Investigation of turbulent flow in vortex cold-wall combustion chamber under different spark ignition times

Abstract

Hydrogen is used as vortex working medium, a new structure of vortex cold-wall combustion chamber was adopted. Numerical investigation was performed to analyze the turbulent flow under different spark starting times, 2 ms (case 1), 3 ms (case 2), 4 ms (case 3) and 5 ms (case 4). The result shows that in the cold state, a process of disturbance growth and double vortex structure formation is emerged. Except for case 1, the other three cases can successfully ignite the gas mixture in the combustion chamber, the larger the spark ignition time, the greater the probability of successful ignition, the shorter the ignition delay time, and the bigger the pressure peak. For these cases with successful ignition, the flame is mainly concentrated in the inner vortex area, the temperature variation is basically similar, but specie OH shows different variation trend. Considering the probability of successful ignition, ignition delay time and combustion stability, the spark is suitable to start at 3 ms.