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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Continuing research has resulted in significant advances in induction-heated plasma torch technology which extend and enhance its potential for broad range of uses in chemical processing, materials development and testing, and development of large illumination sources. Summaries of these advances are briefly described.
A device for automatically controlling the movement of a welding torch while welding an elongated joint is described. A charge injection television camera is carried on a movable support. The camera includes a matrix of individual light sensing video elements which generate voltages responsive to light reflected off of the joint and surrounding areas of the work piece. The voltages produced by the pixels are converted to digital words which are fed to a microprocessor for generating an error signal. This error signal is fed to a digital motor which is used to drive a movable support upon which the television camera is carried.
The design and operation of a hydrogen-air ignition torch presently being used to burn off excess hydrogen that accumulates in the scrubber exhaust ducts of two rocket engine test facilities at the NASA Lewis Research Center in Cleveland, Ohio, is described.
Simple attachment extends torch to difficult-to-reach joints. Bushing, gasket, and extender mate with gascup to form extension assembly. Extender designed and fabricated to suit particular job.
This paper describes a long-lasting large-amplitude pulsation event, which occurred on January 10, 1983 in the ionosphere and magnetosphere and was characterized by Steen and Rees (1983). Over the 4-h period (0200-0600 UT), the characteristics of the pulsations in the ionosphere changed from being Ps 6 auroral torches toward substorms and back to Ps 6. At GEO, the corresponding characteristics were a modulation of the high-energy particle intensity and plasma dropouts. Based on the ideas presented by Rostoker and Samson (1984), an interpretation of the event is offered, according to which the pulsations are caused by the Kelvin-Helmholtz instability during an interval of strong magnetospheric convection. On the basis of this explanation, a new interpretation of the substorm time sequence is proposed.
This paper presents data from the thermostructural testing of tape-wrapped carbon phenolic. This work has been performed with the use of a plasma torch and loading device in an effort to study the anomalous erosion characteristicfs of that seen in the Space Shuttle Solid Rocket Motor Nozzle STS-8A. Testing is conducted in an effort to determine conditions or parameters involved in this mode of failure.
Numerical solutions of the Navier-Stokes equations for compressible reacting flow in an axisymmetric geometry are presented for a nitrogen plasma torch with both thermal and chemical nonequilibrium. The Navier-Stokes equations are solved using a new axisymmetric finite element/finite volume formulation in which the convective flux is treated by an extension of the approximate Riemann solver due to Osher. The numerical scheme is validated by comparison with a previous solution of the same problem using a different computational scheme. Results obtained using two different models of nonthermal dissociation rates are compared to experimental data.
The hydrogen-oxygen torch igniter described herein has been successfully used for many years at various NASA Lewis Research Center rocket test facilities to provide ignition for rocket engine research hardware. This igniter is inexpensive, simple to operate, and has demonstrated very good reliability. It has been used as an ignition source for rocket engines that utilized a variety of propellant combinations; some of these engines developed up to 40,000 lb of thrust.
Two modifications proposed to improve nucleation and growth of diamond films on surfaces by use of oxyacetylene torch. In one modification, carbon monoxide added to fuel gas; in other, carbon monoxide, methane, and oxygen added in synchronized pulses. Second modification intended not only to improve nucleation and growth of diamond films but also makes films more nearly homogeneous over areas larger than spots of such film grown by oxygen/acetylene-growth technique. Modified technique enables deposition of diamond films on alternative materials-in particular, copper.
Reliable device used to ignite variety of fuels. Used as general-purpose ignitor in other applications, or as hydrogen/oxygen torch. Operation of device straight-forward. Hydrogen and oxygen flow through separate ports into combustion chamber in device, where they ignite by use of surface-gap spark plug. Hot gases flow from this combustion chamber, through injector tube, into larger combustion chamber containing fuel-oxidizer mixture to be ignited.
This paper presents drawings of R0018002 Oxidizer Preburner Tube and 5705565 Torch Weld Jig.
For standard Additive Manufacturing (AM) processes, traditional path planning typically relies on a 2.5-dimensional approach. In wire-arc directed energy deposition (DED), commonly referred to as wire-arc additive manufacturing (WAAM), this 2.5D approach inherently limits final near net shape due to the stair-step effect and restricts the maximum overhang angle achievable without part degradation. To achieve better near net shape and part quality, a 3D planning approach that modulates the tool tip position and angle without process changes is demonstrated in components containing up to 105° of unsupported overhang. The experimental methods are validated with half and fully enclosed cylinder sections containing 90° of overhang. The non-gravity aligned methods are then applied to a commercial WAAM system for a composite tool mold demonstrator part. As a result, the methods developed in this paper enable expansion of WAAM system capabilities to parts containing large overhangs without compromising the net shape or material structure of the resulting parts and without the need for a part positioner.
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