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. 

3D CFD Simulations of Hydrogen Fuelled Spark Ignition Engine

2008 ◽  
Author(s):  
Dinesh D. Adgulkar ◽  
N. V. Deshpande ◽  
S. B. Thombre ◽  
I. K. Chopde
Keyword(s):  
Internal Combustion Engine ◽  
Power Output ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Spark Ignition ◽  
Flame Speed ◽  
Spark Ignition Engine ◽  
Cfd Simulations ◽  
Turbulent Flame Speed ◽  
Combustion Of Hydrogen

By supporting hydrogen as an alternative fuel to the conventional fuel i.e. gasoline, new era of renewable and carbon neutral energy resources can be introduced. Hence, development of hydrogen fuelled internal combustion engine for improved power density and less emission of NOx has become today’s need and researchers are continuously extending their efforts in the improvement of hydrogen fuelled internal combustion engine. In this work, three dimensional CFD simulations were performed using CFD code (AVL FIRE) for premixed combustion of hydrogen. The simplified 3D geometry of engine with single valve i.e. inlet valve was considered for the simulation. Various combustion models for spark ignition for hydrogen i.e. Eddy Breakup model, Turbulent Flame Speed Closure Combustion Model, Coherent Flame model, Probability Density Function model were tested and validated with available simulation results. Results obtained in simulation indicate that the properties of hydrogen i.e. high flame speed, wide flammability limit, and high ignition temperature are among the main influencing factors for hydrogen combustion being different than that of gasoline. Different parameters i.e. spark advance angle (TDC to 40° before TDC in the step of 5°), rotational speed (1200 to 3000 rpm in the step of 300 rpm), equivalence ratio (0.5 to 1.2 in the step of 0.1), and compression ratio (8, 9 and 10) were used to simulate the combustion of hydrogen in spark ignition engine and to investigate their effects on the engine performance, which is in terms of pressure distribution, temperature distribution, species mass fraction, reaction progress variable and rate of heat release for complete cycle. The results of power output for hydrogen were also compared with that of gasoline. It has been observed that power output for hydrogen is almost 12–15% less than that of gasoline.

scholarly journals GAS DISTRIBUTION PHASES HYDRAULIC CONTROLLED INTERNAL COMBUSTION ENGINE VALVES

2022 ◽  
Vol 16 (4) ◽  
pp. 47-52
Author(s):  
Nail Adigamov ◽  
Andrey Negovora ◽  
Larisa Zimina ◽  
Alexey Maximov
Keyword(s):  
Internal Combustion Engine ◽  
High Speed ◽  
Combustion Engine ◽  
Hydraulic Drive ◽  
Internal Combustion ◽  
Valve Timing ◽  
Gas Distribution ◽  
Time Section ◽  
Engine Valves ◽  
Opening And Closing

The efficiency of an agricultural car or tractor depends on the characteristics of the engine determined by the gas distribution mechanism (GRM). Traditional timing with fixed valve timing does not provide high-quality gas exchange at all engine operating modes. The aim of the work is to improve the characteristics of the engine by using the hydraulic drive of the timing valves. The drive allows you to turn off individual valves, set the moments of their opening and closing in an arbitrary way, provide several triggering of the internal combustion engine valves during the operating cycle. The drive is controlled by an electronic control unit (ECU). The advantage of the drive is its ease of integration into the internal combustion engine. The hydraulic drive ensures that the timing valves are lifted to a height of about 14 mm. The law of displacement of the valve, revealed experimentally, is close to trapezoidal. The use of a hydraulic valve drive has a positive effect on the "time-section" factor in the area of low and medium crankshaft rotational speeds. The increment of the factor "time-section" is due to the significant speeds of opening and closing the valves. Due to the peculiarities of the kinematic characteristics of the movement of the valves when using a hydraulic drive for their movement, the use of serial phases of gas distribution of the engine is impractical. Numerical modeling of the operation of the internal combustion engine determined the regularity of the change in valve timing from the high-speed operating mode of the engine. Optimization criterion is the achievement of maximum engine power. When choosing the valve timing, the possibility of meeting the intake and exhaust valves with the engine piston was excluded. The use of optimal phases leads to an increase in power up to 4.5% at a low crankshaft speed. With an increase in the speed mode, the increase in power decreases, and with a high frequency of rotation of the crankshaft, its slight decrease (1.4%) is observed. An increase in torque, up to a power utilization factor of 0.9, and its subsequent decrease, allow stabilizing the vehicle speed on a road with variable resistance. An increase in the working pressure in the hydraulic drive of the valves makes it possible to intensify gas exchange even at a high speed of rotation of the crankshaft

Thermal Analysis and Computer Aided Exhaust Valve Design Automation Using CREO and Microsoft Excel Spreadsheet

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Siraj Chabru ◽  
P. S. Kulkarni
Keyword(s):  
Thermal Analysis ◽  
Internal Combustion Engine ◽  
3D Modeling ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Exhaust Valve ◽  
Valve Design ◽  
Microsoft Excel ◽  
Excel Spreadsheet

3D modeling has widely been used because of their ease in visualization, understanding and generation of manufacturing drawing sheets compared to 2D drafting. 3D Modeling is the timeconsuming process and many draftsmen does not have the skill to draw a 3D object inside a CAD packages. Internal combustion engine consists of two type of valves inlet valve and exhaust valve. The pair of inlet and exhaust valve is called as poppet valves. Exhaust valve is the mechanical object reputedly required nearly in all internal combustion engines. In this paper we are automate the exhaust valve design by creating graphical user tool using visual basic programming language inside the Microsoft excel spreadsheet. This excel spreadsheet is later integrated to CREO database for automatic 3D valve Modeling. Exhaust valve is the nose of the internal combustion engine to eject the exhaust gases out form the engine at a time of exhaust stroke. It is continuously come under the high temperature and pressure. Steady state thermal analysis has been carried out using FEA. To demonstrate our study, we are considered to design and analysis the exhaust valve for Honda CB Twister 110cc having chamfer angle of 45 degrees. For the 3D modeling we use CREO and ANSYS 18.0 is used for FEA analysis.

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.

scholarly journals Analysis of Combined Power and Refrigeration Generation Using the Carbon Dioxide Thermodynamic Cycle to Recover the Waste Heat of an Internal Combustion Engine

2014 ◽  
Vol 2014 ◽  
pp. 1-12
Author(s):  
Shunsen Wang ◽  
Kunlun Bai ◽  
Yonghui Xie ◽  
Juan Di ◽  
Shangfang Cheng
Keyword(s):  
Carbon Dioxide ◽  
Internal Combustion Engine ◽  
Power Output ◽  
Internal Combustion Engines ◽  
Waste Heat ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Thermodynamic System ◽  
Compression Scheme ◽  
Net Power Output

A novel thermodynamic system is proposed to recover the waste heat of an internal combustion engine (ICE) by integrating the transcritical carbon dioxide (CO2) refrigeration cycle with the supercritical CO2power cycle, and eight kinds of integration schemes are developed. The key parameters of the system are optimized through a genetic algorithm to achieve optimum matching with different variables and schemes, as well as the maximum net power output (Wnet). The results indicate that replacing a single-turbine scheme with a double-turbine scheme can significantly enhance the net power output (Wnet) and lower the inlet pressure of the power turbine (P4). With the same exhaust parameters of ICE, the maximumWnetof the double-turbines scheme is 40%–50% higher than that of the single-turbine scheme. Replacing a single-stage compression scheme with a double-stage compression scheme can also lower the value ofP4, while it could not always significantly enhance the value ofWnet. Except for the power consumption of air conditioning, the net power output of this thermodynamic system can reach up to 13%–35% of the engine power when it is used to recover the exhaust heat of internal combustion engines.

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