scholarly journals Research of the efficiency of using the Miller cycle of an internal combustion engine

2021 ◽  
Vol 22 (2) ◽  
pp. 196-204
Author(s):  
Sergei V. Smirnov ◽  
Alexander R. Makarov ◽  
Ivan A. Zaev ◽  
Gulnara T. Khudaibergenova
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Real Data ◽  
Internal Combustion ◽  
Expansion Ratio ◽  
Miller Cycle ◽  
Otto Cycle ◽  
Atkinson Cycle ◽  
Engine Design ◽  
Intake Pressure

The article is devoted to the study of the possibilities of improving the technical and economic indicators of an internal combustion engine (ICE) through the use of the Miller cycle with a shortened intake. A review of scientific works on the use of the Atkinson cycle and Miller cycle in an internal combustion engine is carried out. A comparative analysis of theoretical cycles: Otto cycle, Atkinson cycle and Miller cycle is carried out. Calculated studies of the influence of the expansion ratio and the pressure increase ratio on the efficiency of the Atkinson cycle have been carried out. The ratios are presented that allow using the Miller cycle with a short inlet to obtain the same theoretical efficiency of the cycle as that of the Atkinson cycle. At the same time, the implementation of the Miller cycle in a real engine design significantly exceeds the possibilities of using the Atkinson cycle. The results of the study showed that the use of the Miller cycle with a shortened intake is preferable, but it must necessarily increase the compression ratio and intake pressure through the use of boost. On the example of real data of the main parameters of the cycle, it is shown that the use of the theoretical Miller cycle can provide a significant up to 12.2% increase in the efficiency of the cycle compared to the Otto cycle. The ratios, conditions and recommendations are presented that allow the effective use of the Miller cycle with a shortened intake in a real engine design.

Improving the design of an internal combustion engine with counter pistons

2021 ◽  
pp. 3-6
Author(s):  
Keyword(s):  
Internal Combustion Engine ◽  
Dynamic Characteristics ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Maximum Torque ◽  
Moment Vector ◽  
Engine Design ◽  
Torque Moment ◽  
Dimensional Parameters ◽  
Crank Mechanism

A new layout of a two-cylinder internal combustion engine with counter-pistons is proposed, which increases its efficiency by reducing the pressure angles. The dynamics of the proposed arrangement of a two-shaft crank-slider internal combustion engine, which provides maximum torque moment at maximum gas pressure in the minimum volume of the combustion chamber, is investigated, which reduces the load on the engine design and its weight and dimensional parameters. The research was carried out by comparing the dynamic characteristics of different engines using vector modular models and the KDAM program. Keywords: internal combustion engine, crank mechanism, indicator diagram, dynamic characteristics, torque moment, vector, contour, model, module [email protected]

Performance study of the hypocycloid gear mechanism for internal combustion engine applications

2019 ◽  
pp. 146808741989358 ◽  
Author(s):  
Mostafa A ElBahloul ◽  
ELsayed S Aziz ◽  
Constantin Chassapis
Keyword(s):  
Internal Combustion Engine ◽  
Thermodynamic Model ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Otto Cycle ◽  
Engine Efficiency ◽  
Gear Mechanism ◽  
Crank Mechanism

Fuel conversion efficiency is one of the main concerns in the field of internal combustion engine systems. Although the Otto cycle delivers the maximum efficiency possible in theory, the kinematics of the slider–crank mechanism of the conventional internal combustion engines makes it difficult to reach this level of efficiency in practice. This study proposes using the unique hypocycloid gear mechanism instead of the conventional slider–crank mechanism for the internal combustion engines to increase engine efficiency and minimize frictional power losses. The hypocycloid gear mechanism engine’s kinematics provides the means for the piston-rod assembly to reciprocate in a straight-line motion along the cylinder axis besides achieving a nonlinear rate of piston movement. As a result, this characteristic allows for a true constant-volume combustion, which in turn would lead to higher work output. An in-cylinder gas volume change model of the hypocycloid gear mechanism engine was developed and incorporated into the thermodynamic model for the internal combustion engine cycle. The thermodynamic model of the hypocycloid gear mechanism engine was developed and simulated using MATLAB/Simulink software. A comparison between the conventional engine and the hypocycloid gear mechanism engine in terms of engine performance characteristics showed the enhancements achieved using hypocycloid gear mechanism for internal combustion engine applications. The hypocycloid gear mechanism engine analysis results indicated higher engine efficiency approaching that of the Otto cycle.

SIMULATION OF INTAKE AND EXHAUST VALVE TIMING ON INTERNAL COMBUSTION ENGINE

2017 ◽  
Vol 79 (7-4) ◽  
Author(s):  
Afiq Aiman Dahlan ◽  
Mohamad Shahrafi ◽  
Mohd Farid Muhamad Said
Keyword(s):  
Internal Combustion Engine ◽  
Power Output ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Exhaust Valve ◽  
Miller Cycle ◽  
Average Percentage ◽  
Percentage Difference ◽  
Average Percentage Difference ◽  
Opening And Closing

Internal combustion engine in automotive industry is widely researched to increase its efficiency and power output. Valve system in modern internal combustion engine control the opening and closing timing of intake and exhaust stroke. Its duration affects the performance of the engine at both power output and fuel efficiency. Therefore, this study discusses about the Miller cycle concept that alter the duration of both intake and exhaust valve opening and closing characteristics. The study focusses mainly on finding the optimum timing characteristics on Proton Iriz gasoline engine. A 1-dimensional model has been built using a commercial software called GT-POWER for engine simulation purpose. The engine is then calibrated with the simulation model. The optimization was run in this software to find the best optimum timing of intake and exhaust valve for two categories which are targeting performance and fuel consumption. The results show positive trends in the BSFC results with the maximum percentage difference of 26.27% at 6,250 rpm. The average percentage difference in the BSFC results is 14.12%. For targeting performance, the overall results show an increasing trend in the brake torque curves with maximum percentage difference is 9.83%. The average percentage difference in brake torque is found to be 3.12%. Therefore, this paper concludes that Miller cycle implementation give minimal performance increment. The targeting performance and fuel consumption optimization can also be implement for changing mode of driving. However, the increase compression ratio would also give adverse effects on engine performance and endurance. The Miller cycle is also more suitable to be implement on force induction system. 

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