Abstract
The effects of blockage ratios (BR) of the Shchelkin spiral on characteristics of deflagration-to-detonation transition (DDT) in a vortex flow were examined in order to control the DDT distance without losing the simplicity inherent pulse detonation engines. The DDT distance decreases with increasing the BR of the Shchelkin spiral. However, the optimum value of BR exists. The DDT distance is deteriorated if the BR exceeds the optimum value. Optimizing the BR of the Shchelkin spiral is another way to shorten DDT distance in a vortex flow.
