Experimental and Computational Study of Diesel Spray Under Nonevaporating and Evaporating Conditions - Effects of Nozzle Hole Diameter and Injection Pressure

Proceedings of the Institution of Mechanical Engineers, Part D:

Ogata

et al. 2021

Self Cite

In the present work, effects of nozzle hole size and rail pressure under non-evaporating spray condition are demonstrated. Three single hole injectors with the bore size of 0.101, 0.122, and 0.133 mm are experimented with injection pressures of 140, 45, and 38 MPa respectively to achieve similar injection rate profile. Diesel spray experiments implement Diffused Backlight Illumination Technique where diffused background is obtained for the High Speed Video camera imaging. Experimental results are then validated with computational and analytical studies. The CFD simulation requires the injection rate profile and spray cone angle as a primary input; thus, based on the High Speed Video Camera start of injection frame the 5 kHz Butterworth low-pass frequency filter is applied to the injection rate raw data. While, the spray cone angle is predicted using a simple model obtained from the relationship between the injection velocity, fluctuating velocity at the nozzle exit and total pressure loss factor of the injector. The experimental spray tip penetration of all three injectors is almost identical as the similar injection rate profile is adopted. Although, the mixture characteristics are better for 0.101 mm hole diameter since the smaller hole diameter with highest injection pressure depicts larger spray angle and better atomization. The computational study agrees with experiments qualitatively; however, the quantitative and qualitative agreements are seen in the analytical study.

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Section: Experimental Conditionsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effects of nozzle hole size and rail pressure on diesel spray and mixture characteristics under similar injection rate profile – experimental, computational and analytical studies under non-evaporating spray condition

Proceedings of the Institution of Mechanical Engineers, Part D:

Ogata

et al. 2021

Self Cite

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“…Thus, along with the fatal emissions reduction these factors are necessary for the design and selection of the combustion chamber. 8–13…”

Section: Introductionmentioning

confidence: 99%

“…Thus, along with the fatal emissions reduction these factors are necessary for the design and selection of the combustion chamber. [8][9][10][11][12][13] In contrast, the role of mixture formation in exhaust emission mitigation cannot be ignored too. An atomized spray in a combustion chamber forms an air-fuel mixture by transferring its momentum to ambient gas.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of multi-hole diesel injectors spray under evaporating conditions: Effects of adjacent spray plumes on the macroscopic and mixture characteristics of target spray

Ray

Proceedings of the Institution of Mechanical Engineers, Part D:

et al. 2022

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Previously, diesel sprays of multi-hole injectors were simulated in an environment where only a single spray plume was simulated. Although boundaries were declared as symmetry, the impact of aerodynamic forces between spray plumes was always neglected. In the present work, all spray plumes of diesel injectors are simulated in a cylindrical box mesh considering external effects including umbrella angle, space between nozzle holes, and hole length to hole diameter ratio. To examine the nozzle hole size effect, two 10-hole diesel injectors with hole diameters of 0.101 and 0.133 mm are investigated under 120 MPa injection pressure. Likewise, to understand the effect of injection pressure, the 0.101 mm hole diameter injector is studied under 120 and 140 MPa rail pressures. In experiments, Laser Absorption Scattering diagnostic technique is applied to visualize the vapor phase, measure mixture concentration and characterize air entrainment. Since Diesel fuel does not absorb UV light, Tracer fuel with the composition of 97.5% of n-tridecane and 2.5% α-Methylnaphthalene is used. On the contrary, sprays are simulated in the Eulerian-Lagrangian two-phase fluid framework using KHRT Breakup and Multicomponent Evaporation models. Parameters such as injection rate and initial spray trajectory angle are measured experimentally and used as input for the spray simulation. Computational results correspond with experiments particularly in terms of Penetration and Equivalence Ratio while Spray Angle deviates.

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Effects of full transient Injection Rate and Initial Spray Trajectory Angle profiles on the CFD simulation of evaporating diesel sprays- comparison between singlehole and multi hole injectors

Ray

et al. 2023

Energy