Miniature battery-operated electromagnetic flowmeter
Miniature battery operated electromagnetic blood flowmeter for data acquisition from unrestrained animals
Fryer, T. B.↗
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The design and development of a miniature bi-stable latching solenoid valve for low thrust resistojets
The design approach and development demonstration are presented for a flightweight, miniature, magnetic latching shutoff valve, suitable for use with the ruggedized H2 and NH3 resistojet and the biowaste resistojet. The design criteria established provided for compatibility with specified ruggedized resistojet propellants as well as the biowaste and other propulsion system propellants.
Lynch, R. A.↗
Miniature pressure valve for on-board calibration of pressure transducers.
This paper describes the development and testing of a miniature one-pole, three-position pressure valve and actuation mechanism. This valve was designed primarily for installation with a pressure transducer directly in a wind-tunnel model, thereby reducing lag time effects resulting from long connecting tubes to the transducer. This valve provides for the in-situ calibration of the transducer during testing by providing one position for transducer zero, a second position for a known calibrate pressure, and a third position for measurement of the unknown test pressure. The valve is driven from the spring loaded test pressure position to the zero and calibrate positions by a pneumatically operated dual-piston yoke assembly. Large numbers of transducers can be simultaneously calibrated from a remote location in a matter of seconds.
Rollins, G. N.↗
Design of a miniature hydrogen fueled gas turbine engine
The design, development, and delivery of a miniature hydrogen-fueled gas turbine engine are discussed. The engine was to be sized to approximate a scaled-down lift engine such as the teledyne CAE model 376. As a result, the engine design emerged as a 445N(100 lb.)-thrust engine flowing 0.86 kg (1.9 lbs.) air/sec. A 4-stage compressor was designed at a 4.0 to 1 pressure ratio for the above conditions. The compressor tip diameter was 9.14 cm (3.60 in.). To improve overall engine performance, another compressor with a 4.75 to 1 pressure ratio at the same tip diameter was designed. A matching turbine for each compressor was also designed. The turbine tip diameter was 10.16 cm (4.0 in.). A combustion chamber was designed, built, and tested for this engine. A preliminary design of the mechanical rotating parts also was completed and is discussed. Three exhaust nozzle designs are presented.
Burnett, M.↗
Factors affecting miniature Izod impact strength of tungsten-fiber-metal-matrix
The miniature Izod and Charpy impact strengths of copper, copper-nickel, and nickel-base superalloy uniaxially reinforced with continuous tungsten fibers were studied. In most cases, impact strength was increased by increasing fiber or matrix toughness, decreasing fibermatrix reaction, increasing test temperature, hot working, or heat treating. Notch sensitivity was reduced by increasing fiber content or matrix toughness. An equation relating impact strength to fiber and matrix properties and fiber content was developed. Program results imply that tungsten alloy-fiber/superalloy matrix composites can be made with adequate impact resistance for turbine blade or vane applications.
Winsa, E. A.↗
Miniature biotelemeter giving 10 channels of wideband biomedical data.
A miniature biotelemeter has been developed for sensing and transmitting multiple channels of wideband biomedical data over a radio link. Its small size and weight make it capable of being carried by free-moving laboratory animals as small as rats. Ten data channels each of 5-kHz data bandwidth are provided to permit monitoring of a wide variety of physiological signals. Multichannel telemetry of electroencephalograms, electrocardiograms, electromyograms, state functions, and dynamic processes such as blood flow and body chemistry are possible applications. Utilization of newly available monolithic chip components, low-power COS/MOS MSI digital logic, and state-of-the-art hybrid mounting techniques makes this novel device useful for both research and clinical bioinstrumentation.
Carraway, J.↗
Miniature sheathed thermocouples for turbine blade temperature measurement
An investigation was made of sheathed thermocouples for turbine blade temperature measurements. Tests were performed on the Chromel-Alumel sheathed thermocouples with both two-wire and single-wire configurations. Sheath diameters ranged from 0.25 to 0.76 mm, and temperatures ranged from 1080 to 1250 K. Both steady-state and thermal cycling tests were performed for times up to 450 hr. Special-order and commercial-grade thermocouples were tested. The tests showed that special-order single-wire sheathed thermocouples can be obtained that are reliable and accurate with diameters as small as 0.25 mm. However, all samples of 0.25-mm-diameter sheathed commercial-grade two-wire and single-wire thermocouples that were tested showed unacceptable drift rates for long-duration engine testing programs. The drift rates were about 1 percent in 10 hr. A thermocouple drift test is recommended in addition to the normal acceptance tests in order to select reliable miniature sheathed thermocouples for turbine blade applications.
Holanda, R.↗
Miniature multichannel biotelemeter system
A miniature multichannel biotelemeter system is described. The system includes a transmitter where signals from different sources are sampled to produce a wavetrain of pulses. The transmitter also separates signals by sync pulses. The pulses amplitude modulate a radio frequency carrier which is received at a receiver unit. There the sync pulses are detected by a demultiplexer which routes the pulses from each different source to a separate output channel where the pulses are used to reconstruct the signals from the particular source.
Carraway, J. B.↗
A magnetic field measurement technique using a miniature transducer
The development, fabrication, and application of a magnetometer are described. The magnetometer has a miniature transducer and is capable of automatic scanning. The magnetometer described here is capable of detecting static magnetic fields as low as 1.6 A/m and its transducer has an active area 0.64 mm by 0.76 mm. Thin and rugged, the transducer uses wire, 0.05 mm in diameter, which is plated with a magnetic film, enabling measurement of transverse magnetic fields as close as 0.08 mm from a surface. The magnetometer, which is simple to operate and has a fast response, uses an inexpensive clip-on milliammeter (commonly found in most laboratories) for driving and processing the electrical signals and readout. A specially designed transducer holding mechanism replaces the XY recorder ink pen; this mechanism provides the basis for an automatic scanning technique. The instrument has been applied to the measurements of magnetic fields arising from remanent magnetization in experimental plated-wire memory planes and regions of magnetic activity in geological rock specimens.
Fales, C. L., Jr.↗
A miniature high voltage plasma interaction flight experiment - Project MINX
A miniature high-voltage array was fabricated, incorporating the multi-junction edge illuminated (MJC) cell technique. The array consists of 32 2x2.2 cm MJCs, series connected, capable of 1600 V open circuit at 1 AMO and 1.2 mA short circuit. A solid state, high-voltage relay is connected across each 4-cell subgroup of the array. It was built to test plasma current drain on space systems using high voltage as might occur when a high-voltage solar array is operated from low to synchronous orbit.
Riley, T. J.↗
Miniature load cell instrumentation for finite deformation biaxial testing of elastomers
Accuracy of biaxial test equipment to examine the nonlinear mechanical behavior of thin sheet specimens of elastomeric materials has been hampered by lack of precise determination of the force distribution along the sides of the specimen. It has been necessary to use an effective width established by approximate means to obtain the stress from the overall force applied along the edges. To avoid this experimental difficulty, individual miniature proof-ring load cells utilizing semiconductor strain gages have been developed and applied to the support hooks for the thin sheet specimens. Typical results are shown for time-dependent stress distributions for all degrees of biaxiality. An accurate evaluation of the effective specimen width is now possible.
Arenz, R. J.↗
Miniature probes for use in gas turbine testing
Several examples of miniature probes (null type as well as fixed position) are presented which have proved useful in aircraft and space power systems component testing and are applicable to automotive gas turbine testing. These probes are used to determine component or system performance from the measurement of gas temperature as well as total and static pressure, and flow direction. Detailed drawings of the sensors are presented along with experimental data covering the flow characteristics over the range of intended use.
Glawe, G. E.↗
Feasibility of miniaturized instrumentation of the inflatable sphere for temperature, pressure and acceleration measurement
The feasibility of instrumenting the inflatable passive sphere (presently used to provide upper atmosphere density measurements) with miniaturized thermistors, pressure transducers, and accelerometers was analyzed. Data from the sensors must be transmitted by an onboard telemetry system to a ground receiving station. To assure a sufficiently slow fall velocity for the sphere the additional mass of the sensor and telemetry hardware must be less than 100 grams. Other constraints that must be satisfied by the sensor and telemetry systems include the ability to withstand a 150 g launch acceleration, the ability to function in both high and low temperature and pressure environments and be sufficiently small to be packaged within the body of a 3.81 cm diameter dart. A differential transducer that will measure the difference between ambient and internal sphere pressures is recommended. The application of each type of measurement relative to its ability to monitor sphere malfunction and to provide additional meteorological data is considered.
Luers, J. K.↗
Miniature probe for transonic flow direction measurements
A miniature probe is developed for measuring flow direction in one plane as well as stagnation pressure in the boundary layer and near wake of a transonic airfoil. The probe tip geometry and calibration curves are given, along with near wake survey data obtained for a supercritical airfoil. The advantages of the probe are ruggedness, ease of fabrication, ability to measure flow direction at a point, and insensitivity to out-of-plane velocity components.
Spaid, F. W.↗
Miniature probes for use in gas turbine testing
Because of space limitations and system complexity in many applications associated with gas turbine testing, extremely small flow measuring probes have sometimes been required. This paper presents several examples of these miniature probes - null type as well as fixed position - which have proved useful in aircraft and space power systems component testing and are applicable to automotive gas turbine testing. These probes are used to determine component or system performance from the measurement of gas temperature as well as total and static pressure, and flow direction. Detailed drawings of the sensors are presented along with experimental data covering the flow characteristics over the range of intended use.
Glawe, G. E.↗
Evaluation of the gravity independent miniature analytical system
The miniature fast analyzer is an automated, analytical instrument developed for potential use for biochemical analyses conducted in space flight. The gravity independent fast analyzer system is described which consists of a 17 place rotor type spectrophotometer and computerized data acquisition system weighing only 30 pounds and occupying a volume of 1 cubic foot.
Wallace, L. D.↗
A miniaturized pointing mount for Spacelab missions
A Miniaturized Pointing Mount (MPM) for Spacelab missions is defined and simulation results are described. This mount is proposed to complement the Spacelab Instrument Pointing System (IPS). It uses the same mount isolator concept as the Spacelab IPS but is much more efficient and economical for the accommodation of small shuttle payloads. The MPM is built from star tracker assemblies left over from the Apollo Telescope Mount program thereby assuring low cost and development risk. Simulation results indicate a high level of instrument stability can be expected. The short development time of the MPM would permit it to serve as a precursor to the Spacelab IPS for verifying critical new concepts such as the mount isolation and hold down mechanisms.
Fritz, C. G.↗
Performance of some miniature pressure transducers subjected to high rotational speeds and centripetal accelerations
The performance characteristics of several miniature pressure transducers were determined at centripetal accelerations up to 11,200 g's at a rotational speed of 23,000 rpm. The variation in centripetal acceleration was produced by changing radial position of the transducer relative to the center of rotation. Residual zero outputs and transducer sensitivities were determined at 23,000 rpm and compared with those determined at 0 rpm. The actual pressures at the various transducer locations differ from the center line impressed pressures due to a rotational effect. Corrections for this effect were made. A brief description of the test apparatus is included.
Minkin, H. L.↗