Internal Combustion Spark Ignition Engine Research Articles

Thermodynamic Analysis of the Combustion Process in Hydrogen-Fueled Engines with EGR

This article presents a novel approach to the analysis of heat release in a hydrogen-fueled internal combustion spark-ignition engine with exhaust gas recirculation (EGR). It also discusses aspects of thermodynamic analysis common to modeling and empirical analysis. This new approach concerns a novel method of calculating the specific heat ratio (cp/cv) and takes into account the reduction in the number of moles during combustion, which is characteristic of hydrogen combustion. This reduction in the number of moles was designated as a molar contraction. This is particularly crucial when calculating the average temperature during combustion. Subsequently, the outcomes of experimental tests, including the heat-release rate, the initial combustion phase (denoted CA0-10) and the main combustion phase (CA10-90), are presented. Furthermore, the impact of exhaust gas recirculation on the combustion process in the engine is also discussed. The efficacy of the proposed measures was validated by analyzing the heat-release rate and calculating the mean combustion temperature in the engine. The application of EGR in the range 0-40% resulted in a notable prolongation of both the initial and main combustion phases, which consequently influenced the mean combustion temperature.

Pyrolysis oil blended n-butanol as a fuel for power generation by an internal combustion engine

The article discusses results from the investigation of the n-butanol-pyrolysis oil blend, which can be considered a potential fuel for the internal combustion spark-ignition engine operating in a power generation set. The n-butanol-pyrolysis oil blends were prepared at two ratios of 3:1 (25%) and 1:1 (50%) by volume, respectively. As reference fuels for combustion tests in the engine, regular gasoline (gasoline EU 95) and n-butanol were proposed. The combustion tests were conducted on the single-cylinder research engine at a compression ratio of 11:1 and an equivalence ratio of 1. The experimental analysis was focused on engine performance, combustion phases, knock occurrence, and exhaust emissions. As observed, combustion got slower for butanol-pyrolysis oil blends. CO emission was similar to tests with reference fuels. Unburnt hydrocarbons increased with pyrolysis oil increased to 50% in a blend. NO emissions were reduced. It was found that n-butanol blended pyrolysis oil at a ratio of 3:1 can be successfully applied as the fuel to the spark-ignition engine. Additionally, it was found that this blend is more resistant to combustion knock compared to regular gasoline 95. Hence, the engine can work at a higher compression ratio without any malfunctions caused by combustion knock.

Impact of Pyrolysis Oil Addition to Ethanol on Combustion in the Internal Combustion Spark Ignition Engine

Thermal processing (torrefaction, pyrolysis, and gasification), as a technology can provide environmentally friendly use of plastic waste. However, it faces a problem with respect to its by-products. Pyrolysis oil obtained using this technology is seen as a substance that is extremely harmful for living creatures and that needs to be neutralized. Due to its relatively high calorific value, it can be considered as a potential fuel for internal combustion spark-ignition engines. In order make the combustion process effective, pyrolysis oil is blended with ethanol, which is commonly used as a fuel for flexible fuel cars. This article presents results from combustion tests conducted on a single-cylinder research engine at full load working at 600 rpm at a compression ratio of 9.5:1, and an equivalence ratio of 1. The analysis showed improvements in combustion and engine performance. It was found that, due to the higher calorific value of the blend, the engine possessed a higher indicated mean effective pressure. It was also found that optimal spark timing for this ethanol-pyrolysis oil blend was improved at a crank angle of 2–3° at 600 rpm. In summary, ethanol-pyrolysis oil blends at a volumetric ratio of 3:1 (25% pyrolysis oil) can successfully substitute ethanol in spark-ignition engines, particularly for vehicles with flexible fuel type.

Mean effective pressure oscillations in an IC-SI engine after the addition of hydrogen-rich gas

Fluctuations during the combustion of hydrogen-enriched gasoline in an Internal Combustion Spark Ignition (IC-SI) engine were investigated. The energy share of the hydrogen-rich fuel for the engine was varied as 0%, 5%, 10%, and 20%, respectively. The cyclic combustion pressure was measured and its cyclic oscillations were expressed by indicated mean effective pressure per cycle. The statistical and multifractal analyses applied to the corresponding time series showed considerable changes in the engine dynamics for hydrogen percentages ranging from 5% to 20%. The mean indicated pressure and the maximum pressure in the combustion chamber of the engine running under steady conditions were measured.

Cycle parameters of an internal combustion spark-ignition gas piston engine with an electronic control system

The purpose of the work is to develop methods of managing the cycle of bifuel and single-fuel vehicleswith engines running both on petrol and gas fuel as well as physically and mathematically reasonable algorithmsfor an electronic control system. On the basis of full-scale tests of an internal combustion spark-ignition pistonengine and a technique developed for designing an ejeсtor with non-stationary physical parameters of workingbodies a method of compensating power losses by ejecting a portion of air with the help of pressure differenceon the valve of a gas electromagnetic injector is proposed. On the basis of the theoretical analysis and experimentaldata an algorithm of determining the fuel injection rate taking into account the subcritical or critical fueldischarge from the injector nozzle, the change in the speed of sound, the gas fuel pressure undershoot in the processof fuel feeding and the power supply voltage on the electromagnetic coil of the gas injector is developed. Amethod of determining the ignition advance angle when switching from petrol to gas fuel is developed for anelectronic control system of an internal combustion spark-ignition engine which serves as the basis for calculatingthe adjusting factors for liquefied petroleum gas and compressed natural gas.

Computerised Simulation of Spark Ignition Internal Combustion Engine

Improving the performance of internal combustion engines is one of the major concerns of researchers. Experimental studies are more expensive than computational studies. Also using computational techniques allows us to obtain all the required data for the cylinder, which could not be measured. In this study, solution of the two dimensional, four stroke spark ignition (SI) engine with port injection is considered. The efficiency of an SI engine depends on several complicated processes including injection, mixture preparation, and Combustion and exhaust flow. In the Present work Turbulence flow conditions are considered. Standard k-€ turbulence model for fluid flow and eddy break-up model for turbulent combustion were utilized. CFD analysis has been used extensively to improve each of these processes. In this paper discuss simulates the Intake, Compression, Expansion and Exhaust process with hexane fuel combustion. In-Cylinder model for simulating reciprocating engine, General strategies for modelling valve opening, closing and Discrete phase Model (DPM) for simulating port injection. Key- words: Internal Combustion Spark ignition engine, CFD, Hexane, Combustion, Simulation.

Use of Hydrogen in Fiat Lancia Petrol engine, Combustion Process and Determination of Optimum Valve Timing

To our path towards green economy, Hydrogen is often regarded to have a potential growth in the coming future. However, the high cost of operation of fuel cell has often been a setback. If we could make use of hydrogen gas as a fuel directly, the scope of development broadens. Owing to these aspects, this work primarily focuses on the simulation technique of an Internal Combustion Spark Ignition Engine powered by Hydrogen gas. The simulations of various stages have been carried out using the discrete approach, thereby investigating the pressures and temperatures at various instants in the cycle. For the relative performance discussion we have simulated the different cycles as ideal cycle, air fuel cycle and actual cycle. The resultant cyclic graph indicates various discrepancies between ideal, air fuel and actual cycle. This analysis serves as a tool for a better understanding of the variables involved and helps in optimizing engine design and fixing of various parameters, including the determination of valve timings. Besides this, backfire, is the commonly faced problem with the hydrogen engines. To reduce this effect, a fuel injectoris used for adding the gaseous fuel to the combustion chamber. Keyword: Actual cycle, air fuel cycle, backfire, discrete approach, fuel injector, fuel cell, hydrogen, ideal cycle, spark plug, valve timings ,Fiat Lancia,inlet valve, exhaust valve, optimum valve timing .

Nonlinear air-to-fuel ratio and engine speed control for hybrid vehicles

Internal combustion spark ignition engine management systems regulate the fuel, spark, and idle air subsystems to achieve sufficient engine performance at acceptable fuel economy and tailpipe emission levels. Engine control units also monitor other engine processes, using a suite of sensors, and periodically check the system actuators' operation to satisfy legislated onboard diagnostics. The majority of production engines regulate the air-to-fuel ratio using a speed-density, or air-flow, control strategy. In this approach, the mass of air drawn into a given cylinder is calculated using the engine speed, manifold absolute pressure, and inlet air temperature. Based on the air mass, appropriate fuel amounts are injected to achieve stoichiometric operation. However, the wide range of operating conditions, inherent induction process nonlinearities, and gradual component degradations due to aging have prompted research into model-based algorithms. In this paper, a nonlinear model-based control strategy will be proposed for simultaneous air-to-fuel ratio control and speed tracking in hybrid electric vehicles. The motivation for engine speed management resides in the integrated control of the engine and a continuously variable transmission for increased efficiency. The proposed backstepping controller uses an observer to reduce the inputs to manifold air mass (e.g., manifold absolute pressure and inlet air temperature) and engine speed. The underlying engine model describes the air intake, fuel injection, and rotational dynamics. For comparison purposes, an existing multisurface sliding mode controller and an integrated speed-density air-to-fuel controller with attached engine speed regulation have been implemented. The performance of each controller is studied using an analytical engine model with representative numerical results presented and discussed to provide insight into the overall performances.

Dynamic Model of the Intake Dynamics of a SI Engine Including Internal EGR and Fuel Film Effects

Ths paper presents a mean value model of the dynamic behavior for the intake manifold of an internal combustion spark ignition engine. The scope is to estimate in real time the mass flow rate of the air required by the engine and its thermodynamic conditions taking into account the effects related to the pressure and temperature dynamic, the heat exchange both in the intake manifold and in the pipes toward each cylinder, the fuel film and the influence of the exhaust gas internal recirculation.The final model is composed by physic and black box models, with the goal to have a simple description of the main quasi-stationary phenomena that occur in that part of the engine which starts at the throttle body down to the cylinder volume during the intake stroke. This model can be used as a starting point for the development of a complete black-box model that can be implemented in the central unit for the optimization of the fuel injection. The validation of the model has been carried out with experimental data sampled in a prototype vehicle with the engine equipped with pressure and temperature transducers in addition to the normal electronic measurement equipment The tests has been performed after the engine warm up phase, and in different working situations (urban, mountain and highway) and the results obtained are quite good.

Self-ignition ahead of the flame front in piston spark-ignition engines

The hypothesis that engine knock is a result of competition of two types of chemical reaction—frontal frontal and volumetric—is put forward. A mathematical model for mixture self-ignition ahead of the flame front in an internal-combustion spark-ignition engine is constructed. The operation process was calculated numerically with variation of the ignition angle, the degree of compression, and the rotation frequency of the crankshaft. A critical condition for the occurrence of engine knock is obtained by approximate analytical solution of the problem. Comparison of theoretical results for ten engine parameters and operation with experimental data of different authors confirms the validity of the proposed hypothesis on the occurrence of engine knock.