scholarly journals The calculation of lean mixture burning in model combustors with flow swirling

2020 ◽  
Vol 1675 ◽  
pp. 012064
Author(s):  
A I Maiorova ◽  
A Yu Vasilyev ◽  
E I Sokolova
Keyword(s):  
Lean Mixture ◽  
Flow Swirling

INFLUENCE OF FLOW SWIRLING ON COMBUSTION OF ALUMINUM POWDER AEROSUSPENSION IN A CHAMBER WITH EXTENSION

2020 ◽  
Author(s):  
A. Yu. Krainov ◽  
◽  
K. M. Moiseeva ◽  
V. A. Poryazov ◽  
◽  
...  
Keyword(s):  
Dynamic Model ◽  
Aluminum Powder ◽  
Swirling Flow ◽  
Numerical Study ◽  
Mathematical Formulation ◽  
Expansion Chamber ◽  
Flow Swirling ◽  
Air Suspension

A numerical study of combustion of the aluminum-air suspension in the swirling flow in the expansion chamber has been performed. The physical and mathematical formulation of the problem is based on the dynamic model of the multiphase reacting media.

Diluents and Lean Mixture Combustion Modeling for SI Engines with a Quasi-Dimensional Model

1995 ◽  
Author(s):  
Wen Dai ◽  
George C. Davis ◽  
Matthew J. Hall ◽  
Ronald D. Matthews
Keyword(s):  
Dimensional Model ◽  
Lean Mixture ◽  
Combustion Modeling ◽  
Si Engines

Effective indicators of a hydrogen engine operating on a lean mixture and equipped with a modified fuel supply system

Trudy NAMI ◽  
2021 ◽  
pp. 58-66
Author(s):  
R. Z. Kavtaradze ◽  
B. Sun ◽  
A. S. Golosov ◽  
Zh. Chen ◽  
Ts. Chzhan ◽  
...  
Keyword(s):  
Power Control ◽  
Alternative Fuels ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Supply System ◽  
Practical Significance ◽  
High Quality ◽  
Lean Mixture ◽  
Fuel Supply ◽  
Fuel Supply System

Introduction (problem statement and relevance). Limited oil reserves and tightening environmental standards are forcing engine manufacturers to switch to alternative fuels in the near future, among which hydrogen is the most promising. The advantages of hydrogen are high specific heat of combustion and high combustion rate. Wide concentration limits of hydrogen combustion make it possible to use high-quality power control, thereby providing an increase in the efficiency of a hydrogen engine when compared to the basic internal combustion engine.The purpose of the study was to ensure the operation of a serial gasoline engine running on hydrogen with a new experimental fuel supply system, as well as the modification of the intake manifold design without abnormal phenomena during combustion when operating on a lean mixture, and to obtain efficient and ecological characteristics of a hydrogen engine under bench test conditions, as a result.Methodology and research methods. The work is experimental, the reliability of the results obtained is confirmed by the use of modern means for measuring and processing experimental data. The obtained results of measuring nitrogen oxides are adequate to the known Zel'dovich thermal mechanism. The value of the results lies in the fact that they show the feasibility of transferring serial internal combustion engines to hydrogen; in addition, these results are used to develop and verify mathematical 3D models of the hydrogen engine working process.Scientific novelty and results. A new system providing the necessary characteristics (pressure, duration and cycle dose) for supplying hydrogen to the intake system with two injectors for each cylinder was designed, installed and tested on the prototype engine.Practical significance. The expediency of the working cycle creation and efficiency of a hydrogen engine with an experimental lean-burn fuel supply system was confirmed, which made it possible to provide high-quality power control with external mixture formation and forced ignition.

Experimental determination of flame speed and flame stretch using an optically accessible, spark-ignition engine

2019 ◽  
pp. 146808741987771 ◽  
Author(s):  
Behdad Afkhami ◽  
Yanyu Wang ◽  
Scott A Miers ◽  
Jeffrey D Naber
Keyword(s):  
Flame Front ◽  
Flame Propagation ◽  
Engine Speed ◽  
Spark Ignition ◽  
Flame Speed ◽  
Dominant Factor ◽  
Lean Mixture ◽  
Flame Stretch ◽  
Flame Development ◽  
The Rich

The current research experimentally studied flame speed and stretch under engine in-cylinder conditions. A direct-injection, spark-ignition, and optically accessible engine was utilized to image the flame propagation, and E10 was selected as the fuel. Also, three fuel–air mixtures (stoichiometric, lean, and rich) were examined. The flame front was located by processing high-speed images. This study introduces a novel approach for calculation of equivalent spherical flame radius for analysis of flame speed and stretch. Flame front propagation analysis showed that during the flame propagation period, the stretch decreased until the flame front touched the piston surface. This was a common trend for stoichiometric, lean, and rich mixtures, which occurred because the flame radius was the dominant factor in the stretch calculation. In addition, the rich fuel–air mixture showed a lower flame stretch compared to stoichiometric or lean mixture. This was the result of a lower Markstein number for the rich fuel–air mixture. To study the sensitivity of different fuel–air mixtures to the flame stretch, the trajectory of the flame centroid was tracked until the flame front touched the piston surface. The results showed that the end centroid for the lean mixture deviated from the start point more than those of the rich and stoichiometric mixtures because the lean mixture had a higher flame stretch and lower flame speed. Furthermore, comparing the flame stretch at three different engine speeds revealed that increasing the engine speed increased the flame stretch, especially during the early flame development period. According to previous studies which discussed flame stretch as a flame extinguishment mechanism, the probability of flame extinction is higher when the engine speed is higher. Also, uncertainty analysis was conducted to determine the effect of camera setting on the flame stretch. Results showed that a maximum relative uncertainty of 4.5% occurred during the early flame development.

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