Temperature History in the Combustion Chamber of a Spark Ignition Engine

1974 ◽  
Author(s):  
K. S. Varde ◽  
G. G. Lucas
Keyword(s):  
Combustion Chamber ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Temperature History

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.

Unsteady in-cylinder heat transfer in a spark ignition engine: Experiments and modelling

2001 ◽  
Vol 215 (6) ◽  
pp. 747-760 ◽  
Author(s):  
D J Oude Nijeweme ◽  
J. B. W. Kok ◽  
C. R. Stone ◽  
L Wyszynski
Keyword(s):  
Boundary Layer ◽  
Heat Flux ◽  
Combustion Chamber ◽  
Energy Equation ◽  
Spark Ignition ◽  
Surface Heat ◽  
Spark Ignition Engine ◽  
Unexpected Result ◽  
Reynolds Analogy ◽  
Law Of The Wall

Instantaneous heat flux measurements have shown that, in the expansion stroke, heat can flow from the wall into the combustion chamber, even though the bulk gas temperature is higher than the wall temperature. This unexpected result has been explained by modelling of the unsteady flows and heat conduction within the gas side thermal boundary layer. This modelling has shown that these unsteady effects change the phasing of the heat flux, compared with that which would be predicted by a simple convective correlation based on the bulk gas properties. Twelve fast response thermocouples have been installed throughout the combustion chamber of a pent roof, four-valve, single-cylinder spark ignition engine. Instantaneous surface temperatures and the adjacent steady reference temperatures were measured, and the surface heat fluxes were calculated for motoring and firing at different speeds, throttle settings and ignition timings. To make comparisons with these measurements, the combustion system was modelled with computational fluid dynamics (CFD). This was found to give very poor agreement with the experimental measurements, so this led to a review of the assumptions used in boundary layer modelling. The discrepancies were attributed to assumptions in the law of the wall and Reynolds analogy, so instead the energy equation was solved within the boundary layer. The one-dimensional energy conservation equation has been linearized and normalized and solved in the gas side boundary layer for a motored case. The results have been used for a parametric study, and the individual terms of the energy equation are evaluated for their contribution to the surface heat flux. It was clearly shown that the cylinder pressure changes cause a phase shift of the heat flux forward in time.

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.

Post-Combustion In-Cylinder Vaporization During Cranking and Startup in a Port-Fuel–Injected Spark Ignition Engine

2005 ◽  
Vol 128 (2) ◽  
pp. 397-402 ◽  
Author(s):  
Jim S. Cowart
Keyword(s):  
Combustion Chamber ◽  
Liquid Fuel ◽  
Combustion Process ◽  
Spark Ignition ◽  
Liquid Films ◽  
Spark Ignition Engine ◽  
Fuel Vapor ◽  
Intake Port ◽  
Warm Up ◽  
Flame Ionization

During port-fuel–injected (PFI) spark-ignition (SI) engine startup and warm-up fuel accounting continues to be a challenge. Excess fuel must be injected for a near stoichiometric combustion charge. The “extra” fuel that does not contribute to the combustion process may stay in the intake port or as liquid films on the combustion chamber walls. Some of this combustion chamber wall liquid fuel is transported to the engine’s oil sump and some of this liquid fuel escapes combustion and evolves during the expansion and exhaust strokes. Experiments were performed to investigate and quantify this emerging in-cylinder fuel vapor post-combustion cycle by cycle during engine startup. It is believed that this fuel vapor is evaporating from cylinder surfaces and emerging from cylinder crevices. A fast in-cylinder diagnostic, the fast flame ionization detector, was used to measure this behavior. Substantial post-combustion fuel vapor was measured during engine startup. The amount of post-combustion fuel vapor that develops relative to the in-cylinder precombustion fuel charge is on the order of one for cold starting (0 °C) and decreases to ∼13 for hot starting engine cycles. Fuel accounting suggests that the intake port puddle forms quickly, over the first few engine cranking cycles. Analysis suggests that sufficient charge temperature and crevice oxygen exists to at least partially oxidize the majority of this post-combustion fuel vapor such that engine out hydrocarbons are not excessive.

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