Spark Plug Research Articles

Development of nitric oxide generators to produce high-dose nitric oxide for inhalation therapy

BackgroundSeveral nitric oxide (NO) generating devices have been developed to deliver NO between 1 part per million (ppm) and 80 ppm. Although inhalation of high-dose NO may exert antimicrobial effects, the feasibility and safety of producing high-dose (more than 100 ppm) NO remains to be established. In the current study, we designed, developed, and tested three high-dose NO generating devices. MethodsWe constructed three NO generating devices: a double spark plug NO generator, a high-pressure single spark plug NO generator, and a gliding arc NO generator. The NO and NO2 concentrations were measured at different gas flows and under various atmospheric pressures. The double spark plug NO generator was designed to deliver gas through an oxygenator and mixing with pure oxygen. The high-pressure and gliding arc NO generators were used to deliver gas through a ventilator into artificial lungs to mimic delivering high-dose NO in the clinical settings. The energy consumption was measured and compared among the three NO generators. ResultsThe double spark plug NO generator produced 200 ± 2 ppm (mean ± SD) of NO at gas flow of 8 L/min (or 320 ± 3 ppm at gas flow of 5 L/min) with electrode gap of 3 mm. The nitrogen dioxide (NO2) levels were below 3.0 ± 0.1 ppm when mixing with various volumes of pure oxygen. The addition of a second generator increased the delivered NO from 80 (with one spark plug) to 200 ppm. With the high-pressure chamber, the NO concentration reached 407 ± 3 ppm with continuous air flow at 5 L/min when employing the 3 mm electrode gap under 2.0 atmospheric pressure (ATA). When compared to 1 ATA, NO production was increased 22% at 1.5 ATA and 34% at 2 ATA. The NO level was 180 ± 1 ppm when connecting the device to a ventilator with a constant inspiratory airflow of 15 L/min, and NO2 levels were below 1 (0.93 ± 0.02) ppm. The gliding arc NO generator produced up to 180 ± 4 ppm of NO when connecting the device to a ventilator, and the NO2 level was below 1 (0.91 ± 0.02) ppm in all testing conditions. The gliding arc device required more power (in watts) to generate the same concentrations of NO when compared to double spark plug or high-pressure NO generators. ConclusionsOur results demonstrated that it is feasible to enhance NO production (more than 100 ppm) while maintaining NO2 level relatively low (less than 3 ppm) with the three recently developed NO generating devices. Future studies might include these novel designs to deliver high doses of inhaled NO as an antimicrobial used to treat upper and lower respiratory tract infections.

Investigation of propane direct injection performance in a rapid compression and expansion machine: Pathways to diesel marine engine efficiency parity with spark discharge duration strategies

This paper explores pathways to achieve marine diesel-like, high-efficiency combustion fueled with propane in a RCEM research engine. Analyzing the novel technique of liquid propane injection is worthwhile given the potential for using propane in high-efficiency compression ignition engines. Since propane has a low cetane number, spark plug operating is provided to achieve reliable ignition. Investigations into combustion and the effect of spark discharge energy on propane direct injection were done through experiments on a modified head large bore RCEM with three spark ignition strategies and simulations. The findings demonstrate that the simultaneous ignition strategy had the greatest total released energy (roughly 190 mJ/s). When the SOI of the direct injection propane was set at 20oCA BTDC, diesel more efficiently than propane (on average, 3.46%). The benefits of the chosen strategy for achieving diesel efficiency parity were shown by the increasing of combustion efficiency when the spark period was lengthened.

Comparative evaluation based on FEA of thermal analysis of IC engine cylinder using different materials

Because it seals the working ends of the cylinder and houses a combustion chamber, as well as a spark plug and valves, the cylinder head is an important component of an IC engine. The heat created in the combustion chamber is very dynamic, allowing just a few microseconds to transmit the heat, which if not dispersed will cause the piston to squeeze due to overheating. As a result, excellent waste heat distribution through the cylinder body is critical to the IC engine's smooth operation. As the geometry of cylinder is problematical and the temperature within the combustion chamber is still indefinite, heat transmission through the cylinder body comprises of conduction through fins and convective heat transfer owing to surrounding air movement. Traditional heat transfer evaluation methods are quite difficult. The primary goal of this study is to examine and analyse the heat transmission of cylinder bodies constructed of various materials, including Aluminium alloy, magnesium alloy, cast iron, and stainless steel. The vehicle's speed was limited to 40 km/h, and the fin thickness was limited to 3 mm for all materials. SolidWorks is used to model the cylinder engine block with rectangular fins as well as its thermal analysis. According to thermal study results, heat dissipation is optimum in the Aluminium alloy 6061, whereas stainless steel has the least dissipation.

A novel multiple spark ignition strategy to achieve pure ammonia combustion in an optical spark-ignition engine

Ammonia is an attractive carbon-free fuel that has the potential to reduce the need for conventional hydrocarbons (HC) and reduce emissions of undesirable pollutants such as CO, CO2, particulates, and unburned hydrocarbons. However, ammonia has different combustion characteristics than conventional HC fuel. Ammonia is difficult to ignite and has a low combustion rate, resulting in large cyclic variations. In addition, nitrogen oxides (NOx) emissions in the exhaust tract are a major challenge when using ammonia as a fuel directly in engines. In this study, the effect of multiple spark ignition sites on the combustion of pure ammonia in an optical spark ignition engine (SI) was investigated. The experiment was conducted with four spark plugs mounted equidistantly on a special metal liner and one spark plug fitted at the top of the cylinder head. The multiple flames emitted from the different spark ignition sites were captured by natural flame luminosity (NFL) imaging. In the results, the conventional single spark ignition is compared with multiple ignitions. It was found that single spark ignition resulted in lower in-cylinder pressure, longer combustion duration, and higher combustion instability due to the poor ammonia fuel combustion rate. However, firing multiple spark plugs significantly improved combustion stability, increased engine power, and shortened the combustion period under the same operating conditions. In addition, the flame kernels produced by multiple ignition sites resulted in higher NOx emissions in the exhaust tract due to the higher temperatures in the cylinder. In addition, this study also investigated the effect of three different air–fuel equivalence ratios (λ) of 1.0, 1.2, and 1.4 on the combustion characteristics of ammonia fuel. The maximum NOx level was obtained for λ: 1.2 because the excess air in the mixture oxidizes the ammonia and provides abundant oxygen to generate more NOx. Further reducing the ammonia fuel and increasing the excess air to λ: 1.4 dramatically reduced NOx emissions due to the lower pressures and temperatures in the cylinder resulting from the longer combustion period.

Experimental Study of Spark Ignition Engine Performance under Different Electronic Control Units, Hole Injectors and Spark Plugs

The passage discusses the use of technology in vehicle fuel systems, specifically the injection system technology that is replacing conventional fuel systems. One crucial component of the fuel injection system is the Engine Control Unit (ECU), which controls the distribution of current to all engine components. While standard ECUs used on motorcycles today have limitations, racing ECUs provide more quality and can improve engine performance. The study aims to evaluate the engine's performance after modifications with an upgraded racing ECU using an 8-hole injector and racing spark plugs in the ignition system to enhance the motorcycle's performance. The methods and analysis section details the tools utilized, including the chassis dynamometer, and the parameters used in the study. The results and discussions section presents the collected data and compares it with previous studies to validate the observations.

Contribution Of Hurdle Jump And Hollow Sprint Training To 100 Meter Running Outcomes In PASI Athletes Medan 2022

The purpose of this study was to find out how much the contribution made from the Hurdle jump exercise and the Hollow Sprint Exercise to the results of the 100-meters run for PASI Medan athletes in 2022. The method used in this research is the experimental method with stages, (1) pre-test ( 2) treatment (3) posttest. For the pre-test and post-test using research instruments, namely: standing broad jump test, 30 meters run, 100 meters run. This research was conducted in the Jasdam field, data collection began in July-September, this study used 8 samples. The results of the study are: (1) in the first hypothesis the contribution given from hurdle jump training to the results of the 100 meter run is 96.72%, then it is known that the value of Fcount (177.09) > Ftable (5.99) with ά=0, 05, it can be concluded that there is a significant contribution from hurdle jump training to 100 meter running results for PASI Medan Athletes in 2022. (2) in the second hypothesis the contribution given from hollow sprint training to 100 meter running results is 91.66%, then it is known price Fcount (65.98) > Ftable (5.99) with ά = 0.05, it can be concluded that there is a significant contribution from the hollow sprint exercise to the results of the 100 meter run in PASI Medan Athletes in 2022. (3) in the third hypothesis the contribution given jointly from the hurdle jump and hollow sprint exercises to the 100 meter running result of 99.06% then it is known that the price of Fcount (263.76) > Ftable (5.99) with ά = 0.05, it can be concluded that there is contri jointly significant spark plugs from hurdle jump and hollow sprint exercises to the results of the 100-meter run in PASI Medan Athletes in 2022. From the results of the study it can be concluded that the hurdle jump exercises and hollow sprint exercises contribute to the 100-meter running results, therefore This form of exercise is highly recommended for athlete trainers to increase the explosive power and speed that athletes have.

An experimental study of a strategy to improve the combustion process of a hydrogen-blended ammonia engine under lean and WOT conditions

Ammonia and hydrogen are two carbon-free alternative fuels for engines. Considering that there are few studies on improving an ammonia-hydrogen engine's lean combustion performance, this investigation based on an engine with the Miller cycle employs hydrogen direct injection (HDI) and NH3 port injection and then proposes an adjustment strategy to vary the start of injection (SOI) of HDI for affecting the engine combustion process. When ammonia volume share (AVS) is greater than 50%, the engine shows poor performance. Nevertheless, the stratification effect of hydrogen jets may be used to elevate the hydrogen concentration around spark plug by properly delaying SOI and then creating the locally rich mixture with a high hydrogen share, which prominently promotes the flame kernel formation, shortens CA0-90, reduces CoVPmax, and enables the engine to reach approximately 36% BTE. It is notable that very late SOI can slightly deteriorate the heat release process and lower engine performance.

Analysis of the Influence of the Spark Plug on Exhaust Gas Composition

This paper analyses the influence of the type of electrode in a spark plug on exhaust gas emission. The objects of the research were the following vehicles of different years of production: the Volkswagen Beetle 1300, the Honda Nighthawk 650, the BMW e46 318i, the Hyundai i10, and the Audi A4 B6. The vehicles were powered by petrol and LPG. Spark plugs were selected for the vehicles, with different kinds of construction for the main electrodes and different numbers of poles but with similar heat values. A comparative analysis of the composition of the exhaust gas mixture was performed, depending on the set of spark plugs used. The amount of CO, HC, CO2, and O2 emissions was analysed. The results were compared with the applicable exhaust gas emission standards. Both in the case of E5 95 petrol and LPG gas, lower exhaust gas emissions were observed when iridium spark plugs were used.

Research of dynamic phenomena in a model engine stand

Abstract The highest loads on the elements of the crank–piston system of the internal combustion engine occur during the combustion phase which takes place successively in individual cylinders. Smaller, but also significant, loads occur beyond this phase when dynamic forces begin to play a dominant role. The latter depends on the degree of wear of the engine components. The aim of this article was to analyze the stresses in a model stand for testing dynamic phenomena in an internal combustion engine operating without the combustion process. A stand has been developed which includes a combustion engine driven by an electric motor placed on a mobile frame. The coast-down method was used to estimate the average values of the equivalent moment of inertia of the engine for various cylinder configurations with a lack of compression process due to a significant weakening of the valve springs or significant wear of the valve seats. This lack of compression was simulated on a bench by partially loosening the spark plug mounting. The article presents the values of the determined mean values of the equivalent moment of inertia of the engine and the stress values in the stand frame obtained from its model developed with the use of the finite element method. The obtained values were important from the point of view of the engine dynamics simulation process outside the combustion area and the safe foundation and operation of the stand frame during the experimental tests.

Investigation of In-Cylinder Pressure Measurement Methods within a Two-Stroke Spark Ignition Engine

<div>This work describes an investigation of measurement techniques for the indicated mean effective pressure (IMEP) on a 55 cc single-cylinder, 4.4 kW, two-stroke, spark ignition (SI) engine intended for use on Group 1 and Group 2 remotely piloted aircraft (RPAs). Three different sensors were used: two piezoelectric pressure transducers (one flush mount and one measuring spark plug) for measuring in-cylinder pressure and one capacitive sensor for determining the top dead center (TDC) position of the piston. The effort consisted of three objectives: to investigate the merits of a flush mount pressure transducer compared to a pressure transducer integrated into the spark plug, to perform a parametric analysis to characterize the effect of the variability in the engine test bench controls on the IMEP, and to determine the thermodynamic loss angle for the engine. The results indicate that as a spark plug, the measuring spark plug is not statistically different from the stock spark plug at the 95% confidence level. The results indicate a statistically significant, 4% difference in the measured IMEP between the pressure transducer in the measuring spark plug and the flush mount transducer. The results also suggest a statistically significant difference in performance between the modified and unmodified engine heads, verifying the suppositions of other researchers who suggested that even a small modification to a combustion chamber this size could measurably affect the engine performance. While run-to-run variation resulted in a 2% to 5% variation in IMEP, a sensitivity analysis determined that 1% to 3% of that variation arose from variability in the control variables, while the remainder was caused by variation in other engine operating parameters. Between 1000 rpm and 2000 rpm, where the engine was typically motored to determine the TDC, the thermodynamic loss angle was 0.3 crank angle degrees (CAD) to 0.7 CAD, larger than loss angles observed in automotive-sized gasoline engines. The results indicate that using tabulated thermodynamic loss angles to set the TDC location of the engine using a mono-directional peak pressure method would lead to a −1% to −2.5% bias in the IMEP.</div>

Feasibility study on electrically conductive joining of MoSi2 electrodes for spark plugs

AbstractDespite the often outstanding functional as well as (high temperature‐) mechanical properties of ceramics, their usage is often limited due to their inherent brittleness. This also compromises the joining with metals, which is often indispensable for engineering applications. In this context, electrically conductive ceramics like MoSi2 are promising materials for the application as electrodes where high temperatures in harsh environments are present (e.g., in spark plugs for large gas engines). Due to the difficult joining of the respective materials, long‐term experiments are thereby often still pending. In this work, adhesive bonding, brazing, tungsten inert gas‐, and resistance welding were performed to evaluate their applicability for generating electrically conductive as well as mechanically reliable joints between MoSi2 and Inconel 600, aiming to utilize MoSi2 electrodes in spark plugs. Fractographic analyses are performed to understand cracks associated with the high (thermo‐) mechanical stresses. Additionally, a finite element model was set up for a deeper understanding of the observed fracture behavior. While adhesive bonding is acceptable for short‐term experiments at low temperatures, brazing and resistance welding may qualify for fast and reliable manufacturing of spark plugs with ceramic electrodes.

Algorithms for calculating the reliability of an aircraft engine capacitive ignition system for different operating conditions

An algorithm is developed for calculating the reliability of a high-voltage two-channel capacitive ignition system of an aircraft engine under normal conditions and in case of damage of individual elements that ensure the durability of the ignition system under impacts not provided for by normal operation conditions. The assessment is carried out on the basis of reliability design schemes, taking into account the laws of discharge processes in semiconductor spark plugs. Expressions are obtained to determining the probability of fail safe operation of the ignition system. Keywords: two-channel capacitive ignition system, probability, fail safe operation, durability, discharge processes, design scheme, reliability. elaint@yandex.ru, yushkova-usatu@bk.ru, aliyakarimowa@yandex.ru

Optimasi konsumsi bahan bakar pada mesin bensin menggunakan artificial neural network

The engine control unit (ECU) is the primary component of the current injection technique used in spark ignition (SI) engines. The combustion system, which includes injection timing and ignition timing, is controlled by the engine map recorded in the ECU. To maximize an engine's performance, ECU remapping can be used. Remapping is currently not efficient because the data is typically employed in a trial-and-error fashion. To solve these issues, artificial neural network (ANN) techniques are being developed. In this study, engine remapping for fuel economy optimization is predicted using an artificial neural network (ANN). The purpose of this study is to use ANN to compare motorbike performance between before and after engine remapping (Artificial Neural Network). A set of dynamometers is used in this study approach to assess the performance of the 4 stroke, 160 CC spark plug ignition engine in terms of fuel consumption, power, and torque. A current (standard) engine map that contains a number of data from the electronic control unit (ECU) is used to start the optimization process. Pertalite and Pertamax, which are purchased from the closest gas station, are the fuels used in this study. In addition, optimization utilizing ANN is carried out with the goal of 10% increases in torque and power while maintaining a consistent fuel consumption. Following re-implementation into the ECU, the outcomes of the ANN training will be tested again on the dynamometer. The study's finding is that by using the training function, it is possible to improve machine performance using the regression value of R = 0.98993 and the ANN prediction outcomes. Comparing the optimized engine performance to the factory default engine performance, torque increased 10.9% and power rose 9.5%.

Combustion and Exhaust Emission Improvement in a 3-Cylinder Mpfi Engine Through Downsizing

This research aims to compare the potential and existing conditions of a small-sized spark ignition (SI) engine with a 1.0-liter capacity suitable for cylinder deactivation. The cylinder deactivation strategy is used to solve the issues of inefficient combustion and increased exhaust emission under part loading. Consequently, the possibility of implementing cylinder deactivation in terms of decreased exhaust pollution has been assessed. A computerized, 1.0-liter, 4-stroke, water-cooled, spark-ignition engine with an open engine control unit (ECU) and multi-point fuel injection (MPFI) was used for the trials. Both modes were tested at 2500 revolutions per minute (RPM) under loads of 15, 30, and 45 N-m. The spark plug and fuel injector deactivate the cylinder. The results show that when the highest possible load is used, the peak cylinder pressure is 55.78% higher, and the maximum heat release rate is 53.96% more in the deactivation mode than in the traditional mode. In deactivation mode, the mass fraction consumed is larger at each crank angle point, suggesting a faster rate of combustion and increased combustion efficiency. The increased mean gas temperature permits the catalytic converter to perform more efficiently after downsizing. When compared to the conventional mode, carbon monoxide (CO) emission is almost non-existent at full load, unburned hydrocarbon (UHC) is reduced by 92.89%, and oxides of nitrogen (NOx) are reduced by 35% in the deactivation mode. Furthermore, the experiment indicated that, when employed at part load, the deactivation mode is more beneficial than the standard mode in terms of better combustion stability and lesser emissions.

Combustion of Lean Methane/Propane Mixtures with an Active Prechamber Engine in Terms of Various Fuel Distribution

The possibilities for reducing the fuel consumption of internal combustion engines focus mainly on developing combustion systems, as one such solution is a two-stage combustion system using jet ignition. The combustion of gaseous mixtures with a high excess air ratio leads to an increase in overall efficiency and a reduction in the emissions of selected exhaust components. In such a convention, gas combustion studies were conducted in the methane/propane configuration. Using an active prechamber where spark plugs were placed and direct injection through a check valve, the fuel dose was minimized into the prechamber. The tests were conducted for a constant center of combustion (CoC). The combustion process in both the prechamber and main chamber was analyzed using a test stand equipped with a 0.5 dm3 single-cylinder engine. The engine was controlled by varying the fuel supply to the prechamber and main chamber in excess air ratio λ = 1.3–1.8. The study analyzed thermodynamic indices such as the combustion pressure in both chambers, based on which the SoC in both chambers, the rate and amount of heat released, AI05, AI90 and, consequently, the indicated efficiency were determined. Based on the results, it was found that the use of CH4/C3H8 combination degraded the thermodynamic indicators of combustion more than using only the base gas (methane). In addition, the stability of the engine’s operation was decreased. The advantage of using propane for the prechamber is to obtain more beneficial ecological indicators. For the single-fuel system, a maximum indicated efficiency of more than 40% was obtained, while with the use of propane for the prechamber, a maximum of 39.3% was achieved.

Coil High Voltage Spark Plug Boots Insulators Material Selection Using MCDM, Simulation, and Experimental Validation

The examination and choice of an alternate composite material for the high-voltage circuit of Otto cycle internal combustion engines—more commonly known as gasoline engines—are presented in the research that follows. To do this, multicriteria selection procedures are employed, and the outcomes are validated through the use of thermal character simulation software and standard laboratory tests. Nylon is the recommended material for Coils on Plug (COP) high-voltage insulators. Four of the six multicriteria selection techniques utilized in this study were found to be effective. It was discovered through the virtual simulation process that, even in the same environment with the same edge circumstances, the thermal behavior of the materials differs dramatically because the quadrants exhibit different behavior depending on the material. Given that nylon has a lower elasticity modulus than silicone, it was determined that the dimensions are crucial for the nylon Spark Plug Boot (SPB) to comply with the dielectric isolation process. It must have a minimal clearance in order to be related to the geometry of the spark plug and perform the perfect insulation in this manner.

Optical study of knocking phenomenon in a spark-ignition engine by using high-speed OH* chemiluminescence imaging: A multiple ignition sites approach

Knock in a spark-ignition (SI) engine is a complicated combustion phenomenon that stimulates high-pressure oscillations inside the combustion chamber and restricts engine performance. This study presents a high-speed OH* chemiluminescence imaging technique to investigate the knock mechanism resulting from firing multiple spark plugs. The experiment was performed using a customized liner having three spark plugs installed at equal spacing, and to compare the results with conventional SI conditions, in which one spark plug was mounted at the center of the cylinder head. In addition, multiple pressure transducers were used at various locations to record the frequencies induced by the pressure oscillations inside the cylinder during knocking events. The results showed that firing a single central spark plug generated mild knock with late combustion phasing and lower power output. However, adding more spark plugs could advance the initiation of autoignition and produce higher knock intensity along with lower combustion duration for the same operating conditions. Additionally, a weak OH* chemiluminescence intensity oscillation was monitored before the autoignition of the unburned charge occurred. The crank angle location of peak OH* intensity and peak HRR showed a good linear curve fit with a positive slope. Furthermore, the larger amount of unburned mass fraction produced stronger pressure waves due to multiple autoignition sites, and the unburned mass fraction exhibited a good linear relationship with unburned temperature and end-gas area at the knock onset point. Moreover, the frequency spectrum recorded by the multiple pressure sensors illustrated that in the case of a single central spark plug only circumferential acoustic waves were formed with low power intensity. However, multiple ignition sites promoted both circumferential and radial pressure waves inside the combustion chamber because of multiple autoignitions occurring both near the center and cylinder wall.

Understanding hydrogen jet dynamics for direct injection hydrogen engines

The energy paradigm is shifting toward carbon-free and low-emission alternative fuels. Among the many candidates, hydrogen is considered a promising option thanks to its favorable fuel properties, including zero carbon content, high gravimetric energy density, and fast flame speed, despite its technical fuel production and storage challenges. Direct injection technology has been identified as the best approach for applying hydrogen in combustion engines to overcome the accompanying issues, such as backfire and low energy density. However, studies have yet to be conducted on hydrogen jet behavior in direct injection systems, specifically, studies that elucidate engine design and injection parameter optimization in the combustion system. Therefore, we aimed to assess hydrogen jet behavior through experiments and computational approaches comprehensively. Hydrogen was injected at 10 MPa using the direct injection method into a constant volume chamber under a quasi-steady ambient condition. Z-type high-speed Schlieren imaging was performed using a high-speed camera to visualize the hydrogen jet structure, which depicted the hydrogen jet’s vapor intermittency and vortex structure. We also performed a computational fluid dynamics (CFD) simulation to understand the aerodynamics of the jet. The results showed the formation of vortical flow in the inner core region, where the pressure was comparatively lower than that on the outer side of the jet. Our further investigation of the injection strategy showed that multiple injections were more beneficial in forming a favorable hydrogen-air mixture near the spark plug than a single injection case.

Chemical Effect of DME on the Combustion and Heat Release of SI-CAI Hybrid Combustion Based on Micro Flame Ignition Strategy

ABSTRACT Gasoline SI-CAI combustion has shown its advantages in expanding the operating range of high-efficiency combustion. However, the high cyclic variation occurs since the presence of exhaust gas limits the spark ignition and its controllability by auto-ignition. To further improve the stability and reliability of hybrid combustion, MFI (Micro Flame Ignition) strategy has been proposed. Although the phenomenon of MFI hybrid combustion was learned before, the chemical effect of high-activity fuel DME (Dimethyl Ether) and its inter-reaction with gasoline to the combustion process has yet to be studied. In this paper, the carbon tracer method was used to separate the reaction of DME and gasoline in CFD (Computational Fluid Dynamics) simulation, and chemical reaction kinetic analysis was carried out. The congregate DME could produce formaldehyde by 2-step oxidation of DME spontaneously, which led to a high flame speed than the spark ignition. The discrete MFI strategy showed a two-times flame speed ignited by the spark plug, which led to the mid-product of gasoline enhancing the first step of DME oxidation. Although the discrete DME showed high chemical activity in the whole cylinder, the high temperature and pressure caused by DME’s auto-ignition led to a shorter ignition delay for the auto-ignition process in the congregate MFI strategy.

Effects of water injection on a partially ceramic coated piston spark plug ignition engine

Yanma odasından dışarıya transfer edilen ısı miktarı yanma verimini direkt etkilemektedir. Isı transfer miktarının artması yanma verimini azaltmaktadır. Motorlarda termal kaplama yöntemleri ile ısı transfer miktarı azaltılarak yanma verimi artmaktadır. Fakat yanma odasının tamamının termal malzeme ile kaplanması buji ateşlemeli motorlarda vuruntu temayülünün artmasına ve emisyon değerlerinin kötüleşmesine neden olmaktadır. Vuruntu temayülünün ve emisyon değerlerinin azaltılmasında en etkiyi yöntemlerinden biri de su-buhar enjeksiyon yöntemidir. Su enjeksiyon yöntemi ile motor performans parametrelerinde kötüleşme olmadan emisyon değerleri kayda değer oranlarda azaltılabilmektedir. Çalışmada, motor verimini arttırmak için piston üst yüzeyi ısı rezervi yüksek MgOZrO2 seramik malzeme ile kısmi kaplanmıştır. Kaplamalı motora, anlık yakıt tüketiminin %10, %20 ve %30 kütlesel oranlarında emme manifolduna su püskürtülmüştür. İki yöntem aynı anda kullanılarak performans parametreleri ve egzoz emisyonlarında iyileşmeler elde edilmiştir. TBL pistonlu motorda güç, tork, özgül yakıt sarfiyatı, efektif verim ve HC emisyonları iyileşirken NOx emisyonları artmaktadır. Emme manifolduna su enjeksiyon yapılması durumunda ise performans parametrelerinde kötüleşme olmadan artan NOx emisyonları azalmaktadır. % 20 su püskürtme oranında motor torku ve efektif güçte % 4,1, özgül yakıt sarfiyatında, %3,8 ve efektif verimde %3,9 oranlarında iyileşmeler saptanmıştır. NOx emisyonlarında %30 su püskürtme oranında standart motor verilerine göre %20 oranında azalma elde edilmiştir. Ayrıca %20 su püskürtme oranında HC emisyonlarında % 33’e varan oranlarda azalmalar saptanmıştır.