Heat Transfer in the Straight Section of an Exhaust Port of a Spark Ignition Engine

1979 ◽  
Author(s):  
G. L. Malchow ◽  
S. C. Sorenson ◽  
R. O. Buckius
Keyword(s):  
Heat Transfer ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Straight Section ◽  
Exhaust Port

Simulation of Extended Expansion Lean Burn Spark Ignition Engine

2004 ◽  
Author(s):  
A. Manivannan ◽  
R. Ramprabhu ◽  
P. Tamilporai ◽  
S. Chandrasekaran
Keyword(s):  
Heat Transfer ◽  
Compression Ratio ◽  
Thermal Efficiency ◽  
Numerical Study ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Valve Closure ◽  
Intake Valve ◽  
Lean Burn ◽  
Atkinson Cycle

This paper deals with Numerical Study of 4-stoke, Single cylinder, Spark Ignition, Extended Expansion Lean Burn Engine. Engine processes are simulated using thermodynamic and global modeling techniques. In the simulation study following process are considered compression, combustion, and expansion. Sub-models are used to include effect due to gas exchange process, heat transfer and friction. Wiebe heat release formula was used to predict the cylinder pressure, which was used to find out the indicated work done. The heat transfer from the cylinder, friction and pumping losses also were taken into account to predict the brake mean effective pressure, brake thermal efficiency and brake specific fuel consumption. Extended Expansion Engine operates on Otto-Atkinson cycle. Late Intake Valve Closure (LIVC) technique is used to control the load. The Atkinson cycle has lager expansion ratio than compression ratio. This is achieved by increasing the geometric compression ratio and employing LIVC. Simulation result shows that there is an increase in thermal efficiency up to a certain limit of intake valve closure timing. Optimum performance is attained at 90 deg intake valve closure (IVC) timing further delaying the intake valve closure reduces the engine performance.

Thermophysical Properties of Working Substance and Heat Transfer in a Hydrogen Combustion Engine

2003 ◽  
Author(s):  
T. Shudo ◽  
H. Oka
Keyword(s):  
Heat Transfer ◽  
Combustion Chamber ◽  
Heat Loss ◽  
Thermophysical Properties ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Spark Ignition ◽  
Hydrogen Combustion ◽  
Spark Ignition Engine ◽  
Combustion Engines

Hydrogen is a clean alternative to fossil fuels for internal combustion engines and can be easily used in spark-ignition engines. However, the characteristics of the engines fueled with hydrogen are largely different from those with conventional hydrocarbon fuels. A higher burning velocity and a shorter quenching distance for hydrogen as compared with hydrocarbons bring a higher degree of constant volume and a larger heat transfer from the burning gas to the combustion chamber wall of the engines. Because of the large heat loss, the thermal efficiency of an engine fueled with hydrogen is sometimes lower than that with hydrocarbons. Therefore, the analysis and the reduction of the heat loss are crucial for the efficient utilization of hydrogen in internal combustion engines. The empirical correlations to describe the total heat transferred from the burning gas to the combustion chamber walls are often used to calculate the heat loss in internal combustion engines. However, the previous research by one of the authors has shown that the widely used heat transfer correlations cannot be properly applied to the hydrogen combustion even with adjusting the constants in them. For this background, this research analyzes the relationship between characteristics of thermophysical properties of working substance and heat transfer to the wall in a spark-ignition engine fueled with hydrogen.

Preliminary Testing of Metal-Based Thermal Barrier Coating in a Spark-Ignition Engine

2009 ◽  
Author(s):  
Michael Marr ◽  
James S. Wallace ◽  
Larry Pershin ◽  
Sanjeev Chandra ◽  
Javad Mostaghimi
Keyword(s):  
Heat Transfer ◽  
Thermal Barrier Coating ◽  
Substrate Surface ◽  
Temperature Fluctuations ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Thermal Barrier ◽  
Cylinder Wall ◽  
Test Results ◽  
Barrier Coating

A novel metal-based thermal barrier coating was tested in a spark-ignition engine. The coating was applied to the surface of aluminum plugs and exposed to in-cylinder conditions through ports in the cylinder wall. Temperatures were measured directly behind the coating and within the plug 3 and 11 mm from the surface. In-cylinder pressures were measured and analyzed to identify and quantify knock. Test results suggest the coating does not significantly reduce overall heat transfer, but it does reduce the magnitude of temperature fluctuations at the substrate surface. It was found that heat transfer can be reduced by reducing the surface roughness of the coating. The presence of the coating did not promote knock.

scholarly journals Comparative Study of the Effective Release Energy, Residual Gas Fraction, and Emission Characteristics with Various Valve Port Diameter-Bore Ratios (VPD/B) of a Four-Stroke Spark Ignition Engine

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1330 ◽  
Author(s):  
Nguyen Xuan Khoa ◽  
Ocktaeck Lim
Keyword(s):  
Load Condition ◽  
Experimental System ◽  
Optimization Method ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Pressure Increase ◽  
Intake Port ◽  
Exhaust Port ◽  
Residual Gas Fraction ◽  
Residual Gas

In this research, the residual gas, peak firing pressure increase, and effective release energy were completely investigated. To obtain this target, the experimental system is installed with a dynamo system and a simulation model was setup. Through combined experimental and simulation methods, the drawbacks of the hardware optimization method were eliminated. The results of the research show that the valve port diameter-bore ratio (VPD/B) has a significant effect on the residual gas, peak firing pressure increase, and effective release energy of a four-stroke spark ignition engine. In this research, the engine was performed at 3000 rpm and full load condition. Following increased IPD/B ratio of 0.3–0.5. The intake port and exhaust port diameter has a contrary effect on engine volumetric efficiency, the residual gas ratio increase 27.3% with larger intake port and decrease 18.6% with larger exhaust port. The engine will perform optimal thermal efficiency when the trapped residual gas fraction ratio is from 13% to 14%. The maximum effective release energy was 0.45 kJ at 0.4 intake port-bore ratio, and 0.451 kJ at 0.35 exhaust port-bore ratio. The NOx emission increases until achieved a maximum value after that decrease even VPD/B was still increasing. With a VPD/B ratio of 0.35 to 0.4, the engine works without the misfiring.

Modifications to Quasi-Dimensional Burning Model of Spark Ignition Engines

2009 ◽  
Author(s):  
M. R. Modarres Razavi ◽  
A. Hosseini ◽  
M. Dehnavi
Keyword(s):  
Heat Transfer ◽  
Combustion Chamber ◽  
Numerical Solution ◽  
Taylor Expansion ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Spark Ignition Engines ◽  
Algebraic Functions ◽  
Spark Plug ◽  
Burning Model

The way in which position of spark plug affects combustion in a spark ignition engine can be analyzed by using two-zone burning model. The purpose of this paper is to extract correlations to simulate the geometric interaction between the propagating flame and the general cylindrical combustion chamber. Eight different cases were recognized. Appropriate equations to calculate the flame area (Af), the burned and the unburned volume (Vb & Vu) and the heat transfer areas related to the burned and unburned regions were derived and presented for each case using Taylor expansion in order to replace numerical solution with trigonometric algebraic functions.

The effect of the stroke-to-bore ratio on combustion, heat transfer and efficiency of a homogeneous charge spark ignition engine of given displacement

2000 ◽  
Vol 1 (2) ◽  
pp. 191-208 ◽  
Author(s):  
Z. S. Filipi ◽  
D. N. Assanis
Keyword(s):  
Heat Transfer ◽  
Flame Front ◽  
Turbulent Flame ◽  
Spark Ignition ◽  
Point Of View ◽  
Spark Ignition Engine ◽  
Combustion Heat ◽  
Geometric Point ◽  
Long Stroke ◽  
Homogeneous Charge

This study investigates how the selection of the stroke-to-bore (S/B) ratio affects combustion, heat transfer and overall efficiency in a homogeneous charge spark ignition (SI) engine of a given displacement. Initially, flame front area maps and wall areas in contact with burned gases are examined from a purely geometric point of view, for S/B ratios of 0.7, 1.0 and 1.3. Subsequently, a quasi-dimensional turbulent flame entrainment model is used to quantify the extent to which turbulence versus geometric factors are responsible for the observed combustion, heat transfer and cycle efficiency behaviour, as the S/B ratio varies. Calculations are performed for a range of engine speeds and loads, as well as for operation with 15 per cent exhaust gas recirculation (EGR). Results show that the S/B ratio has a significant effect on both turbulence levels and the geometric interaction of the flame front with the combustion chamber walls. In general, a longer stroke leads to higher thermal efficiency through faster burning and lower overall chamber heat loss. These effects are non-linear, being more dramatic when the S/B ratio is increased from below unity than from above unity. The potential of the long-stroke engine for brake fuel economy improvement can be exploited to the fullest at low speeds, while friction losses gradually diminish it at higher speeds.

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