Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Representatives”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Comparison of the radiation flux profiles and spectral detail from three detailed nongray radiation models at conditions representative of hypervelocity earth entry

The radiation models were compared on the basis of the approaches used for the transport calculations and absorption coefficients and of results obtained for the radiation flux profiles and spectral distributions. The calculated results were for shock layer conditions representative of manned earth reentry from an interplanetary mission. The three models are RATRAP, RADICAL, and MDAC. The results show that significant differences exist in the radiation flux computed by the three models. The RADICAL model was found to depend on fewer approximations, to include more detail, and to require less computer time than the other models.

Suttles, J. T.↗
NASA NTRS1973

Representative Space Shuttle missions and their impact on shuttle design.

Four representative Space Shuttle missions for the 1980's are described: mission 1, a third stage deployment and retrieval mission; mission 2, a combination orbiting element revisit and sortie mission; mission 3, a rapid payload retrieval and return mission; and mission 4, a 30-day earth observation sortie mission. The first three missions are proposed baseline reference missions, and, as such, their mission requirements must be met by the baseline shuttle configuration developed by NASA contractors. Typically, these missions impact the design in terms of such basics as shuttle launch payload capability, payload bay size, performance of the orbital maneuvering system (OMS) and the reaction control system (RCS), the basic 7-day orbital system lifetime, and the thermal protection system for high cross-range entry. To illustrate that vehicle design may be subject to requirements from other mission types as well, mission 4 is included. Each description stresses mission requirements having unique impact on vehicle design.

Young, K. A.↗
NASA NTRS1974

Simulator study of minimum acceptable level of longitudinal stability for a representative STOL configuration during landing approach

A fixed-base simulator study was conducted to determine the minimum acceptable level of longitudinal stability for a representative turbofan STOL (short take-off and landing) transport airplane during the landing approach. Real-time digital simulation techniques were used. The computer was programed with equations of motion for six degrees of freedom, and the aerodynamic inputs were based on measured wind-tunnel data. The primary piloting task was an instrument approach to a breakout at a 60-m (200-ft) ceiling.

Grantham, W. D.↗
NASA NTRS1974

High shear stress behavior of some representative lubricants

Shear stress independent behavior observed for representative, synthetic, nonblended lubricants is found to be of the same magnitude as the shear stress in sliding elastohydrodynamic contacts. It is shown that dissipation heating is the only mechanism of importance in the generation of deviations from constant viscosity as measured with capillary tube viscometric methods. Newtonian end corrections for capillary tubes are found to be constant for nonblended liquid lubricants.

Jakobsen, J.↗
NASA NTRS1977

Analysis of flight equipment purchasing practices of representative air carriers

The process through which representative air carriers decide whether or not to purchase flight equipment was investigated as well as their practices and policies in retiring surplus aircraft. An analysis of the flight equipment investment decision process in ten airlines shows that for the airline industry as a whole, the flight equipment investment decision is in a state of transition from a wholly informal process in earliest years to a much more organized and structured process in the future. Individual air carriers are in different stages with respect to the formality and sophistication associated with the flight equipment investment decision.

Source record↗
NASA NTRS1977

A Representative Shuttle Environmental Control System

The Representative Shuttle Environmental Control System (RSECS) provides a ground test bed to be used in the early accumulation of component and system operating data, the evaluation of potential system improvements, and possibly the analysis of Shuttle Orbiter test and flight anomalies. Selected components are being subjected to long term tests to determine endurance and corrosion resistance capability prior to Orbiter vehicle experience. Component and system level tests in several cases are being used to support flight certification of Orbiter hardware. These activities are conducted as a development program to allow for timeliness, flexibility, and cost effectiveness not possible in a program burdened by flight documentation and monitoring constraints.

Brose, H. F.↗
NASA NTRS1978

Representative shuttle evaporative heat sink

The design, fabrication, and testing of a representative shuttle evaporative heat sink (RSEHS) system which vaporizes an expendable fluid to provide cooling for the shuttle heat transport fluid loop is reported. The optimized RSEHS minimum weight design meets or exceeds the shuttle flash evaporator system requirements. A cold trap which cryo-pumps flash evaporator exhaust water from the CSD vacuum chamber test facility to prevent water contamination of the chamber pumping equipment is also described.

Hixon, C. W.↗
NASA NTRS1978

Extreme ultraviolet composite spectra of representative solar features

The spectral identifications and absolute intensities of lines in the EUV spectrum for various solar features, such as the quiet sun, active regions, coronal holes, and the off-limb corona, are presented and discussed. Composite spectra have been assembled and processed from the ATM ultraviolet spectrometer data with a spectral resolution of 1.6 A over the range 280-1350 A. These spectra represent a self-consistent set of observations with good photometric calibration, in which intercomparison of intensities from different regions is used to assist in line identifications and to draw general conclusions on average physical conditions in the solar atmosphere. The quiet-sun line intensities obtained near solar minimum are compared with OSO 6 results near solar maximum to provide an estimate for the changes over the solar cycle.

Vernazza, J. E.↗
NASA NTRS1979

Aerodynamic heating to representative SRB and ET protuberances

Heating data and data scaling methods which can be used on representative solid rocket booster and external tank (ET) protuberances are described. Topics covered include (1) ET geometry and heating points; (2) interference heating test data (51A); (3) heat transfer data from tests FH-15 and FH-16; (4) individual protuberance data; and (5) interference heating of paint data from test IH-42. A set of drawings of the ET moldline and protuberances is included.

Engel, C. D.↗
NASA NTRS1979

Criteria for representing circular arc and sine wave spar webs by non-curved elements

The basic problem of how to simply represent a curved web of a spar in a finite element structural model was addressed. The ratio of flat web to curved web axial deformations and longitudinal rotations were calculated using NASTRAN models. Multiplying factors were developed from these calculations for various web thicknesses. These multiplying factors can be applied directly to the area and moment of inertia inputs of the finite element model. This allows the thermal stress relieving configurations of sine wave and circular arc webs to be simply accounted for in finite element structural models.

Jenkins, J. M.↗
NASA NTRS1980

Exploratory piloted simulator study of the effects of winglets on handling qualities of a representative agricultural airplane

The effects on handling qualities of adding winglets to a representative agricultural aircraft configuration during swath-run maneuvering were evaluated. Aerodynamic data used in the simulation were based on low-speed wind tunnel tests of a full scale airplane and a subscale model. The Cooper-Harper handling qualities rating scale, supplementary pilot comments, and pilot vehicle performance data were used to describe the handling qualities of the airplane with the different wing-tip configurations. Results showed that the lateral-directional handling qualities of the airplane were greatly affected by the application of winglets and winglet cant angle. The airplane with winglets canted out 20 deg exhibited severely degraded lateral directional handling qualities in comparison to the basic airplane. When the winglets were canted inward 10 deg, the flying qualities of the configuration were markedly improved over those of the winglet-canted-out configuration or the basic configuration without winglets, indicating that proper tailoring of the winglet design may afford a potential benefit in the area of handling qualities.

Ogburn, M. E.↗