Study on spray characteristics of micro-nano bubble premixed fuel

To achieve active control of the combustion process of internal combustion engines, thereby improving thermal efficiency and reducing HC and CO emissions of the engine, a preparation method of micro-nano bubble premixed fuel (MBPF) is proposed, and the spray characteristics of the MBPF are investigated and compared with the ordinary diesel. The results showed that the incorporation of micro-nano bubbles not only enhances the spray radial development of spray, but also strengthens the effects of shearing ability of airflow to liquids. As a result, the fuel spray cone angle, maximum spray width and spray area are all increased, while the fuel spray tip penetration ability along the axial direction is suppressed. The above effect is further enhanced when the bubble concentration of the MBPF increases. With the increase of both the injection pressure and injection back pressure, the optimization effect brought by the micro-nano bubbles is gradually diminished, leading to less difference between MBPF and ordinary diesel, but the spray atomization quality of MBPF is still better than the ordinary diesel. According to the results of this study, the MBPF is more suitable for combustion optimization of engines with lower injection pressure or lower compression ratio.