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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.

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NASA NTRS1978

Energy impact assessment of NASA's past, present, and future space launch vehicles

An approach to analyze the total energy required for overall support of space launch vehicles is outlined along with some of the basic data required for such analyses. Selected results obtained by using this approach are presented for various past (some are already phased out), present, and future NASA launch vehicles, including an estimate of the total annual energy required to support one projected NASA launch vehicle traffic model. The material presented is expected to give a better insight into the details of an energy impact analysis. Major conclusions are that: (1) for expendable launch vehicle systems, the energy required to manufacture hardware and support launch operations is most significant; (2) for totally reusable systems, the energy required to process/manufacture propellants and fluids is by far the most significant contributor; and (3) up to 1991, the projected highest annual energy requirement for the NASA launch vehicles does not constitute a significant energy impact relative to the nation's total energy needs.

Rice, E. E.↗

NASA NTRS1979

Toward the renewables - A natural gas/solar energy transition strategy

The inevitability of an energy transition from today's non-renewable fossil base toward a renewable energy base is considered from the viewpoint of the need for a national transition strategy. Then, one such strategy is offered. Its technological building blocks are described in terms of both energy use and energy supply. The strategy itself is then sketched at four points in its implementation; (1) initiation, (2) early transition, (3) late transition, and (4) completion. The transition is assumed to evolve from a heavily natural gas-dependent energy economy. It then proceeds through its transition toward a balanced, hybrid energy system consisting of both centralized and dispersed energy supply technologies supplying hydrogen and electricity from solar energy. Related institutional, environmental and economic factors are examined briefly.

Hanson, J. A.↗

NASA NTRS1980

The SERI solar energy storage program

In support of the DOE thermal and chemical energy storage program, the solar energy storage program (SERI) provides research on advanced technologies, systems analyses, and assessments of thermal energy storage for solar applications in support of the Thermal and Chemical Energy Storage Program of the DOE Division of Energy Storage Systems. Currently, research is in progress on direct contact latent heat storage and thermochemical energy storage and transport. Systems analyses are being performed of thermal energy storage for solar thermal applications, and surveys and assessments are being prepared of thermal energy storage in solar applications. A ranking methodology for comparing thermal storage systems (performance and cost) is presented. Research in latent heat storage and thermochemical storage and transport is reported.

Copeland, R. J.↗

NASA NTRS1980

Kinetic energy budget during strong jet stream activity over the eastern United States

Kinetic energy budgets are computed during a cold air outbreak in association with strong jet stream activity over the eastern United States. The period is characterized by large generation of kinetic energy due to cross-contour flow. Horizontal export and dissipation of energy to subgrid scales of motion constitute the important energy sinks. Rawinsonde data at 3 and 6 h intervals during a 36 h period are used in the analysis and reveal that energy fluctuations on a time scale of less than 12 h are generally small even though the overall energy balance does change considerably during the period in conjunction with an upper level trough which moves through the region. An error analysis of the energy budget terms suggests that this major change in the budget is not due to random errors in the input data but is caused by the changing synoptic situation. The study illustrates the need to consider the time and space scales of associated weather phenomena in interpreting energy budgets obtained through use of higher frequency data.

Fuelberg, H. E.↗

NASA NTRS1981

Thermodynamic limits to the efficiency of solar energy conversion by quantum devices

The second law of thermodynamics imposes a strict limitation to the energy converted from direct solar radiation to useful work by a quantum device. This limitation requires that the amount of energy converted to useful work (energy in any form other than heat) can be no greater than the change in free energy of the radiation fields. Futhermore, in any real energy conversion device, not all of this available free energy in the radiation field can be converted to work because of basic limitations inherent in the device itself. A thermodynamic analysis of solar energy conversion by a completely general prototypical quantum device is presented. This device is completely described by two parameters, its operating temperature T sub R and the energy threshold of its absorption spectrum. An expression for the maximum thermodynamic efficiency of a quantum solar converter was derived in terms of these two parameters and the incident radiation spectrum. Efficiency curves for assumed solar spectral irradiance corresponding to air mass zero and air mass 1.5 are presented.

Buoncristiani, A. M.↗

NASA NTRS1983

A study of the kinetic energy generation with general circulation models

The history data of winter simulation by the GLAS climate model and the NCAR community climate model are used to examine the generation of atmospheric kinetic energy. The contrast between the geographic distributions of the generation of kinetic energy and divergence of kinetic energy flux shows that kinetic energy is generated in the upstream side of jets, transported to the downstream side and destroyed there. The contributions from the time-mean and transient modes to the counterbalance between generation of kinetic energy and divergence of kinetic energy flux are also investigated. It is observed that the kinetic energy generated by the time-mean mode is essentially redistributed by the time-mean flow, while that generated by the transient flow is mainly responsible for the maintenance of the kinetic energy of the entire atmospheric flow.

Chen, T.-C.↗

NASA NTRS1984

Spectral characteristics and meridional variations of energy transformations during the first and second special observation periods of FGGE

The global features and meridional spectral energy transformation variations of the first and second special observation periods of the First Global GARP Experiment (FGGE) are investigated, together with the latitudinal distribution of the kinetic energy balance. Specific seasonal characteristics are shown by the spectral distributions of the global transformations between (1) zonal mean and eddy components of the available potential energy, (2) the zonal mean and eddy components of the kinetic energy, and (3) the available potential energy and the kinetic energy. Maximum kinetic energy production is found to occur at subtropical latitudes, with a secondary maximum at higher middle latitudes. Between these two regions, there is another region characterized by the adiabatic destruction of kinetic energy above the lower troposphere.

Kung, E. C.↗

NASA NTRS1984

Stellar fibril magnetic systems. I - Reduced energy state

The remarkable fibril structure of the magnetic fields at the surface of the sun (with fibrils compressed to 1,000-2,000 gauss) lies outside existing statistical theories of magnetohydrodynamic turbulence. The total energy of the fibril field is enhanced by a factor of more than 100 above the energy for the mean field in a continuum state. The magnetic energy density within a fibril is of the order of 100 times the local kinetic energy density, so that no simple application of equipartition principles is possible. It is pointed out that the total energy of the atmosphere (thermal + gravitational + magnetic) is reduced by the fibril state of the field by avoiding the magnetic inhibition of the convective overturning, suggesting that the formation of the observed intense fibril state may be in response to the associated energy reduction. Calculation of the minimum total energy of a polytropic atmosphere permeated by magnetic fibrils yields theoretical fibril fields of the order of 1-5 kilogauss when characteristics appropriate to the solar convective zone are introduced, in rough agreement with the actual fields of 1-2 kilogauss. The polytrope model, although crude, establishes that a large reduction in total energy is made possible by the fibril state.

Parker, E. N.↗

NASA NTRS1985

Anisotropy and the knee of the energy spectrum

The measured cosmic ray energy spectrum exhibits clear structure (the knee) at approx 3 x 10 to the 15th power eV (sea level shower size approx 3 x 10 to the 5th power particles). Additionally, at energies in this general region, there occur apparent changes in shower development such that the observed characteristics of showers at this energy appear different to those characteristics observed at somewhat higher energies. At energies just below this region, the cosmic ray anisotropy amplitude apparently begins a progressive increase with energy. The latter effect does not clearly fit with the first two since there appears to be no significant change exactly at the knee. However, the phase of the first harmonic of the anisotropy appears to show a substantial change just where the energy spectrum shows structure and in the middle of the shower development changes. The first harmonic phase appears to change from approx. 18 hours R.A. to approx. 5 hours R.A. as the energy of observation moves through the knee. In this paper the latter change is examined in some detail by taking into account information contained in the second harmonic of the anisotropy.

Clay, R. W.↗

NASA NTRS1985

Lateral distribution of high energy hadrons and gamma ray in air shower cores observed with emulsion chambers

A high energy event of a bundle of electrons, gamma rays and hadronic gamma rays in an air shower core were observed. The bundles were detected with an emulsion chamber with thickness of 15 cm lead. This air shower is estimated to be initiated with a proton with energy around 10 to the 17th power to 10 to the 18th power eV at an altitude of around 100 gmc/2. Lateral distributions of the electromagnetic component with energy above 2 TeV and also the hadronic component of energy above 6 TeV of this air shower core were determined. Particles in the bundle are produced with process of the development of the nuclear cascade, the primary energy of each interaction in the cascade which produces these particles is unknown. To know the primary energy dependence of transverse momentum, the average products of energy and distance for various average energies of secondary particles are studied.

Matano, T.↗

NASA NTRS1985

Measurement of energy distribution in flowing hydrogen microwave plasmas

An electrothermal propulsion concept utilizing a microwave plasma system as the mechanism to convert electromagnetic energy into kinetic energy of a flowing gas is investigated. A calorimetry system enclosing a microwave plasma system has been developed to accurately measure the energy inputs and outputs of the microwave plasma system. The rate of energy transferred to the gas can be determined to within + or - 1.8 W from an energy balance around the microwave plasma system. The percentage of the power absorbed by the microwave plasma system transferred to the hydrogen gas as it flows through the system is found to increase with the increasing flow rate, to decrease with the increasing pressure, and to be independent of the absorbed power. An upper bound for the hydrogen gas temperature is estimated from the energy content, heat capacity, and flow rate of the gas stream. A lower bound for an overall heat-transfer coefficient is then calculated, characterizing the energy loss from the hydrogen gas stream to the air cooling of the plasma discharge tube wall. The heat-transfer coefficient is found to increase with the increasing flow rate and pressure and to be independent of the absorbed power. This result indicates that a convective-type mechanism is responsible for the energy transfer.

Chapman, R.↗

NASA NTRS1986

Budgets of divergent and rotational kinetic energy during two periods of intense convection

The derivations of the energy budget equations for divergent and rotational components of kinetic energy are provided. The intense convection periods studied are: (1) synoptic scale data of 3 or 6 hour intervals and (2) mesoalphascale data every 3 hours. Composite energies and averaged budgets for the periods are presented; the effects of random data errors on derived energy parameters is investigated. The divergent kinetic energy and rotational kinetic energy budgets are compared; good correlation of the data is observed. The kinetic energies and budget terms increase with convective development; however, the conversion of the divergent and rotational energies are opposite.

Buechler, D. E.↗

NASA NTRS1986

MAX '91: An advanced payload for the exploration of high energy processes on the active sun

The results of a NASA science working group established to study a follow-on to the Solar Maximum Mission are given. A complement of instruments is suggested, with the primary objective of studying the physics of energetic processes in cosmic plasmas by observing high-energy phenomena in solar flares. High-quality flare observations will be possible with these instruments during the next peak in solar activity expected to last from 1990 through at least 1995. The primary objective of MAX '91 is to study energetic processes in cosmic plasmas by observing high-energy phenomena in solar flares. These processes, which are of general astrophysical importance, include energy release, particle acceleration, and energy transport. Results from comprehensive observing programs conducted during the last solar cycle have demonstrated the great scientific potential of high-energy emissions for addressing these central physical processes. Consequently, a payload optimized for observations of high-energy solar flare phenomena is suggested for MAX '91. It consists of the following four specific instruments: (1) a Fourier-transform X-ray and gamma-ray imager covering the energy range from a few keV to 1 MeV with arcsecond spatial resolution; (2) a cooled germanium X-ray and gamma-ray spectrometer with keV spectral resolution covering the energy range from 10 keV to 50 MeV; (3) Bragg spectrometers with high spectral resolution at wavelengths between 1 and 9 angstrons; and (4) a soft X-ray, EUV, or UV imaging instrument with arcsecond spatial resolution.

Source record↗

NASA NTRS1987

Energy dissipation associated with crack extension in an elastic-plastic material

Crack extension in elastic-plastic material involves energy dissipation through the creation of new crack surfaces and additional yielding around the crack front. An analytical procedure, using a two-dimensional elastic-plastic finite element method, was developed to calculate the energy dissipation components during a quasi-static crack extension. The fracture of an isotropic compact specimen was numerically simulated using the critical crack-tip-opening-displacement (CTOD) growth criterion. Two specimen sizes were analyzed for three values of critical CTOD. Results from the analyses showed that the total energy dissipation rate consisted of three components: the crack separation energy rate, the plastic energy dissipation rate, and the residual strain energy rate. All three energy dissipation components and the total energy dissipation rate initially increased with crack extension and finally reached constant values.

Shivakumar, K. N.↗

NASA NTRS1987

Turbulence as a contributor to intermediate energy storage during solar flares

Turbulence is considered as a method for converting the energy observed as mass motions during the impulsive phase into thermal energy observed during the gradual phase of solar flares. The kinetic energy of the large-scale eddies driven by the upflowing material continuously cascades to smaller scale eddies until viscosity is able to convert it into thermal energy. The general properties of steady state, homogeneous, fluid turbulence is a nonmagnetic plasma and the properties of turbulent decay are reviewed. The time-dependent behavior of the velocities and energies observed by the X-Ray Polychromator (XRP) instrument on the SMM during the November 5, 1980 flare are compared with the properties of turbulence. This study indicates that turbulence may play a role in flare energies and may account for a fraction of the total amount of thermal energy observed during the gradual phase. The rate at which the observed flare velocities decrease is consistent with the decay of turbulent energy but may be too rapid to account for the entire time delay between the impulsive and gradual phases.

Bornmann, P. L.↗

NASA NTRS1987

On calculating ionospheric conductances from the flux and energy of precipitating electrons

Auroral zone conductances can be estimated from the energy flux and average energy of precipitating electrons. Revised expressions are presented that relate height-integrated Hall and Pedersen conductance to the flux and average energy of a Maxwellian. It is shown that the accuracy of this method depends on the minimum and maximum energy within which the distribution is integrated to get the energy flux and average energy. It is also confirmed that the conductances produced by some of the more common auroral spectral distributions are similar to those produced by a Maxwellian with the same average energy and energy flux. The application of these results is demonstrated using precipitating electron measurements made by the Hilat satellite during a pass over Greenland.

Robinson, R. M.↗

NASA NTRS1987

Energy dissipation associated with crack extension in an elastic-plastic material

Crack extension in elastic-plastic material involves energy dissipation through the creation of new crack surfaces and additional yielding around the crack front. An analytical procedure, using a two-dimensional elastic-plastic finite element method, was developed to calculate the energy dissipation components during a quasi-static crack extension. The fracture of an isotropic compact specimen was numerically simulated using the critical crack-tip-opening-displacement (CTOD) growth criterion. Two specimen sizes were analyzed for three values of critical CTOD. Results from the analysis showed that the total energy dissipation rate consisted of three components: the crack separation energy rate, the plastic energy dissipation rate, and the residual strain energy rate. All three energy dissipation components and the total energy dissipation rate initially increased with crack extension and finally reached constant values.

Shivakumar, K. N.↗

NASA NTRS1989

Kinetic energy equations for the average-passage equation system

Important kinetic energy equations derived from the average-passage equation sets are documented, with a view to their interrelationships. These kinetic equations may be used for closing the average-passage equations. The turbulent kinetic energy transport equation used is formed by subtracting the mean kinetic energy equation from the averaged total instantaneous kinetic energy equation. The aperiodic kinetic energy equation, averaged steady kinetic energy equation, averaged unsteady kinetic energy equation, and periodic kinetic energy equation, are also treated.

Johnson, Richard W.↗