Original scientific paper

https://doi.org/10.21278/TOF.472035621

Spray Characteristics of a Rotating Fuel Injector in a Direct Injection Diesel Engine

Kuppusamy Sengottaiyan ; Department of Mechanical Engineering, R.M.K. Engineering College, Chennai, India
Mangudi Rangasamy Swaminathan ; Department of Mechanical Engineering, Anna University, CEG, Chennai, India
Charles Augustine Vencent ; Department of Mechanical Engineering, Anna University, CEG, Chennai, India
Govindaraj Kumaresan ; Department of Mechanical Engineering, Anna University, CEG, Chennai, India

Abstract

Diesel engines are used extensively due to their higher performance, better fuel efficiency and low maintenance. Their major drawback is that they emit considerably higher NOx and particulate matter. The fuel injection parameters and spray characteristics have a major role in combustion and emission formation. A conventional injector produces spray mainly along the axial direction, which results in the poor mixing of air and fuel. This study aims to overcome this poor mixing issue by developing a rotating injector by functionally modifying the existing three-orifice injector to enable injector rotation. A modified fuel injection system is developed to accommodate a rotating fuel injector with a sleeve. The rotating injector provides an angular momentum to the fuel, establishing a co-swirl motion to the fuel and modifying the spray characteristics. The spray images were observed using a high-resolution camera. A comparison and analysis of the spray characteristics were carried out using image processing techniques. A detailed comparison was made of a conventional injection system with two-, three- and five-orifice injectors, a Common Rail Direct Injection system, and a rotating injection system. OpenCV Python was used for spray edge detection, the colour thresholding of images, determining the spray angle, and cross-sectional fuel dispersion area calculations. The overall spray cone angle is greater for the Rotational Direct Injection system. The rotating injection spray was found to disperse over a wider angle, with an almost negligible air gap and over a greater cross-sectional area. The rotation of the injector reduces the local high concentration of the fuel, and the structure of the highly homogeneous fuel-air mixture.

Keywords

rotating injector; dispersion; co-swirl; air gap; spray cone angle

Hrčak ID:

304045

URI

https://hrcak.srce.hr/304045

Publication date:

3.7.2023.

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