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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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The applicability of CAMAC and NIM to various payloads was studied. A major result is summarized in tabular form showing the applicability of standard available CAMAC and NIM modules to the six experimental payloads chosen. It was concluded that CAMAC has wide applicability within the experiments considered.
Features basic to the integrated utility system, such as solid waste incineration, heat recovery and usage, and water recycling/treatment, are compared in terms of cost, fuel conservation, and efficiency to conventional utility systems in the same mean-climatic area of Washington, D. C. The larger of the two apartment complexes selected for the test showed the more favorable results in the three areas of comparison. Restrictions concerning the sole use of currently available technology are hypothetically removed to consider the introduction and possible advantages of certain advanced techniques in an integrated utility system; recommendations are made and costs are estimated for each type of system.
A family of mercury ion thruster modules has been developed which extends the basic design of the Hughes-developed 1-mlb Engineering Model Thruster to accommodate the extended thrust range from 0.5 mlb to 4 mlb. In the subject program, separate Discharge Chamber Modules (DCM's) have been optimized for operation at nominal thrust levels T = 0.5 mlb and 2 mlb; DCM optimization is continuing at thrust level T = 4 mlb. Performance optimization required modification of the beam-extraction system and of discharge-chamber components; however, the cathodes and mechanical structure are unchanged from the Engineering Model design. Performance data on the optimized modules are given.
The advent of the Shuttle launch vehicle and Spacelab have resulted in adequate weight and volume such that experiment electronics can be implemented at relatively low cost using spaceflight versions of CAMAC and NIM modules. Studies of 10 modules by manufacturers have shown that power reduction overall by a factor of about 3 can be accomplished. This is adequate both from the point of view of consumption and temperature rise in vacuum. Our studies have shown that a stock of about 45 module types is required and a listing is given. The changes required in these modules in order to produce spaceflight versions are described. And finally, the further studies, prototyping and testing leading to eventual flight qualification are described.
In the study described, a scanning dual-channel cross-beam laser Doppler velocimeter (developed for measuring simultaneously the two orthogonal components of flow velocity and turbulence intensity) was used to measure the instantaneous velocity characteristics of a model helicopter rotor and in a vortex wake survey experiment on a Boeing 747 aircraft model. Particular attention is given to a special purpose dual-loop frequency tracker developed to track and demodulate 10 microsecond wide pulse burst Doppler signals with a study cycle of 25% (or narrower signals at a higher duty cycle) generated by the laser Doppler velocimeter.
The paper presents the technical feasibility of generating electricity by using a gas turbine in conjunction with a paraboloid of revolution (dish) solar concentrator. A conceptual design of a dish concentrator is obtained by parametrically examining the significant optical parameters. The optical performance analysis was conducted using a Monte Carlo ray-trace simulation program. The performance of four candidate thermodynamic cycles utilizing two working fluids was analyzed; the cycles were the regenerative and nonregenerative Brayton cycles of both open and closed type. Air and helium were the working fluids for the open and closed type respectively. Heat transfer from the solar radiation to the gas flowing in metal tubes at the receiver was also analyzed. A paraboloid of revolution dish with a cavity receiver using an open air regenerative Brayton cycle turbine emerged as a technically feasible concept in the power range from 30 to 100 KWth per module.
Heat-Pipe panel assembled by joining series of Heat-Pipe modules is presented. Each module is identical and includes own radiator Fin and Fluid-Header section. Arrangement gives high turn-down ratio permitting ammonia heat pipes to freeze under low conditions.
Chassis-mounted module makes it easy to remove and attach ground wires. With module, more ground connections are made in smaller area and no terminal lugs, lockwashers, or locknuts are required. Device also reduces holes that are punched or drilled in chassis for ground connections.
The fundamentals of a computer program, simulated monochromatic atmospheric radiative transfer (SMART), which calculates atmospheric path transmission, solar radiation, and thermal radiation in the 4.6 micrometer spectral region, are described. A brief outline of atmospheric absorption properties and line by line transmission calculations is explained in conjunction with an outline of the SMART computational procedures. Program flexibility is demonstrated by simulating the response of a gas filter correlation radiometer as one example of an atmospheric infrared sensor. Program limitations, input data requirements, program listing, and comparison of SMART transmission calculations are presented.
The basic module consists of a minicomputer, low cost peripheral storage device (disk) and a modest number (8-12) of microcomputer modules. A simple arrangement, where the microcomputers are connected to a single time multiplexed bus, only communicating to the host minicomputer, will be efficient. By running the machine in a dedicated mode for long periods of time, it will be possible to obtain a large number of solutions. As such, the device should be useful as a research tool. A scheme is outlined to assemble a number of these computing modules in parallel to decrease computing time. The advantages and disadvantages are discussed of using a number of these systems assembled in a loosely coupled configuration, each independently computing a separate flow, to give a very high throughput.
An appendix providing the technical data required for computerized control and/or monitoring of selected MIST subsystems is presented. Specific computerized functions to be performed are as follows: (1) Control of the MIST heating load simulator and monitoring of the diesel engine generators' cooling system; (2) Control of the MIST heating load simulator and MIST heating subsystem including the heating load simulator; and (3) Control of the MIST air conditioning load simulator subsystem and the MIST air conditioning subsystem, including cold thermal storage and condenser water flows.
The use and operation of a group of computer programs to perform a flutter analysis of a single planar wing are described. This system of programs is called FAST for Flutter Analysis System, and consists of five programs. Each program performs certain portions of a flutter analysis and can be run sequentially as a job step or individually. FAST uses natural vibration modes as input data and performs a conventional V-g type of solution. The unsteady aerodynamics programs in FAST are based on the subsonic kernel function lifting-surface theory although other aerodynamic programs can be used. Application of the programs is illustrated by a sample case of a complete flutter calculation that exercises each program.
The study aims at illustrating the effects of strut and injector interactions and strut wakes not totally simulated in previous, less complex, direct-connect hardware. In addition, the influence of the relative location of the injectors on opposite sides of each strut and the effect of injector spacing are evaluated. It is shown that better mixing efficiency is attained by locating the fuel injectors on opposite sides of a strut so that the jets come together, rather than being staggered, in the strut wake. It is not possible to determine the combustion efficiency by means of a one-dimensional analysis of the wall pressure.
A prototype NaI(Tl) detector (the Cluster of 54) of spherical geometry subtending a solid angle of 7.5% of 4pi at its center, has recently been assembled and tested. This detector consists of 54 close-packed but optically isolated NaI(Tl) modules and the associated electronic circuitry. The Cluster of 54 is the predecessor of an almost complete spherical detector, the Crystal Ball, which will cover 94% of 4pi. The latter detector is now under construction and is especially designed for the study of gamma-rays produced in electron-positron collisions at colliding beam facilities. This article outlines the mechanical, optical, and electronic assembly of the prototype system.
The core electronics subsystems on unmanned spacecraft, which have been sent over the last 20 years to investigate the moon, Mars, Venus, and Mercury, have progressed through an evolution from simple fixed controllers and analog computers in the 1960's to general-purpose digital computers in current designs. This evolution is now moving in the direction of distributed computer networks. Current Voyager spacecraft already use three on-board computers. One is used to store commands and provide overall spacecraft management. Another is used for instrument control and telemetry collection, and the third computer is used for attitude control and scientific instrument pointing. An examination of the control logic in the instruments shows that, for many, it is cost-effective to replace the sequencing logic with a microcomputer. The Unified Data System architecture considered consists of a set of standard microcomputers connected by several redundant buses. A typical self-checking computer module will contain 23 RAMs, two microprocessors, one memory interface, three bus interfaces, and one core building block.
The relationship between multivariable zeros and inverse systems was explored. A definition of zero module is given in such a way that it is basis independent. The existence of essential right and left inverses were established. The way in which the abstract zero module captured previous definitions of multivariable zeros is explained and examples are presented.
Results of development work on an existing controller and solarstat subsystem for use with solar heating and cooling systems are presented. The deliverable end items, program objectives, and how they were accomplished are described. It is shown that the products developed are marketable and suitable for public use.
Current heat pipe radiator technology is reviewed and the results from three state-of-the-art hardware programs are summarized. Heat pipe radiators are shown to be an improvement over all-fluid loop panels for long duration space missions, when micrometeoroid survivability is important. Finally, several heat pipe radiator design concepts are presented which would enhance Shuttle mission capabilities by either extending mission life and/or augmenting heat rejection capability.