Numerical Study of Ignition Process in Vortex Cold Wall Combustion Chamber

Numerical simulation in a hydrogen-oxygen vortex cold-wall combustion chamber is carried out to analyze the effects of energy density, spark duration, and spark position on the ignition process. The results show that energy density not only determines whether ignition is successful or not but also affects ignition delay time. For the same spark energy, spark duration is key to the success of ignition. When spark duration is short, despite its higher energy density, the spark exothermic duration may be lower than the ignition delay time, which leads to ignition failure, so a longer spark duration should be selected as much as possible. Spark position can affect the success probability of the ignition, and has an important influence on the combustion stability. When the spark is placed near an area with high hydrogen concentration, it can increase the success probability and shortens ignition delay time, but combustion stability is poor and the temperature distribution in the combustion chamber shows obvious asymmetry. The ignition delay time of the engine is between 260μs-300μs, and the pressure response during the ignition start of the engine is obtained.