion-Controlled Char Oxidation and Its Effect on Steady-State Ablation of Plastic Materials.

Descriptive Note : Technical rept.,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CEN TER

Personal Author(s) : Walberg, Gerald D.

PDF Url : ADA307270

Report Date : JUL 1966

Pagination or Media Count : 46

Abstract : An analysis of diffusion-controlled char oxidation has been carried out and differs from previous analyses in one important respect: previous investigators have assumed that only the carbon present in the char would react, but the present analysis has shown that the carbon present in both the char and the pyrolysis gases (i.e., all the carbon originally present in the virgin plastic) reacts and that the reaction rate is determined by the rate at which oxygen can be supplied by diffusion through the boundary layer plus pyrolysis of the plastic. Because of this fact, the char oxidation rate, the steady-state ablation rate, the boundary-layer composition at the char surface, and the heat released by chemical reactions were found to be dependent on the composition of the virgin plastic and the pyrolysis gases. p4

Descriptors :   *STEADY STATE, *ABLATION, *OXIDATION, *DIFFUSION, *PLASTICS, *CHARRING, REACTION TIME, BOUNDARY LAYER, CARBON, GASES, SURFACES, OXYGEN, CHEMICAL REACTIONS, HEAT, ANALYTICAL CHEMISTRY, PYROLYSIS.

Subject Categories : Plastics
      Physical Chemistry
      Polymer Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE