On the fuel injection rate profile as boundary conditions for diesel spray combustion simulations

Fuel ◽  
2020 ◽  
Vol 276 ◽  
pp. 118026 ◽  
Author(s):  
Xinyi Zhou ◽  
Tie Li ◽  
Ping Yi ◽  
Zhifei Zhang ◽  
Ning Wang ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Fuel Injection ◽  
Injection Rate ◽  
Diesel Spray ◽  
Spray Combustion ◽  
Rate Profile ◽  
Fuel Injection Rate

scholarly journals A calculation method and experiment study of high-pressure common rail injection rate with solenoid injectors

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110261
Author(s):  
Ziguang Gao ◽  
Guoxiu Li ◽  
Chunlong Xu ◽  
Hongmeng Li ◽  
Min Wang
Keyword(s):  
High Pressure ◽  
Input Data ◽  
Fuel Injection ◽  
Injection Rate ◽  
Common Rail ◽  
Common Rail System ◽  
Rail System ◽  
Rate Profile ◽  
Fuel Injection Rate ◽  
High Pressure Common Rail

The high-pressure common rail system has been widely used owing to its precise control of fuel injection rate profile, which plays a decisive role in cylinder combustion, atomization, and emission. The fuel injection rate profile of high-pressure common rail system was studied, and a fuel injection rate profile calculation model is proposed. The model treats the injector as a black box. Some measured data are needed to calculate the parameters in the model. The rise and fall of injection rate is regarded as trigonometric function to reduce the complexity and increase the accuracy. The model was verified using two different types of fuel injectors. The model calculation results were evaluated under various data input conditions. The results show that the model has good applicability to different input data and injectors. In addition, because the model building requires a large amount of experimental data, a comprehensive analysis of various input data was also conducted. The injection profile was analyzed from a new perspective and the regularity of injection rate profile was established.

scholarly journals An Analysis on the Effects of the Fuel Injection Rate Shape of the Diesel Spray Mixing Process Using a Numerical Simulation

2020 ◽  
Vol 10 (14) ◽  
pp. 4983 ◽  
Author(s):  
Intarat Naruemon ◽  
Long Liu ◽  
Dai Liu ◽  
Xiuzhen Ma ◽  
Keiya Nishida
Keyword(s):  
Fuel Injection ◽  
Gradual Increase ◽  
Combustion Efficiency ◽  
Injection Rate ◽  
Gradual Decrease ◽  
Diesel Spray ◽  
Ambient Temperatures ◽  
Before And After ◽  
Fuel Mixing ◽  
Fuel Injection Rate

In diesel engines, fuel mixing is an important process in determining the combustion efficiency and emissions level. One of the measures used to achieve fuel mixing is controlling the nature and behavior of the fuel spray by shaping the injection rate. The mechanism underlying the behavior of the spray with varying injection rates before the start of combustion is not fully understood. Therefore, in this research, the fuel injection rate shape is investigated to assess the spraying and mixing behavior. Diesel sprays with different ambient temperatures and injection pressures are modeled using the CONVERGE-CFD software. The validation is performed based on experimental data from an Engine Combustion Network (ECN). The verified models are then used to analyze the characteristics of the diesel spray before and after the end-of-injection (EOI) with four fuel injection rate shapes, including a rectangular injection rate shape (RECT), a quick increase gradual decrease injection rate shape (QIGD), a gradual increase gradual decrease injection rate shape (GIGD), and a gradual increase quick decrease injection rate shape (GIQD). The spray vapor penetrations, liquid lengths, evaporation ratios, Sauter mean diameter (SMDs), distributions of turbulence kinetic energy, temperatures, and equivalence ratios were compared under different injection rate shapes. The results show that the QIGD injection rate shape can enhance mixing during injection, while the GIQD injection rate shape can achieve better mixing after the EOI.

scholarly journals A Study of Combustion Characteristics of Two Gasoline–Biodiesel Mixtures on RCEM Using Various Fuel Injection Pressures

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3265
Author(s):  
Ardhika Setiawan ◽  
Bambang Wahono ◽  
Ocktaeck Lim
Keyword(s):  
Heat Release ◽  
Ignition Delay ◽  
Fuel Injection ◽  
Injection Pressure ◽  
Fuel Mixture ◽  
Injection Rate ◽  
Injection Duration ◽  
Late Start ◽  
Fuel Injection Rate ◽  
Injection Pressures

Experimental research was conducted on a rapid compression and expansion machine (RCEM) that has characteristics similar to a gasoline compression ignition (GCI) engine, using two gasoline–biodiesel (GB) blends—10% and 20% volume—with fuel injection pressures varying from 800 to 1400 bar. Biodiesel content lower than GB10 will result in misfires at fuel injection pressures of 800 bar and 1000 bar due to long ignition delays; this is why GB10 was the lowest biodiesel blend used in this experiment. The engine compression ratio was set at 16, with 1000 µs of injection duration and 12.5 degree before top dead center (BTDC). The results show that the GB20 had a shorter ignition delay than the GB10, and that increasing the injection pressure expedited the autoignition. The rate of heat release for both fuel mixes increased with increasing fuel injection pressure, although there was a degradation of heat release rate for the GB20 at the 1400-bar fuel injection rate due to retarded in-cylinder peak pressure at 0.24 degree BTDC. As the ignition delay decreased, the brake thermal efficiency (BTE) decreased and the fuel consumption increased due to the lack of air–fuel mixture homogeneity caused by the short ignition delay. At the fuel injection rate of 800 bar, the GB10 showed the worst efficiency due to the late start of combustion at 3.5 degree after top dead center (ATDC).

Suppression of Instabilities in Gaseous Fuel High-Pressure Combustor Using Non-Coherent Oscillatory Fuel Injection

2003 ◽  
Author(s):  
D. Shcherbik ◽  
E. Lubarsky ◽  
Y. Neumeier ◽  
B. T. Zinn ◽  
K. McManus ◽  
...  
Keyword(s):  
High Pressure ◽  
Active Control ◽  
Fuel Injection ◽  
Injection Rate ◽  
Open Loop ◽  
Combustion Instabilities ◽  
Open Loop Control ◽  
Pressure Oscillations ◽  
Loop Control ◽  
Fuel Injection Rate

This paper describes the application of active, open loop, control in effective damping of severe combustion instabilities in a high pressure (i.e., around 520 psi) gas turbine combustor simulator. Active control was applied by harmonic modulation of the fuel injection rate into the combustor. The open-loop active control system consisted of a pressure sensor and a fast response actuating valve. To determine the dependence of the performance of the active control system upon the frequency, the fuel injection modulation frequency was varied between 300 and 420 Hz while the frequency of instability was around 375 Hz. These tests showed that the amplitude of the combustor pressure oscillations strongly depended upon the frequency of the open loop control. In fact, the amplitude of the combustor pressure oscillations varied ten fold over the range of investigated frequencies, indicating that applying the investigated open loop control approach at the appropriate frequency could effectively damp detrimental combustion instabilities. This was confirmed in subsequent tests in which initiation of open loop modulation of the fuel injection rate at a non resonant frequency of 300Hz during unstable operation with peak to peak instability amplitude of 114 psi and a frequency of 375Hz suppressed the instability to a level of 12 psi within approximately 0.2 sec (i.e., 75 periods). Analysis of the time dependence of the spectra of the pressure oscillations during suppression of the instability strongly suggested that the open loop fuel injection rate modulation effectively damped the instability by “breaking up” (or preventing the establishment of) the feedback loop between the reaction rate and combustor oscillations that drove the instability.

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