SEARCH · Engineering Papers
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Finite difference solution for compressible turbulent boundary layer equations of swept slab with leading edge blowing
Grove patterns on ablated surfaces of Teflon 8-foot high temperature structures tunnel
Preliminary lunar orbit attitude sequence for mission F
Pressure broadened line widths in electric field induced fundamental hydrogen spectral band, noting linear variation with density
Technology relevance to organizational structure, discussing planning models based on problem solving and performance
Specific heat of amorphous polymethyl methacrylate and polystyrene by pulse method below 4 K, comparing Debye and acoustic values
Finite difference method for solving equations for compressible turbulent boundary layers on swept infinite cylinders
Survey of group of industrial organizations to determine pertinent properties, policies, and practices related to Federal procurement
Hypersonic shock/density ratio effects in aerothermodynamic heating of space shuttle configuration
Water vapor condensation effects on methane-air combustion gases for aerodynamic test medium
Model cloudy atmosphere construction, reviewing computational techniques for radiative transfer analysis
Height variations of Venusian cloud tops at planet equatorial and polar regions
Laboratory analog simulation of absorption line spectra in cloudy planetary atmospheres, comparing with computational model based on plane parallel atmosphere
An investigation was conducted in the Langley 20-inch Mach 6 tunnel to define the aerodynamic heat transfer to the radioisotope fuel cask (heat source) of the SNAP-19/Pioneer power system. The shape of the SNAP-19/Pioneer heat source is that of a hexagonal prism with flat ends; the fineness ratio, based on maximum (edge to edge) diameter, is 1.61. Phase-change-paint heat-transfer data and schlieren photographs were obtained on four possible 1/2-scale entry configurations of the SNAP-19/Pioneer heat source. Tests were conducted over a wide range of attitudes and at nominal Reynolds numbers, based on the length of the unablated configuration, of 33,000; 84,000; and 2,200,000.
The absorption spectra of methane at low temperature with application to Jupiter atmospheric methane absorption is discussed. Experiments were made between 11,900 and 11950/cm. Attempts were made to observe single lines and determine the intensity of the spectra.
Since no methods are available for determining the magnitude of the errors incurred when the semiinfinite slab assumption is violated, a computer program was developed to calculate the heat-transfer coefficients to both sides of a finite, one-dimensional slab subject to the boundary conditions ascribed to the phase-change coating technique. The results have been correlated in the form of correction factors to the semiinfinite slab solutions in terms of parameters normally used with the technique.
The theory of the formation of spectral lines in a cloudy planetary atmosphere is studied in detail. It is shown that models based upon homogeneous, isotropically scattering atmospheres cannot be used to reproduce observed spectroscopic features of phase effect and the shape of spectral lines for weak and strong bands. The theory must, therefore, be developed using an inhomogeneous (gravitational) model of a planetary atmosphere, accurately incorporating all the physical processes of radiative transfer. Such a model of the lower Venus atmosphere, consistent with our present knowledge, is constructed. The results discussed in this article demonstrate the effects of the parameters that describe the atmospheric model on the spectroscopic features of spectral line profile and phase effect, at visible and near infrared wavelengths. This information enables us to develop a comprehensive theory of line formation in a Venus atmosphere.
We demonstrate in this article that there is spectroscopic evidence for the structure of the visible Venus cloud layers. From physically realistic models of the lower Venus atmosphere, we have shown that only observations of the phase variations of the CO2 bands in the Venus spectrum can provide the information for a unique identification of the structure of the cloud layers. It is proved that Venus cannot have a single dense cloud layer, but must have two scattering layers; a thin aerosol layer situated in the lower stratosphere, overlying a dense cloud deck. The aerosol plays an important role in the scattering of radiation, so that its identification provides an explanation of the reflecting layer-scattering model controversy for the interpretation of spectra formed in a cloudy planetary atmosphere.