Mechanical & Fluid Systems

Bubble Eliminator Based on Centifugal Flow

This device contains no moving parts.

The fluid bubble eliminator (FBE) is a device that removes gas bubbles from a flowing liquid. The FBE contains no moving parts and does not require any power input beyond that needed to pump the liquid. In the FBE, the buoyant force for separating the gas from the liquid is provided by a radial pressure gradient associated with a centrifugal flow of the liquid and any entrained bubbles. A device based on a similar principle is described in Centrifugal Adsorption Cartridge System (Nasa Tech Briefs August 2004, MSC-22863), which appears on page 48 of this issue. The FBE was originally intended for use in filtering bubbles out of a liquid flowing relatively slowly in a bioreactor system in microgravity. Versions that operate in normal Earth gravitation at greater flow speeds may also be feasible.

Posted in: Briefs, Mechanical Components, Mechanics, Gases, Test equipment and instrumentation

Inflatable Emergency Atmospheric-Entry Vehicles

Ballutes would act as inexpensive, lightweight atmospheric decelerator "lifeboats."

In response to the loss of seven astronauts in the Space Shuttle Columbia disaster, large, lightweight, inflatable atmospheric-entry vehicles have been proposed as means of emergency descent and landing for persons who must abandon a spacecraft that is about to reenter the atmosphere and has been determined to be unable to land safely. Such a vehicle would act as an atmospheric decelerator at supersonic speed in the upper atmosphere,and a smaller, central astronaut pod could then separate at lower altitudes and parachute separately to Earth.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Disaster and emergency management, Emergency management, Entry, descent, and landing

Lightweight Deployable Mirrors With Tensegrity Supports

Extremely lightweight, deployable structures could be made by assembling tensegrity modules.

The upper part of Figure 1 shows a small-scale prototype of a developmental class of lightweight, deployable structures that would support panels in precise alignments. In this case, the panel is hexagonal and supports disks that represent segments of a primary mirror of a large telescope. The lower part of Figure 1 shows a complete conceptual structure containing multiple hexagonal panels that hold mirror segments.

Posted in: Briefs, Mechanical Components, Mechanics, Mirrors

SiC-Based Miniature High-Temperature Cantilever Anemometer

SiC-Based Miniature High-Temperature Cantilever Anemometer This compact, minimally intrusive sensor functions at temperature as high as 600 °C

The figure depicts a miniature cantilever- type anemometer that has been developed as a prototype of compact, relatively nonintrusive anemometers that can function at temperatures up to 600 °C and that can be expected to be commercially mass-producible at low cost. The design of this anemometer, and especially the packaging aspect of the design, is intended to enable measurement of turbulence in the high-temperature, high-vibration environment of a turbine engine or in any similar environment.

Posted in: Briefs, Mechanical Components, Mechanics, Test equipment and instrumentation

Inlet Housing for a Partial-Admission Turbine

Inlet Housing for a Partial-Admission Turbine The housing is shaped to smooth the inlet flow.

An inlet housing for a partial-admission turbine has been designed to cause the inlet airflow to make a smooth transition from an open circular inlet to an inlet slot. The smooth flow is required for purposes of measuring inlet flow characteristics and maximizing the efficiency of the turbine.

Posted in: Briefs, Mechanical Components, Mechanics, Gas turbines

Farm Equipment Manufacturer Shortens Design Cycle With Analysis Software

The design of new tilling machinery is accelerated using finite element analysis software.

Humans have been using tools to make farming easier since the dawn of civilization. Since the turn of the 20th century, the growing use of mechanized power to till and sow fields has enabled farmers to realize incredible efficiency gains in the production of low-cost, safe, and nutritious foods and other crops, such as fibers. Today, bigger machines require less manpower to plant the crops that feed and clothe a swelling world population.

Posted in: Briefs, Mechanical Components, Mechanics, CAD, CAM, and CAE, Design processes, Agricultural vehicles and equipment

Rotating Reverse-Osmosis for Water Purification

Rotating Reverse-Osmosis for Water Purification This device would resist fouling.

A new design for a water-filtering device combines rotating filtration with reverse osmosis to create a rotating reverse- osmosis system. Rotating filtration has been used for separating plasma from whole blood, while reverse osmosis has been used in purification of water and in some chemical processes. Reverse-osmosis membranes are vulnerable to concentration polarization — a type of fouling in which the chemicals meant not to pass through the reverse-osmosis membranes accumulate very near the surfaces of the membranes. The combination of rotating filtration and reverse osmosis is intended to prevent concentration polarization and thereby increase the desired flux of filtered water while decreasing the likelihood of passage of undesired chemical species through the filter. Devices based on this concept could be useful in a variety of commercial applications, including purification and desalination of drinking water, purification of pharmaceutical process water, treatment of household and industrial wastewater, and treatment of industrial process water.

Posted in: Briefs, Mechanical Components, Mechanics, Water treatment

Robotic End Effectors for Hard-Rock Climbing

End effectors emulate equipment used by human climbers.

Pasadena, California Special-purpose robot hands (end effectors) now under development are intended to enable robots to traverse cliffs much as human climbers do. Potential applications for robots having this capability include scientific exploration (both on Earth and other rocky bodies in space), military reconnaissance, and outdoor search and rescue operations.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Robotics

Blade-Pitch Control for Quieting Tilt-Rotor Aircraft

Actively induced harmonic blade-pitch oscillations reduce BVI noise.

A method of reducing the noise generated by a tilt-rotor aircraft during descent involves active control of the blade pitch of the rotors. This method is related to prior such noise- reduction methods, of a type denoted generally as higher-harmonic control (HHC), in which the blade pitch is made to oscillate at a harmonic of the frequency of rotation of the rotor.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Propellers and rotors, Acoustics, Noise, Rotary-wing aircraft

Solar Array Panels With Dust-Removal Capability

Inexpensive, low-power piezoelectric buzzers would be built in.

It has been proposed to incorporate piezoelectric vibrational actuators into the structural supports of solar photovoltaic panels, for the purpose of occasionally inducing vibrations in the panels in order to loosen accumulated dust. Provided that the panels were tilted, the loosened dust would slide off under its own weight. Originally aimed at preventing obscuration of photovoltaic cells by dust accumulating in the Martian environment, the proposal may also offer an option for the design of solar photovoltaic panels for unattended operation at remote locations on Earth.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Sensors and actuators, Particulate matter (PM), Solar energy, Vibration

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