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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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At least 703 records · Page 39
All sourcesNASA NTRSDOE OSTI
NASA NTRS1977

Gravitational effects on chemically reacting laminar boundary layer flows over a horizontal flat plate

A theoretical study of the chemically reacting laminar boundary layer flow over a horizontal flat plate with gravitationally induced buoyant force is presented. A diffusion flame sheet model was used to describe the combustion process. The effects of gravity on the purely force convection flow can be characterized by a dimensionless coordinate quantity, which is involved in the generation of the governing equations. A numerical solution of the zero and first order governing equations subject to the appropriate physical boundary conditions was obtained. It is shown that the cross stream buoyancy induced body force acts effectively to produce a streamwise pressure gradient in the fluid adjacent to the plate surface. It is concluded that buoyancy plays an important role in boundary layer diffusion flames.

Lavid, M.↗
NASA NTRS1978

Simple tool removes IC flat packs

Handtool has bifurcated handle that can be tightened so that clamping head grips pack securely. Tool easily removes hybrid integrated-ciruit flat packs from printed-wiring boards. It does not damage circuit or board; thus, board can be reused with replacement circuit, and old circuit can be analyzed for faults and, if possible, repaired.

Eggebeen, J.↗
NASA NTRS1979

Hot-air flat-plate solar collector-design package

Report contains design data, performance specifications, and drawings for hot-air flat-plate solar-energy collector. Evaluation consists of tests on thermal performance time constance, and incidence angle modifier test. Results are presented in table and graph form and are analyzed in detail.

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NASA NTRS1977

Preliminary design review package on air flat plate collector for solar heating and cooling system

Guidelines to be used in the development and fabrication of a prototype air flat plate collector subsystem containing 320 square feet (10-4 ft x 8 ft panels) of collector area are presented. Topics discussed include: (1) verification plan; (2) thermal analysis; (3) safety hazard analysis; (4) drawing list; (5) special handling, installation and maintenance tools; (6) structural analysis; and (7) selected drawings.

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NASA NTRS1978

Analysis of a suspension system for a wheel rolling on a flat track

A flexure strut wheel suspension system is described which keeps a wheel flat against the track and maintains a small interface moment. Equations are presented for the evaluation of this moment. A comparison of the flexure strut system is made with a rigid link design containing pivot bearings.

Mcginness, H.↗
NASA NTRS1978

Design and installation package for the Sunmat Flat Plate solar collector

The information used in evaluating the design of a liquid flat plate solar collector is reported. Included in this package are subsystem performance specification, installation, operation and maintenance manuals, collector sizing guides, and detailed drawings of the single-glazed collector.

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NASA NTRS1978

Development of flat-plate solar collectors for the heating and cooling of buildings: Executive summary

An efficient, low cost, flat-plate solar collector was developed. Computer aided mathematical models of the heat process in the collector were used in defining absorber panel configuration; determining insulation thickness; and in selecting the number, spacing, and material of the covers. Prototypes were built and performance tested. Data from simulated operation of the collector are compared with predicted loads from a number of locations to determine the degree of solar utilization.

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NASA NTRS1978

Certification and verification for Calmac flat plate solar collector

Information used in the certification and verification of the Calmac Flat Plate Collector is presented. Contained are such items as test procedures and results, information on materials used, installation, operation, and maintenance manuals, and other information pertaining to the verification and certification.

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NASA NTRS1977

Velocity and temperature profiles in near-critical nitrogen flowing past a horizontal flat plate

Boundary layer velocity and temperature profiles were measured for nitrogen near its thermodynamic critical point flowing past a horizontal flat plate. The heated surface was oriented both facing upward and downward. The results were compared to earlier work in which measurements were made for vertically upward flow. The boundary layer temperatures ranged from below to above the thermodynamic critical temperature. For wall temperatures below the thermodynamic critical temperature there was little variation between the velocity and temperature profiles in the three orientations. In all three orientations the point of crossing into the critical temperature region is marked by a significant flattening of the velocity and temperature profiles and also a decrease in heat transfer coefficient. As the heat flux and, consequently, wall temperature are further increased significant changes occur in the velocity and temperature profiles. Examination of near-critical heat transfer in these three flow orientations offers insights into the relative role of buoyancy forces in this regime.

Simoneau, R. J.↗
NASA NTRS1978

Transverse flat plate heat pipe experiment

This paper describes a Shuttle-launched flight experiment to evaluate the performance of a transverse flat plate heat pipe that serves as an integral temperature control/mounting panel for electronic equipment. A transverse heat pipe is a gas-controlled variable conductance heat pipe that can handle relatively large thermal loads. An experiment designed to flight test the concept over a 6-9 month period is self-sufficient with respect to electrical power, timing sequences, and data storage.

Edelstein, F.↗
NASA NTRS1978

Pressure pulsations on a flat plate normal to an underexpanded supersonic jet

An experiment was devised to study the interaction between an underexpanded supersonic gas jet and a flat plate, with the plate located in a region in which the interaction produces shock wave and flow fluctuations. Nitrogen gas at ambient stagnation temperature flowed through a convergent nozzle with exit diameter of 2.03 cm and impinged on a square metal plate normal to the jet. Results revealed local peak pressure fluctuations on the plate at nozzle pressure ratios of about 2 and 4.5, with the latter case producing fluctuations of the same order as the mean pressure on the plate; the frequency of the oscillations was as large as 20 kHz. For choked jet flow at ambient pressure higher than atmospheric, the pressure fluctuations would increase accordingly, and adjacent solid structures would therefore be subjected to proportionately higher normal stresses.

Back, L. H.↗
NASA NTRS1978

Flat-sided rectilinear trough as a solar concentrator - An analytical study

Formulas are derived for the concentration factor and irradiance distribution at the base of the flat-sided linear trough. Performance is affected by the number of reflections the solar rays undergo before reaching the base, the cone apex angle, and the coefficient of reflection. Results are presented graphically in such a way that one can choose the optimum configuration, which is the minimum material required, to achieve a given concentration factor. Practical concentration factors range from 1.5 to 4 depending on the geometry and coefficient of reflection.

Burkhard, D. G.↗
NASA NTRS1977

Navier-Stokes solution for the laminar and turbulent supersonic flow near the trailing edge of a flat plate

The present paper deals with problems of two-dimensional laminar and turbulent flow of a viscous incompressible fluid near the trailing edge of a thin flat plate. The complete system of Navier-Stokes equations is solved by means of MacCormack's finite-difference scheme. In the laminar case, the results are compared with the triple deck solution of Daniels (1973). The comparisons indicate that the asymptotic triple deck theory for supersonic trailing-edge flow is accurate within five percent for Reynolds numbers greater than 1000. In the turbulent case, the Prandtl-Van Driest-Clausner algebraic eddy viscosity model is used, showing that the region of upstream influence is roughly of the order of the boundary layer thickness.

Hussaini, M. Y.↗
NASA NTRS1979

Ensuring flat cuts in longwall mining

Minicomputer-controlled towed vehicle automatically determines flatness of wall of coal or other mineral as it is being cut by mining machine and allows machine operator to correct cut as necessary. Vehicle is used for longwall mining.

Campbell, R. A.↗
NASA NTRS1979

Flat-flame burner

Aqueous solutions of inorganic salts are aspirated and then nebulized into mixing chamber of flat-flame burner to study behavior of inorganic salts in flames.

Fryburg, G. C.↗
NASA NTRS1979

High-energy-density flat flexible capacitors

Manufacturing technique produces flat flexible capacitors of energy density greater than 0.1 J/g. Exposure of some of metalized surface of each layer provides sufficient film surface to ensure good electrical connection to each layer of capacitor.

Parker, R. D.↗
NASA NTRS1980

Weathering of a flat-plate solar collector

Report contains performance evaluation of flat-plate liquid solar collector after 14-months of natural weathering. Collector efficiency was calculated and plotted as function of inlet liquid temperature. Measurements were made of ambient temperature, inlet and outlet temperatures, differential temperature and pressure, liquid flow rate, insolation, and windspeed.

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