The ADPAC software is a computational fluid dynamics (CFD) code for analysis of flows in turbomachines. The outstanding feature of ADPAC is the ability to solve the Navier-Stokes equations for complex three-dimensional (3D) flow fields that include multiple flow paths, and the modeling of...

A paper summarizes early findings from a continuing study of the dynamics of the transport and distribution of matter within the Solar system. In the study, the stable and unstable manifolds of the periodic and quasi-periodic orbits around the Lagrangian points L1 and L2 of the Sun/planet...

A report describes experiments in which digital particle-image velocimetry (digital PIV) was used to measure the flow field in the diffuser of a high-speed centrifugal compressor. In digital PIV, a sheet of pulsed laser light illuminates a flow field seeded with small tracer particles,...

Coating alumina fibers with sputtered metal has been proposed as a means to enable the fibers to retain more strength when the fibers are incorporated into metal-matrix composites. If the alumina fibers could be made to retain more strength, then it would be possible to manufacture such...

Hydrazine, monomethylhydrazine, and unsymmetrical dimethylhydrazine can be detected and measured at concentrations as low as 10 parts per billion in the presence of ammonia at concentrations as high as 10 parts per million (greater than the odor threshold concentration of ammonia,...

Glenn-HT is a computational fluid dynamics (CFD) computer code for the analysis of three-dimensional flow and convective heat transfer in a gas turbine. Glenn-HT has been evolving during the past few years at Glenn Research Center, and at least 35 technical papers relative to this code have...

In a proposed method of tailoring some of the mechanical properties of metal-matrix, oxide-matrix, and ceramic-matrix composite materials, Kirkendall defects (microscopic pores as described below) would be introduced into thin interfacial layers between the fibers and the matrices. This...

Electrolytic cells for the continuous generation of hydrogen peroxide in streams of water have been developed. Cells of this type could be incorporated into wastewater-treatment systems based on advanced oxidation processes that utilize hydroxyl radicals. In addition to H2O2- generating...

NESTEM is a computer code that is a combination of a heat-transfer-analysis subprogram and a NASA in-house probabilistic-analysis code called "NESSUS" (for Numerical Evaluation of StochasticStructures Under Stress). NESTEM can be used to analyze a complex combustor thermal environment with...

A report discusses the design of inflatable Sun shields proposed for use in keeping the primary mirror of the Next generation Space Telescope (NGST) at a temperature "d60 K. The report summarizes a paper presented at the 33rd Intersociety Energy Conversion Engineering Conference in August 1998 at...

The Systems Improved Numerical Differencing Analyzer/Fluid Integrator (SINDA/FLUINT) software system has been upgraded by addition of a capability for simulating fluid mixtures that include condensable vapors. SINDA/FLUINT is the NASA standard software system for computational simulation of...

A report proposes the development of spaceborne telescope/camera systems that would be lightweight, relatively inexpensive alternatives to current systems based on glass mirrors. In a system of the proposed type, the primary reflector (typically a paraboloid several meters in diameter)...

A paper proposes a method of mutual coherent laser tracking of two spacecraft for detecting gravitational radiation. Each spacecraft would transmit a laser beam to, and receive a similar laser beam from, the other spacecraft. Each spacecraft would also coherently transpond a laser beam...

A proposed automated apparatus would travel along a hanging cable, optically inspecting it all around. The proposal was made to eliminate lowering human inspectors in baskets along emergency-egress slidewires at Kennedy Space Center launch pads. The apparatus would include a motor drive system, a video camera...

An optical sensor for measuring the partial pressure of dissolved oxygen in water is based on the effect of oxygen quenching on the fluorescence lifetime of an optically excited ruthenium complex immobilized in a recently developed polymer. In the operation of this sensor, the fluorescence...

A software library has been developed for adaptive refinement of unstructured (that is, irregular) tetrahedral or triangular meshes that define two- or three-dimensional coordinates or volume elements used in parallel (that is, multiprocessor) finite-element or finite-volume computations. This...