Sensitivity Analysis of Fuel Injection Characteristics of GDI Injector to Injector Nozzle Diameter

Li, Xinhai; Cheng, Yong; Ji, Shaobo; Yang, Xue; Wang, Lu

doi:10.3390/en12030434

Cited by 11 publications

(7 citation statements)

References 15 publications

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“…The latter trends regarding the changes in area utilisation and bulk velocity inside the altered spray hole agree well with results from CFD-studies by Li and co-workers [18]. Since the absolute values of measured momentum flux need to be interpreted with caution, they are not used to retrieve area and velocity coefficients directly.…”

Section: Resultssupporting

confidence: 85%

Characterisation of Internal Flow Conditions in GDI Injectors by Means of Spray-Hole-Individual Mass Flow Rate and Momentum Flux Measurements

Miller

Leick

et al. 2021

ICLASS

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High-pressure multi-hole injectors for gasoline direct injection (GDI) engines allow a flexible optimisation of the individual spray hole properties to specific engines and combustion strategies. One degree of freedom within this spray targeting process is the mass flow rate of each spray plume, which is mainly controlled by the corresponding spray hole diameter. As a first approximation, it can safely be assumed that the flow rate scales with the spray hole crosssectional area, but due to the complex flow pattern within the valve seat, some deviations are likely to occur. This was investigated using four specially designed real-size research injectors with two almost identical spray holes -except for their diameters, one of them constant and the other variable. Combining the results of spray-hole-individual mass flow rate and spray force measurements, the spray-hole-individual discharge coefficients can be separated into area and velocity coefficients. Under the choked flow conditions typical of GDI, the discharge and area coefficients increase while the velocity coefficients decrease as spray holes become smaller. At the same time, the flow inside the unaltered spray hole is affected as well, although the discharge coefficient remains constant because of reciprocal trends between the area and velocity coefficients.

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Section: Resultssupporting

confidence: 85%

Characterisation of Internal Flow Conditions in GDI Injectors by Means of Spray-Hole-Individual Mass Flow Rate and Momentum Flux Measurements

Miller

Leick

et al. 2021

ICLASS

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“…To verify the gas-liquid flow in the micro-nozzles, it is necessary to verify the cavitation model and the turbulence model. As mentioned earlier, a visualization experiment through a simplified nozzle at the angle of 0 °has been carried out (Salvador et al, 2010;Qiu et al, 2016;Li et al, 2018;Li et al, 2019). The results show that with the increase of the injection pressure, a variation process of cavitation that is approximate to that in the experiment is simulated as Figure 1.…”

Section: Model Verificationmentioning

confidence: 76%

Sensitivity of Injection Characteristics to the Nozzle Hole Angle of a GDI Injector: A CFD Analysis

Shang

Wang

et al. 2022

Front. Energy Res.

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The increase in injection pressure makes it more challenging to accurately control the injection quantity of the injector of a gasoline direct injection (GDI), thus necessitating the optimization of the parameters of the nozzle holes and the clarification of such parameters in terms of their influence on the injection characteristics, so as to improve the injector’s consistency of injection characteristics. This article adopts the computational fluid dynamics (CFD) approach to investigate the influence of nozzle angle on the gas-liquid flow, cavitation state, and fuel injection rate in the hole. The results show that when the angle of concentric holes of the nozzle exceeds 65° and keeps rising further, it will lead to the gradual decrease of the injection rate during the stable period and the continuous rise of the sensitivity to the nozzle angle. The rising injection pressure would increase the sensitivity of the injection characteristics to the angle of the concentric holes, with the strongest level of sensitivity ranging between 70° and 75°. The negative pressure area on the upper inner wall of the hole would increase with the accretion of the hole angle. As the negative eccentricity rises, the injection rate would gradually drop in both the transition period and the stable period. In contrast, the increase of positive eccentricity would lead to the gradient escalation of the injection rate in the stable period. The impact of negative eccentricity is greater than that of positive eccentricity, implying that it is necessary to reduce the deviation of negative eccentricity as much as possible during the machining and positioning process so as to ensure positioning accuracy.

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“…The Bernoulli equation (Eq. 3) was used to determine the amount of fuel injected into the cylinder based on the crank angle degree (CAD) [44]. The exit velocity of the fuel through the injector nozzle hole is obtained using Eq.…”

Section: Experimental Methodologymentioning

confidence: 99%

Determination of the effects of the simultaneous use of ethanol-diesel emulsion as the main fuel and post-injection fuel in a diesel engine on engine performance and emissions

Gürbüz

2021

International Journal of Automotive Engineering and Technologies

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In this article, the effects of heated ethanol diesel blend on emissions were investigated experimentally. Additionally, the effect of post-injection strategies on emissions in the AVL Boost model engine, which has the same characteristics as the experimental engine running with ethanol-diesel emulsion fuel, was investigated as a simulation. In a special designed mixer, the ethanol-diesel emulsion (E10) formed with 10% ethanol and 2% isopropyl was stirred at 40 °C. The emulsion temperature was kept constant between 35-40 °C during the experiments. The homogeneous residence time of the blended fuel improved with increasing temperature. Post-injection strategy tests at 2 different crank angles were mathematically analyzed separately for ethanol diesel emulsion as a postinjection fuel in the simulation software. NOx emissions decreased with E10 fuel at low speeds compared to E0 fuel. Slightly increased NOx emissions in the Bpi2 strategy compared to the Bpi1 strategy. In addition, soot emissions reduced with Bpi1 at all engine speeds. The brake specific fuel consumption with the E10 blend increased by 4.36% compared to E0. However, the brake specific fuel consumption was slightly reduced in the Bpi1 and Bpi2 injection strategies tests compared to the E10 experiment.

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Sensitivity Analysis of Fuel Injection Characteristics of GDI Injector to Injector Nozzle Diameter

Cited by 11 publications

References 15 publications

Characterisation of Internal Flow Conditions in GDI Injectors by Means of Spray-Hole-Individual Mass Flow Rate and Momentum Flux Measurements

Characterisation of Internal Flow Conditions in GDI Injectors by Means of Spray-Hole-Individual Mass Flow Rate and Momentum Flux Measurements

Sensitivity of Injection Characteristics to the Nozzle Hole Angle of a GDI Injector: A CFD Analysis

Determination of the effects of the simultaneous use of ethanol-diesel emulsion as the main fuel and post-injection fuel in a diesel engine on engine performance and emissions

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