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Hexagonal and nonhexagonal cell phenolic honeycomb design as energy dissipating material noting processing, composite constituents, cell configuration and usage environment
An absorbing sphere model based on the Landau-Zener method was developed for calculating the energy dependence of the total cross sections for the reaction A(+) + B(-) yields A star + B + Delta E, in which A or B may be atomic or molecular species. It was found that the cross sections were highly dependent on the electron detachment energy of B(-). The ionization total cross sections for Ne star (2p5 3s 3P) + Ar were calculated over a large energy range and compared with experiments.
A point matrix kernel for radiation transport, developed by the transmission matrix method, has been used to develop buildup factors and energy spectra through slab layers of different materials for a point isotropic source. Combinations of lead-water slabs were chosen for examples because of the extreme differences in shielding properties of these two materials.
A method is presented for calculating laminar viscous, compressible flows in which pressure gradients are assumed to be neglibible in energy conservation and in developing property relations, but not in momentum conservation. The equations are developed from Navier-Stokes equations in a noninertial reference frame. The method is an extension of an approximate method developed for calculating combined forced and contained natural convection in a rotating tank. The restriction to small density and temperature variations in the previous method is removed. For illustration, a two-dimensional simulation of the rotating tank problem is formulated, and the numerical computation procedure to be used is indicated.
Future costs of silicon solar cells are projected on the basis of more than a thousand-fold increase in volume. If no major application of new manufacturing technology is made, the cost remains excessive for any large scale energy system. However, the development of a multiple-ribbon crystal growth process could permit a 300-fold reduction in cell costs to about $375/kW of cell output.
The development of a wind energy system is outlined that supplies reliable energy at a cost competitive with other energy systems. A government directed industry program with strong university support is recommended that includes meteorological studies to estimate wind energy potentials and determines favorable regions and sites for wind power installations. Key phases of the overall program are wind energy conversion systems, meteorological wind studies, energy storage systems, and environmental impact studies. Performance testing with a prototype wind energy conversion and storage system is projected for Fiscal 1977.
An annular arc accelerator (ANAA) shock tube driver has been developed that deposits the energy of an arc discharge into a flowing gas, which then expands and cools without any delay for the opening of a diaphragm. A simplified one-dimensional flow analysis of the ANAA shock tube has been performed, which indicates that shock velocities greater than 40 km/sec may be obtained using a 300-kJ capacitor bank. The ANAA driver consists of a high-pressure driver, an expansion section, and an electrode section. In operation, the cold gas driver is pressurized until the diaphragm bursts, sending a pressure front down the expansion tube to the arc section. When the accelerated flow arrives at the electrode section, a 100-capacitor, 300-kJ capacitor bank is discharged either by breaking an insulating diaphragm between the electrodes or by the triggering of a series of external switches. Shock velocities of 28 km/sec have been obtained, and modifications are described that are expected to improve performance.
Secondary electrochemical battery has been developed which has high energy/ weight density. Battery is rechargeable and works on reaction between hydrogen and bromine.
An energy converter for the development of wet steam geothermal fields is described. A project to evaluate and characterize a helical rotary screw expander for geothermal applications is discussed. The helical screw expander is a positive displacement machine which can accept untreated corrosive mineralized water of any quality from a geothermal well. The subjects of corrosion, mineral deposition, the expansion process, and experience with prototype devices are reported.
A recently developed model predicts an energy dependent phase lag in the modulated cosmic ray density U(t) given by U(t) approximately equal to US (t - tau) where US is the solution to the Fokker-Planck equation under time independent conditions and tau is the average time spent by particles inside the modulating region. The delay times tau are functions of modulating parameters R (the radius of the modulating cavity), V (the solar wind velocity), and K (the effective average diffusion-coefficient which is a function of energy). This model is applied to predict the time evolution of the modulated cosmic ray proton spectrum over a simulated solar cycle. A modulation produced mostly by varying R over the solar cycle is less consistent with the observations.
Heterojunction and graded band gap type solar cells are theoretically investigated. A computer program is developed to account for energy band gap variations and the resulting built-in electric fields which result from heterojunctions and graded energy band gaps. This program is used in studying solar cell operation under various optical irradiation conditions. Results are summarized.
An X-ray burst from a 0.5 x 10 deg region centered near NGC 1851 (MX 0513-40) was detected in observations made with the Uhuru X-ray observatory on September 19, 1972. The source was observed for 15 seconds with a peak rate of 0.5 that of the Crab (2-6 keV) and was not detected above 0.01 of the Crab in observations 4.5 minutes before or after this event. During the observation, the spectrum developed a low-energy cutoff. NGC 1851 is the second globular cluster identified as a source of X-ray bursts, which suggests that all X-ray bursts may originate in globular clusters, some of which may be optically obscured.
A parametric sensitivity study and definition of the conceptual design is presented. A computer program containing the solar irradiance, solar array, and energy balance models was developed to determine the sensitivities of solar insolation and the corresponding solar array output at five sites selected for this study as well as the performance of several solar array/battery systems. A baseline electrical configuration was chosen, and three design options were recommended. The study indicates that the most sensitive parameters are the solar insolation and the inverter efficiency. The baseline PST selected is comprised of a 133 sg m solar array, 250 ampere hour battery, one to three inverters, and a full shunt regulator to limit the upper solar array voltage. A minicomputer controlled system is recommended to provide the overall control, display, and data acquisition requirements. Architectural renderings of two photovoltaic residential concepts, one above ground and the other underground, are presented. The institutional problems were defined in the areas of legal liabilities during and after installation of the PST, labor practices, building restrictions and architectural guides, and land use.
Social and economic trends which could affect the growth of aviation in the next thirty years are examined. The possible effect of these trends together with the effects of national policies, environmental concerns, possible and probable technological advancements and the world energy problem on the developments in conventional subsonic passenger transports, long-range, high-speed aircraft, short haul operations, and air cargo transport are discussed. Passenger volume predictions from different sources are presented and contrasted, and the efficiency of turboprops and turbofans is compared.
From the light absorption model the absorption of light in the photosynthetically active region of the spectrum was calculated for a Penjamo wheat crop for several situations including: (1) the percent absorption of the incident radiation by a canopy having a four layer structure; (2) the percent absorption of light by the individual layers within a four layer canopy and by the underlying soil; (3) the percent absorption of light by each vegetative canopy layer for variable sun angle; and (4) the cumulative solar energy absorbed by the developing wheat canopy as it progresses from a single layer through its growth stages to a three layer canopy. This calculation was also presented as a function of the leaf area index.
The application of solar energy to agricultural and industrial process heat requirements is discussed. This energy end use sector has been the largest and it appears that solar energy can, when fully developed and commercialized, displace from three to eight or more quads of oil and natural gas in U.S. industry. This potential for fossil fuel displacement in the agricultural and industrial process heat area sector represents a possible savings of 1.4 to 3.8 million barrels of oil daily.
Various developments in the Aircraft Energy Efficiency (ACEE) program are discussed. Terminal-area operations are considered with emphasis on the Terminal Configured Vehicle program. Consideration is also given to aircraft systems studies and economics (including noise reduction programs), coal-derived fuels for aviation systems (including LH2-fueled aircraft), and transport-aircraft concepts (including laminar flow control).
A light absorption model (LAM) for vegetative plant canopies has been derived from the Suits reflectance model. From the LAM the absorption of light in the photosynthetically active region of the spectrum (400-700 nm) has been calculated for a Penjamo wheat crop for several situations including (a) the percent absorption of the incident radiation by a canopy of LAI 3.1 having a four-layer structure, (b) the percent absorption of light by the individual layers within a four-layer canopy and by the underlying soil, (c) the percent absorption of light by each vegetative canopy layer for variable sun angle, and (d) the cumulative solar energy absorbed by the developing wheat canopy as it progresses from a single layer through its growth stages to a three-layer canopy. This calculation is also presented as a function of the leaf area index and is shown to be in agreement with experimental data reported by Kanemasu on Plainsman V wheat.