Mechanical & Fluid Systems

A report discusses the problem of controlling the maneuvers of multiple spacecraft flying in formation and, more specifically, making the entire formation rotate about a given axis and synchronizing the rotations of the individual spacecraft with the rotation of the formation. Such...

Efforts are underway to develop microfabricated flow controllers and pressure regulators that contain as few discrete components as feasible and that are cheaper, more robust, and orders of magnitude smaller than are currently commercially available devices that have similar capabilities. The...

A compact actuator generates rotary or linear motion with a large torque or force, respectively. The original version of this actuator is designed to pull a wedge that, until pulled, prevents retraction of the proposed extended nose landing gear of the space shuttle. The original version is also...

An improved closed-loop, two-stage pulse-tube refrigerator provides 4 W of cooling power at a temperature of 15 K. The original intended application of this refrigerator is in preventing boiloff of liquid hydrogen from a propellant tank aboard a spacecraft. The basic refrigerator design can also be...

Computational test cases have been selected from archived sets of data acquired some years ago in wind-tunnel experiments on a clipped delta wing equipped with a hydraulically actuated trailing-edge control surface. In some of the experiments, the wing was subjected to pitching...

A magnetostrictive motor and its drive circuit and control system have been designed to be especially suitable for robotic applications in which there are requirements for precise, high-force linear actuators. The motor includes a laminated armature made of the magnetostrictive alloy...

Model Rocket Engine Software System (MRECS) is a system of control software that was originally intended for use in controlling rocket engines but is also applicable to almost any real-time, closed- loop process-control system — for example, the feedback control system of a robot. MRECS...

A proposed ground- based apparatus would accelerate a spacecraft to speed of about mach 1, thus making it possible to increase the payload and/or reduce the cost of launching the space- craft into orbit. The apparatus would include a track along which the spacecraft would ride on a sled. Hundreds of...

A report presents a study oriented toward optimization of synthetic jet actuators. [A syn- thetic jet actuator is a fluidic control device that partly resembles a loudspeaker. It typically comprises a piezo- electric actuator/ diaphragm situated in a cavity, facing an orifice or nozzle at the opposite end of...

A report discusses wind-tunnel tests of a scale model of a con- ceptual two-engine jet airplane designed to carry 10 passengers, have a range of 4,000 miles (≈6,400 km), cruise at a mach number of 2.0, and generate a low sonic boom [char- acterized by a shock overpressure of ≤ 0.5...

The Smart Umbilical Mating System (SUMS) is an automated, three-degreeof- freedom, scalable system for quickly mating, demating, and/or remating ganged umbilicals. SUMS connects electrical and fluid paths between spacecraft and ground support equipment whether liftoff or side mount for NON T-0...

A proposed apparatus would effect friction stir welding (FSW) along a circumferential path to join two pipes. The apparatus is denoted an “orbital FSW system” because the circumferential motion of the FSW head would be similar to the motions of welding heads in commercial orbital fusion welding...

Some improvements have been made to enhance the role of water as a test solvent for determining the amount of hydrocarbon nonvolatile residue (NVR) present on an item of hardware that is required to be totally or nearly devoid of such residue. Water is now used as an NVR-testing solvent...

A report discusses tests of finger seals, which were described in “Pressure- Balanced, Low-Hysteresis Finger Seal” (LEW-16840), which appears on page 52 in this issue. Like a labyrinth or brush seal, a finger seal is used (typically in a gas turbine) to minimize a leakage flow along a rotating shaft. The report describes...

The proposed Plant Harvesting Mechanization System (PHARMS) would comprise machinery and controls for semiautomated harvesting of plants grown in a controlled environment. The PHARMS was conceived as a prototype of harvesters to be incorporated into life-support systems of spacecraft and...