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Results for “ignition system”

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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At least 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Flexure Upgrade System Engineering Project

At the National Ignition Facility (NIF), a system of lasers is used to implode and blow-up targets and create temperatures and pressures unlike any other place on earth. There are many target types that are used on experiments, but they can be broadly put in two categories – room temperature targets and cold targets. All targets can be mounted on any of the three target positioners on NIF, and two of these three target positioners can cryogenically cool the targets in the low Kelvin range for the cold targets. To minimize the ice buildup and infrared light exposure to these cold targets, a shroud surrounds the targets and seals the target from the outer environment. By shrouding the target, air, water, and other molecules have a difficult time reaching the target and some particles get cryo trapped into the shrouds themselves.

42 ENGINEERING↗
NASA NTRS1989

Improved plasma torch for ignition and flame holding in supersonic combustion

A plasma torch system designed for ignition and flame-holding in supersonic combustion studies has been modified, in order to decrease electrode wear and increase stability, through the incorporation of a flow swirler in the gas inlet that adds vortex-stabilization to the arc. The torch body was redesigned in order to achieve superior alignment of the electrodes; the electrode gap was made continuously adjustable, thereby allowing fine tuning during torch operation. Table operation of the improved torch has been demonstrated in pure nitrogen, eliminating the requirement of argon gas for arc stabilization.

O'Brien, W. F.↗
DOE OSTI2019

Supervisory control of a compression ignition engine

A system for controlling the combustion behavior of an engine is provided. The engine is equipped with a plurality of control subsystems that influence combustion in the engine. The system includes a controller configured to receive a plurality of inputs, to determine a desired subsystem states to operate the engine, and to determine a target value for each of a plurality of control parameters, wherein the target values for one or more control parameters depends on the values of the plurality of inputs. The controller is further configured to communicate the target values of control parameters to the control subsystems.

Roth, Gregory T.↗
DOE OSTI2019

Ultra-compact system for characterization of physical, chemical and ignition properties of fuels

The present disclosure relates to a miniaturized fuel laboratory system having exterior dimensions enabling the system to be at least one of hand-holdable or contained on a component. The system makes use of a processor, a fuel inlet port for receiving a quantity of fuel to be used as a fuel test sample, and at least one fuel sensor in communication with the fuel inlet port for receiving the fuel test sample. The processor uses the information obtained by the fuel sensor to determine at least one characteristic of the fuel test sample.

Mcnenly, Matthew J.↗
DOE OSTI2021

Ultra-compact system for characterization of physical, chemical and ignition properties of fuels

The present disclosure relates to a miniaturized fuel laboratory system that makes use of a housing, a processor housed within the housing, and a fuel inlet port supported from the housing for receiving a quantity of fuel to be used as a fuel test sample. The system may also have at least one fuel sensor housed in the housing in communication with the fuel inlet port for receiving the fuel test sample and carrying out combustion thereof. An electronic component may be housed in the housing, which enables communication with an external remote subsystem. A database may be incorporated which contains at least one of stored fuel characteristics or stored fuel analysis models, accessible by the processor. The processor may use fuel oxidation information generated by the fuel sensor, and at least one of the stored fuel characteristics or stored combustion models, to determine at least one fuel characteristic of the fuel test sample.

McNenly, Matthew J.↗
DOE OSTI2011

Stability Measurements for Alignment of the NIF Neutron Imaging System Pinhole Array

The alignment system for the National Ignition Facility's neutron imaging system has been commissioned and measurements of the relative stability of the 90-315 DIM, the front and the back of the neutron imaging pinhole array and an exploding pusher target have been made using the 90-135 and the 90-258 opposite port alignment systems. Additionally, a laser beam shot from the neutron-imaging Annex and reflected from a mirror at the back of the pinhole array was used to monitor the pointing of the pinhole. Over a twelve hour period, the relative stability of these parts was found to be within {approx} {+-}18 {micro}m rms even when using manual methods for tracking the position of the objects. For highly visible features, use of basic particle tracking techniques found that the front of the pinhole array was stable relative to the 90-135 opposite port alignment camera to within {+-}3.4 {micro}m rms. Reregistration, however, of the opposite port alignment systems themselves using the target alignment sensor was found to change the expected position of target chamber center by up to 194 {micro}m.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2022

Wildfire Mitigation Plans in Power Systems: A Literature Review

Some of the deadliest wildfires in the U.S., such as California’s 2018 wildfires, have been ignited by power systems. In an effort to prevent and minimize the ignition of wildfires, or control them if ignited, energy companies have developed wildfire mitigation plans. This paper provides energy companies and power system operators, engineers, researchers, and suppliers an overview of the state-of-the-art studies that address key topics in these wildfire mitigation plans and compares the wildfire mitigation plans of several energy companies. The key topics include grid design and system hardening, asset management and inspection, situational awareness and forecasting, operational response, vegetation management, public safety power shutoff, and risk-spend efficiency. Here this paper also presents a comparison of several energy companies’ decision-making criteria for initiating a public safety power shutoff. Finally, we discuss opportunities for future research studies that could help energy companies prevent wildfire ignitions.

42 ENGINEERING↗
NASA NTRS2018

Associative Polymers to Control Formation of Particulate Matter from Ignitable Compositions and Related Compositions, Methods and Systems

Described herein are associative polymers capable of controlling formation of particulate matter from a non-polar ignitable composition upon ignition of the non-polar ignitable composition, alone or in combination with control of a physical and/or chemical property of the non-polar compositions and related compositions, methods and systems. Associative polymers herein described have a non-polar backbone and functional groups presented at ends of the non-polar backbone, with a number of the functional groups presented at the ends of the non-polar backbone formed by associative functional groups capable of undergoing an associative interaction with another associative functional group with an association constant (k) such that the strength of each associative interaction is less than the strength of a covalent bond between atoms and in particular less than the strength of a covalent bond between backbone atoms.

Kornfield, Julia A.↗
DOE OSTI2011

Control System For Cryogenic THD Layering At The National Ignition Facility

The National Ignition Facility (NIF) is the world largest and most energetic laser system for Inertial Confinement Fusion (ICF). In 2010, NIF began ignition experiments using cryogenically cooled targets containing layers of the tritium-hydrogen-deuterium (THD) fuel. The 75 {micro}m thick layer is formed inside of the 2 mm target capsule at temperatures of approximately 18 K. The ICF target designs require sub-micron smoothness of the THD ice layers. Formation of such layers is still an active research area, requiring a flexible control system capable of executing the evolving layering protocols. This task is performed by the Cryogenic Target Subsystem (CTS) of the NIF Integrated Computer Control System (ICCS). The CTS provides cryogenic temperature control with the 1 mK resolution required for beta-layering and for the thermal gradient fill of the capsule. The CTS also includes a 3-axis x-ray radiography engine for phase contrast imaging of the ice layers inside of the plastic and beryllium capsules. In addition to automatic control engines, CTS is integrated with the Matlab interactive programming environment to allow flexibility in experimental layering protocols. The CTS Layering Matlab Toolbox provides the tools for layer image analysis, system characterization and cryogenic control. The CTS Layering Report tool generates qualification metrics of the layers, such as concentricity of the layer and roughness of the growth boundary grooves. The CTS activities are automatically coordinated with other NIF controls in the carefully orchestrated NIF Shot Sequence.

42 ENGINEERING↗
DOE OSTI2020

Spark-ignited direct-injection engine combustion systems

A direct-injection stratified charge internal combustion engine includes a combustion cylinder to receive an air-fuel mixture, and an air intake port to inlet air into the combustion cylinder. The direct-injection engine also includes a fuel injector configured to deliver fuel within the cylinder in a spray pattern substantially aligned to a cylinder central axis to create the air-fuel mixture. A spark igniter is located within a path of the spray pattern to ignite combustion of the air-fuel mixture. The direct-injection engine further includes a movable piston defining a lower boundary of the combustion cylinder to contain the combustion of the air-fuel mixture. The piston is configured to include a bowl portion having local geometric features located on an intake port side of the combustion cylinder to redirect fluid flow towards a vortex in fluid communication with a combustion location near the cylinder central axis.

42 ENGINEERING↗
NASA NTRS2005

Preventing Accidental Ignition of Upper-Stage Rocket Motors

A report presents a proposal to reduce the risk of accidental ignition of certain upper-stage rocket motors or other high energy hazardous systems. At present, mechanically in-line initiators are used for initiation of many rocket motors and/or other high-energy hazardous systems. Electrical shorts and/or mechanical barriers, which are the basic safety devices in such systems, are typically removed as part of final arming or pad preparations while personnel are present. At this time, static discharge, test equipment malfunction, or incorrect arming techniques can cause premature firing. The proposal calls for a modular out-of-line ignition system incorporating detonating-cord elements, identified as the donor and the acceptor, separated by an air gap. In the safe configuration, the gap would be sealed with two shields, which would prevent an accidental firing of the donor from igniting the system. The shields would be removed to enable normal firing, in which shrapnel generated by the donor would reliably ignite the acceptor to continue the ordnance train. The acceptor would then ignite a through bulkhead initiator (or other similar device), which would ignite the motor or high-energy system. One shield would be remotely operated and would be moved to the armed position when a launch was imminent or conversely returned to the safe position if the launch were postponed. In the event of failure of the remotely operated shield, the other shield could be inserted manually to safe the system.

Hickman, John↗
DOE OSTI2023

Neutron imaging of inertial confinement fusion implosions

We review experimental neutron imaging of inertial confinement fusion sources, including the neutron imaging systems that have been used in our measurements at the National Ignition Facility. These systems allow measurements with 10 µm resolution for fusion deuterium–deuterium and deuterium–tritium neutron sources with mean radius up to 400 µm, including measurements of neutrons scattered to lower energy in the remaining cold fuel. These measurements are critical for understanding the fusion burn volume and the three-dimensional effects that can reduce the neutron yields.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2014

Advanced Natural Gas Reciprocating Engine(s)

The objective of the Cummins ARES program, in partnership with the US Department of Energy (DOE), is to develop advanced natural gas engine technologies that increase engine system efficiency at lower emissions levels while attaining lower cost of ownership. The goals of the project are to demonstrate engine system achieving 50% Brake Thermal Efficiency (BTE) in three phases, 44%, 47% and 50% (starting baseline efficiency at 36% BTE) and 0.1 g/bhp-hr NOx system out emissions (starting baseline NOx emissions at 2 – 4 g/bhp-hr NOx). Primary path towards above goals include high Brake Mean Effective Pressure (BMEP), improved closed cycle efficiency, increased air handling efficiency and optimized engine subsystems. Cummins has successfully demonstrated each of the phases of this program. All targets have been achieved through application of a combined set of advanced base engine technologies and Waste Heat Recovery from Charge Air and Exhaust streams, optimized and validated on the demonstration engine and other large engines. The following architectures were selected for each Phase: Phase 1: Lean Burn Spark Ignited (SI) Key Technologies: High Efficiency Turbocharging, Higher Efficiency Combustion System. In production on the 60/91L engines. Over 500MW of ARES Phase 1 technology has been sold. Phase 2: Lean Burn Technology with Exhaust Waste Heat Recovery (WHR) System Key Technologies: Advanced Ignition System, Combustion Improvement, Integrated Waste Heat Recovery System. Base engine technologies intended for production within 2 to 3 years Phase 3: Lean Burn Technology with Exhaust and Charge Air Waste Heat Recovery System Key Technologies: Lower Friction, New Cylinder Head Designs, Improved Integrated Waste Heat Recovery System. Intended for production within 5 to 6 years Cummins is committed to the launch of next generation of large advanced NG engines based on ARES technology to be commercialized worldwide.

Pike, Edward↗
NASA NTRS1996

Guide for Oxygen Hazards Analyses on Components and Systems

Because most materials, including metals, will burn in an oxygen-enriched environment, hazards are always present when using oxygen. Most materials will ignite at lower temperatures in an oxygen-enriched environment than in air, and once ignited, combustion rates are greater in the oxygen-enriched environment. Many metals burn violently in an oxygen-enriched environment when ignited. Lubricants, tapes, gaskets, fuels, and solvents can increase the possibility of ignition in oxygen systems. However, these hazards do not preclude the use of oxygen. Oxygen may be safely used if all the materials in a system are not flammable in the end-use environment or if ignition sources are identified and controlled. These ignition and combustion hazards necessitate a proper oxygen hazards analysis before introducing a material or component into oxygen service. The objective of this test plan is to describe the White Sands Test Facility oxygen hazards analysis to be performed on components and systems before oxygen is introduced and is recommended before implementing the oxygen component qualification procedure. The plan describes the NASA Johnson Space Center White Sands Test Facility method consistent with the ASTM documents for analyzing the hazards of components and systems exposed to an oxygen-enriched environment. The oxygen hazards analysis is a useful tool for oxygen-system designers, system engineers, and facility managers. Problem areas can be pinpointed before oxygen is introduced into the system, preventing damage to hardware and possible injury or loss of life.

Stoltzfus, Joel M.↗
NASA NTRS2005

A Brief Study on Toxic Combustion Products of the Polymers Used in High-Pressure Oxygen Systems

One likely cause of polymer ignition in a high-pressure oxygen system is the adiabatic-compression heating of polymers caused by pneumatic impact. Oxidative pyrolysis or combustion of polymers in a high-pressure oxygen system could generate toxic gases. This paper investigates the feasibility of using the NASA pneumatic-impact system to conduct adiabatic-compression combustion tests and determines the toxic combustion products produced from the burning of five selected polymers. Five polymers commonly used in high-pressure oxygen systems, Zytel(Registered TradeMark) 42 (Nylon 6/6), Buna N (nitrile rubber), Witon(Registered TradeMark) A (copolymer of vinylidene fluoride and hexafluoropropylene), Neoflon(Registered TradeMark) (polychlorotrifluoroethylene), and Teflon(Registered TradeMark) (polytetrafluoroethylene), were tested in the NASA pneumatic-impact test system at 17.2-MPa oxygen pressure. The polymers were ignited and burned; combustion products were collected in a stainless-steel sample bottle and analyzed using various methods. The results show that the NASA pneumatic-impact system is an appropriate test system to conduct adiabatic-compression combustion tests and to collect combustion products for further chemical analysis. The composition of the combustion product gas generated from burning the five selected polymers are presented and discussed.

Hshieh, Fu-Yu↗