Mechanical Components

Nuclear Reactor Cooling Valve Design Optimized With FEA

Finite element analysis simulated the valve’s condition following an earthquake. Atomic Energy of Canada, Ltd., a subcontractor of Societatea Nationala Nucleoelectrica S.A. (SNN) of Romania, contracted Badger Meter to model, test, and produce a set of precision valves for Cernavoda Unit 2, the second nuclear power plant in Cernavoda, Romania. The main concern for the construction and operation of the valves was their survivability and continued functioning after enduring an earthquake. In nuclear power plants, such valves control the cooling of the nuclear reactors where continued flow of water around the nuclear core is essential for safety. After the earthquake that precipitated the eruption of Mt. Saint Helens in 1980, testing criteria for valves routinely has included their capability to ensure the safe functioning of the reactor after seismic events, at least in terms of cooling capacity.

Posted in: Mechanical Components, Briefs

Read More >>

Inferring Gear Damage From Oil-Debris and Vibration Data

Data fusion increases the reliability and reduces the difficulty of gear-damage diagnosis. system for real-time detection of surface- fatigue-pitting damage to gears for use in a helicopter transmission is based on fuzzy-logic used to fuse data from sensors that measure oil-borne debris, referred to as “oil debris” in the article, and vibration signatures. A system to detect helicopter-transmission gear damage is beneficial because the power train of a helicopter is essential for propulsion, lift, and maneuvering, hence, the integrity of the transmission is critical to helicopter safety. To enable detection of an impending transmission failure, an ideal diagnostic system should provide real-time monitoring of the “health” of the transmission, be capable of a high level of reliable detection (with minimization of false alarms), and provide human users with clear information on the health of the system without making it necessary for them to interpret large amounts of sensor data.

Posted in: Mechanical Components, Briefs, TSP

Read More >>

Self-Deployable Spring-Strip Booms

These structures can be stowed compactly with small forces and become rigid once deployed. Booms and other structures consisting mainly of thin spring strips are undergoing development. These structures are designed to be lightweight, to be compactly stowable, and to be capable of springing to stable configurations at full extension once released from stowage. Conceived for use as self-deploying structures in outer space, portable structures of this type may also be useful on Earth in applications in which there are requirements for light weight and small transportation volume.

Posted in: Mechanical Components, Briefs, TSP

Read More >>

Lightweight Energy Absorbers for Blast Containers

Aluminum foam liners tested for possible replacement of solid lead liners. Kinetic-energy- absorbing liners made of aluminum foam have been developed to replace solid lead liners in blast containers on the aft skirt of the solid rocket booster of the space shuttle. The blast containers are used to safely trap the debris from small explosions that are initiated at liftoff to sever frangible nuts on hold-down studs that secure the spacecraft to a mobile launch platform until liftoff.

Posted in: Mechanical Components, Briefs, TSP

Read More >>

Brush-Wheel Samplers for Planetary Exploration

A report proposes brush-wheel mechanisms for acquiring samples of soils from remote planets. In simplest terms, such a mechanism would contain brush wheels that would be counter-rotated at relatively high speed. The mechanism would be lowered to the ground from a spacecraft or other exploratory vehicle. Upon contact with the ground, the counterrotating brush wheels would kick soil up into a collection chamber. Thus, in form and function, the mechanism would partly resemble traditional street and carpet sweepers. The main advantage of using of brush wheels (in contradistinction to cutting wheels or other, more complex mechanisms) is that upon encountering soil harder than expected, the brushes could simply deflect and the motor(s) could continue to turn. That is, sufficiently flexible brushes would afford resistance to jamming and to overloading of the motors used to rotate the brushes, and so the motors could be made correspondingly lighter and less power hungry. Of course, one could select the brush stiffnesses and motor torques and speeds for greatest effectiveness in sampling soil of a specific anticipated degree of hardness.

Posted in: Mechanical Components, Briefs, TSP

Read More >>

Probe Without Moving Parts Measures Flow Angle

Flow angle is computed from forces measured by use of strain gauges. The measurement of local flow angle is critical in many fluid-dynamic applications, including the aerodynamic flight testing of new aircraft and flight systems. Flight researchers at NASA Dryden Flight Research Center have recently developed, flight-tested, and patented the force-based flow-angle probe (FLAP), a novel, force-based instrument for the measurement of local flow direction. Containing no moving parts, the FLAP may provide greater simplicity, improved accuracy, and increased measurement access, relative to conventional moving-vane-type flow-angle probes.

Posted in: Mechanical Components, Briefs

Read More >>

Noncircular Cross Sections Could Enhance Mixing in Sprays

Preliminary results suggest that elliptical cross sections may be best. A computational study has shown that by injecting drops in jets of gas having square, elliptical, triangular, or other noncircular injection cross sections, it should be possible to increase (relative to comparable situations having circular cross section) the entrainment and dispersion of liquid drops. This finding has practical significance for a variety of applications in which it is desirable to increase dispersion of drops. For example, in chemical-process sprays, increased dispersion leads to increases in chemical-reaction rates; in diesel engines, increasing the dispersion of drops of sprayed fuel reduces the production of soot; and in household and paint sprays, increasing the dispersion of drops makes it possible to cover larger surfaces.

Posted in: Mechanical Components, Briefs, TSP

Read More >>

White Papers

Back to Basics of Electrical Measurement
Sponsored by Keithley
Future Advances in Body Electronics
Sponsored by Freescale
Next-Generation, Miniature High Voltage Power Modules
Sponsored by EMCO High Voltage
Discover The Advantages Of Pure Fused Silica Capillary Tubing In Medical Applications
Sponsored by Molex
Introduction to Hypervisor Technology
Sponsored by Curtiss-Wright Controls Embedded Computing
OEM Optical System Development
Sponsored by Ocean Optics

White Papers Sponsored By: