Numerical Simulation Study on the Flame Development Characteristics of Ammonia Ignited by Hydrogen Jet

Based on the CFD method, the hydrogen jet ignition characteristics of ammonia combustion were analyzed by Converge fluid simulation software. The development of jet flames, jet intensity, changes in chemical composition, and variations in turbulent kinetic energy in the main combustion chamber were studied under different equivalence ratios in the pre-chamber and main combustion chamber. The results from the simulation indicated that the equivalence ratio in the pre-chamber had a significant effect on the jet ignition performance. When the equivalence ratio in the main combustion chamber was fixed at 0.8 and the pre-chamber equivalence ratio increased from 1.0 to 1.6, the jet ignition effect in the pre-chamber was initially enhanced and then weakened. The best jet ignition effect was observed at an equivalence ratio of 1.2. When the equivalence ratio in the pre-chamber was fixed at 1.2 and the main combustion chamber equivalence ratio increased from 0.6 to 1.0, the flame development speed in the main combustion chamber increased. The best flame development speed and combustion performance were exhibited when the equivalence ratio was 1.0. The turbulence in the main combustion chamber affected the exchange of matter between the jet and the main combustion chamber. The greater the variation in turbulence kinetic energy, the greater the disturbance caused inside the constant volume combustion bomb, and the faster the combustion rate.