A laser ignition system for the M230 cannon

Lean-burn natural gas engines remain attractive as they offer low emissions with simultaneous high engine efficiency. The low carbon to hydrogen ratio in natural gas minimizes the carbon dioxide emission, while the low-temperature operation reduces NOx formation. However, to preserve engine specific power, turbo-charged operation is required, which results in an unfavorable environment for the spark ignition system. In this study, the performance of three ignition systems - Spark Ignition (SI), Laser Ignition (LI), and Prechamber Laser Ignition (PCLI) - were assessed through tests in a single-cylinder natural gas engine. Both λ and ignition timing sweeps were performed while maintaining a constant speed of 1800 rpm and a load of 10 bar BMEP. Emissions and combustion data analysis, while complying with allowable emission regulation and ignition stability requirements, showed the best performance to be achieved with the PCLI system. This is attributed to improved ignition with the use of a laser, volumetric ignition facilitated by spatially distributed flame jets, and increased in-cylinder turbulence. This results in reduced ignition delay and shortened combustion duration.

Combustion characteristics of a variable compression ratio laser-plasma ignited compressed natural gas engine

The objective of this paper is to share the results obtained from in-depth analysis using a down hole mechanics and dynamics monitoring sub, which lead to the first successful Gullfaks Satellite 14 ¾ x 17 ½ -in Rathole elimination operation through challenging lithology. Shallow gas is encountered in the Gullfaks South area at a true vertical depth of between 335-339m (from MSL), and a casing design incorporating a 16-in liner is utilized to isolate this interval. A 14 ¾ x 17 ½ -in section is then drilled to isolate weak and unstable formations, and in all previous wells this section was drilled with a two run strategy. The first run to drill to section target depth (TD) while hole opening, followed by a dedicated second run to open the rathole. An opportunity was identified to improve well construction performance by eliminating the dedicated run to open the rat-hole, and tailoring the bit design to overcome the challenging lithology and high levels of shock and vibration seen on offset wells. Detailed pre-job planning and BHA design analysis was combined with new downhole technologies to overcome these challenges. Dual reamers were used within a Rotary Steerable System (RSS) BHA to drill the 14 ¾ x 17 ½ -in section and eliminate the rat-hole in one run. This innovative approach involved drilling to section target depth (TD) using an upper ball drop reamer, tool positioned 45 meters behind the bit for hole enlargement while drilling, and then pulling back to position the bit at rat-hole shoulder. At this point the upper reamer was de-activated and a lower on demand hydraulically activated reamer, mounted directly above the RSS was opened to eliminate the rat-hole. Due to excessive shocks & vibrations experienced on offset wells, a down hole drilling mechanics & dynamics sub was utilized to provide real-time information about downhole forces and BHA motions, combined with a tailored bit design to control depth of cut in sandy intervals. This unprecedented approach resulted in 2.5 days saving.

A new type of fiber-optic connector designed to meet military stress requirements has been demonstrated. This reliable optical card-edge (ROC) connector is a multifiber backplane connector (four fiber, blind mate). The connector uses a unique, expanded beam coupling design and micromachined silicon optical subassemblies to provide optimum coupling under high levels of shock and vibration. An additional feature of the ROC connector is its ability to self-seal or shield the optical fiber ends when unmated, protecting the fibers and internal mechanisms from environmental contamination and abusive handling. The authors discuss the design features of the ROC connector with respect to military stress requirements, and present the prototype test results. Based on the test results, it is concluded that the ROC connector can provide a nominal insertion loss of 0.75 dB with a standard deviation of 0.2 dB. The connector provides superb repeatability (standard deviation of 0,1 dB), and shows no evidence of degradation for the nearly 500 insertions and extractions measured (with no cleaning). >

Comparative study of laser ignition and conventional electrical spark ignition systems in a hydrogen fuelled engine

Past research has shown that laser ignition provides a potential means to reduce emissions and improve engine efficiency of gas-fired engines to meet longer-term DOE ARES (Advanced Reciprocating Engine Systems) targets. Despite the potential advantages of laser ignition, the technology is not seeing practical or commercial use. A major impediment in this regard has been the 'open-path' beam delivery used in much of the past research. This mode of delivery is not considered industrially practical owing to safety factors, as well as susceptibility to vibrations, thermal effects etc. The overall goal of our project has been to develop technologies and approaches for practical laser ignition systems. To this end, we are pursuing fiber optically coupled laser ignition system and multiplexing methods for multiple cylinder engine operation. This report summarizes our progress in this regard. A partial summary of our progress includes: development of a figure of merit to guide fiber selection, identification of hollow-core fibers as a potential means of fiber delivery, demonstration of bench-top sparking through hollow-core fibers, single-cylinder engine operation with fiber delivered laser ignition, demonstration of bench-top multiplexing, dual-cylinder engine operation via multiplexed fiber delivered laser ignition, and sparking with fiber lasers. To the best of our knowledge, each of these accomplishments was a first.

Produced water accounts for greater than 80 percent by volume of the residual material generated in the natural gas industry. Cost-effective and environmentally acceptable disposal of these waters is critical to the continued economic production of natural gas. The Gas Research Institute (GRI) has recently completed a comprehensive assessment of the demographics of produced water characterized according to volumes and geographic location of the gas producing geologic provinces of the United States. This information in association with both the federal and state environmental regulations has been used to identify potential cost-effective produced water treatment research opportunities which are described in this paper. The study involved the use of a computer-based engineering-economic model, Produced Water Management Options Model (PWMOM), which combines engineering process models with a cost performance data base to predict the economics of a spectrum of unit water treatment processes and treatment trains. Various produced water scenarios, i.e., volumes, qualities and regulatory requirements, were evaluated and categorized to focus on the natural gas producing regions of the U.S. where produced waters could be surface discharged under the National Pollutant Discharge Elimination System (NPDES). Residual brines from produced water treatment would continue to be injected. Unit process technologies evaluated include deoiling (removal of free oil & grease), iron removal, dissolved organic removal (soluble organic treatment) and partial demineralization. Federal and state regulations were reviewed to identify where surface discharge could be or has been practiced to determine where cost-effective treatment could increase the opportunity for non-injection disposal alternatives. To complete this analysis, surface treatment costs were generated with PWMOM and compared to deep well injection costs. Costs for deep well injection were generated using Salt Water Injection Model (SWIM), a model developed by GRI earlier in this research project. Promising technologies that have been identified include aerobic biological oxidation using fluidized beds, partial demineralization using electrodialysis and reverse osmosis, and a natural freeze-thaw evaporation process for cold climates. Laboratory and pilot studies that have been initiated to evaluate these processes are described here. Additional surface water discharge opportunities may exist where beneficial use such as irrigation or watering livestock is possible and where treatment will ensure that the release to surface waters will not violate water quality standards.

sponsive to the enactment of the Comprehensive Environmental Compensation and Liability Act of 1980 (CERCLA). Nor were they moved into action by the Superfund Amendments and Reauthorization Act of 1986 (SARA). However, the attention of many lenders was attracted by a series of court decisions which imposed upon lenders liability for the cost of cleaning environmentally damaged or contaminated property once belonging to their borrowers. (See Olexa, this issue, for a discussion of this series of cases.) Contemporaneously, countless additional state and federal environmental regulations have been enacted to control and/or repair environmental damage (Olexa 1990, Bock et al.). The purpose of this paper is to describe lenders' responses to environmental regulations and case law, and the potential effect of these regulations on loan demand from the perspective of institutional management. First, the issues are identified and briefly discussed. Next is an examination of the reactions of various lenders and

A cross-functional team of environmental regulatory experts, plant managers, and plant engineers have been working since 1991 on the development, implementation and maintenance of the Environmental Compliance Management System. The Environmental Compliance Management System is a practical and accurate method of determining the applicability of the state and federal environmental regulations and of establishing standard and straightforward procedures to meet these requirements. The Environmental Compliance Management System allows individual manufacturing facilities to avoid the additional manpower that would be required to read, digest and decide on the applicability and plan of action to meet the requirements of all the environmental regulations.

Continued compliance of Hanford operations with all applicable state and federal environmental regulations, with the exception of suspended particulates from several steam power plants, was demonstrated by the environmental and effluent data collected during 1978. Included in the environmental data collected were measurements of external radiation, and radionuclide analyses of air samples, Columbia River water, other surface waters, wildlife, soil, and vegetation. Periodically all roadways, railways, and active as well as retired waste disposal sites were surveyed to detect any abnormal levels of radioactivity.

Optical sensitisation of energetic crystals with gold nanoparticles for laser ignition

An optical interrupter for high-power transfer is developed for application in laser ignition or initiation systems, to prevent unintended detonation of a laser detonator while ensuring that detonation will reliably take place when needed. The optical switch acting as a high-power optical energy interrupter is investigated through simulations and experiment. The prototype of this novel optical interrupter, which has been designed and fabricated, employs microelectromechanical system V-grooves for precise positioning of optical fibers, a miniature cam for the actuator, and a stepper motor for the drive source. The cam’s rotary movement displaces the input fiber so that it is aligned with the output fiber. The main performance parameters have been achieved. The insertion loss is found to be 0.4dB (without antireflection coatings) with a maximum power handling capacity of 2MW. Switching time is approximately 50ms with channel isolation between the on and off states of 20dB.

This research describes the function and principles of ignition systems in aircraft reciprocating engines. Physical-chemical processes, which are part of combustion, and the factors affecting them are defined in detail. Types of ignition systems are divided based on main parts and frequency of appearance in aircraft engines. Components of ignition and their function in electric and magnetic circuits are individually described. The future development in ignition systems is defined. The research includes an analysis of the pros and cons of laser ignition in its application in aviation. It presents Low-Temperature Combustion or Volumetric Ignition using Low-Temperature Plasma. An example may be the Microwave-assisted Plasma Ignition System. Engine speed and vacuum in intake are the main parameters influencing the ignition timing curve in Electronic Control Unit Master developed by IMF Soft. This ECU is used in the designed ignition system of testing engine. The designed timing curves were tested, and the results of engine power and torque were compared. In conclusion, the optimal timing curve is evaluated for this reciprocating engine.

Over the past 30 years numerous studies and laboratory experiments have researched the use of laser energy to ignite gas and fuel-air mixtures. The actual implementation of this laser application has still to be fully achieved in a commercial automotive application. Laser Plug Ignition as a replacement for Spark Plug Ignition in the internal combustion engines of automotive vehicles, offers several potential benefits such as extending lean burn capability, reducing the cyclic variability between combustion cycles and decreasing the total amount of ignition costs, and implicitly weight and energy requirements. The paper presents preliminary results of cycle variability study carried on a SI Engine equipped with laser Plug Ignition system. Versus classic ignition system, the use of the laser Plug Ignition system assures the reduction of the combustion process variability, reflected in the lower values of the coefficient of variability evaluated for indicated mean effective pressure, maximum pressure, maximum pressure angle and maximum pressure rise rate. The laser plug ignition system was mounted on an experimental spark ignition engine and tested at the regime of 90% load and 2800 rev/min, at dosage of λ=1.1. Compared to conventional spark plug, laser ignition assures the efficiency at lean dosage.

: The United States (US) Army and the other services are mandated to comply with all federal, state, and local environmental regulations. Recent concerns over potential human exposure to depleted uranium (DU) at US Army test ranges, primarily, have resulted in research into numerous innovative remediation technologies. Developing methods and processes for estimating the life cycle costs (LCC) of implementing these various techniques is important in identifying cost-effective solutions. Total ownership costs (TOC) models were developed for four candidate alternatives using two new technologies; Alternative 1- Physical Separation and Chemical Treatment; Alternative 2- Selective Excavation; Alternative 3- Selective Excavation with Physical Separation and Chemical Treatment; Alternative 4- Containment and Monitoring. The team chose a generic sandy soil site roughly 10 miles square for cost estimates. A bottom up estimate was applied to all alternatives in order to get a baseline cost; Alternative 3 had the best estimate for an efficient and effective remediation method. A cost estimating relationship was generated and simulation-based costing (SBC) was then applied to Alternative 3. Lastly, two alternatives were evaluated for DU remediation of catchboxes. Identifying the key cost drivers from SBC modeling is significant to future investments in research and development.