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We compare the peculiar velocity field within 65 $h^{-1}$ Mpc predicted from 2MASS photometry and public redshift data to three independent peculiar velocity surveys based on type Ia supernovae, surface brightness fluctuations in ellipticals, and Tully-Fisher distances to spirals. The three peculiar velocity samples are each in good agreement with the predicted velocities and produce consistent results for $\beta_{K}=\Omega\sbr{m}^{0.6}/b_{K}$. Taken together the best fit $\beta_{K} = 0.49 \pm 0.04$. We explore the effects of morphology on the determination of $\beta$ by splitting the 2MASS sample into E+S0 and S+Irr density fields and find both samples are equally good tracers of the underlying dark matter distribution, but that early-types are more clustered by a relative factor $b\sbr{E}/b\sbr{S} \sim 1.6$. The density fluctuations of 2MASS galaxies in $8 h^{-1}$ Mpc spheres in the local volume is found to be $\sigma\sbr{8,K} = 0.9$. From this result and our value of $\beta_{K}$, we find $\sigma_8 (\Omega\sbr{m}/0.3)^{0.6} = 0.91\pm0.12$. This is in excellent agreement with results from the IRAS redshift surveys, as well as other cosmological probes. Combining the 2MASS and IRAS peculiar velocity results yields $\sigma_8 (\Omega\sbr{m}^/0.3)^{0.6} = 0.85\pm0.05$., Comment: 11 pages, ApJ accepted

General analyses implemented in FORTRAN IV for studying the energy transfer in the combined decomposition/char zone of a charring ablator are described.

The decomposition of ablative composites is described along with the transport phenomena of pyrolysis gases which result from the decomposition of these plastics as they flow through the porous char of char-forming ablators. The pyrolysis products are those formed by the thermal degradation of nylon-phenolic resin and silicone elastomer composites. Emphasis is placed on the nature and extent of chemical reactions of the pyrolysis products and the char, along with the energy absorbed by the combined pyrolysis and char zone. Chemical reactions with thermodynamically consistent kinetic data are determined in order to develop a realistic analysis for predicting the thermal performance of ablative heat shields.

Analysis of reacting flow of pyrolysis products through char layer of low density, nylon phenolic resin, charring ablators and porous graphite

The results of a stagnation-line analysis of the radiative heating of a phenolic-nylon ablator are reported. The analysis includes flowfield coupling with the ablator surface, equilibrium chemistry, multicomponent or binary diffusion and a coupled line and continuum radiation calculations. Users manual and operating instructions for the computer programs listed in the report are included.

Nonequilibrium modeling of pyrolysis gas products flow through char layer of ablative heat shield

Thermodynamic properties in polynomial form for carbon, hydrogen, nitrogen, and oxygen systems form 300 to 15000 K

Charring ablative composites pyrolysis products composition determination, comparing chemical analysis techniques

Ablative heat shield char layer, examining reacting nonequilibrium pyrolysis gas flow

Equilibrium composition computed for reacting- gas-solid composite materials using material and energy constraints

Determining composition of pyrolysis products from degradation of ablative materials

Conservation equations for analysis of interaction of ablating protection systems and stagnation region heating

Energy transfer in pyrolysis product flow through char layer of nylon phenolic resin ablator

Charring ablator char zone nonequilibrium flow and chemical reaction kinetics as function of temperature, using thermal environment simulator

Energy transfer in reacting flow of pyrolysis products through char layer of nylon-phenolic resin charring ablator

Experimental simulation to establish accuracy of nonequilibrium flow model with system simulating charring during ablation

Differential equation of temperature profile in carbon zone of ablator simulated using digital- analog simulator language /MIMIC

Momentum equation solved for frozen flow in char zone of charring ablator

The Hertz-Knudsen analysis is shown to accurately predict the sublimation rate from a charring ablator. Porosity is shown to have a significant effect on the surface temperature. The predominant carbon species found in the vapor is C3, which agrees well with the results of previous investigations.

Coupled ablator shock layer solutions for the stagnation point are presented for typical hyperbolic entry atmospheric flight conditions. These solutions were obtained by numerically solving the stagnation line shock layer equations and quasi-steady ablator equations. These equations included ablation and radiation coupling within the viscous shock layer, line and continuum radiation for both air and phenolic-nylon ablation species and local thermodynamic equilibrium throughout. The results presented provide a sound basis for understanding many of the processes characteristic of hypersonic shock layer heating.