Characteristic features of the process of mixture formation upon fuel injection into a high-temperature air flow

2008 ◽  
Vol 81 (2) ◽  
pp. 264-273
Author(s):  
A. I. Maiorova ◽  
V. V. Tret’yakov
Keyword(s):  
High Temperature ◽  
Fuel Injection ◽  
Air Flow ◽  
Mixture Formation ◽  
Characteristic Features

Injection of Kerosene Into a High-Temperature and High-Speed Air Crossflow

2020 ◽  
Author(s):  
Wang Yulan ◽  
Mu Yong ◽  
Fan Xiongjie ◽  
Zhao Qianpeng ◽  
Xu Gang
Keyword(s):  
High Temperature ◽  
Weber Number ◽  
High Speed ◽  
Fuel Injection ◽  
Air Flow ◽  
Windward Side ◽  
Leeward Side ◽  
Inertia Force ◽  
Fuel Flow ◽  
Jet Trajectory

Abstract The jet of kerosene into high-temperature and high-speed air crossflow was studied experimentally, to study the characteristics of penetration and evaporation in afterburner. A fuel injection bar with a 0.6 mm diameter plain orifice was used in the experiment. The angle between jet and air flow was 90°. The tests were conducted at atmospheric pressure. The air temperature was between 400 °C to 800 °C, and the air velocity increased from 100 m/s to 250 m/s, which was close to the working condition of the afterburner. The jet flow rate also increased from 5 kg/h to 40 kg/h. Fuel-PLIF was used to visualize the trajectory and structure of the jet trajectory. It was observed that the core region of the jet (the largest volume flow) was close to the windward side, and the leeward side of the jet had a relatively wide peripheral area due to the shear of the high-speed airflow. The jet trajectory is affected by viscosity force, inertia force and surface tension in different proportion under high-temperature and high-speed airflow. The jet penetration is related to the momentum ratio (q), air flow Weber number (We0), and aerodynamic Weber number (Wea). In experiment, q ranged from 2 to 236, We0 ranged from 72 to 735, and Wea ranged from 0.36–41. The relationship between penetration to these variables was established. The plume width and evaporation distance under different test conditions were compared. The results show that the plume width varied within a narrow range in high-temperature and high-speed air crossflow, and the fuel evaporation distance was much more affected by the fuel flow than the airflow condition, basically in a linear correlation with fuel flow. The results are of great significance to the size design and arrangement of the stabilizers in afterburners.

Evaporation of a water-alcoholic solution drop in a high-temperature air flow

2021 ◽  
Author(s):  
Boris V. Borisov ◽  
Ruslan T. Zakiev ◽  
Alexander S. Naumkin
Keyword(s):  
High Temperature ◽  
Air Flow ◽  
Alcoholic Solution

scholarly journals Impact of injection strategies on combustion characteristics, efficiency and emissions of gasoline compression ignition operation in a heavy-duty multi-cylinder engine

2018 ◽  
Vol 21 (8) ◽  
pp. 1426-1440 ◽  
Author(s):  
Buyu Wang ◽  
Michael Pamminger ◽  
Ryan Vojtech ◽  
Thomas Wallner
Keyword(s):  
High Temperature ◽  
Thermal Efficiency ◽  
Fuel Injection ◽  
Pressure Rise ◽  
Pilot Injection ◽  
Low Temperature Combustion ◽  
Compression Ignition ◽  
Temperature Combustion ◽  
Gas Recirculation ◽  
Direct Fuel Injection

Gasoline compression ignition using a single gasoline-type fuel for direct/port injection has been shown as a method to achieve low-temperature combustion with low engine-out NOx and soot emissions and high indicated thermal efficiency. However, key technical barriers to achieving low-temperature combustion on multi-cylinder engines include the air handling system (limited amount of exhaust gas recirculation) as well as mechanical engine limitations (e.g. peak pressure rise rate). In light of these limitations, high-temperature combustion with reduced amounts of exhaust gas recirculation appears more practical. Furthermore, for high-temperature gasoline compression ignition, an effective aftertreatment system allows high thermal efficiency with low tailpipe-out emissions. In this work, experimental testing was conducted on a 12.4 L multi-cylinder heavy-duty diesel engine operating with high-temperature gasoline compression ignition combustion with port and direct injection. Engine testing was conducted at an engine speed of 1038 r/min and brake mean effective pressure of 1.4 MPa for three injection strategies, late pilot injection, early pilot injection, and port/direct fuel injection. The impact on engine performance and emissions with respect to varying the combustion phasing were quantified within this study. At the same combustion phasing, early pilot injection and port/direct fuel injection had an earlier start of combustion and higher maximum pressure rise rates than late pilot injection attributable to more premixed fuel from pilot or port injection; however, brake thermal efficiencies were higher with late pilot injection due to reduced heat transfer. Early pilot injection also exhibited the highest cylinder-to-cylinder variations due to differences in injector behavior as well as the spray/wall interactions affecting mixing and evaporation process. Overall, peak brake thermal efficiency of 46.1% and 46% for late pilot injection and port/direct fuel injection was achieved comparable to diesel baseline (45.9%), while early pilot injection showed the lowest brake thermal efficiency (45.3%).

Analysis of Mixture Formation and Flame Development of Diesel Combustion Using a Rapid Compression Machine and Optical Visualization Technique

2013 ◽  
Vol 315 ◽  
pp. 293-298 ◽  
Author(s):  
Amir Khalid ◽  
Bukhari Manshoor
Keyword(s):  
Fuel Injection ◽  
Injection Pressure ◽  
Exhaust Emissions ◽  
Combustion Characteristics ◽  
Diesel Combustion ◽  
Rapid Compression Machine ◽  
Mixture Formation ◽  
Optical Visualization ◽  
Flame Development ◽  
Rapid Compression

Mixture formation plays as a key element on burning process that strongly affects the exhaust emissions such as nitrogen oxide (NOx) and Particulate Matter (PM). The reductions of emissions can be achieved with improvement throughout the mixing of fuel and air behavior. Measurements were made in an optically-accessible rapid compression machine (RCM) with intended to simulate the actual diesel combustion related phenomena. The diesel combustion was simulated with the RCM which is equipped with the Denso single-shot common-rail fuel injection system, capable of a maximum injection pressure up to 160MPa. Diesel engine compression process could be reproduced within the wide range of ambient temperature, ambient density, swirl velocity, equivalence ratio and fuel injection pressure. The mixture formation and combustion images were captured by the high speed camera. Analysis of combustion characteristics and observations of optical visualization of images reveal that the mixture formation exhibit influences to the ignition process and flame development. Therefore, the examination of the first stage of mixture formation is very important consideration due to the fuel-air premixing process linked with the combustion characteristics. Furthermore, the observation of a systematic control of mixture formation with experimental apparatus enables us to achieve considerable improvements of combustion process and would present the information for fundamental understanding in terms of reduced fuel consumption and exhaust emissions.

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