SEARCH · Search NASA

Results for “total”

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.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6

All sources NASA NTRS DOE OSTI

NASA NTRS1974

Effect of wall to total temperature ratio variation on heat transfer to the leeside of a space shuttle configuration at M equals 10.3

An experimental study has been conducted of the influence of wall to total temperature ratio on the heat transfer to the leeside of a 040A space shuttle configuration. The heat transfer tests were made at a Mach number of 10 and a Reynolds number of one million per foot for angles of attack from 0 deg to 30 deg. Range of wall to total temperature ratio was from 0.16 to 0.43. Where the heat transfer was relatively high and the laminar boundary layer attached, the local heat transfer decreased by about 20 percent as the wall to total temperature ratio was increased from the minimum to the maximum test value. On regions of separated flow and vortex reattachment, very low heating rates were measured at some conditions and indicate significant changes are occurring in the leeside flow field. No single trend of heat transfer variation with wall to total temperature ratio could be observed.

Dunavant, J. C.↗

NASA NTRS1977

Variational energy principle for compressible, baroclinic flow. 1: First and second variations of total kinetic action

The case of a cold gas in the absence of external force fields is considered. Since the only energy involved is kinetic energy, the total kinetic action (i.e., the space-time integral of the kinetic energy density) should serve as the total free-energy functional in this case, and as such should be a local minimum for all possible fluctuations about stable flow. This conjecture is tested by calculating explicit, manifestly covariant expressions for the first and second variations of the total kinetic action in the context of Lagrangian kinematics. The general question of the correlation between physical stability and the convexity of any action integral that can be interpreted as the total free-energy functional of the flow is discussed and illustrated for the cases of rectillinear and rotating shearing flows.

Schmid, L. A.↗

NASA NTRS1977

Periodic variations of total ozone and of its vertical distribution

The phase and amplitude of the annual, semiannual, and quasi-biennial oscillations to total ozone data for the Northern Hemisphere in the period 1957-1972 and for Northern Hemisphere ozonesonde data for variable periods from 1962-1974 have been plotted as functions of latitude, longitude, and altitude. The largest annual wave amplitude in total ozone occurs over eastern Siberia. In total ozone, the region of maximum quasi-biennial oscillation (QBO) coincides with that of the annual wave. The major feature of the QBO in the vertical distribution is the maximum amplitude in the arctic just above the tropopause. As for the semiannual wave, the maximum in total ozone lies in the arctic, displaced slightly to the Siberian side. In the vertical, its maximum amplitude is near 18 km. The phase appears to progress poleward, with maxima at high latitudes occurring in March-April.

Wilcox, R. W.↗

NASA NTRS1983

Strainrange partitioning: A total strain range version

Procedures are presented for expressing the Strainrange Partitioning (SRP) method for creep fatigue life prediction in terms of total strain range. Inelastic and elastic strain-range - life relations are summed to give total strain-range - life relations. The life components due to inelastic strains are dealt with using conventional SRP procedures while the life components due to elastic strains are expressed as families of time-dependent terms for each type of SRP cycle. Cyclic constitutive material behavior plays an important role in establishing the elastic strain-range - life relations as well as the partitioning of the inelastic strains. To apply the approach, however, it is not necessary to have to determine the magnitude of the inelastic strain range. The total strain SRP approach is evaluated and verified using two nickel base superalloys, AF2-1DA and Rene 95. Excellent agreement is demonstrated between observed and predicted cyclic lifetimes with 70 to 80 percent of the predicted lives falling within factors of two of the observed lives. The total strain-range SRP approach should be of considerable practical value to designers who are faced with creep-fatigue problems for which the inelastic strains cannot be calculated with sufficient accuracy to make reliable life predictions by the conventional inelastic strain range SRP approach.

Halford, G. R.↗

NASA NTRS1982

Active-region evolution and solar rotation variations in solar UV irradiance, total solar irradiance, and soft X rays

Variations in the total solar irradiance, solar UV spectral irradiance, and solar soft X-ray emission caused by active region evolution and solar rotation are analyzed by using concurrent measurements from the NIMBUS 7 and GOES satellites. The observations are interpreted by using simple empirical models that relate ground-based observations of the size and location of sunspots and plages to the full-disk temporal variations. It is found that the major dips in the photospheric total solar irradiance S, which are evident in both satellite measurements and model predictions, are usually not accompanied by outstanding enhancements in the chromospheric and upper photospheric UV spectral irradiance or coronal X rays. The main cause of this difference between the variability of S and of the UV flux is that the total chromospheric plage enhancements are not outstanding at those times when the total sunspot are outstanding. X rays are even more variable because of a much wider CMD sensitivity.

Donnelly, R. F.↗

NASA NTRS1983

Strainrange partitioning - A total strain range version

Procedures are presented for expressing the Strainrange Partitioning (SRP) method for creep fatigue life prediction in terms of total strain range. Inelastic and elastic strain-range - life relations are summed to give total strain-range - life relations. The life components due to inelastic strains are dealt with using conventional SRP procedures while the life components due to elastic strains are expressed as families of time-dependent terms for each type of SRP cycle. Cyclic constitutive material behavior plays an important role in establishing the elastic strain-range life relations as well as the partitioning of the inelastic strains. To apply the approach, however, it is not necessary to have to determine the magnitude of the inelastic strain range. The total strain SRP approach is evaluated and verified using two nickel base superalloys, AF2-1DA and Rene 95. Excellent agreement is demonstrated between observed and predicted cyclic lifetimes with 70 to 80 percent of the predicted lives falling within factors of two of the observed lives. The total strain-range SRP approach should be of considerable practical value to designers who are faced with creep-fatigue problems for which the inelastic strains cannot be calculated with sufficient accuracy to make reliable life predictions by the conventional inelastic strain range SRP approach.

Halford, G. R.↗

NASA NTRS1986

Further interpretation of satellite measurements of Antarctic total ozone

Both dynamical and chemical mechanisms have been advanced to explain the decrease in total ozone in the Antarctic spring. Further analysis of satellite measurements show that during any one year, the September decline in total ozone near the South Pole is compensated by an increase at midlatitudes. The total ozone amount from 44 deg S to the pole remains almost unchanged from August through November even though both the polar and midlatitude values reach extremes during this period. These observations suggest that the variations within the spring season in south polar total ozone are governed by dynamical redistribution rather than chemical processes.

Stolarski, Richard S.↗

NASA NTRS1987

Predictions for the total solar eclipse of 1988

A total eclipse of the sun will be widely visible from the East Indies on March 18, 1988. Detailed predictions for this event are presented which include tables of geographic coordinates for the northern limit, center line and southern limit of the path of totality, local circumstances for 40 cities within the total and partial eclipse paths, the lunar-limb profile, and maps depicting the path of totality. The author discusses the general characteristics of the eclipse, local circumstances from various points along the central path and the Saros-series history.

Espenak, Fred↗

NASA NTRS1987

An analysis of tropopause pressure and total ozone correlations

A study of the relationship between total ozone and tropopause pressure was carried out using Total Ozone Mapping Spectrometer (TOMS) data and National Meteorological Center (NMC) global analyses. The medium scales generally show correlations greater than 0.6 throughout the middle latitudes of both hemispheres with some regions exceeding 0.8. The areas of highest correlations seem to be associated with the storm track regions of both the Northern and Southern Hemispheres. A detailed spectral analysis is performed for the medium scales on five pairs of time series of area averaged tropopause pressure and total ozone. In middle latitudes, total ozone and tropopause pressure exhibit generally similar distributions in the power spectrum. In the subtropics and tropics the power in ozone drops off more rapidly with increasing frequency than the power in tropopause pressure. Only in the Northern Hemisphere middle latitudes does one find a clear association between increased power in ozone and tropopause pressure and maxima in the coherency spectrum. Results for large scales are more complicated, showing generally positive correlations at middle latitudes.

Schubert, Siegfried D.↗

NASA NTRS1988

An analysis of the 7-year record of SBUV satellite ozone data - Global profile features and trends in total ozone

Results are presented from an analysis of Nimbus 7 SBUV monthly-average total ozone data for the November 1978 - September 1985 period. Linear drifts are estimated for the differences between SBUV and Dobson ground station total ozone data. The results show an average negative linear drift in SBUV data relative to Dobson data of about -0.4 percent per year. The global estimate of the relation between total ozone and solar flux variations is 0.97 + or - 0.61/100 solar flux units, representing a change of total ozone over the 7-year period associated with solar flux variations of about -0.20 + or - 0.13 percent per year.

Reinsel, Gregory C.↗

NASA NTRS1987

The characterization of an air pollution episode using satellite total ozone measurements

A case study is presented which demonstrates that measurements of total ozone from a space-based platform can be used to study a widespread air pollution episode over the southeastern U.S. In particular, the synoptic-scale distribution of surface-level ozone obtained from an independent analysis of ground-based monitoring stations appears to be captured by the synoptic-scale distribution of total ozone, even though about 90 percent of the total ozone is in the stratosphere. Additional analyses of upper air meteorological data, other satellite imagery, and in situ aircraft measurements of ozone likewise support the fact that synoptic-scale variability of tropospheric ozone is primarily responsible for the observed variability in total ozone under certain conditions. The use of the type of analysis discussed in this study may provide an important technique for understanding the global budget of tropospheric ozone.

Fishman, Jack↗

NASA NTRS1989

The sensitivity of total ozone and ozone perturbation scenarios in a two-dimensional model due to dynamical inputs

The sensitivity of the total ozone distribution in the Douglass et al. (1989) photochemical model to the dynamical inputs of ozone and the zone perturbation scenarios was investigated by computing the residual circulation from three sets of heating rates (used in computing the advection field). The model ozone results were compared to solar backscattered UV ozone data (SBUV). It was found that, depending on the dynamical inputs, the modeled global average total ozone varied up to 10 percent (with even more substantial seasonal and latitudinal variabilities), indicating that total ozone in the middle to high latitudes is very sensitive to the advection field below 100 mbar, the region where the heating rates are most uncertain. The modeled total ozone showed better agreement with solar SBUV climatology when computed horizontal eddy diffusion was used.

Jackman, Charles H.↗

NASA NTRS1989

Global patterns of the quasi-biennial oscillation in total ozone

The global structure of the quasi-biennial oscillation (QBO) in total ozone is examined using nine years of total ozone measurements from the Nimbus 7 Total Ozone Mapping Spectrometer. It is shown that the interannual variations of total ozone near the equator are dominated by the QBO and that extratropical anomalies of either sign are largest in the winter season in each hemisphere. Coherent patterns of correlation are found between the equatorial ozone and eddy variances of the ozone field at the equator and in the adjacent subtropics.

Bowman, Kenneth P.↗

NASA NTRS1991

Interannual variations of ozone - Interpretation of 4 years of satellite observations of total ozone

Observations show that the monthly zonal mean total ozone between 1978 and 1982 varies by as much as 5 percent with respect to the 4-year average. These variations have been analyzed with the aid of a two-dimensional chemistry transport model. Observed temperatures and meridional stream functions, calculated from data, were used as inputs for the model. Deviations of the model-calculated total ozone from the 4-year mean were compared with the observed variations. It is shown that a substantial part of the observed variability of total ozone is reproduced by the model, despite uncertainties in the heating rates and without any special attempts to obtain consistent eddy diffusion or otherwise to tune the model. Results indicate that the temperature dependence of the ozone gas phase chemistry plays a negligible role in explaining the observed interannual variations in total ozone. A large part of the variability can be explained by the year-to-year differences in the transport circulation. The variability of the diabatic circulation is shown to be largely independent of the ozone fluctuations and to be a consequence of the observed temperature variations.

Schneider, Hans R.↗

NASA NTRS1991

Ground-based infrared measurements of HNO3 total column abundances - Long-term trend and variability

The long-term trend and variability of the total column amount of atmospheric nitric acid (HNO3) have been investigated. The study was based on time series of infrared solar absorption spectra recorded at two sites, the International Scientific Station of the Jungfraujoch (ISSJ) in the Swiss Alps (altitude 3.6 km, latitude 46.5 N, longitude 8.0 E) and the National Solar Observatory McMath solar telescope facility on Kitt Peak (altitude 2.1 km, latitude 31.9 N, longitude 111.6 W), Arizona. Measurements of HNO3 absorption features recorded at Kitt Peak between 1980 and 1990 and measurements of the same features in ISSJ solar spectra obtained in June 1951 and June 1986 to June 1990 provide quantitative estimates of the long-term trend in the HNO3 total vertical column. It is found that the trend deduced for each site is equal to zero within the measurement uncertainty. The modern ISSJ measurements show that the fitted trend is (-0.16 + or - 0.50) percent/yr, 2 sigma, which indicates that there has been no detectable change in HNO3 total column over three decades. The Kitt Peak measurements show marked variability in the HNO3 total column, but no obvious seasonal cycle is observed.

Rinsland, C. P.↗

NASA NTRS1992

Ground-based infrared measurements of carbonyl sulfide total column abundances - Long-term trends and variability

Attention is given to total vertical column abundances of carbonyl sulfide (OCS) derived from time series of high-resolution IR solar absorption spectra recorded near Tucson, Arizona, and in the Swiss Alps. The analysis of both data sets is based on nonlinear least squares spectral fittings of narrow intervals centered on lines of the intense nu3 band of OCS, the P(37) transition at 2045.5788/cm, and the P(15) transition at 2055.8609/cm, with a consistent set of spectroscopic line parameters. The Arizona measurements, recorded on 20 different days between May 1977 and March 1991, show a 10-percent peak-to-peak seasonal cycle with a summer maximum and a winter minimum and a trend in the total column abundance equal to (0.1 +/-0.2) percent/yr, 2sigma. The Alpine total columns exhibit a more complex seasonal variation than noted in the Arizona data. The results from the two sites indicate that there has been no significant change in the OCS total column abundance at northern midlatitudes over the last decade.

Rinsland, C. P.↗

NASA NTRS1935

Total-head Meter with Small Sensitivity to Yaw

The total-head meter is essentially a venturi, housing a pitot tube for obtaining the total head. In yaw the flow within the nozzle is deflected, depending upon the degree of yaw, to a greater or lesser extent into the axial direction of the nozzle. After experimenting with several nozzle forms as to their suitability, the best design was finally adopted. When, with the chosen nozzle form, the total head is 0.5 entrance section diameter downstream, the instrument supplies the genuine total head at low Reynolds Numbers up to 43 degrees yaw.

Kiel, G↗

NASA NTRS1994

Long-term changes in the statistical distribution of Dobson total ozone in selected Northern Hemisphere geographical regions

The daily averages of total column amount of ozone taken in the period 1964-1988 at a network of 24 Dobson stations have been analyzed. Year-round data as well as summer data (May - Aug.) and winter data (Dec. - March) have been examined in the following regions: latitude bands (30 deg N - 39 deg N, 40 deg N - 52 deg N, 30 deg N - 60 deg N), North America, Europe, and Japan. To find year-to-year changes in the shape of the annual statistical distribution of total ozone (ASDTO) for these regions, we analyze trends in the following statistic characteristics of ASDTO: mean, standard deviation, median, and 10 and 90 percentiles. Time series of the statistical characteristics for the selected regions have been combined by averaging the individual stations values of these characteristics. The trends have been calculated by the multiple regression model adjusted for: the 11-year solar cycle, the Southern Oscillations effects, and for serial correlations. We have found that: a) in all regions (excluding Japan, North America), the shape of ASDTO has been drifting towards low ozone values. The drift seems to be not accompanied with a transformation in the shape of ASDTO. The drift speed (the rate of decrease in the annual means of total ozone) is of order 1-3 percent per decade (in the period 1970-1988). b) In Japan, the interannual changes in the shape of ASDTO have not been revealed. c) In North America, the drift of the year-round ASDTO (the year-round ASDTO comprises all the daily means of total ozone in a given year) has been accompanied with a transformation in the shape. The shape of the year round ASDTO becomes narrower. d) In all regions, except Japan and the band 30 deg - 39 deg N, the winter ASDTO (the winter ASDTO comprises the data taken in the period December in a given year through March next year) moves faster towards low ozone values than the summer ASDTO (the summer ASDTO comprises the data taken in the period May through August in a given year).

Krzyscin, Janusz W.↗