Mechanical & Fluid Systems

Access our comprehensive library of technical briefs on mechanical and fluid systems, from engineering experts at NASA and government, university, and commercial laboratories.

Briefs: Mechanical & Fluid Systems

NASA's F-15B #836 is a two-seat version of the F-15, which is a high-performance, supersonic, all-weather fighter airplane. The F-15B is used as a test-bed aircraft for a wide variety of...

Briefs: Mechanical & Fluid Systems

Space structures in general experience free-free vibrational boundary conditions that are not readily replicable on the ground. To conduct vibration tests of such structures on Earth,...

Briefs: Mechanical & Fluid Systems

A change in the design of the engine inlets of the T-38 airplane significantly reduces takeoff distances while increasing safety margins. Although the newer inlet design (see Figure 1) is based on well-known...

Briefs: Mechanical & Fluid Systems

Some changes in the design and construction of the leading edges of metal airplane wings have shown promise as means to suppress laminar-to-turbulent flow transitions. The...

Briefs: Mechanical & Fluid Systems

The figure shows an oil tunnel and associated equipment used in experiments, using the full-flow-field tracking (FFFT) technique, to characterize flows in beds packed with poly (methyl...

Briefs: Mechanical & Fluid Systems

NASA Dryden Flight Research Center is supporting a Phase II Small Business Innovation Research (SBIR) contract between the U.S. Air Force Research Labs and Kelly Space & Technology (KST). KST's...

Briefs: Mechanical & Fluid Systems

Direct measurement of aircraft-engine thrust by use of strain gauges offers several advantages over traditional model-based methods of calculating thrust, provided that care is...

Briefs: Mechanical & Fluid Systems

The Perseus B remotely piloted vehicle (RPV) has achieved a record altitude for a single-engine, propeller-driven airplane of 60,260 ft (18,367 m) on June 27, 1998. The Perseus B is one of...

Briefs: Mechanical & Fluid Systems
Model-Based Monitoring for Spacecraft Thruster Leakage

A report describes a method of detecting leakage in one of the 16 thrusters of the Cassini spacecraft. The detection method, implemented as part of the spacecraft flight software, is based on the fact that the three-axis rotational motion of a spacecraft is governed by the Euler's equation....

Briefs: Mechanical & Fluid Systems

Improved pressure-relief valves have been developed for systems that contain gases and liquids in a variety of pneumatic, hydraulic, and cryogenic applications. These valves could...

Briefs: Mechanical & Fluid Systems

Streamlined fairings have been invented for housing single or multiple microphones to measure noise in flowing gases and liquids. Each fairing of this type is designed to minimize the...

Briefs: Mechanical & Fluid Systems

The figure depicts an improved apparatus for three- or four-point bending tests of stripe specimens. In a bending test, the specimen is subjected to tension along its top surface and compression along...

Briefs: Mechanical & Fluid Systems
Using Genetic Algorithms in Spacecraft Vibration Control

Three software products are being developed to help satisfy the needs of NASA and of private industry for reconfigurable active control systems to suppress vibrations in Reusable Launch Vehicles (RLVs) and other structures. These potentially highly marketable products are the...

Briefs: Mechanical & Fluid Systems

Two techniques have been proposed (see figure) for controlling the buoyancies and thus the altitudes of robotic lifting balloons (aerobots) that would carry scientific instruments...

Briefs: Mechanical & Fluid Systems
Equipping Quick-Disconnect Fittings To Detect Leaks

Quick-disconnect fittings on hoses and bellows can be equipped with sensors to detect leaks and misalignments that cause leaks. Experiments have shown that four types of sensors are effective for this purpose: force sensors, strain gauges, pressure transducers, and microphones. Of these, force...

Briefs: Mechanical & Fluid Systems

This airplane is expected to be safe from destruction by flutter instabilities.

Briefs: Mechanical & Fluid Systems

A flutterometer is being developed for use as a data-analysis tool for flight flutter testing. The tool is based on an on-line implementation of a robust flutter-analysis technique, called the "* method,"...

Briefs: Mechanical & Fluid Systems

A mathematical model represents the dynamic response of a pressure sensor that (a) comprises a transducer connected to a pressure-sensing port via a pneumatic tube and (b) is operated...

Briefs: Mechanical & Fluid Systems
Improved Mufflers for General Aviation

Innovative designs of mufflers for engines of small airplanes have been investigated in an effort to satisfy conflicting demands to maximize the reduction of exhaust noise while minimizing back pressure, size, and weight. Automotive-type muffler designs are not suitable for this purpose because they entail...

Briefs: Mechanical & Fluid Systems

Harmonic drive gearing is recognized by designers for its zero backlash, high gear ratios, and compact design features. A recent development by HD Systems incorporates a large hollow shaft...

Briefs: Mechanical & Fluid Systems

An acoustic-radiation-pressure phased array (ARPPA) is undergoing development at Lewis Research Center. ARPPAs are envisioned as general-purpose, nonintrusive tools for manipulating both...

Briefs: Mechanical & Fluid Systems

Structural Analysis/Design (STRAND) and Neural Net Computation (NETCOM) are developmental modular computer programs that exploit the speedup afforded by parallel and neural-network...

Briefs: Mechanical & Fluid Systems

Acoustic-radiation pressure can be used to improve performance in the dispensing of liquid drops into gases or vacuum and in dispensing gas bubbles into liquids. In a typical application...

Briefs: Mechanical & Fluid Systems

An improved "sensor-integrating" algorithm has been developed for use in extracting partial information on the time-varying attitude of a balloon-borne robotic instrumentation...

Briefs: Mechanical & Fluid Systems

Latching devices have been developed to provide electrical connections, secure mechanical and thermal connections, and optical alignment for mounting electronically controlled...

Briefs: Mechanical & Fluid Systems

Window assemblies (see figure) have been developed to satisfy special requirements pertaining to ease of replacement, alignment, sealing, and resistance to vibration in a spaceborne...

Briefs: Mechanical & Fluid Systems

A two-body design has enabled an instrumented penetrator projectile to function with increased tolerance to initial misalignment among (a) the longitudinal axis of the penetrator, (b) the...

Briefs: Mechanical & Fluid Systems

Multifinger electroactive-polymer grippers (MEPGs) are simple, compact, lightweight robotic end effectors with fingers that bend and function similarly to human fingers. The fingers are made...

Briefs: Mechanical & Fluid Systems

A novel airdata system based on flush-mounted pressure sensors has been developed for the X-33 aerospace vehicle. Denoted the "X-33 flush airdata sensing" (FADS) system, it was...

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