High-frequency spiral detonation end-on records of premixed C₂H₂+2.5O₂ with different argon dilution

In order to study the internal structure of premixed gas detonation, detonation experiments and calculation analysis of C₂H₂+2.5O₂ premixed gas diluted with different concentrations of argon were performed. Firstly, the detonation experiment was carried out in a pipe with an internal diameter of 63.5 mm. The detonation end-on structures of C₂H₂+2.5O₂ premixed gas under different initial pressures were recorded by using smoke glass. Digital image processing was used to analyze the three-point of smoked glass records to reduce human errors. Then, the regular graphics were obtained after the examination of experimental results, the calculations of experimental results were performed using a verified program. From the end-on structure, the closed graph is fitted with circle. The uniformity of cell size was expressed by the variance of cell radius. The regularity of the distribution of cell lattices was expressed by the variance of the distance between the centers of adjacent cells. By comparing the variance of the radius and the variance of the center distance with the change of cell number in different argon dilution, the size and distribution regulation of C₂H₂+2.5O₂ premixed gas under different argon dilution were given. With the increase of argon concentration, the size and distribution of the cell is more regular.