Experimental Investigation on Effect of Wall Roughness and Lubricant Film on the Adhered Fuel Film of N-Butanol-Diesel Blends after Spray Impingement

Xingyu Liang,Hongsheng Zhang,Hanzhengnan Yu,Gequn Shu,Xiuxiu Sun,Ming Ge,Yuesen Wang

doi:10.3390/en11061576

Xingyu Liang, Hongsheng Zhang + Show 5 more

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https://doi.org/10.3390/en11061576

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Abstract

The effect of wall roughness with different lubricant film thicknesses on the characteristics of adhered fuel films of diesel-n-butanol blending fuels after spray impingement has been investigated. Four steel plates with different types of roughness (root mean square height-Sq) that were coated with different lubricant film thicknesses (hl) were used as impinged walls. The experimental conditions included dry walls (hl = 0), semi-wetted walls (SWW) with different thin oil films (0 < hl/Sq < 1), and fully wetted walls (FWW) with a thick lubricant film (hl > Sq). The results indicate that the adhered fuel mass ratio (ε) of blended fuel with 25% n-butanol (B25) was higher than that of blended fuel with 15% n-butanol (B15) under the same conditions. ε increased with an increase in Sq on the dry walls, but, under SWW conditions, it decreased with an increase in oil film thickness. The fuel film morphology was almost unaffected by the change in Sq, but the results implied that the roughness parameter-Skewness (Ssk) exerted a greater impact. The mean thickness ha and accumulated diameter Dl of the adhered fuel film increased with an increase in hl, but, under FWW conditions, the effect of the roughness on the adhered film’s features was insignificant.

Highlights

A “trade-off” relationship exists between nitrogen oxide (NOx) and soot emissions [1]
To resolve this problem, advanced combustion modes have been proposed such as homogeneous charge-compression ignition (HCCI) and premixed charge-compression ignition (PCCI) [2,3]
Weber number (We) have found that the particularity of ξ2 is that the skewness of the height distribution, Ssk, is lower than the other three plates and it means a higher convex extent is analyzed above

Summary

Introduction

A “trade-off” relationship exists between nitrogen oxide (NOx) and soot emissions [1]. To resolve this problem, advanced combustion modes have been proposed such as homogeneous charge-compression ignition (HCCI) and premixed charge-compression ignition (PCCI) [2,3]. Injection is a key technology that can extend the mixing time of liquid fuel and air to achieve a homogeneous mixture and a high efficient combustion. Part of the injected fuel will impact the cylinder liner or piston head. The adhered fuel film evaporates slowly and dilutes the lubricant film on the cylinder liner [4,5].

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