Numerical Investigation of Spray Collapse in GDI with OpenFOAM

Gärtner, Jan Wilhelm; Ye, Feng; Kronenburg, A.; Stein, Oliver T.

doi:10.3390/fluids6030104

Cited by 14 publications

(12 citation statements)

References 34 publications

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“…However, it is unclear if the effects will be similar for a six-hole injector or if the collapse will be stronger (as observed for high-pressure sprays), leading to an increased penetration and decreased spray angle. One could expect a different collapse mechanism in low-pressure systems than in the case of high-pressure sprays, in which, as the simulations suggest, the collapse is driven by the interaction of the shocks in the centre between the plumes [17,18]. While in the case of low-pressure sprays formed at Rp << 50, shocks are not expected [19].…”

Section: Introductionmentioning

confidence: 93%

Spray collapse in low-pressure injection systems operating in flash-boiling conditions

Kapusta

2021

ICLASS

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Flash-boiling sprays formed by initially separated plumes, under a high degree of overheating, may collapse into a single spray cloud; leading to increases in the spray penetration and narrowing of the spray angle. This effect is not only dependent on the degree of overheating, but also on the number of nozzles. It is important to note that these, and most of the other observations related to flashing sprays were made for high-pressure systems. In this study, the spray collapse process is investigated for low injection pressure in order to verify if the effects of the flash boiling on spray formation will be dependent on the number of nozzles, as was observed for high-pressure sprays. For this purpose, the water sprays formed by a commercial six-hole injector were compared with the results obtained for a two-hole injector. The sprays were analysed in terms of global spray structure and global spray parameters, such as the spray penetration and the spray angle. The sprays did show major differences, and both collapsed at the highest considered temperature. However, in the case of the six-hole injector the collapse was noticed also for lower temperatures. Despite the collapse, no considerable increase in penetration was observed in any of the cases.

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Section: Introductionmentioning

confidence: 93%

Spray collapse in low-pressure injection systems operating in flash-boiling conditions

Kapusta

2021

ICLASS

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“…However, in most studies, Euler-Euler multiphase modelling is used to gather detailed information on flashing jet expansion near the injector's nozzle. Rapid evaporation of fuel leads to large temperature and density gradients [19,20]. This may cause shock waves, which can be the reason for the spray collapse mechanism [4,21].…”

Section: Introductionmentioning

confidence: 99%

“…Along with adaptive mesh refinement, the Euler-Euler approach with a volume-of-fluid model allows the prediction of the occurrence of shock waves in high-superheat cases and in liquified gaseous fuel simulations [21]. Gärtner et al [20] investigated a multiphase propane spray using OpenFOAM. They reported that the results from the simulations were in line with the assumption that the spray collapses due to the interaction of the shock waves.…”

Section: Introductionmentioning

confidence: 99%

Liquid Propane Injection in Flash-Boiling Conditions

et al. 2021

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This study aimed to investigate the influence of flash-boiling conditions on liquid propane sprays formed by a multi-hole injector at various injection pressures. The focus was on spray structures, which were analysed qualitatively and quantitatively by means of spray-tip penetration and global spray angle. The effect of flash boiling was evaluated in terms of trends observed for subcooled conditions. Propane was injected by a commercial gasoline direct injector into a constant volume vessel filled with nitrogen at pressures from 0.1 MPa up to 6 MPa. The temperature of the injected liquid was kept constant. The evolution of the spray penetration was observed by a high-speed camera with a Schlieren set-up. The obtained results provided information on the spray evolution in both regimes, above and below the saturation pressure of the propane. Based on the experimental results, an attempt to calibrate a simulation model has been made. The main advantage of the study is that the effects of injection pressure on the formation of propane sprays were investigated for both subcooled and flash-boiling conditions. Moreover, the impact of the changing viscosity and surface tension was limited, as the temperature of the injected liquid was kept at the same level. The results showed that despite very different spray behaviours in the subcooled and flash-boiling regimes, leading to different spray structures and a spray collapse for strong flash boiling, the influence of injection pressure on propane sprays in terms of spray-tip penetration and spray angle is very similar for both conditions, subcooled and flash boiling. As for the numerical model, there were no single model settings to simulate the flashing sprays properly. Moreover, the spray collapse was not represented very well, making the simulation set-up more suitable for less superheated sprays.

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“…The Special Issue "Modelling of Reactive and Non-Reactive Multiphase Flows" collects 11 papers covering a broad range of topics dealing with applications of non-reactive [1][2][3][4][5][6] and reactive [7][8][9][10][11] multiphase flows in natural environment as well as technical applications. The contributions address important numerical and modelling issues, which not only cover fundamental physics but also address the aspect of application.…”

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confidence: 99%

“…The work of Gärtner et al [7] represents the transition from non-reactive to reactive multiphase flows. During certain operating conditions in spark-ignited direct injection engines, the injected fuel is superheated and begins to rapidly vaporize.…”

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confidence: 99%