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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 235 records · Page 13

Aerodynamic Characteristics for Internal-Balance and Frise Type Ailerons on an NACA 6 Series Low-Drag Tip Section of the Wing for the XP-63 Airplane

At the request of the Army Air Forces, Materiel Command, tests were made in the two-Dimensional low-turbulence tunnel of a mode l submitted by Bell Aircraft Corporation as the tip section of the wing of the xp-63 airplane. " The model was a NACA 66, 2x-2l6 a = 0.6 airfoil section of 50-inch chord and made of dural according to standard sheet-metal practice. The model was fitted for an internal-balance aileron with a tab and a Frise type aileron. Several alterations of the skirts and balance on the internal- balance aileron were tested to obtain the various aerodynamic characteristics of the aileron.

AILERONS - DEFLECTION↗

Wind-Tunnel Investigation of Control-Surface Characteristics XX : Plain and Balanced Flaps on an NACA 0009 Rectangular Semispan Tail Surface

Correlation is established between aerodynamic characteristics of control surfaces in two-dimensional and three-dimensional flow. Slope of lift curve was affected little by overhang and balance-nose shape, but increased by sealing flap-nose gap. Effectiveness of balancing tab was same for sealed plain flap and unsealed overhang flap. Changes in hinge-moment coefficient were diminished by sealing gap. Values measured by three-dimensional flow disagreed with two-dimensional flow values until aspect ratio corrections were made.

CONTROL SURFACES, BALANCED↗

Simple key locks turbine rotor blades

Symmetrical, cruciform key has end tabs which bend up to lock tubine rotor blades against axial displacement. The key locks without introducing aerodynamic resistance or upsetting rotor balance.

Source record↗

Sheet metal strip unrolls to form circular boom

Preformed metal strip, coiled flat on a storage drum, unrolls to form a cylindrical boom. Tabs and slots on opposite sides of the strip interlock to form a continuous circular cross section. This retractable boom can be used as a spacecraft antenna, gravity gradient, or positioning device.

Source record↗

Metal-shearing energy absorber

Device, consisting of tongue of thin aluminum alloy strip, pull tab, slotted steel plate which serves as cutter, and steel buckle, absorbs mechanical energy when its ends are subjected to tensile loading. Device is applicable as auxiliary shock absorbing anchor for automobile and airplane safety belts.

Fay, R. J.↗

Foldable patterns form construction blocks

Building blocks with interlocking tabs can be constructed from flat sheets of material using minimum of tools and equipment. Blocks can be used for storing and shipping supplies to remote areas, then filled with soil and stacked to form inhabitable structures which can be dismantled and reused.

Huber, W. C.↗

Experimental investigation of stability and stall flutter of a free-floating wing V/STOL model

An experimental investigation was made of the static and dynamic stability characteristics of a one-fourth scale model of a tilt-propeller free-wing V/STOL aircraft. The effects of wing pivot location, wing chord, trailing-edge angle, propeller tilt angle, and thrust were studied, and a limited evaluation was made of high-lift devices. A dynamically similar wing was used to measure frequency and damping ratio from transient response data in the linear aerodynamic regime and the results were compared to quasi-steady and unsteady aerodynamic theory. It was found that at high trim angles of attack, in the nonlinear aerodynamic regime, stall flutter oscillations occurred with typical amplitudes ranging from 15 to 20 deg. Wing control tab deflection was effective in initiating and terminating stall flutter but variations in configuration or operating conditions did not greatly influence the occurrence of characteristics of the oscillations.

Ormiston, R. A.↗

One hundred ampere-hour nickel-cadmium battery cells of improved design

Nickel cadmium battery cells with 100 ampere hour capacity were developed. The design features, notably extension of the current collector tab to the full width of the battery plate, and the location of the cell terminals on the opposite ends, resulted in a reduction of internal impedance, and improved electrical performance with expected improvement in thermal performance. Tables of data and performance curves are included to support the theoretical considerations.

Kantner, E.↗

Experimental performance of an internal resistance heater for Langley 6-inch expansion tube driver

An experimental investigation of the heating characteristics of an internal resistance heating element was conducted in the driver of the Langley 6-inch expansion tube to obtain actual operating conditions, to compare these results to theory, and to determine whether any modification need be made to the heater element. The heater was operated in pressurized helium from 138. MN/sq m to 62.1 MN/sq m. This investigation revealed large temperature variations within the heater element caused primarily by area reductions at insulator locations. These large temperature variations were reduced by welding small tabs over all grooves. Previous predictions of heater element and driver gas temperature were unacceptable so new equations were derived. These equations predict element and gas temperature within 10 percent of the test data when either the constant power cycle or the interrupted power cycle is used. Visual observation of the heater element, when exposed to the atmosphere with power on, resulted in a decision to limit the heater element to 815 K. Experimental shock Mach numbers are in good agreement with theory.

Creel, T. R., Jr.↗

Thermistor holder for skin-temperature measurements

Sensing head of thermistor probe is supported in center area of plastic ring which has tabs so that it can be anchored in place by rubber bands or adhesive tapes. Device attaches probes to human subjects practically, reliably, and without affecting characteristics of skin segment being measured.

Greenleaf, J. E.↗

Flutter suppression and gust alleviation using active controls

Application of the aerodynamic energy approach to some problems of flutter suppression and gust alleviation were considered. A simple modification of the control-law is suggested for achieving the required pitch control in the use of a leading edge - trailing edge activated strip. The possible replacement of the leading edge - trailing edge activated strip by a trailing edge - tab strip is also considered as an alternate solution. Parameters affecting the performance of the activated leading edge - trailing edge strip were tested on the Arava STOL Transport and the Westwind Executive Jet Transport and include strip location, control-law gains and a variation in the control-law itself.

Nissim, E.↗

Properties criteria for components and materials used in lightweight solar arrays

The present work describes the characteristics and design criteria for components and materials used in lightweight substrate solar arrays. This includes descriptions of wraparound-electrode solar cells, cell covers, and cell interconnects. Cell cover systems briefly discussed are fused silica, cerium stabilized glass, microsheet, FEP (tape, heat laminated, and spray on), and ESB 7070 glass integral covers. The majority of solar arrays orbited have used either silver, Kovar, copper, or molybdenum as interconnect metals. Data are presented comparing the Young's modulus E, ultimate tensile strength, coefficient of expansion, thermal conductivity, and percent elongation of these and other interconnect candidate materials. Guidelines for the use of end tab wraparound cells are listed.

Lott, D. R.↗

Influence of specimen features on the strength of boron/epoxy-reinforced metal

Experimental results are presented which indicate that the ultimate tensile strength of aluminum reinforced with boron/epoxy composite may be significantly affected by the configuration of the specimen, and whether it was individually laid-up or cut from a larger piece of material. Coupon specimens which were individually laid-up exhibited strengths close to that predicted by theory. However, specimens cut from large plates had strengths about 38 percent of predicted values. All specimens had a one-half inch (12.7 mm) wide gage section. For individually laid-up specimens, it was found that specimens which were loaded through fiberglass tabs yielded higher ultimate tensile strengths than modified dogbone specimens with load introduction through stepped load-transfer regions. Machining along the edges was found to have little influence on the strength of the specimens used in this study.

Herakovich, C. T.↗

Experimental studies of flow separation and stalling on two-dimensional airfoils at low speeds. Phase 2: Studies with Fowler flap extended

Results were given on experimental studies of flow separation and stalling on a two-dimensional GA(W)-1 17 percent thick airfoil with an extended Fowler flap. Experimental velocity profiles obtained from a five tube probe survey with optimum flap gap and overlap setting (flap at 40 deg) are shown at various stations above, below, and behind the airfoil/flap combination for various angles of attack. The typical zones of steady flow, intermittent turbulence, and large scale turbulence were obtained from a hot wire anemometer survey and are depicted graphically for an angle of attack of 12.5 deg. Local skin friction distributions were obtained and are given for various angles of attack. Computer plots of the boundary layer profiles are shown for the case of the flap at 40 deg. Static pressure contours are also given. A GA(W)-2 section model was fabricated with 30 percent Fowler flaps and with pressure tabs.

Seetharam, H. C.↗

Shock position sensor for supersonic inlets

Static pressure taps or ports are provided in the throat of a supersonic inlet, and signals indicative of the pressure at each of the ports is fed to respective comparators. Means are also provided for directing a signal indicative of the total throat pressure to the comparators. A periodic signal is superimposed on the total throat pressure so that the signal from the static pressure tabs is compared to a varying scan signal rather than to total throat pressure only. This type of comparison causes each comparator to provide a pulse width modulated output which may vary from 0% 'time on' to 100% 'time on'. The pulse width modulated outputs of the comparators are summed, filtered, and directed to a controller which operates a bypass valve such as a door whereby air is dumped from the inlet to prevent the shock wave from being expelled out the front.

Dustin, M. O.↗

The reduction of aileron operating force by differential linkage

It is shown that the control force of ordinary ailerons may be reduced to zero over a range of deflections and at a given flight condition by the use of an appropriate differential movement. Approximations to the ideal motion obtainable with a simple linkage are discussed and a chart that enables the selection of an appropriate crank arrangement is presented. Various aspects of the practical application of the system are discussed and it is concluded that a small fixed tab, deflected to trim both ailerons upward, would be advantageous.

Jones, R. T.↗

Ten deg off-axis tensile test for intralaminar shear characterization of fiber composites

A combined theoretical and experimental investigation was conducted to assess the suitability of the 10 deg off-axis tensile test specimen for the intralaminar shear characterization of unidirectional composites. Composite mechanics, a combined-stress failure criterion, and a finite element analysis were used to determine theoretically the stress-strain variation across the specimen width and the relative stress and strain magnitudes at the 10 deg plane. Strain gages were used to measure the strain variation across the specimen width at specimen midlength and near the end tabs. Specimens from Mod-I/epoxy, T-300/epoxy, and S-glass/epoxy were used in the experimental program. It was found that the 10 deg off-axis tensile test specimen is suitable for intralaminar shear characterization and it is recommended that it should be considered as a possible standard test specimen for such a characterization.

Chamis, C. C.↗