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In the paper, the effect of water injection and different air/fuel ratio (AFR) on the gasoline engine performance and emissions was investigated theoretically. A four cylinder SI engine model was built using GT-Power professional software. The gasoline fuel was injected directly to the cylinder and the water was injected into the intake manifold with different mass flow rate. The calculated engine outputs were: cylinder pressure and temperature, brake torque, brake power, mean effective pressure, thermal efficiency, carbon monoxide, hydrocarbon, and nitrogen oxide emissions. The results of simulations shows that the increased water mass flow rate resulted in improved engine performance and decreased emissions compared to neat gasoline fuel. However, we found that the excessive increase of the water amount inside the cylinder resulted in deteriorated engine performance and, consequently, poorly combustion efficiency.

The internal combustion engine is considered as one of the main sources for air pollution due to hydrocarbon fuel combustion. The increased of the land transport usage require improvement the engine efficiency and combustion process technology to reduce engine emissions. A turbocharged engine and the gaseous fuel replacement are a green tools proposed by researchers to enhance fuel saving and emissions reduction. In this paper both methods have been investigated. The methane fuel is a preferred gaseous fuel due to it is lower carbon to hydrogen ratio resulting in less HC and CO emissions. In this paper a turbocharged compression ignition engine with methane/diesel dual fuel is simulated using professional GT-power code to investigate the effect of methane percentage in mixture on the engine performance and emissions. A turbocharged 6 cylinders compression ignition engine has been built and investigated. During the simulation the methane/diesel ratios were varied from pure diesel with zero percent methane to 90% methane concentration by mass with 10% increment every run. The results show that the engine brake power and specific fuel consumption increased while thermal efficiency decreased for lower CH4 concentration. For higher CH4 percentage the brake power and thermal efficiency increased while specific fuel consumption decreased. Moreover, NO emission has 35% reduction compared to neat diesel fuel when 50% of methane added to the mixture. Conversely, the CO and HC concentration increased when the methane ratio is less than 50% compared to neat diesel combustion. In general, the engine efficiency improved when methane added to diesel fuel in CI engine with turbocharger boost resulting in less emissions and cleaner environment.

Several automobile manufacturers are interested in investigating of dual fuel internal combustion engines, due to high efficiencand low emissions. Many alternative fuels have been used in dual fuel mode for IC engine, such as methane, hydrogen, and natural gas. In the present study, a reactivity controlled compression ignition (RCCI) engine using gasoline/diesel (G/D) dual fuel has been investigated. The effectof mixing gasoline with diesel fuel on combustion characteristic, engine performance and emissions has been studied. The gasoline was injected in the engine intake port, to produce a homogeneous mixture with air. The diesel fuel was injected directly to the combustion chamber during compression stroke to initiate the combustion process. A direct injection compression ignition engine has been built and simulated using ANSYS Forte professional code. The gasoline amount in the simulation varied from (50%-80%) by volume. The diesel fuel was injected to the cylinder in two stages. The model has been validated and calibrated for neat diesel fuel using available data from the literature. The results show that the heat release rate and the cylinder pressure increased when the amount of added gasoline is between 50%-60% volume of the total injected fuels, compared to the neat diesel fuel. Further addition of gasoline will have a contrary effect. In addition, the combustion duration is extended drastically when the gasoline ratio is higher than 60% which results in an incomplete combustion. The NO emission decreased drastically as the gasoline ratio increased. Moreover, addition of gasoline to the mixture increased the engine power, thermal efficienc and combustion efficienc compared to neat diesel fuel.

The spark ignition engine is the most widely used in land transport sector. Hence, studies to predict and improve its behavior continue to be essential. The behavior of the intake and exhaust systems is important because these systems govern the air flow into the engine's cylinders. Inducting the maximum air flow at full load at any given speed and retaining that mass within the engine's cylinders is a primary design goal. The higher the air flow, the larger the amount of fuel that can be burned and the greater the power produced. The important parameter is the volumetric efficiency along with equal air flows to each engine cylinder. The valves and ports, which together provide the major restriction to intake and exhaust flows, largely decouple the manifolds from the cylinders. In this work it was intended to find out the effect of variable valve lift and throat diameter on the performance of the SI engine, namely volumetric efficiency, power, brake specific fuel consumption, and pollutants. Hence, it contributes toward having greener cars in the future. A specially designed computer program (Lotus) was used to predict the gas flows, combustion and overall performance. The results of this investigation show that increasing the valve lift is relatively more effective than throat diameter in boosting volumetric efficiency and power and reducing specific fuel consumption, nitrogen oxide and carbon monoxide emissions. A 10% increase in valve lift resulted in an improvement of 1.8% in η v , 3.3% in power and a decrease of 1.5% in BSFC and (0.3–0.8)% in engine emissions. However, a 10% increase in valve throat diameter causes 50% less effects than the valve lift.

The thrust of this paper is to present a novel approach to obtain the closed-form solutions of large deflection of beams subjected to inclined non-conservative load and tip-end moment. The beams are free at one end and spring-hinged at the other end, the spring at the hinged support is assumed to be nonlinear. The mathematical formulation based on Euler–Bernoulli nonlinear beam theory is presented, and the governing differential equation for the problem is established. The nonlinear governing differential equation was solved using the elliptic integral approach. The results were extensively analyzed and compared with existing solutions based on various numerical methods in the literature. The analytical solution presented shows very good agreements with those from literature with more adequateness, efficiency, and less time effort.

The combustion of hydrogen–diesel blend fuel was investigated under simulated direct injection (DI) diesel engine conditions. The investigation presented in this paper concerns numerical analysis of neat diesel combustion mode and hydrogen enriched diesel combustion in a compression ignition (CI) engine. The parameters varied in this simulation included: H2/diesel blend fuel ratio, engine speed, and air/fuel ratio. The study on the simultaneous combustion of hydrogen and diesel fuel was conducted with various hydrogen doses in the range from 0.05% to 50% (by volume) for different engine speed from 1000 – 4000 rpm and air/fuel ratios (A/F) varies from 10 – 80. The results show that, applying hydrogen as an extra fuel, which can be added to diesel fuel in the (CI) engine results in improved engine performance and reduce emissions compared to the case of neat diesel operation because this measure approaches the combustion process to constant volume. Moreover, small amounts of hydrogen when added to a diesel engine shorten the diesel ignition lag and, in this way, decrease the rate of pressure rise which provides better conditions for soft run of the engine. Comparative results are given for various hydrogen/diesel ratio, engine speeds and loads for conventional Diesel and dual fuel operation, revealing the effect of dual fuel combustion on engine performance and exhaust emissions.

Mixtures of hydrogen and methane are considered viable alternative fuels to gasoline due to lower overall pollutant emissions. The basic intent of the present work is to evaluate the effect of using blend hydrogen–methane fuel with varying fuel induction systems for spark ignition engines on its overall performance and emission. Firstly a model of blends hydrogen–methane ICE has been designed and validated by experimental data. The model is used as an engine simulator. Equivalence ratio, fuel injection system, hydrogen–methane ratio, and engine speed are selected as the effective and controllable parameters on engine emissions and performance characteristics. Secondly, the effects of variation parameters on emissions and performance characteristics of the modeled engine are illustrated. Finally, the reasons of the engine behavior and characteristics under variations of these parameters are fully discussed. The analysis of the results shows that the addition of some hydrogen to methane between 0.4 and 0.6 H2 with equivalence ratio near to stoichiometric and engine speed between 2000 and 3000 rpm produces notable improvements to engine performance and emissions.

The problem with fixed valve timing that the valve train is set by the automaker for peak efficiency running at a specific point in the engine’s operating range. When the vehicle is moving slower or faster than this ideal operating point the engine’s combustion cycle fails to properly burn the air/fuel mixture leading to considerably compromised engine performance and wastes fuel. Variable Valve Timing (VVT) is a solution developed to overcome this engine deficiency, dynamically altering the valve's opening and closing for optimal performance at any speed. The intension in this work is to contribute towards pursuing the development of variable valve timing (VVT) for improving the engine performance. This investigation covers the effect of exhaust valve opening (EVO), and closing (EVC) angle on engine performance and emissions. The aim is to optimize engine power and brake specific fuel consumption (BSFC) where the effect of engine speed has also been considered. Power, BMEP, BSFC, NO, and CO were calculated and presented to show the effect of varying valve timing on them for all the valve timing cases. The calculations of engine performance were carried out using the simulation and analysis engineering software: LOTUS”, and engine emissions were calculated using “ZINOX” program. Sensitivity analysis shows that the reduction of 10% of (EVO) angle gave a reduction of around 2.5% in power and volumetric efficiency, also a slight increase in nitrogen oxide (NO) and carbon monoxide (CO), while a 10% decrease in (EVC) causes around 1% improvement in Power. The effects of different (VVT) from the simulations are analyzed and compared with those in the reviewed literature.

Continuous variable valve actuating (CVVA) technology provides high potential in achieving high performance, low fuel consumption and pollutant reduction. To get full benefits from (CVVT) various types of mechanisms have been proposed and designed. Some of these mechanisms are in production and have shown significant benefits in improving engine performance. In this investigation a newly designed gear drive mechanism that controls the intake valve opening (IVO) and closing (IVC) angles is studied. The control scheme is based on maximizing the engine brake power (P) and specific fuel consumption (BSFC) at any engine speed by continuously varying the phase between the cam shaft angle and the crank shaft angle. A single-cylinder engine is simulated by the “LOTUS” software to find out the optimum phase angle for maximum power and minimum fuel consumption at a given engine speed. The mechanism is a planetary gear drive designed for precise and continuous control. This mechanism has a simple design and operation conditions which can change the phase angle without limitation.

Internal combustion engines are a main power source for vehicles. Improving the engine power is important which involved optimizing combustion timing and quantity of fuel. Variable valve timing (VVT) can be used in this respect to increase peak torque and power. In this work Artificial Neural Network (ANN) is used to model the effect of the VVT on the power and genetic algorithm (GA) as an optimization technique to find the optimal power setting. The same proposed technique can be used to improve fuel economy or a balanced combination of both fuel and power. Based on the findings of this work, it was noticed that the VVT setting is more important at high speed. It was also noticed that optimal power can be obtained by changing the VVT settings as a function of speed. Also to reduce computational time in obtaining the optimal VVT setting, an ANN was successfully used to model the optimal setting as a function of speed.