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Reciprocating Piston Engine Distributed Generators
Published in H. Lee Willis, Walter G. Scott, Distributed Power Generation, 2018
H. Lee Willis, Walter G. Scott
Spark-ignition engines ignite the fuel-air mixture compressed into the cylinder end with a spark, which starts the combustion at a single point, from which a “flame front” burns outward through the volume of the combustion chamber (the compressed cylinder end). While this occurs very quickly, it takes a measurable amount of time for the flame front to make its way through the combustion chamber. To a degree, this is a desirable trait. The gradually exploding mixture produces a period of continuous pressure on the piston, rather than one intense explosive “slap.”
Gas Power Cycles
Published in Irving Granet, Jorge Luis Alvarado, Maurice Bluestein, Thermodynamics and Heat Power, 2020
Irving Granet, Jorge Luis Alvarado, Maurice Bluestein
Ignition in the spark ignition engine is initiated by an electrical spark at or near the completion of the compression stroke of the fuel–air mixture. In the compression ignition engine, air alone is compressed, and fuel ignition occurs when the fuel is injected into the cylinder at or near top dead center.
Fuels and combustion & emissions
Published in Allan Bonnick, Automotive Science and Mathematics, 2008
Combustion in spark ignition engines such as the petrol engine is initiated by the spark at the sparking plug and the burning process is aided by factors such as combustion chamber design, temperature in the cylinder, and mixture strength.
Chemical Effect of DME on the Combustion and Heat Release of SI-CAI Hybrid Combustion Based on Micro Flame Ignition Strategy
Published in Combustion Science and Technology, 2023
Yifang Feng, Tao Chen, Zhuoxiao Yao, Hua Zhao
At the locations of the spark plug, due to the DME of case 1 being in the pit of the piston, the laminar flame speed showed only a 10% increase than the contrast of the gasoline-air mixture at the same equivalent ratio as shown in Figure 8. However, the discrete DME near the spark plug in case 2 showed a doubled flame speed than gasoline and the spark ignition in case 1. The mass fraction of DME increased, leading to a change in the reaction path. From the sensitivity analysis of temperature shown in Figure 9, the temperature was mainly affected by the C3-C4 mid-products from gasoline in case 1 and by the 2-step oxidation of DME in case 2. At this stage, the OH produced by gasoline reacted with the DME and its mid-product of the first step oxidation in case 1, which enhanced the oxidation of DME. Although in case 2, the temperature is most sensitive to the oxidation of DME and the mid-product of gasoline, such as HO2 and OH, enhanced both the two-step DME oxidation as well.
A Computational Study on the Influence of the Hydrous Ethanol Water Content in Spark-Ignition Engine Performance and in Flame Development
Published in Heat Transfer Engineering, 2023
Fabiano Alves dos Santos, Albino José Kalab Leiroz
The turbulent flame speed is obtained in the correlations related to the laminar flame speed based on the local turbulence conditions. Once Eqs. (1–6) are solved, the laminar flame speed is determined using the a power law expression given by Metghalchi and Keck [38, 39] as where represents the inert diluent mass fraction, and The exponents and in Eq. (7) are fuel independent, and only function of the equivalence ratio [38, 39]. In the present work, for the high temperature and pressure prevailing in an spark-ignition internal combustion engine, the exponents were chosen as and [40].
Performance analysis of vortex flow through a swirler by computational fluid dynamics technique
Published in International Journal of Ambient Energy, 2020
From the graph, it is clear that the Chemical Energy Difference is equivalent to thermal energy evolved at the reaction. But the point is for activation energy. In different cases, the activation energy generation processes are different. In this work, the internal combustion engine has been discussed; therefore the focus of discussion will be only on the subject. In the internal combustion engine activation energy is provided by two different ways for two different types of engines (S.I. Engine and C.I. Engine). In case of the S.I. Engine, the activation energy is provided by the spark ignition by the spark plug at almost the end of compression stroke for a four-stroke engine. On the other hand, for the C.I. Engine, the same is provided by a sudden injection of fuel in the highly compressed air. The main cause of activation energy formation under highly compressed air is due to a temperature increase by sudden compression. In the internal combustion engine, combustion in a very short space that produces a mechanical thrust which gives a jerk on the piston and hence the engine works. As 100% efficiency cannot be achieved in practice, the combustion efficiency is affected by many factors like swirl number or turbulence inside the chamber, piston bowl geometry, fuel injector pattern, fuel injector position and orientation, the temperature of combustion chamber, etc. If the efficiency can be increased, the amount of heat generated will be increased and enhances the thrust on the piston to increase engine and emission performance.