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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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2002

Portable propellant cutting assembly, and method of cutting propellant with assembly

A propellant cutting assembly and method of using the assembly to cut samples of solid propellant in a repeatable and consistent manner is disclosed. The cutting assembly utilizes two parallel extension beams which are shorter than the diameter of a central bore of an annular solid propellant grain and can be loaded into the central bore. The assembly is equipped with retaining heads at its respective ends and an adjustment mechanism to position and wedge the assembly within the central bore. One end of the assembly is equipped with a cutting blade apparatus which can be extended beyond the end of the extension beams to cut into the solid propellant.

Sharp, Roger A.↗
NASA NTRS2025

Laser Cutting of Anorthosite and Norite in Vacuum

Lasers have previously been evaluated to cut and drill through rock in high pressure and atmospheric conditions to support deep drilling for oil & gas, as well as breaking or cutting rock near the surface. This research evaluates using lasers to cut rocks in a lunar environment. Anorthosite and norite samples were cut in a rough vacuum (<1 Torr) environment using a continuous wave (CW) 2 kW laser. Power and cutting speed are varied to control the total power input. In total 30, 38mm cuts are performed with power levels ranging from 25% (525 W) to 100% (2100 W) and total energy inputs from 0.090 – 4.34 kJ/cm. The cuts are bisected and inspected with optical and scanning electron microscopy. The bisected areas are measured to determine the specific energy for material removal (J/mm 3 ) and the extent of the heat affected zone.

Laser Cutting↗
NASA NTRS1988

Comparison of axillary bud growth and patatin accumulation in potato leaf cuttings as assays for tuber induction

Single-node leaf cuttings from potatoes (Solanum tuberosum L.) cvs. Norland, Superior, Norchip, and Kennebec, were used to assess tuber induction in plants grown under 12, 16, and 20 h daily irradiation (400 micromol s-1 m-2 PPF). Leaf cuttings were taken from plants at four, six and 15 weeks after planting and cultured for 14 d in sand trays in humid environments. Tuber induction was determined by visually rating the type of growth at the attached axillary bud, and by measuring the accumulation of the major tuber protein, patatin, in the base of the petioles. Axillary buds from leaf cuttings of plants grown under the 12 h photoperiod consistently formed round, sessile tubers at the axils for all four cultivars at all harvests. Buds from cuttings of plants grown under the 16 and 20 h photoperiods exhibited mixed tuber, stolon, and leafy shoot growth. Patatin accumulation was highest in petioles of cuttings taken from 12 h plants for all cultivars at all harvests, with levels in 16 and 20 h cuttings approx. one-half that of the 12 h cuttings. Trends, both in visual ratings of axillary buds and in petiole patatin accumulation, followed the harvest index (ratio of tuber to total plant dry matter), suggesting that either method is an acceptable assay for tuber induction in the potato.

NASA Discipline Number 61-10↗
NASA NTRS1975

Are clear-cut areas estimated from LANDSAT imagery reliable?

The reliability of LANDSAT imagery for estimation of clear-cut areas was evaluated by comparison with data obtained from high-altitude photos and logging historical map and from field inspections. A mature forest was selected as a test site because of its continuous clear-cut operation. The forest is about 50 km northwest of Victoria, British Columbia, Canada, and consists of 9092 ha. Areas clear-cut within the past year were overestimated by 12.9%, those clear-cut 1-year or more by 2.2%, whereas uncut mature timber was underestimated by 3.6%. Three clear-cut areas were missed in the logging map and two in the LANDSAT enhancement. The difference between area estimates was significant when all 26 areas were included but not when 2 overestimated areas were excluded from the analysis. The study indicates that LANDSAT imagery color enhancement is a useful tool in up-dating clear-cut areas for long-term planning in forest management.

Lee, Y. J.↗
NASA NTRS1986

Laser Cutting of Thin Nickel Bellows

Laser cutting technique produces narrow, precise, fast, and repeatable cuts in thin nickel-allow bellows material. Laser cutting operation uses intense focused beam to melt material and assisting gas to force melted material through part thickness, creating void. When part rotated or moved longitudinally, melting and material removal continuous and creates narrow, fast, precise, and repeatable cut. Technique used to produce cuts of specified depths less than material thickness. Avoids distortion, dents, and nicks produced in delicate materials during lathe trimming operations, which require high cutting-tool pressure and holding-fixture forces.

Butler, C. L.↗
NASA NTRS2009

Computerized Machine for Cutting Space Shuttle Thermal Tiles

A report presents the concept of a machine aboard the space shuttle that would cut oversized thermal-tile blanks to precise sizes and shapes needed to replace tiles that were damaged or lost during ascent to orbit. The machine would include a computer-controlled jigsaw enclosed in a clear acrylic shell that would prevent escape of cutting debris. A vacuum motor would collect the debris into a reservoir and would hold a tile blank securely in place. A database stored in the computer would contain the unique shape and dimensions of every tile. Once a broken or missing tile was identified, its identification number would be entered into the computer, wherein the cutting pattern associated with that number would be retrieved from the database. A tile blank would be locked into a crib in the machine, the shell would be closed (proximity sensors would prevent activation of the machine while the shell was open), and a "cut" command would be sent from the computer. A blade would be moved around the crib like a plotter, cutting the tile to the required size and shape. Once the tile was cut, an astronaut would take a space walk for installation.

Ramirez, Luis E.↗
NASA NTRS1978

Optimum wall impedance for spinning modes: A correlation with mode cut-off ratio

A correlating equation relating the optimum acoustic impedance for the wall lining of a circular duct to the acoustic mode cut-off ratio, is presented. The optimum impedance was correlated with cut-off ratio because the cut-off ratio appears to be the fundamental parameter governing the propagation of sound in the duct. Modes with similar cut-off ratios respond in a similar way to the acoustic liner. The correlation is a semi-empirical expression developed from an empirical modification of an equation originally derived from sound propagation theory in a thin boundary layer. This correlating equation represents a part of a simplified liner design method, based upon modal cut-off ratio, for multimodal noise propagation.

Rice, E. J.↗
NASA NTRS1978

Optimum wall impedance for spinning modes - A correlation with mode cut-off ratio

A correlating equation relating the optimum acoustic impedance for the wall lining of a circular duct to the acoustic mode cut-off ratio is presented and compared to exact calculations. The optimum impedance was correlated with cut-off ratio because the cut-off ratio appears to be the fundamental parameter governing the propagation of sound in the duct. Modes with similar cut-off ratios respond in a similar way to the acoustic liner. The correlating equation is useful for the design of suppressors for aircraft engine inlets having a steady mean flow with a boundary layer and spinning mode noise source excitation. The correlation is a semi-empirical expression developed from an empirical modification of an equation originally derived from sound propagation theory in a thin boundary layer. Exact calculations of the optimum wall impedance were made over a wide range of frequency parameters, boundary layer thicknesses and flow Mach numbers to develop and verify the correlation. This correlating equation represents a part of a simplified liner design method, based upon modal cut-off ratio, for multimodal noise propagation.

Rice, E. J.↗
NASA NTRS1980

The effects of cutting or of stretching skeletal muscle in vitro on the rates of protein synthesis and degradation

Skeletal muscle preparations using cut muscle fibers have often been used in studies of protein metabolism. The present paper reports an investigation of the effect of muscle cutting or stretching in vitro on the rates of protein synthesis and/or degradation. Protein synthesis and content, and ATP and phosphocreatine levels were monitored in soleus and extensor digitorum longus muscles from the rat with various extents of muscle fiber cuts and following stretching to about 120% the resting length. Rates of protein synthesis are found to be significantly lower and protein degradation higher in the cut muscles than in uncut controls, while ATP and phosphocreatine concentrations decreased. Stretched intact muscles, on the other hand, are observed to have higher concentrations of high-energy phosphates than unstretched muscles, while rates of protein degradation were not affected. Results thus demonstrate that the cutting of skeletal muscle fibers alters many aspects of muscle metabolism, and that moderate decreases in ATP concentration do not alter rates of protein concentration in intact muscles in vitro.

Seider, M. J.↗
NASA NTRS1984

Tubing and cable cutting tool

A hand held hydraulic cutting tool was developed which is particularly useful in deactivating ejection seats in military aircraft rescue operations. The tool consists primarily of a hydraulic system composed of a fluid reservoir, a pumping piston, and an actuator piston. Mechanical cutting jaws are attached to the actuator piston rod. The hydraulic system is controlled by a pump handle. As the pump handle is operated the actuator piston rod is forced outward and thus the cutting jaws are forced together. The frame of the device is a flexible metal tubing which permits easy positioning of the tool cutting jaws in remote and normally inaccessible locations. Bifurcated cutting edges ensure removal of a section of the tubing or cable to thereby reduce the possibility of accidental reactivation of the tubing or cable being severed.

Mcsmith, D. D.↗
NASA NTRS1995

Automated Laser Cutting In Three Dimensions

Computer-controlled machine-tool system uses laser beam assisted by directed flow of air to cut refractory materials into complex three-dimensional shapes. Velocity, position, and angle of cut varied. In original application, materials in question were thermally insulating thick blankets and tiles used on space shuttle. System shapes tile to concave or convex contours and cuts beveled edges on blanket, without cutting through outer layer of quartz fabric part of blanket. For safety, system entirely enclosed to prevent escape of laser energy. No dust generated during cutting operation - all material vaporized; larger solid chips dislodged from workpiece easily removed later.

Bird, Lisa T.↗
NASA NTRS2008

Displaying CFD Solution Parameters on Arbitrary Cut Planes

USMC6 is a Fortran 90 computer program for post-processing in support of visualization of flows simulated by computational fluid dynamics (CFD). The name "USMC6" is partly an abbreviation of "TetrUSS - USM3D Solution Cutter," reflecting its origin as a post-processor for use with USM3D - a CFD program that is a component of the Tetrahedral Unstructured Software System and that solves the Navier-Stokes equations on tetrahedral unstructured grids. "Cutter" here refers to a capability to acquire and process solution data on (1) arbitrary planes that cut through grid volumes, or (2) user-selected spheroidal, conical, cylindrical, and/or prismatic domains cut from within grids. Cutting saves time by enabling concentration of post-processing and visualization efforts on smaller solution domains of interest. The user can select from among more than 40 flow functions. The cut planes can be trimmed to circular or rectangular shape. The user specifies cuts and functions in a free-format input file using simple and easy-to-remember keywords. The USMC6 command line is simple enough that the slicing process can readily be embedded in a shell script for assembly-line post-processing. The output of USMC6 is a data file ready for plotting.

Pao, S. Paul↗
NASA NTRS1966

Vibrator improves spark erosion cutting process

Variable frequency mechanical vibrator improves spark erosion cutting process. The vibration of the cutting tip permits continual flushing away of residue around the cut area with nondestructive electric transformer oil during the cutting process.

Thrall, L. R.↗
NASA NTRS1974

Apparatus for cutting elastomeric materials

Sharp thin cutting edge is held in head of milling machine designed for metal working. Controls of machine are used to position cutting edge in same plane as vibrating specimen. Controls then are operated, making blade come into contact with specimen, to cut it into shapes and sizes desired. Cut surfaces appear mirror-smooth; vibrating mechanism causes no visible striations.

Corbett, A. B.↗
NASA NTRS1976

Acoustic liner optimum impedance for spinning modes with mode cut-off ratio as the design criterion

The theoretical optimum acoustic impedance for higher order spinning modes was studied in cylindrical ducts with a boundary layer at the outer edge of a uniform flow. All of the propagating modes were considered from highly propagating to nearly cut-off. It was observed that the mode cut-off ratio uniquely determined the optimum wall impedance and maximum possible attenuation for a given boundary layer thickness, Mach number and frequency. The implications of this phenomenon are quite important in noise suppressor design. Instead of the acoustic power distribution among all of the propagating modes, only the power distribution as a function of cut-off ratio needs to be known. Also, the far field radiation pattern is a function of modal cut-off ratio, and much needed information for liner design can be obtained from these more easily obtained data.

Rice, E. J.↗
NASA NTRS1977

A description of the software analysis from flight and simulation data of the course cut limiter in the TCV b-737 area navigation computer

During automatic horizontal path captures, the (Terminal Configured Vehicle) B-737 airplane maintained smaller than designed path intercept angles and experienced a sawtooth bank angle oscillation during its turn towards the path. From flight data, it was determined that these anomalies were caused by the improper output of the course cut limiter in the horizontal path control law. The output from the course cut limiter did not obtain its full value and it was calculated stepwise discontinuously. The automatic horizontal path captures were then conducted on the TCV B-737 airplane real-time simulation. The path intercept angles were maintained properly and no bank angle oscillation was encountered. Data showed that the course cut limiter was calculated at its full value in a continuous manner. The intermediate calculations of the course cut limiter in the airplane's navigation computer were rewritten and rescaled in such a manner that truncation errors could be minimized. The horizontal path capture tests were then reflown. The airplane maintained the proper path intercept angle and no bank angle oscillations occurred on any of the tests.

Knox, C. E.↗
NASA NTRS1978

Chevron cutting: Experiment with new runway mixtures

Chevron cutting is shown to occur in different forms depending on the type of tire and the rubber on the running surface. Hardest wear is shown by the main tires of the B-747. Four defects occurred, in the form of two rip separation and two breakouts of the running surface. Tires capped by Thompson are more affected than any of the other rubber-capping fabrics. For Thompson tires, Chevron Cutting is greatly reduced with a fiberglass-rubber mixture. For Goodyear tires, it is eliminated with spiral wrap rubbercapping; resistance to damages through cuts seems to be more positive for Goodyear tires. For Mader tires, the extent of Chevron Cutting is generally smaller than for Thompson cappings.

Tyran, K.↗