Characteristics of Adhesion Diesel Fuel on an Impingement Disk Wall. Part 3: Ambient Pressure Effect

Akop, Mohd Zaid; Zama, Yoshio; Furuhata, Tomohiko; Arai, Masataka

doi:10.1615/atomizspr.2014010224

Cited by 12 publications

(10 citation statements)

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“…Figure 13(a) shows liquid fuel adhered in all the pressure conditions due to small impingement distance. In general, liquid film on a wall surface tended to decrease with increased injection pressure, 18 because the impinged spray spreads to wider area and the distribution of the spray is more uniform as the injection pressure rises. However, these photographs look similar in all injection pressures due to the same amount of injected fuel.…”

Section: Resultsmentioning

confidence: 99%

Effects of injection pressure and impingement distance on flat-wall impinging spray flame and its heat flux under diesel engine-like condition

Mahmud

Kurisu

Nishida

et al. 2019

Advances in Mechanical Engineering

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Heat loss is one of the main causes of energy losses in modern direct injection diesel engines. This heat loss of the engine occurs during combustion, mainly due to the heat transfer between the impinging spray flame and the piston cavity wall. It is of more critical in small size engines. In order to decrease heat transfer, we need to examine the phenomenon of heat transfer through the combustion chamber walls more fully. To achieve this, we investigated the effects of flame impingement on transient heat flux to the wall. By using a constant volume vessel with a fixed impingement wall, the surface heat flux of the wall at the locations of spray flame impingement was measured with three thin film thermocouple heat flux sensors. The combined effect of impingement distance and injection pressure on the heat transfer was investigated parametrically. The results showed that an increase of injection pressure with longer impinging distance led to an increase in the heat transfer coefficient, which had a dominant effect on local heat flux compared with local temperature distribution. Moreover, we confirmed that the relation between Nusselt number and Reynolds number is a useful measure for describing the heat transfer phenomena in diesel combustion.

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Section: Resultsmentioning

confidence: 99%

Effects of injection pressure and impingement distance on flat-wall impinging spray flame and its heat flux under diesel engine-like condition

Mahmud

Kurisu

Nishida

et al. 2019

Advances in Mechanical Engineering

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“…It depicts various penetration curves in a range of n = 0.5 ± 0.1. Momentum conservation shown by Equation (30) means that the mixture has a unique velocity. When droplets in the spray tip have a higher velocity than that of associated air (existence of local relative velocity between gas and droplet), the exponential index takes a larger value than 0.5.…”

Section: Spray Developmentmentioning

confidence: 99%

“…Exponential index of n = 0.32 is selected as the most fitted line, taking ∆S * = ∆L * = 0.7 correction. According to the velocity decay chart shown in Figure 11, it is estimated that around 50% of longitudinal momentum is lost by the wall impingement [29,30].…”

Section: Wall Impingement Spraymentioning

confidence: 99%

Interpretative Review of Diesel Spray Penetration Normalized by Length and Time of Breakup (Similarity Law of Diesel Spray and Its Application)

Arai

2022

Energies

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Tip penetration of diesel spray is one of the most useful parameters to evaluate diesel combustion dynamics. It has strong relationships with ignition delay, premix/diffusion combustion and engine performance, including exhaust emissions. To discuss general combustion physics in various size sprays, non-dimensional expression of spray tip penetration is reviewed. Length and time of injected fuel jet breakup can be considered as characteristic length and timescale of diesel spray. Then, normalized penetration by length and time of breakup was proposed for the scaling of various diesel sprays. Using the proposed scaling method and similarity law, tip penetrations of various size sprays are collapsed into one simple expression. It becomes a base of similarity law of diesel spray. For example, local or average A/F is uniquely expressed by the normalized length and time of breakup. Penetration of a wall impingement spray is also expressed uniquely by this normalization method and physical parameters affecting the wall impingement spray are explained. Injection rate shaping effect at an initial stage of injection is clearly demonstrated by using this scaling. Further, mixing degrees of diesel spray at an ignition timing and in a combustion phase can be reasonably explained by the equivalence ratio change with non-dimensional elapsed time after injection start.

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“…Fujimoto and colleagues [18][19][20][21] investigated the fuel spray impinging on the flat wall under both gasoline and diesel engine conditions. Akop et al [22][23][24][25] weighed the adhered fuel mass on an impingement disk wall and characterized the fuel adhesion under different conditions. Both Cheng et al 26 and Schulz and colleagues 27,28 conducted experimental studies on fuel adhesion using the laserinduced fluorescence (LIF) technique.…”

Section: Introductionmentioning

confidence: 99%

Effect of spray impingement distance on piston top fuel adhesion in direct injection gasoline engines

Luo

Nishida

Uchitomi

et al. 2018

International Journal of Engine Research

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Direct injection is an attractive technology for improving fuel economy and engine performance in gasoline engines. However, the adhered fuel formed on the piston surface has significant influence on the combustion efficiency and emissions. To obtain a better understanding of fuel adhesion, this work involved investigation of the spray and impingement on a flat wall through a mini-sac injector with a single hole. Different impingement distances and injection pressures were investigated. The evolution of the impinging spray was obtained by the Mie scattering method. The refractive index matching method was applied to measure fuel adhesion. The mass, area, and thickness of adhesion under different conditions were compared. The experimental results show that the fuel adhesion on the wall increases significantly with a large impingement distance. Moreover, the maximum thickness increases and the thickness uniformity of the fuel adhesion declines under a large impingement distance condition.

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Characteristics of Adhesion Diesel Fuel on an Impingement Disk Wall. Part 3: Ambient Pressure Effect

Cited by 12 publications

References 0 publications

Effects of injection pressure and impingement distance on flat-wall impinging spray flame and its heat flux under diesel engine-like condition

Effects of injection pressure and impingement distance on flat-wall impinging spray flame and its heat flux under diesel engine-like condition

Interpretative Review of Diesel Spray Penetration Normalized by Length and Time of Breakup (Similarity Law of Diesel Spray and Its Application)

Effect of spray impingement distance on piston top fuel adhesion in direct injection gasoline engines

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