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Automotive Engineering ›› 2025, Vol. 47 ›› Issue (7): 1325-1334.doi: 10.19562/j.chinasae.qcgc.2025.07.010

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Study on the Influence of Pre-chamber Jet Angles on the Combustion Performance of Ammonia-Hydrogen Engines

Fu Zhang1(),Haie Chen1,Jun Li1,2,Yu Hu3,Xingxing Hu1,Junming Lai1   

  1. 1.National Energy Key Laboratory for New Hydrogen-Ammonia Energy Technologies,Foshan Xianhu Laboratory,Foshan 528200
    2.School of Vehicle and Mobility,Tsinghua University,Beijing 100091
    3.School of Automotive Engineering,Wuhan University of Technology,Wuhan 430070
  • Received:2025-01-23 Revised:2025-02-16 Online:2025-07-25 Published:2025-07-18
  • Contact: Fu Zhang E-mail:zhangfu@xhlab.cn

Abstract:

The application of ammonia and hydrogen in internal combustion engines is recognized as an effective approach to achieve carbon neutrality. In this paper the effect of hydrogen jet swirl angles and pre-chamber injection hole swirl angles on vortex formation mechanism and combustion performance is studied based on a 2.2L displacement liquid ammonia direct injection engine equipped with active pre-chamber hydrogen injection, employing numerical simulation methods. The results show that the hydrogen jet swirl design generates intense swirl within the pre-chamber during injection, enhancing mixture homogeneity and hydrogen blending ratio, with the indicated thermal efficiency (ITE) increasing from 50.82% to 50.90%. Although the pre-chamber orifice swirl configuration increases turbulent kinetic energy by over 35% at ignition timing, it reduces flame jet velocity, consequently decreasing the ITE from 50.82% to 50.17%. Through optimization of both swirl angles, the maximum ITE of 50.9% is achieved.

Key words: liquid ammonia direct injection, active pre-chamber, hydrogen jet swirl angles, pre-chamber orifice swirl angles