SEARCH · Engineering Papers

Results for “Design Philosophy”

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 199 records · Page 11

All sources NASA NTRS DOE OSTI

NASA NTRS1974

Apollo experience report: Command and service module electrical power distribution on subsystem

A review of the design philosophy and development of the Apollo command and service modules electrical power distribution subsystem, a brief history of the evolution of the total system, and some of the more significant components within the system are discussed. The electrical power distribution primarily consisted of individual control units, interconnecting units, and associated protective devices. Because each unit within the system operated more or less independently of other units, the discussion of the subsystem proceeds generally in descending order of complexity; the discussion begins with the total system, progresses to the individual units of the system, and concludes with the components within the units.

Munford, R. E.↗

NASA NTRS1974

MSFC Skylab Orbital Workshop, volume 1

The technical aspects of the Skylab-Orbital Workshop are discussed. Original concepts, goals, design philosophy, hardware, and testing are reported. The final flight configuration, overall test program, and mission performance are analyzed. The systems which are examined are: (1) the structural system, (2) the meteoroid shield systems, and (3) the environmental/thermal control subsystem.

Source record↗

NASA NTRS1973

Automatic control in planetary exploration in the 1980s

Based on an examination of the planetary missions in the 1980s and their related objectives, a broad assessment of the automatic control capabilities required for these missions is presented. The ten outer-planet, terrestrial-planet, and small-body missions considered involve various operations encompassing a complex series of modes including cruise, maneuver, and powered flight control. In addition to routine navigation and attitude control, onboard control is required to point scientific instruments and antennas with respect to the vehicle and to maneuver the spacecraft in time-constrained or hazardous environments. These 1980 missions aimed at exploring new areas of the solar system will be more demanding. New design philosophies and increased performance capabilities will be required to meet the constraints imposed by science requirements and mission-cost effectiveness.

Moore, J. W.↗

NASA NTRS1974

Recent advancements in information extraction methodology and hardware for earth resources survey systems

The present work discusses some recent developments in preprocessing and extractive processing techniques and hardware and in user applications model development for earth resources survey systems. The Multivariate Interactive Digital Analysis System (MIDAS) is currently being developed, and is an attempt to solve the problem of real time multispectral data processing in an operational system. The main features and design philosophy of this system are described. Examples of wetlands mapping and land resource inventory are presented. A user model developed for predicting the yearly production of mallard ducks from remote sensing and ancillary data is described.

Erickson, J. D.↗

NASA NTRS1975

Power processing for electric propulsion

The inclusion of electric thruster systems in spacecraft design is considered. The propulsion requirements of such spacecraft dictate a wide range of thruster power levels and operational lifetimes, which must be matched by lightweight, efficient, and reliable thruster power processing systems. Electron bombardment ion thruster requirements are presented, and the performance characteristics of present power processing systems are reviewed. Design philosophies and alternatives in areas such as inverter type, arc protection, and control methods are discussed along with future performance potentials for meeting goals in the areas of power process or weight (10 kg/kW), efficiency (approaching 92 percent), reliability (0.96 for 15,000 hr), and thermal control capability (0.3 to 5 AU).

Finke, R. C.↗

NASA NTRS1974

Design considerations for the Shuttle/Orbiter closed-circuit television subsystem

The Shuttle/Orbiter Program requirements relative to operational and performance parameters of the CCTV (closed circuit television) subsystem and their influence upon design considerations are presented. The anticipated use of the CCTV for rendezvous, docking, manipulator arm operation, satellite inspection and general orbiter operations is outlined to establish the performance requirements of each subsystem element. Typical physical characteristics, interface parameters, and remote-control design philosophy are briefly described.

Perry, W. E.↗

NASA NTRS1974

Earth resources technology satellite /ERTS/ data collection and transmission buoys for inland, neritic and oceanic waters

As a result of a consortium of several industries and organizations, an economical, versatile, and stable data collection and transmission buoy has been designed, developed, and deployed to gather and transmit water quality data to a ground receiving station at three-minute intervals and to the earth resources technology satellite (ERTS) as it passes over the deployed buoy every 12 hours. The buoy system, designed for both fresh and salt water application, gathers data inclusive of temperature measurement, conductivity, relative acidity, dissolved oxygen, current speed, and direction. The mechanical design philosophy used to determine and satisfy boundary conditions involving stability, ease of deployment, servicing and maintenance, minimal manufacturing costs, and fresh and salt water installation capability is discussed. The development of peripheral handling equipment and anchoring systems is described.

Chapman, W. S.↗

NASA NTRS1975

Systems integration studies for supersonic cruise aircraft

Technical progress in each of the disciplinary research areas affecting the design of supersonic cruise aircraft is discussed. The NASA AST/SCAR Program supported the integration of these technical advances into supersonic cruise aircraft configuration concepts. While the baseline concepts reflect differing design philosophy, all reflect a level of economic performance considerably above the current foreign aircraft as well as the former U.S. SST. Range-payload characteristics of the study configurating show significant improvement, while meeting environmental goals such as takeoff and landing noise and upper atmospheric pollution.

Mascitti, V. R.↗

NASA NTRS1976

Validation of scramjet exhaust simulation technique

Scramjet/airframe integration design philosophy for hypersonic aircraft results in configurations having lower aft surfaces that serve as exhaust nozzles. There is a strong coupling between the exhaust plume and the aerodynamics of the vehicle, making accurate simulation of the engine exhaust mandatory. The experimental verification of the simulation procedure is described. The detonation tube simulator was used to produce an exact simulation of the scramjet exhaust for a Mach 8 flight condition. The pressure distributions produced by the exact exhaust flow were then duplicated by a cool mixture Argon and Freon 13B1. Such a substitute gas mixture validated by the detonation tube technique could be used in conventional wind tunnel tests. The results presented show the substitute gas simulation technique to be valid for shockless expansions.

Hopkins, H. B.↗

NASA NTRS1976

The F-12 series aircraft approach to design for control system reliability

The F-12 series aircraft control system design philosophy is reviewed as it pertains to functional reliability. The basic control system, i.e., cables, mixer, feel system, trim devices, and hydraulic systems are described and discussed. In addition, the implementation of the redundant stability augmentation system in the F-12 aircraft is described. Finally, the functional reliability record that has been achieved is presented.

Schenk, F. L.↗

NASA NTRS1976

Software handlers for process interfaces

The principles involved in the development of software handlers for custom interfacing problems are discussed. Handlers for the CAMAC standard are examined in detail. The types of transactions that must be supported have been established by standards groups, eliminating conflicting requirements arising out of different design philosophies and applications. Implementation of the standard handlers has been facilititated by standardization of hardware. The necessary local processors can be placed in the handler when it is written or at run time by means of input/output directives, or they can be built into a high-performance input/output processor. The full benefits of these process interfaces will only be realized when software requirements are incorporated uniformly into the hardware.

Bercaw, R. W.↗

NASA NTRS1975

Power processing for electric propulsion

The potential of achieving up to 30 per cent more spacecraft payload or 50 per cent more useful operating life by the use of electric propulsion in place of conventional cold gas or hydrazine systems in science, communications, and earth applications spacecraft is a compelling reason to consider the inclusion of electric thruster systems in new spacecraft design. The propulsion requirements of such spacecraft dictate a wide range of thruster power levels and operational lifetimes, which must be matched by lightweight, efficient, and reliable thruster power processing systems. This paper will present electron bombardment ion thruster requirements; review the performance characteristics of present power processing systems; discuss design philosophies and alternatives in areas such as inverter type, arc protection, and control methods; and project future performance potentials for meeting goals in the areas of power processor weight (10 kg/kW), efficiency (approaching 92 per cent), reliability (0.96 for 15,000 hr), and thermal control capability (0.3 to 5 AU).

Finke, R. C.↗

NASA NTRS1976

A report on the aerodynamic design and wind tunnel test of a Prop-Fan model

Recent transport aircraft system studies have shown that the Prop-Fan propulsion system offers the potential for significant fuel savings over high bypass turbofans employing the same core engine technology for each. This important finding has encouraged more detailed study of the Prop-Fan aerodynamics and has led to NASA sponsorship of a wind tunnel research program to explore the projected high efficiency levels of advanced propeller configurations for 0.80 Mach number, high-altitude cruise operation. The aerodynamic design philosophy for the Prop-Fan model is discussed. The geometric characteristics and predicted performance of the wind tunnel model are presented. Finally, the preliminary test results are reviewed and compared to the performance goals originally projected.

Rohrbach, C.↗

NASA NTRS1976

Stabilizing feedback control for dynamical systems with bounded uncertainty

The theories of differential games and generalized dynamic systems are used to deduce stabilizing controllers for quasi-linear systems. Attention is given to a class of dynamic systems subject to parameter and input uncertainty whose values range in a given compact set. Using a worst case design philosophy, a feedback control is derived that assures uniform asymptotic (Liapunov) stability of the origin under all admissible uncertainties.

Gutman, S.↗

NASA NTRS1977

The sun-tracking control of solar collectors using high-performance step motors

Sun-tracking solar energy-focusing devices involving a central receiver, thermionic conversion, or a distributed solar thermal collector system are described. The Perkins solar collector uses a fixed focal point about which an 18 m-diameter parabolic dish moves on tracks. The elevation axis also moves on a circular track. A microprocessor manipulates sun sensor information and sun ephemeris data to ensure correct placement. Stepper motors are digital devices which provide direct interface with digital electronics and a wide dynamic range, and could easily be associated with the microprocessors. Design philosophy, performance criteria, wind load analysis, and control system requirements are also discussed.

Hughes, R. O.↗

NASA NTRS1977

Influence of temperature change on optimum laminate design

Results of a laminate optimization study, which includes prescribed temperature change and mechanical loading conditions, are presented. Minimum-weight designs for balanced symmetric laminates are obtained subject to strength, membrane stiffness, and minimum thickness requirements, while including and omitting temperature change effects. Based on a first ply failure design philosophy and employing a linear thermoelastic analysis, it is shown that taking temperature decrease effects into account leads to substantial weight penalties in strength critical fiber composite laminates. Numerical results are presented for representative fiber composite materials based on three commonly used combined stress failure criteria.

Schmit, L. A., Jr.↗

NASA NTRS1978

Modification of the continuous flow diffusion chamber for use in zero-gravity

The design philosophy and performance characteristics of the continuous flow diffusion chamber developed for use in ground-based simulation of some of the experiments planned for the atmospheric cloud physics laboratory during the first Spacelab flight are discussed. Topics covered include principle of operation, thermal control, temperature measurement, tem-powered heat exchangers, wettable metal surfaces, sample injection system, and control electronics.

Keyser, G.↗

NASA NTRS1979

Validation of scramjet exhaust simulation technique at Mach 6

Current design philosophy for hydrogen-fueled, scramjet-powered hypersonic aircraft results in configurations with strong couplings between the engine plume and vehicle aerodynamics. The experimental verification of the scramjet exhaust simulation is described. The scramjet exhaust was reproduced for the Mach 6 flight condition by the detonation tube simulator. The exhaust flow pressure profiles, and to a large extent the heat transfer rate profiles, were then duplicated by cool gas mixtures of Argon and Freon 13B1 or Freon 12. The results of these experiments indicate that a cool gas simulation of the hot scramjet exhaust is a viable simulation technique except for phenomena which are dependent on the wall temperature relative to flow temperature.

Hopkins, H. B.↗