scholarly journals Measurement of temperature, fuel concentration and equivalence ratio fields using tracer LIF in IC engine combustion

2000 ◽  
Vol 71 (5) ◽  
pp. 717-723 ◽  
Author(s):  
S. Einecke ◽  
C. Schulz ◽  
V. Sick
Keyword(s):  
Equivalence Ratio ◽  
Ic Engine ◽  
Fuel Concentration ◽  
Engine Combustion

A Pathway to Ultra-Lean IC Engine Combustion: The Narrow Throat Pre-chamber

2021 ◽  
pp. 175-203
Author(s):  
Manuel Alejandro Echeverri Marquez ◽  
Ponnya Hlaing ◽  
Priybrat Sharma ◽  
Emre Cenker ◽  
Jihad Badra ◽  
...  
Keyword(s):  
Ic Engine ◽  
Engine Combustion

Local fuel concentration, ignition and combustion in a stratified charge spark combustion in a stratified charge spark ignited direct injection engine: Spectroscopic, imaging and pressure-based measurements

2003 ◽  
Vol 4 (2) ◽  
pp. 61-86 ◽  
Author(s):  
T. D. Fansler ◽  
M. C. Drake ◽  
B Stojkovic ◽  
M. E. Rosalik
Keyword(s):  
High Speed ◽  
Equivalence Ratio ◽  
Direct Injection ◽  
Injection Timing ◽  
Cylinder Pressure ◽  
Engine Operation ◽  
Stratified Charge ◽  
Fuel Concentration ◽  
Spark Gap ◽  
Ignition And Combustion

A recently developed spark emission spec-troscopy technique has been used to measure the effects of fuel injection timing, spark timing and intake swirl level on the individual-cycle fuel concentration at the spark gap in a wall-guided spark ignited direct injection (SIDI) engine. The fuel-concentration measurements were made simultaneously with measurements of individual-cycle spark discharge energy and cylinder pressure. Endoscopic imaging of the fuel spray and high-speed imaging of combustion (both broadband and spectrally resolved) augment these quantitative data. For optimum engine operation, the fuel-air equivalence ratio at the spark gap just after spark breakdown is rich on average (〈φ〉 ≈1.4–1.5) and varies widely from cycle to cycle (∼25 per cent). The evolution with crank angle of the mean equivalence ratio and its cycle-to-cycle fluctuations are correlated with the cylinder pressure, heat release and imaging data to provide insights into fuel transport and mixture preparation that are important to understanding and optimizing ignition and combustion in SIDI engines. For example, causes of misfires and partial burns have been determined.

scholarly journals Measurement of burning velocity on DME fuel-air mixtures using microgravity technique

2005 ◽  
Vol 122 (3) ◽  
pp. 56-60
Author(s):  
Satoshi OKAJIMA
Keyword(s):  
Experimental Data ◽  
Equivalence Ratio ◽  
Initial Conditions ◽  
Burning Velocity ◽  
Flammability Limit ◽  
Engine Combustion ◽  
Temperature And Pressure ◽  
Lower Flammability Limit ◽  
Flame Behavior ◽  
Micro Gravity

Experiment has been carried out to examine the fundamental combustion characteristics of DME fuel-air mixtures using micro-gravity technique, which is achieved in freely falling chamber. The initial conditions of temperature and pressure are 293 K and 0.10 MPa, respectively and the equivalence ratio is the range from stoichiometoric proportion to near the lower flammability limit. The results obtained in the study are as follows:(1) micro-gravity technique is very useful to analyze the flame behavior even at very lean mixtures, and (2) the burning velocity of DME fuel- air mixture is nearly the same with that of methane-air mixture at the range of all the equivalence ratios investigated and those values of DME fuel are 10.0 cm/s and 32.0 cm/s at 0.62 and 0.90 of equivalence ratio, respectively, and (3) from these experimental data it is suggested that the application to the engine combustion of DME fuel is not so impossible.

A Detailed Analysis of Thermoacoustic Interaction Mechanisms in a Turbulent Premixed Flame

2004 ◽  
Author(s):  
Bruno Schuermans ◽  
Valter Bellucci ◽  
Felix Guethe ◽  
Franc¸ois Meili ◽  
Peter Flohr ◽  
...  
Keyword(s):  
Heat Release ◽  
Acoustic Field ◽  
Turbulence Intensity ◽  
Equivalence Ratio ◽  
Transfer Functions ◽  
Turbulent Flame ◽  
Interaction Mechanism ◽  
Flame Speed ◽  
Fuel Concentration ◽  
Turbulent Flame Speed

A combined theoretical and experimental analysis of thermoacoustic interaction mechanisms of a lean pre-mixed swirl-stabilized gas turbine burner is presented. A full-scale gas turbine burner has been tested in an atmospheric test rig. The test facility was equipped with loudspeakers to excite the acoustic field and with arrays of microphones to measure the response of the acoustic field to the forcing signal. With this set-up transfer matrices relating the acoustic pressure and velocity on both sides of the flame front have been measured. A laser absorption measurement technique allowed for measurement of the fluctuations of fuel concentration in the mixture. Heat release fluctuations were monitored using a photo-multiplier. The measurement of the acoustic field, heat release and equivalence ratio fluctuations have been measured simultaneously. Special attention has been given to the role of fuel concentration fluctuations in the thermoacoustic interaction mechanism. In order to be able to clearly separate this mechanism from other possible mechanisms, all the experiments have been performed in pre-premixing mode as well. In pre-premixing mode the fuel is injected far upstream of the burner in order to avoid fuel concentration fluctuations at the burner location. This is in contrast with premixing mode where fuel and air are mixed in the burner. An acoustic flame model has been derived. The model includes the well-known interaction mechanism of equivalence ratio fluctuations but also includes a novel mechanism that is caused by fluctuations of vorticity. This latter mechanism relates the turbulent flame speed via turbulence intensity fluctuations to the acoustic field. The idea is that periodic acoustic fluctuations cause periodic changes of the turbulence intensity. The turbulence intensity strongly affects the turbulence flame speed. The fluctuations of the turbulent flame speed result in fluctuations of the heat release. This turbulence intensity fluctuation model has been compared with the measured pre-premix transfer functions and shows an excellent agreement. The measured transfer functions in premix mode have been compared with the model that includes fluctuations of fuel concentration and turbulence intensity. Also in this case a very good agreement is found. Moreover, it has been demonstrated that the phase relation between measured equivalence ratio fluctuation and heat release corresponds to the model.

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