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At least 883 records · Page 49
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Design of a Meso-Scale Test of a Fracture Thermal Energy Storage (FTES) System

This paper will present the characterization, scaling, and design of an intermediate-scale field test of a fracture thermal energy storage system (FTES). Seasonal storage of thermal energy has the potential to both significantly reduce the total energy requirements for heating and cooling of buildings, but also allow for the flexibility to store thermal energy from intermittent sources. With approximately half of global energy consumption currently being used for heating and cooling, this represents an important path to reducing greenhouse gas (GHG) emissions. The concept of FTES is to drill two or more wells into a low permeability formation, generally at a depth of less than a few hundred meters, and then generate hydraulic fractures to create flow paths for water to circulate between the wells. Hot or cold thermal energy can then be stored in the surrounding rock mass by circulating hot or cold water through the fractures, which will heat or cool the rock mass. To recover the stored energy, ambient temperature water can be then circulated through the fractures, which will then be heated or cooled by the rock mass. Fractures inherently have a very large ratio of surface area to volume. This allows for very high heat fluxes to and from the rock mass to be achieved despite the relatively low thermal conductivity of most geologic formations. Because large fractures can be made with low-cost equipment and with only inexpensive and environmentally safe materials such as water and sand, the cost to construct even large FTES systems is expected to be quite low. This paper will present what the performance requirements, size, and operating conditions of a full-scale system to operate a commercial building. The paper will describe how these full-scale system characteristics will be used as a design basis for an intermediate-scale FTES test to be conducted at the Sanford Underground Research Facility (SURF) in Lead, SD.

Burghardt, Jeffrey A.↗
NASA NTRS1972

Previous design restraints and radiation damage effects of low energy particles

Spacecraft design fluences and damage by low energy electrons and protons are summarized. For electron energies 5 MeV, the design fluence is 10 to the 11th power electrons/sq cm; for energies 5 MeV, the integral spectrum is assumed to go as 1/E sq. The design fluences for proton energies 30 MeV is 1.5 x 10 to the 9th power protons/sq cm; for energies 100 MeV, it is 5 x 10 to the 14th power protons/sq cm. The radioisotope thermoelectric generator gamma and neutron radiation constraints are listed. Damage due to electron energies 0.5 MeV and proton energies 10 MeV are summarized for effects on spacecraft thermal surfaces, reflective surfaces, and refractive materials. The high frequency noise figure for field effect transistors may increase markedly, and another effect is the buildup of charge on insulating surfaces, resulting in large electric fields.

Trainor, J. H.↗
NASA NTRS1972

On the magnon interaction in haematite. I - Magnon energy of optical mode.

The effect of magnon interaction on the magnon energies of haematite was studied by the use of a recently developed random phase approximation. In this study, the spin Hamiltonian and the magnon energy were written in a power series of (1/S), where S denotes the magnitude of spin. It is known that the expression of magnon energy is rigorous up to the second term of this series. It is found that the optic mode energy is small if the free optic mode energy is small, which is contrary to Herbert's (1969) conclusion. This direct proportionality between the optic mode energy and the free optic mode energy was not confirmed in the higher order terms of 1/S.

Nagai, O.↗
NASA NTRS1973

Conclusions and recommendations of the United States Solar Energy Panel

The United States Solar Energy Panel was charged with assessing the potential of solar energy as a national energy resource. Three areas evolved where solar energy could supply significant amounts of the U.S. future energy needs: (1) energy for heating and cooling of buildings, (2) the production of fuels, and (3) the generation of electrical power. It was concluded that with adequate R&D support over the next 30 years, solar energy could provide at least 35 percent of the heating and cooling of future buildings, greater than 30 percent of the methane and hydrogen needed in the U.S. for gaseous fuels, and greater than 20 percent of the electrical power needs of the U.S. All of this could be done with a minimal effect on the environment and a substantial savings of nonrenewable fuels.

Cherry, W. R.↗
NASA NTRS1974

Solar energy research and utilization

The role of solar energy is visualized in the heating and cooling of buildings, in the production of renewable gaseous, liquid and solid fuels, and in the production of electric power over the next 45 years. Potential impacts of solar energy on various energy markets, and estimated costs of such solar energy systems are discussed. Some typical solar energy utilization processes are described in detail. It is expected that at least 20% of the U.S. total energy requirements by 2020 will be delivered from solar energy.

Cherry, W. R.↗
NASA NTRS1974

The National Geothermal Energy Research Program

The continuous demand for energy and the concern for shortages of conventional energy resources have spurred the nation to consider alternate energy resources, such as geothermal. Although significant growth in the one natural steam field located in the United States has occurred, a major effort is now needed if geothermal energy, in its several forms, is to contribute to the nation's energy supplies. From the early informal efforts of an Interagency Panel for Geothermal Energy Research, a 5-year Federal program has evolved whose objective is the rapid development of a commercial industry for the utilization of geothermal resources for electric power production and other products. The Federal program seeks to evaluate the realistic potential of geothermal energy, to support the necessary research and technology needed to demonstrate the economic and environmental feasibility of the several types of geothermal resources, and to address the legal and institutional problems concerned in the stimulation and regulation of this new industry.

Green, R. J.↗
NASA NTRS1974

Rating aircraft on energy

Questions concerning the energy efficiency of aircraft compared to ground transport are considered, taking into account as energy intensity the energy consumed per passenger statute mile. It is found that today's transport aircraft have an energy intensity potential comparable to that of ground modes. Possibilities for improving the energy density are also much better in the case of aircraft than in the case of ground transportation. Approaches for potential reductions in aircraft energy consumption are examined, giving attention to steps for increasing the efficiency of present aircraft and to reductions in energy intensity obtainable by the introduction of new aircraft utilizing an advanced technology. The use of supercritical aerodynamics is discussed along with the employment of composite structures, advances in propulsion systems, and the introduction of very large aircraft. Other improvements in fuel economy can be obtained by a reduction of skin-friction drag and a use of hydrogen fuel.

Maddalon, D. V.↗
NASA NTRS1975

Mode shift strategies in intercity transportation and their effect on energy consumption

Policies are examined which, if implemented, could lead to significant energy savings in intercity travel in the northeast corridor arena, without restricting the traveler's freedom of mode choice. The effects on arena energy consumption of introducing new, more energy-efficient aircraft are investigated; and several strategies unrelated to the implementation of new aircraft are introduced to yield reductions in overall intercity energy use. In both parts of this analysis, resulting changes in patronage (modal share) and energy use are demonstrated, leading to new insights into the effectiveness of different potential policies for achieving energy conservation. Some observations on induced demand trends that could be associated with certain strategies and the resultant potential effect on energy conservation are provided.

Sokolsky, S.↗
NASA NTRS1976

Interactions of satellite-speed helium atoms with satellite surfaces. 2: Energy distributions of reflected helium atoms

Energy transfer in collisions of satellite-speed (7,000 m/sec) helium atoms with a cleaned 6061-T6 satellite-type aluminum surface was investigated using the molecular-beam technique. The amount of energy transferred was determined from the measured energy of the molecular-beam and the measured spatial and energy distributions of the reflected atoms. Spatial distributions of helium atoms scattered from a 6061-T6 aluminum surface were measured. The scattering pattern exhibits a prominent backscattering, probably due to the gross surface roughness and/or the relative lattice softness of the aluminum surface. Energy distributions of reflected helium atoms from the same surface were measured for six different incidence angles. For each incidence angle, distributions were measured at approximately sixty scattering positions. At a given scattering position, the energy spectra of the reflected helium atoms and the background gas were obtained using the retarding-field energy analyzer.

Liu, S. M.↗
NASA NTRS1976

A proposed concept for the extraction of energy stored in magnetic or electric fields in space

It is known that enormous energy resources associated with electric, magnetic, gravitational, and other fields exist in space. It is also known that the major difficulty in 'tapping' this energy arises from the extremely low density level at which this energy exists. An analytical study has been made of a particular scheme that appears promising for an efficient utilization of some of these energy resources in propulsion. The principle involves the exchange of energy between a fluctuating magnetic field and a velocity field of electrically conducting fluid in turbulent motion located onboard a spacecraft. Under certain conditions the total energy of the turbulent flow field onboard the spacecraft can be increased and this increase appears in the form of Joulean heat. The utilization of the fluctuating part of the magnetic field, in the form of Joulean dissipation (because of its random character) does not introduce any drag on the spacecraft. The application appears promising for flights in the vicinity of Jupiter and other planets. The rate at which energy is gained by the conducting fluid is of the order of 100 watts when the rms value of the fluctuating magnetic field strength is about 1 gauss.

Papailiou, D. D.↗
NASA NTRS1977

Mechanical energy storage device for hip disarticulation

An artificial leg including a trunk socket, a thigh section hingedly coupled to the trunk socket, a leg section hingedly coupled to the thigh section and a foot section hingedly coupled to the leg section is outlined. A mechanical energy storage device is operatively associated with the artificial leg for storage and release of energy during the normal walking stride of the user. Energy is stored in the mechanical energy storage device during a weight-bearing phase of the walking stride when the user's weight is on the artificial leg. Energy is released during a phase of the normal walking stride, when the user's weight is removed from the artificial leg. The stored energy is released from the energy storage device to pivot the thigh section forwardly about the hinged coupling to the trunk socket.

Vallotton, W. C.↗
NASA NTRS1977

Observations in energy balance in man during spaceflight

An investigation was undertaken of the changes in metabolic energy balance which occur in weightlessness. Daily energy intake was determined each day throughout the 28-, 59-, and 84-day flights for each of the nine Skylab astronauts. The energy content of the urine and feces was also measured. Changes in body composition were inferred from measurements of weight, volume, water, and total exchangeable potassium before and after flight. During flight, changes were followed by a daily measurement of body mass and by metabolic balance. Examination of the data reveal losses in body weight during the 1st and 2nd months of flight, a loss in body water and protein during the 1st month and a loss of fat during the 1st, 2nd, and 3rd months of flight. The energy input was about 41.7 kcal/kg per day on the ground, and 43.7 kcal/kg per day after 3 months in space. The increase in net energy input of about 1.6% per month is significant (P less than 0.05). When the net energy input is expressed on the basis of total body potassium, the increase in the resulting normalized net energy input of about 3.7% per month is also significant (P less than 0.05).

Rambaut, P. C.↗
NASA NTRS1977

On the localness of the spectral energy transfer in turbulence

Data for the energy transfer function are used to estimate the degree of localness of energy transfer in homogeneous turbulence. It is found that in regions where the energy which enters a wavenumber band is greater than the energy leaving, much of the energy entering the band is produced by wavenumbers an order of magnitude smaller. Thus for both low and high Reynolds numbers, spectral energy transfer is nonlocal. The tendency of the energy to jump between separated wavenumber regions agrees with the theory that turbulence forms concentrated regions of large velocity gradients. It is also felt that the universal equilibrium theory may be applicable if the Reynolds number of the turbulence is very high.

Deissler, R. G.↗
NASA NTRS1978

Kinetic energy budgets during the life cycle of intense convective activity

Synoptic-scale data at three- and six-hour intervals are employed to study the relationship between changing kinetic energy variables and the life cycles of two severe squall lines. The kinetic energy budgets indicate a high degree of kinetic energy generation, especially pronounced near the jet-stream level. Energy losses in the storm environment are due to the transfer of kinetic energy from grid to subgrid scales of motion; large-scale upward vertical motion carries aloft the kinetic energy generated by storm activity at lower levels. In general, the time of maximum storm intensity is also the time of maximum energy conversion and transport.

Fuelberg, H. E.↗
NASA NTRS1977

Relationship between the kinetic energy budget and intensity of convection

Synoptic data collected over the eastern United States during the fourth Atmospheric Variability Experiment, April 24 and 25, 1975, is used to study the relationship between the kinetic energy budget and the intensity of convective activity. It is found that areas of intense convective activity are also major centers of kinetic energy activity. Energy processes increase in magnitude with an increase in convection intensity. Large generation of kinetic energy is associated with intense convection, but large quantities of energy are transported out of the area of convection. The kinetic energy budget associated with grid points having no convection differs greatly from the budgets of the three categories of convection. Weak energy processes are not associated with convection.

Fuelberg, H. E.↗
NASA NTRS1978

Energy. A continuing bibliography with indexes, issue 18

This issue of Energy lists 1038 reports, journal articles, and other documents announced between April 1, 1978 and June 30, 1978 in Scientific and Technical Aerospace Reports (STAR) or in International Aerospace Abstracts (IAA). The coverage includes regional, national and international energy systems; research and development on fuels and other sources of energy; energy conversion, transport, transmission, distribution and storage, with special emphasis on use of hydrogen and of solar energy. Also included are methods of locating or using new energy resources. Of special interest is energy for heating, lighting, for powering aircraft, surface vehicles, or other machinery.

Source record↗
NASA NTRS1978

Radiation energy conversion in space; Conference, 3rd, NASA Ames Research Center, Moffett Field, Calif., January 26-28, 1978, Technical Papers

Concepts for space-based conversion of space radiation energy into useful energy for man's needs are developed and supported by studies of costs, material and size requirements, efficiency, and available technology. Besides the more studied solar power satellite system using microwave transmission, a number of alternative space energy concepts are considered. Topics covered include orbiting mirrors for terrestrial energy supply, energy conversion at a lunar polar site, ultralightweight structures for space power, radiatively sustained cesium plasmas for solar electric conversion, solar pumped CW CO2 laser, superelastic laser energy conversion, laser-enhanced dynamics in molecular rate processes, and electron beams in space for energy storage.

Billman, K. W.↗
NASA NTRS1978

Energy conservation through sealing technology

Improvements in fluid film sealing resulting from a proposed research program could lead to an annual energy saving, on a national basis, equivalent to about 37 million bbl of oil or 0.3% of the total U.S. energy consumption. Further, the application of known sealing technology can result in an annual saving of an additional 10 million bbl of oil. The energy saving would be accomplished by reduction in process heat energy loss, reduction of frictional energy generated, and minimization of energy required to operate ancillary equipment associated with the seal system. In addition to energy saving, cost effectiveness is further enhanced by reduction in maintenance and in minimization of equipment for collecting leakage and for meeting environmental pollution standards.

Stair, W. K.↗