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In this paper, results from a novel and promising technique referred to as Interacting-Sprays injection concept is presented. ...A single-cylinder compression-ignition two-stroke research engine with optically-accessible head, mounted on a high-speed CFR engine crankcase was used to investigate the combustion and emission characteristics of this injection system. The Interacting-Sprays injection system produces two separate independently-control led sprays with a good degree of adjustability with regard to their fuel quantities and injection timings. ...Results are presented to show the effects of the varied injection system characteristics on the combustion and exhaust emissions ( NOx and smoke). The effects of the injection timing and time separation between the first and second injections of the Interacting-Sprays injection system are explored.

This study is focused on the effect of fuel properties and cetane number on HCCI-DI combustion to understand the combustion and emission behavior of a direct injection HCCI engine using double injection strategy with blends of n-heptane and isooctane as fuel. ...A significant improvement in NOX and smoke emissions are observed in HCCI combustion when compared with the conventional single injection combustion for all five blends of the fuel. ...An innovative low cost dual injection strategy is developed to investigate HCCI-DI combustion. This study is focused on the effect of fuel properties and cetane number on HCCI-DI combustion to understand the combustion and emission behavior of a direct injection HCCI engine using double injection strategy with blends of n-heptane and isooctane as fuel.

The results show that while there is never a large difference between the thermal efficiency of pure HCCI without water injection and TSCI with water injection, certain injection conditions can cause the combustion efficiency to decrease due to excessive forced thermal stratification, late combustion phasing, and longer burn durations. ...A CFD investigation has been conducted to study the efficiency and emissions characteristics of Thermally Stratified Compression Ignition (TSCI) combustion with direct water injection. The motivation for using this new low temperature combustion mode is its ability to control the heat release process by introducing a forced and controlled thermal stratification beyond what would occur naturally. ...In this case, TSCI is enabled using direct water injection. The added degree of control over the combustion process allows for a significantly broader operable load range compared to HCCI.

The proposal was defined as water injection in the intake manifold (one injection valve per cylinder) of a 4-stroke, 4-cylinder engine arranged in line with direct fuel injection (Otto cycle), with 1592 cm3 of total volume, equipped with turbocharger and air to air intercooler – which allows the reduction of this temperature and prevents negative effects. ...This study focuses on the analysis of a proposal for a solution of one of the problems presented by internal combustion engines: the high temperature inside the combustion chamber. The proposal was defined as water injection in the intake manifold (one injection valve per cylinder) of a 4-stroke, 4-cylinder engine arranged in line with direct fuel injection (Otto cycle), with 1592 cm3 of total volume, equipped with turbocharger and air to air intercooler – which allows the reduction of this temperature and prevents negative effects. ...Simulations of the system operation were carried out aided by AVL Boost software, considering the injection of 12.5% of distilled water with the engine running at full load. The results of the simulation indicated an average temperature decrease of 25.51 K, in addition to the reduction in the emission of NOX and CO2, but there was an increase in CO emission.

THE main purpose of this paper is to illustrate the results or effects of water and water-alcohol injection on aircraft-engine performance. Water offers the best rate of cooling at high power output and, the authors point out, should be used without any additive where cooling is of paramount importance.

The results are compared to the separate direct injection of fuel and water. The experiments were carried out on a rapid compression and expansion machine. ...Problems of soot and NOx emissions caused by diffusive combustion of wall adhering fuel can be reduced by emulsions with a sufficient water content. For the same amount of water the pressure rise rates can be substantially reduced with separate water injection. ...For the same amount of water the pressure rise rates can be substantially reduced with separate water injection.

The amount of water injected was varied, and the results were compared with baseline data where no water injection was used. Water injection was a very effective means to reduce NOx emissions. Direct injection of water into the cylinder reduced NOx emissions by 95% with an 8% fuel consumption penalty, and NOx emissions were reduced by 85% without any fuel consumption penalty. ...Experiments were conducted in this study to quantify the effects of direct injection of water into the combustion chamber of a port-fueled, hydrogen IC engine. The effects of DI water injection on NOx emissions, load, and engine efficiency were determined for a broad range of water injection timing. ...The effects of DI water injection on NOx emissions, load, and engine efficiency were determined for a broad range of water injection timing. The amount of water injected was varied, and the results were compared with baseline data where no water injection was used.

The following study describes an on-board fuel tailoring process based on a novel and compact catalytic fuel evaporator, capable of optimizing Homogenous Charge Compression Ignition (HCCI) combustion. ...The following study describes an on-board fuel tailoring process based on a novel and compact catalytic fuel evaporator, capable of optimizing Homogenous Charge Compression Ignition (HCCI) combustion. Evaporation tests with conventional diesel were performed revealing a significant amount of long-chain alkane cracking. ...As a consequence of these cracking reactions, the presented experiments demonstrate that the produced fuel vapor has altered combustion properties as compared to the feeding diesel stream. Further tests using a constant volume chamber at 30 bar, over the temperature range 500 to 1120 K, indicated that ignition delay time and auto ignition temperature of this fuel vapor can be shifted from diesel to gasoline.

Hydrogen Internal Combustion Engine (ICE) vehicles using a traditional ICE that has been modified to use hydrogen fuel are an important mid-term technology on the path to the hydrogen economy. ...The paper presents some details of an initial investigation of the CAD and CAE modeling of a novel design where two jet ignition devices per rotor are replacing the traditional two spark plugs for a faster and more complete combustion. ...The paper presents some details of an initial investigation of the CAD and CAE modeling of a novel design where two jet ignition devices per rotor are replacing the traditional two spark plugs for a faster and more complete combustion. The CAE model (by using the GT-SUITE software [7]) is developed first to describe the wide open throttle operation of the baseline two rotor twin spark plugs per rotor, gasoline port fuel injected Mazda Renexis high power engine.

The model accounts for gas species properties, includes valves opening/closing, wall heat transfer, a water injection model and a combustion model. The influence of some injection parameters, i.e. Water/Fuel ratio (W/F), Start Of water Injection (SOI) and Water Injection Duration (WID), on engine performances and efficiency is discussed in details. ...Water/Fuel ratio (W/F), Start Of water Injection (SOI) and Water Injection Duration (WID), on engine performances and efficiency is discussed in details. ...The parametric analysis is performed by injecting water when the chemical heat release is complete, in order to avoid the interaction between injected water and combustion. Finally, the effects of spark advance on water injection efficiency gain have been investigated.

This study highlights the positive impact of water injection on knock mitigation and overfueling limitation. Direct water injection is the preferred configuration for knock mitigation due to a greater fuel consumption reduction. ...This also implies a decrease of the combustion efficiency and an increase in pollutant emissions. Water injection is one way to overcome both limitations. ...A downsized direct injection spark ignition single-cylinder engine was used with different water injection configurations, port or direct injection.

CFD parameters were tuned and validated against the experimental results of spray profile and spray tip penetration measured in the combustion vessel (CV). With the validated CFD model, water spray injection into an engine in-cylinder configuration was simulated. ...Experiments were conducted in an optically accessible pressure vessel using a high-speed Schlieren imaging to visualize the transient water spray. The experimental conditions included a range of injection pressures of 34, 68, and 102 bar and ambient temperatures of 30 - 200°C, which includes flash-boiling and non-flash-boiling conditions. ...The engine CFD results showed that water injection at 90° BTDC showed better vaporization and decreased the formation of liquid wall film on piston surface, cylinder head, and cylinder wall compared with those for 60° BTDC water injection.

In this paper, results from a single cylinder light duty research engine are presented using a novel ramped combustion chamber focused at mid to high engine loads. The ramped combustion chamber improves mixing and enables more retarded injection timings than those possible on conventional bowl designs. ...Electrification offers a medium to long term solution, but there remains a need to significantly reduce internal combustion engine emissions in the short and medium term, and potentially in the long term for long range inter city transportation. Late injection low temperature combustion (LTC) has the potential to achieve ultra-low emissions levels in a compression ignition engine by increasing the lean pre-mixed burn fraction. ...The ramped combustion chamber improves mixing and enables more retarded injection timings than those possible on conventional bowl designs. This combustion strategy has enabled LTC conditions to be achieved at lower dilution rates, typically 20-30% at loads up to 15bar IMEP.

In recent studies, direct water injection is used in HCCI combustion to stabilize combustion and increase the operation range. ...This paper outlines the thermodynamic influence and evaluation of the potential of water injection for HCCI combustion. Investigations were performed on two single cylinder research engines using different fuels to investigate the effect of direct water injection on HCCI combustion. ...Investigations were performed on two single cylinder research engines using different fuels to investigate the effect of direct water injection on HCCI combustion. In this work, the required energy to achieve autoignition is obtained using internal exhaust gas recirculation which is controlled via negative valve overlap.

In this paper, P2 architecture is used to investigate the effects of water injection benefits in a mild hybrid system. Electrification of the conventional powertrain uses the benefits of an electric drive in the low load-low speed region where the conventional SI engine is least efficient and as the load demand increases the IC Engine is used in its more efficient operating region. ...However, the engine efficiency is limited by combustion knocking at higher loads thus ignition retard is used to avoid knocking and fuel enrichment becomes must to operate the engine at MBT (Maximum Brake Torque) timing; in turn neutralizing the benefits of fuel savings by electrification. Water injection suppresses engine knocking and enables operating at stoichiometric air-fuel ratio. ...In addition to that, the injection of water reduces flame temperature, giving room to ignition advance towards MBT timing.

A single cylinder, four stroke, constant speed, water cooled, direct injection diesel engine typically used in agricultural sector was used for these experiments. ...The scarcity and depletion of conventional petroleum sources are causes of great concern worldwide. Combustion of fossil fuels has led to unprecedented rise in the global CO2 level, leading to global warming. ...Vegetable oils, due to their agricultural origin, are able to reduce CO2 emissions to the atmosphere along with import substitution of petroleum products In the present research, experiment were designed to study the effect of reducing Neem oil's high viscosity by increasing the fuel temperature and thereby its effect on combustion and emission characteristics of the engine. Experiments were also conducted using various blends of Neem oil with mineral diesel to study the effect of reduced blend viscosity on emissions and performance of diesel engine.

In this paper, a novel membrane-based phase separator is described. This device, known as a water recovery heat exchanger (WRHEX), overcomes the inherent deficiencies of current phase-separation technology. ...Specifically, the WRHEX cools and removes water vapor or water droplets from feed-air streams without the use of a vacuum or centrifugal force. ...As is shown in this paper, only a low-power air blower and a small stream of recirculated cool water is required for WRHEX operation. This paper presents the results of tests using this novel membrane device over a wide range of operating conditions.

The engine had been modified based on a two-cylinder mechanical pump diesel engine into common rail diesel engine with capability of direct water injection. The direct water injection system was designed and manufactured independently. ...The present work aims at optimizing diesel engine combustion efficiency with optimized water injection strategy. The engine had been modified based on a two-cylinder mechanical pump diesel engine into common rail diesel engine with capability of direct water injection. ...Customized diesel injector was selected to be used as water injector in this study. Water injection strategy was optimized in detail with injection timing around TDC which ranges from 12°CA BTDC to -5°CA BTDC under 10 bar IMEP.

Here, the analysis is done mainly to study and enhance the evaporation and spatial distribution characteristics of the water injection inside the combustion chamber. Water is directly injected into the cylinder of a naturally aspirated, four-stroke GDI engine. ...The benefits of water injection depend on the rate of water vaporization and its spatial distribution in the combustion chamber. ...Water injection in diesel engines is a successful way to reduce NOx emissions and enhance brake power output.

In this work a novel mixture injection system has been developed and tested on a two stroke scooter engine. This system admits finely atomized gasoline directly into the combustion chamber. ...The highest brake thermal efficiency achieved was 25.5% as against 23% with the manifold injection system. The minimum HC level is 460 ppm where as for manifold injection it is 1360 ppm. ...This system admits finely atomized gasoline directly into the combustion chamber. It employs many components that were individually developed, fabricated, tested and then coupled together.