Ignition Control Research Articles

Towards Safer Primers: A Review

Primers are used to reliably initiate a secondary explosive in a wide range of industrial and defence applications. However, established primer technologies pose both direct and indirect risks to health and safety. This review analyses a new generation of primer materials and ignition control mechanisms that have been developed to address these risks in firearms. Electrically or optically initiated metal, oxide and semiconductor-based devices show promise as alternatives for heavy metal percussive primers. The prospects for wider use of low-cost, safe, reliable and non-toxic primers are discussed in view of these developments.

Comparative research results of CFR Octane Rating Unit Engine and Dacia Single Cylinder SI Engine equipped with classical Spark Plug and LASER Ignition

Nowadays, research has developed new technologies for a better control of the combustion process. Among the new technologies used for Ignition and combustion control, the LASER spark plug system is defined as an innovative technology which could overcome several limitations of classical spark plug. The purpose of the paper is the experimental research of the LASER spark plug used in the spark ignition(SI) engine. Improved performance, ensuring rapid and robust combustion, depends on how the Ignition stage is achieved. An Ignition system that could provide such an enhanced combustion process is the one based on plasma generation using a Q switched solid state LASER that delivers pulses with high MW peak power. The LI device used in the current research was a LASER medium Nd:YAG/Cr4+:YAG ceramic structure (Baikowski Co., Japan) that consisted of a 8.0-mm long, 1.0-at.% Nd:YAG ceramic, optically-bonded to a Cr4+:YAG ceramic with saturable absorption. It was designed, integrated and built to resemble a classical Spark Plug and could be mounted directly on the cylinder of a CFR Octane Rating Unit Engine as well as on a Dacia Single Cylinder SI Engine which led to several results among which: indicated, mediated pressures and their wave dispersion.

GLIDARC reactor power supply with ignition improvement

PurposeThe research purpose of this paper is to confirm that internal overvoltages in the push–pull power inverter can be used to improve the discharge ignition in the gliding arc discharge (GAD) plasma reactor.Design/methodology/approachInvestigations are based on the acquisition of voltage changes that occur together with the development of the discharge column and the imaging the GAD with the use of a high-speed camera.FindingsThe power supply has the distinctive feature of not having the switching overvoltages completely extinguished, as it is in typical push–pull inverters. The overvoltages still exist but only dangerous peaks are cut off. The remaining ones, of a dumped resonance character (Figure 3), are transferred to the secondary coil of the transformer. Correctly shaped overvoltages are used for ignition improvement in the GAD reactor.Practical implicationsGAD plasma reactors have many applications for pollution control, disinfection and sterilization of surfaces and for plasma deposition, surface functionalization, as well as in agricultural and medical treatment. Investigations prove the push–pull inverter’s advantages in comparison with the transformer-type power supply. Properly configured push–pull inverters have good ignition properties and control options, allowing to generate, desirable for many applications, homogeneous non-thermal plasma.Originality/valueThe idea of using switching overvoltages in transistors of push–pull switching-mode power supplies is new and has not been previously used to improve discharges ignition in a non-thermal plasma reactor.

Optimization of the multi-carburant dose as an energy source for the application of the HCCI engine

The issue of utilizing multi-fuels for enhancing the burning process in the “Homogeneous charge compression ignition” HCCI engine cylinder has been developing significantly during the last decades. This technique has established to overcome the difficulties of the engine ignition and knock-like combustion control when distinguished with utilizing a single fuel during the engine management system. Furthermore, the developing concern towards the cleaner environment and the battle against wonderful weather by using the renewable fuel types are urgently required. In this research, the theoretical and experimental study will achieve the possibility of preparing a charged mixture, which consists of the air and three different kinds of alternative fuels. The prepared mixture was introducing into a mixing chamber near the intake manifold of the HCCI engine working at varying load conditions. Those fuels were the natural gas, hydrogen, and “Dimethyl ether” as a biodiesel fuel. The mixture has been utilizing to enhance the HCCI engine performance. However, the non-petroleum based alternative fuel such as “Dimethyl ether” DME has been used as an additive to the mixes of the natural gas or natural gas/hydrogen blends. Current methodology has been acquainting to make the chance of the engine ignition control is accessible, alongside its advantages to keeping away from the engine knocking or misfire operation. The ideal dose of each type of the tri-fuels composition with different percentages of each fuel used has been optimizing. Natural gas fuel is the primary fuel of the engine, and the other two types of fuel have used as additives for renewable fuels. The obtained results showed that there are certain proportions for each kind of the employed fuel in which the possibility of the engine operation without the occurrence of the knock-like combustion or the apparent of misfire operation have been achieving.

The influence of the ignition control on the performance of an aircraft radial piston engine

Aircraft piston engines are built with compromise on performance and safety. The desire to achieve the highest power-to-weight ratio leads to the search for solutions that optimize the combustion process. On the other hand, the need for maximum reliability leads to the simplification of the design at the costs of performance. An example of such a compromise is the ignition system of the ASz-62IR engine. In this engine there is a double magneto ignition system with a fixed ignition advance angle. As part of the modernisation of this engine, an electronically controlled dual ignition system was developed, which allows for optimum control of the ignition advance angle in terms of power. This article discusses the results of bench tests of the ASZ-62IR-16X engine with fixed ignition timing and variable timing control. Functional parameters and toxicity of exhaust gases were analyzed.

Development and experimental validation of a field programmable gate array–based in-cycle direct water injection control strategy for homogeneous charge compression ignition combustion stability

Homogeneous charge compression ignition is a part-load combustion method, which can significantly reduce oxides of nitrogen (NO x) emissions compared to current lean-burn spark ignition engines. The challenge with homogeneous charge compression ignition combustion is the high cyclic variation due to the lack of direct ignition control. A fully variable electromagnetic valve train provides the internal exhaust gas recirculation through negative valve overlap which is required to obtain the necessary thermal energy to enable homogeneous charge compression ignition. This also increases the cyclic coupling as residual gas and unburnt fuel is transferred between cycles through exhaust gas recirculation. To improve combustion stability, an experimentally validated feed-forward water injection controller is presented. Utilizing the low latency and rapid calculation rate of a field programmable gate array, a real-time calculation of residual fuel mass is implemented on a prototyping engine controller. Using this field programmable gate array–based calculation, it is possible to calculate the amount of fuel and the required control interaction during an engine cycle. This controller prevents early rapid combustion following a late combustion cycle using direct water injection to cool the cylinder charge and counter the additional thermal energy from any residual fuel that is transferred between cycles. By cooling the trapped cylinder mass, the upcoming combustion phasing can be delayed to the desired setpoint. The controller was tested at several operating points and showed an improvement in the combustion stability as shown by a reduction in the standard deviation of combustion phasing and indicated mean effective pressure.

Ignition control in a gasoline compression ignition engine with ozone addition combined with a two-stage direct-injection strategy

To control the ignition timing in a gasoline compression ignition (GCI) engine, ozone (O3) was introduced into the intake air. The O-radicals are decomposed from the O3 above 550 K during the compression stroke, and combine into oxygen (O2) in a very short time. The authors adopted two-stage direct injection to mix the fuel injected into the cylinder at very early timings with the O-radicals, before a reduction of the O-radicals would take place. The ignition timing of the second fuel injection for the main combustion is controlled by the heat release from the first fuel injection. In this paper, engine experiments were performed to examine the feasibility of the ignition control with a primary reference fuel, octane number 90 (PRF90). The O3 concentration, the quantity, and the timing of the first injection were changed as experimental parameters. The results showed that a very small quantity of O3, tens of ppm, is sufficient to promote the heat release of the first injected fuel. The heat release increases with the O3 concentration and the quantity of fuel in the first injection. The addition of O3 has no other impact on the ignition when the first injection timing is retarded to around −40°CA ATDC. In this manner, it is possible to control the ignition delays and to alter the combustion state from typical diesel combustion to premixed compression ignition combustion.

Research of Measure and Control System for Laminar Burning Velocity in Constant Volume Combustion Chamber

The synchronization among the central electrode ignition control system, high-speed schlieren imaging system and pressure data acquisition system inside a constant volume combustion chamber (CVCC) should be accurately controlled in the study of the laminar burning velocity of fuel by spherical expansion flame method in a CVCC. In this paper, the digital delay pulse generator and the high-speed data acquisition card are used to control the synchronization among the abovementioned three systems with the control error in 30 μs, and then the schlieren image of the flame front and the pressure inside a CVCC are captured successfully. These lay a solid foundation for the measurement of laminar burning velocity by constant pressure method (CPM) and constant volume method (CVM).

Ion chemistry in premixed rich methane flames

External electric field and plasma assisted combustion show great potential for combustion enhancement, e.g., emission and ignition control. To understand soot suppression by external electric fields and flame ignition in spark ignition engines, flame ion chemistry needs to be investigated and developed. In this work, comprehensive and systematic investigations of neutral and ion chemistry are conducted in premixed rich methane flames. Cations are measured by quadrupole molecular beam mass spectrometry (MBMS), and neutrals are measured by synchrotron vacuum ultra violet photoionization time of flight MBMS (SVUV-PI-TOF-MBMS). The molecular formula and dominant isomers of various measured cations are identified based on literature survey and quantum chemistry calculations. Experimentally, we found that H3O+ is the dominant cation in slightly rich flame (ϕ=1.5), but C3H3+ is the most significant in very rich flames (ϕ=1.8 and 2.0). An updated ion chemistry model is proposed and used to explain the effects of changing equivalence ratio. To further verify key ion-neutral reaction pathways, measured neutral profiles are compared with cation profiles experimentally. Detailed cation and neutral measurements and numerical simulations by this work help to understand and develop ion chemistry models. Deficiencies in our current understanding of ion chemistry are also highlighted to motivate further research.

Ignition and combustion of air/fuel mixture in a long tube induced by microwave subcritical streamer discharge

There have been consistent efforts in developing more efficient combustion for propulsion systems. Ignition and combustion control using cold and non-thermal plasma in microwave discharges have become a major topic of interest. In this study, a microwave subcritical streamer discharge is used to initiate ignition and combustion of premixed air/fuel mixture in a long cylindrical tube. The streamer discharge is arising on the internal surface of the dielectric tube using a passive vibrator in a single pulse regime at atmospheric pressure and temperature. The propagation speed of the combustion front in the quartz cylindrical tube filled by the air/propane mixture is analyzed experimentally and numerically. The streamer discharge creating a multitude of ignition points provides practically instantaneous ignition of the mixture in the entire volume. The speed of streamer induced combustion front has been shown to be higher compared to that initiated by a spark. Increasing the length of streamer discharge leads to increasing the flame propagation speed. The combustion efficiency has also been shown to be higher when using the microwave streamer ignition.

Integral Discrete-time Sliding Mode Control of Homogeneous Charge Compression Ignition (HCCI) Engine Load and Combustion Timing

Abstract Integral Discrete-time Sliding Mode Control (IDSMC) for combustion timing and load control of a single cylinder Homogeneous Charge Compression Ignition (HCCI) engine is designed and tested in simulation. First, a Nonlinear Control Oriented Model (NCOM) which is based on measurements is linearized around one operating point and the linearized model is then validated against the NCOM. The linearized model is then combined IDSMC with fueling rate and Exhaust Valve Closing (EVC) used as actuators. The controller is verified in simulation using the NCOM as a virtual engine. The simulation results indicate that IDSMC has acceptable performance for combustion timing and load control in HCCI engine and the performance is superior to classic PI control.

Properties of Foamed Gel for Coal Ignition Suppression in Underground Coal Mine

ABSTRACTFoamed gel was developed as efficient material for coal ignition control in fire-prevention techniques. The preparation process, structure, key equipment, stability and inhibiting effect of foamed gel are experimentally studied. Foamed gel possesses three-dimensional net structures, consisted of gel particles and aqueous foam. Foaming device is the key equipment that could generate foam and gel simultaneously. In addition, the half-life of foamed gel is beyond 24 h, which is more than six-folders of foam. The “strong-node and weak-rod” structure formed by gel particles is the key reason enhancing the stability of foamed gel. Further, by using coal spontaneous combustion apparatus, the inhibiting effect of foamed gel is conducted by testing the release of CO. The results show that the inhibiting rate of foamed gel is 73.72%, higher than CaCl2 with 57.35% in 100°C. Meanwhile, field application in coal mine suggests that foamed gel can effectively suppress coal fire in gobs.

Control and optimization of spark ignition–controlled auto-ignition hybrid combustion based on stratified flame ignition

Spark ignition–controlled auto-ignition hybrid combustion, also known as spark assisted compression ignition, is of considerable interest in gasoline engines because of its potential to enlarge the operating range of gasoline diluted combustion. However, it was found that the spark ignition–controlled auto-ignition hybrid combustion process was often characterized with large cycle-to-cycle variations. In this research, a new approach by combining the traditional second-order derivative method and Wiebe function fitting method was proposed to identify different heat release stages of spark ignition–controlled auto-ignition hybrid combustion. The heat release characteristics of the spark ignition–controlled auto-ignition hybrid combustion based on stratified flame ignition strategy and its control methods were investigated in detail. The effect of control parameters, including spark timing, direct injection ratio and dilution strategy, on improving the thermal efficiency and decreasing the variation of heat release trace in spark ignition–controlled auto-ignition hybrid combustion based on stratified flame ignition strategy was analysed. The advance of flame propagation ending point and the increase in the average heat release rate in flame propagation stage benefitted the fuel economy and reduced the variations of heat release in spark ignition–controlled auto-ignition hybrid combustion. Although the increase in direct injection ratio contributed to the stability of heat release in the spark ignition–controlled auto-ignition hybrid combustion based on the stratified flame ignition strategy, the thermal efficiency of spark ignition–controlled auto-ignition hybrid combustion cannot be effectively optimized due to the decrease in combustion efficiency. The application of exhaust gas recirculation and air dilution could decrease the variations of heat release process and increase the thermal efficiency of spark ignition–controlled auto-ignition hybrid combustion based on stratified flame ignition strategy.

DEVELOPMENT OF AN ELECTRONIC CONTROL SYSTEM FOR GAS-ENGINES, CONVERTED ON THE BASIS OF TRANSPORT DIESELS TO WORK FOR ON LIQUEFIED PETROLEUM GAS

The expediency and advantage of using gas motor fuels on a relation to traditional liquid motor fuels is shown. Technical solutions for the use of gas motor fuels by diesel engines are presented and analyzed. On the basis of the analysis, the expediency of converting diesel engines into gas engines with forced ignition is justified.An electronic microprocessor control system for gas internal combustion engines with forced ignition has been developed, which has a modular structure consisting of two main and a number of additional subsystems. The structures are described and the principle of operation of the main subsystems is described, including LPG injection subsystem, as well as the ignition control subsystem. An experienced ECU was developed and created. A structural scheme of the electronic control system of a gas engine with an experienced ECU is given. The out motorized tests of the experienced ECU were carried out, which confirmed his operability.

ABCD Analysis of Fingerprint Biometric Attendance Maintenance System

The drastic developments in Information and Communication Technology enabled many types of technology-aided attendance maintenance system in Higher Educational Institutions. A fingerprint is one of the most common and popularly known biometric systems all over the world. The usage of fingerprints for authentication is a universally prevalent solution and a majority of the population has legible fingerprints. This is more than a number of humans who have passports, license and identification cards. It has fairly one of the maximum accurate forms of biometrics available. Fingerprint biometric has been utilized in numerous areas together with entry management and door-lock control, smart cards, vehicle ignition control framework and fingerprint controlled access control system. Because the superior technology allows even extra compact fingerprint sensor size, the variety of application is expanded to the cellular market. One of the important applications of the biometric system is in attendance maintenance and which is incorporated in many of the higher educational institutions. From olden days, three styles of fingerprints may be obtained, namely, exemplar prints, latent prints and plastic prints. In this paper, we study fingerprint attendance maintenance system with its advantages, benefits, constraints, and disadvantages. We use focus group interaction method to gather information on fingerprint biometric attendance system. This paper also discusses some recommendations for fingerprint biometric attendance system. This paper could play an active and supportive role in fingerprint biometric attendance based researches.

Reaction schemes and characteristics in crude oil oxidation process using a TGA testing method

Stage characteristics of heavy oil oxidation is important for ignition and production control of fire flooding. A thermogravimetric (TG) experiment is carried out to study the oxidation process on a certain heavy oil sample mixing with quartz sand. Firstly, based on multicomponent theory of heavy oil, four stages corresponding to earlier low temperature oxidation (LTO), later LTO, fuel deposition and high temperature oxidation (HTO) are identified. The kinetic parameters of each oil oxidation stage are calculated by the Coats-Redfern integral method. It demonstrates that the orders of reaction have a great influence on the results of calculation. Then logical and reasonable reaction equations are derived out based on the mechanism of staged crude oil oxidation. The result shows that phase boundary reaction (also known as interfacial reaction, which is defined as a chemical reaction that occurs on a two phase contact interface.) is the main reaction at the stage of low temperature oxidation. And three dimensional diffusion reactions are primary at the stage of high temperature oxidation reaction. Finally thermogravimetric analysis of different viscosity crude oil verifies that the kinetic process of oxidation is determined by reaction mechanisms. And different mechanisms appears at different reaction stages.

Design of Monitoring and Control System for Multi-Tube Ignition Pulse Detonation Engine

A multi-processers monitoring and control system, which use the Lora as wireless communication technology, was designed to meet needs of mobility, safety, fast frequency adjustment, portability, none affect on PDE thrust test and so on. This paper elaborated on scheme of whole system, local high-speed signal acquisition, storage, data export and ignition control method. Experimental results show that the monitoring and control system was able to implement timely and accurately control and data acquisition of detonation tubes, dynamical parameters changing, remote control and eliminate the damage for human beings caused by PDE, with mobile and portable, high integration, convenient operation, reliable performance characteristics.

Modeling the spatial patterns of human wildfire ignition in Yunnan province, China

Despite wildfire being an important regulator of dryland ecosystems, uncontrolled wildfire can be harmful to both forest ecosystems and human society, and wildfire prevention and control continue to raise worldwide concern. Wildfire management depends on knowledge of wildfire ignitions, both for cause and location. The regimes and factors influencing wildfire ignition have been studied at length. Humans have a profound effect on fire regimes and human activity is responsible for igniting the largest number of fires in our study area. Understanding the spatial patterns of ignitions is foremost to achieving efficiency in wildfire prevention. Previous studies mainly concentrate on overall wildfire risk integrating numerous factors simultaneously, yet the importance of human factors on ignition has not received much attention. In this study, we mapped human accessibility to explore the influence of human activity on wildfire ignition in a simple and straightforward way. A Bayesian weights-of-evidence (WofE) method was developed based on fire hotspots in China's Yunnan province extracted from satellite images and verified as known wildfires for the period 2007–2013. We considered a set of factors that impact fire ignition as associated with human accessibility: the locations of settlements, roads, water and farmland susceptible to human wildfire ignition. Known points of likely wildfire ignition were selected as training samples and all suspected thematic maps of the factors were taken as explanatory layers. Next, the weights of each layer in terms of its explanatory power were computed and used to generate evidence based on a threshold to pass a statistical test. The conditional independence (CI) of each layer was checked with the Agterberg-Cheng test. Finally, the posterior probability was calculated and its precision validated using samples of both presence and absence by withheld validation data. A comparison of WofE models was made to test the predictability. Results show proximity to villages, roads and farmland are strongly associated with human wildfire ignition and that wildfire more often occurs at an intermediate distance from high-density human activity. The WofE method proved more powerful than logistic regression, improving predictive accuracy by 10% and was more straightforward in presenting the association of dependence and independence. In addition, WofE with 1000 m buffer bands is more robust in predicting human wildfire ignition risk than binary or 100 m buffers for the ecoregion studied. Our results are significant for advising practical wildfire management and resource allocation, evaluation of human ignition control and also provides a foundation for future efforts toward integrated wildfire prediction.

Development of a gesture and voice controlled system for burn injury prevention in individuals with disabilities.

Burn injury is a major public health issue in developing countries, with most injuries being largely associated with the use of kitchen stoves. This study details the development of a cost-effective gesture and voice recognition controlled (GVC) system to be used by individuals with disabilities to reduce the likelihood of burn injury and improve their quality of life. The device replaces conventional dial controls with voice and hand gesture recognition sensors and software which are designed to be easily implemented into a household kitchen. Preliminary evaluation of the GVC system's performance in gesture and voice recognition, gas leak detection and ignition control tests were conducted using a Bunsen burner as a stove top surrogate. The voice and gesture recognition tests yielded sensitivities of 88% and 100%, respectively. These results suggest that the GVC system may be a promising solution for burn injury prevention pending further work to improve its reliability and robustness.

Compound disturbance rejection control of spark ignition–controlled-autoignition hybrid combustion for gasoline engines

Spark ignition–controlled-autoignition hybrid combustion is a promising concept because of its capability to achieve a smooth transition between spark ignition combustion and controlled-autoignition combustion, but it suffers from transient control owing to the high sensitivity to the operating conditions. In this paper, a control solution based on the principle of disturbance rejection is proposed for spark ignition–controlled-autoignition hybrid combustion. The complexity, the non-linearity and the cross-coupling inside are removed by idealizing the combustion process into three independent integrators, for the combustion timing channel, the indicated mean effective pressure channel and the λ (excessive air coefficient) channel respectively. All the other dynamics that deviate from the integrators (internal and external) are ‘lumped’ together as the total disturbance for each channel. With the total disturbance estimated in real time via the extended-state observer and eliminated by the disturbance rejection law, the enforced plant, i.e. the integrator, is controlled by a simple proportional controller. To enhance the response further, a non-linear model-inversion-based feedforward controller is added. In order to attenuate the slow time-varying disturbances, four correction factors for the model parameters are embedded in the model for online estimation. Validations by both simulations and experiments confirm the superiority of the proposed solution in terms of a fast transient response and a high robustness. By using the bandwidth-parameterization-based extended-state observer tuning method and a Kalman-filter-based extended-state observer, the controller is easy to tune, making it a promising candidate for applications of spark ignition–controlled-autoignition hybrid combustion.